An Annotated Key Separating Foreign Earthworm Species from the Indigenous South African taxa (Oligochaeta: Acanthodrilidae, Eudrilidae, Glossoscolecidae, Lumbricidae, Megascolecidae, Microchaetidae, Ocnerodrilidae and Tritogeniidae)

ABSTRACT A functional guide for the separation of foreign earthworm taxa (intentionally or coincidentally recorded in South African soils) from native South African taxa is provided. Forty-four earthworm species recorded from South African soils, known as ‘exotics’ or introduced, which were under secondary attention for many years, are placed in the annotated keys. The family characters for the indigenous Acanthodrilinae, Microchaetidae and Tritogeniidae, and generic/specific foreign taxa of the Benhamiinae, Eudrilidae, Glossoscolecidae, Lumbricidae, Megascolecidae and Ocnerodrilidae are highlighted, keyed and illustrated. An expansive glossary covering terminologies used in earthworm taxonomy is provided and a broad bibliography of South African earthworms is included in the references.


INTRODUCTION
Amongst whole soil-dwelling organisms the earthworms (megadrile) are known to be the most important contributors to the soil profile formation. From the time of their evolutionary existence, subterranean armies of earthworms have regularly ploughed, fertilised, enriched and cultivated the land surface of the entire globe. Thanks to their continuous underground work, the surface of the earth has been covered by green grasses, bushes, trees, forests and productive fields, all of which produce food for other living organisms. Consequently, humans have been able to thrive, prosper and create civilisations, and have found in fertile soil a greater wealth than in gold mines. The beneficial role of earthworms in soil fertility has been well researched and recognised, but in recent years these studies have been intensifying. Global food production depends on intensive agricultural growth, and requires a better understanding of biodiversity and the biophysical regulations of soil fertility. This involves further study and observation of a complex range of environmental indicators. Proper knowledge of the soil organisms is therefore essential for understanding the complexities of soil ecosystems (Cortet et al. 1999;Fragoso et al. 1999).
South African soils are usually ranked as biologically diverse, such diversity having been triggered by countless factors in geology, climate, landscape and many other aspects. Therefore, the associated biodiversity of the soils is highly variable and generates significant interest, which in past years has focused on variable soil life forms, including earthworms, as an important ecological component. The earthworm fauna has to some extent been under investigation for many years and about 300 species of the nine families/ subfamilies have been recorded, although it is important to emphasise that these species and the new taxa (still awaiting discovery) need greater attention.
South African earthworms can be separated into two groups: species accepted as indigenous to South African soils, and species introduced to South African soils, either intentionally through anthropogenic means or coincidentally by natural means. Species that belong to the second group are usually termed 'exotics', 'foreign', 'peregrine' or 'introduced', and because they are well known from many parts of the world they have been subjected to various positive or negative ecological evaluations (Burtelow et al. 1998;Lavelle et al. 1999Lavelle et al. , 2006Dlamini et al. 2001;Hendrix et al. 2008;Bhadauria & Saxena 2010;Avendaño-Yáñez et al. 2014). However, sometimes the selection of the species was not clearly indicated, and some of the conclusions should be tested against correctly identified selected species. The South African introduced species may be included also in some study, but if a correct identification at the species level is erroneously presented or omitted, it shall lead to invalid conclusions.
At present, with the development of ecological research there is an increasing awareness and understanding of the role of earthworms in soil fertility, and there is an urgent need for a reliable and comprehensive guide to the earthworms living in South African soil. It is important that this additional information be accessible to soil researchers, ecologists, earthworm producers, vermiculturists, farmers and non-specialists interested in gardening. A lack of identifiers for introduced beneficial species occurring in agriculture may lead to them being mistakenly evaluated as invasive foreign species that compete with indigenous organisms and thus damage the environment. Earthworms are often included in various environmental and agricultural studies, but when identification at species level (often based on the external characters of juvenile specimens) is erroneously presented or omitted, erroneous economic or ecological conclusions may be drawn.
It must be noted that in the body of research on megadrile in South Africa, it is mostly the indigenous microchaetids and acanthodrilids that have receive attention. Only a few papers present information on the occurrence of foreign taxa (Michaelsen 1910a(Michaelsen , 1913Ljungström 1972;Van Bruggen 1978;Zicsi 1998;Plisko 2010), and this information is often limited to a species name and the place where it was found. Some of the papers are commited rather to common foreign species living in composting heaps, vermiculture production, or species used in workshops and laboratories as experimental objects (Reinecke & Ljungström 1969;Venter & Reinecke 1987;Mallett et al. 1987;Hallatt et al. 1990Hallatt et al. , 1992Reinecke et al. 1990;Viljoen et al. 1991;Reinecke et al. 1992;Reinecke & Alberts 1994;Reinecke & Pieters 1997Maleri et al. 2007;Maleri et al. 2008). In many publications only a name (often currently accepted only as a synonym and thus not suitable for any further analysis) with limited description is given. No specific key with the important external and internal characters necessary for the identification of the foreign taxa has ever been produced. Forty-four earthworm species recorded from South African soils, known as the 'exotics' have been neglected for many years.
Following a request from the Soil Ecosystem Research Group (SERG), a group of South African researchers involved in soil biology, who concentrate on experimental ecological research at the sites where introduced species mostly occur, the necessity of producing a key for the earthworms living in these areas became clear. Due to the apparent lack of basic taxonomic knowledge of earthworms amongst specialists in other fields, this current paper was written with as many explanations as possible in order to be accessible to a wide audience.
The purpose of this paper is to provide basic information on the general categorisation of earthworms, and to produce simple keys that allow researchers to distinguish indigenous species from the introduced taxa. However, it must be noted that the identification of earthworms is not an easy task, even for qualified specialists. Examination of the compulsory characters required in earthworm taxonomy includes the external inspection of adult specimens and the study of their anatomy. In addition, such studies should be based on adequately preserved mature specimens and with specific knowledge of distinctive characters. Unfortunately, no juvenile specimens have been identified to species level; sometimes it is possible to identify them to family or genus level, but even that is not reliable. Only mature specimens develop characters leading to their proper identification. Even if mature/clitellate specimens are found together with juveniles, it does not follow that the juveniles belong to the same species, because they could be juveniles of another species of which no mature individuals were detected. Therefore, only adults can be reliably identified to a genus/species level and used for environmental assessment. Considering some of the external features observed in the individuals of various families recorded in South Africa and their preferences of biotopes, only some preliminary identifications on family/genus level could be suggested.
An introductory key is provided below to separate species accredited to eight families (with two subfamilies) of the earthworms living in South African soils, and keys for each family that allow the identification of genera and species. Special attention was paid to indicate characters separating the indigenous Acanthodrilinae, Microchaetidae and Tritogeniidae from these introduced species belonging to the Acanthodrilinae (two species), Benhamiinae (five species), Eudrilidae and Glossoscolecidae (each with only one species), Lumbricidae (18 species), Megascolecidae (11 species group and two species) and Ocnerodrilidae (four species).

MATERIAl AND METHODS
The diagnostic species descriptions were based on references informing on the species occurrence in this country. However, some of the earlier records and information on species occurrence were rather short and indistinct. When the report produced only the species name, with no species description, the species identification was accepted, although the presently known characters of this species were included in the current description. The descriptions of families and genera are based on their recent taxonomic status, compared with these given by Michaelsen (1900), , Brinkhurst and Jamieson (1971), Gates (1972), , Easton (1979), Sims (1987), Csuzdi (1996Csuzdi ( , 2010, Csuzdi and Zicsi (2003), Moreno (2004), Brown and Fragoso (2007), Blakemore (2008a, b, c;2010) and Plisko (2004Plisko ( , 2013. Though this is not a revision of the recorded species, meticulous attention has been paid to synonymic names and to the correct characterisation of features at the family, genus and species level. Individuals can be identified to the family level, as well as to the genus and species, using the separate keys, in conjunction with the glossary herein. It is advisable to compare the descriptions of characteristic features included in the keys with the drawings. The list of references, which consists of a comprehensive bibliography covering the original descriptions of species and genera, may be consulted for clarity of identification. The systematic record of families, genera and species is presented in alphabetical order. A short introduction provides information on family status, followed by the generic  aestavation: a period of inactivity, or dormancy resulting from unfavourable environmental conditions (usually a lack of moisture). ampulla (pl. ampullae): dilated ental end of spermatheca, forming a distal chamber. anal segment: the last part of the body with no coelomic cavity and no setae; not counted as "a segment" in the whole number of the body segments. anecic: refers to the deep burrowing earthworms. annular: refers to the clitellum; the clitellar tissues are encircling the body. In some species a short distance between the clitellar borders not covered by clitellar tissues may be observed (cf. saddle-shaped). anthropochorous: transported by humans, usually unintentionally. asetal: with no setae (peristomium and anal segment do not have setae). autochthonous: native. autotomy: autotomisation, e.g. self-amputation; shedding the caudal region occurs in many earthworm species. balantine: refers to a state of balantine arrangement of the male, prostatic and spermathecae pores in acanthodrilids. balantine arrangement: refers to a reduction of a pair of tubular prostates and a pair of spermathecae, in Acanthodrilidae; the classical balantine condition refers to the occurrence of one pair of prostatic pores in segment 19, and male pores in 17 or 17/18 or 18, and one pair of spermathecae with its pores in intersegmental furrow 7/8 ( Fig. 2A clitellum: a part of the body wall that is formed from glandular cells at maturity and that is involved with forming a cocoon. In the final state of its formation it can be annular (Fig. 5A) or saddle-shaped (Fig. 5B), but the shape varies according to the state of maturity of the individual. The shape and setting on the segments are significant at family, genus and species level. Appears in full capacity on mature individuals. Two types are recognised: 1. saddle-shaped: covering only the dorso-lateral part of the body (as it is in the majority of microchaetids, glossoscolecids, lumbricids and some acanthodrilids) (Fig. 5B). 2. annular: ring-shaped, encircling the body; occurs in megascolecids, in some species of acanthodrilids, eudrilids and ocnerodrilids (Fig. 5A).
cocoon: sometimes termed 'capsule'; it is the egg case secreted by the clitellum, in which embryonic development takes place. Shape and size are species specific. dorsal pore (pl. dorsal pores): intersegmental apertures in the mid-dorsal line, leading to coelomic cavity. Important character in lumbricids. dorsal vessel: blood vessel located above the alimentary canal. endemic: restricted to a certain region or part of region, native. endogeic: refers to earthworms feeding on organic matter in the soil, coming to the surface for organic matter and breeding. epigeic: refers to earthworms living and feeding on soil surface (litter eaters). epilobous: a shape of prostomium with a tongue partly dividing the peristomium, may be open or closed (cf. prolobous, tanylobous, zygolobous). Eudrilidae: a family name. female pores (sing. female pore): the external pores of the oviducts; may be paired or singular. Their position is characteristic to families and genera (singular in megascolecids). genital field: a space, at the ventral side of an individual, between the seminal grooves; an important species character in Benhamiinae species. genital glands: internal glandular swellings, located in the separated segments, usually around the tips of the setae. genital markings: glandular swellings, pits or grooves. In megascolecids variously arranged external sucker-like discs, pits, grooves, often correlated with position of spermathecal pores; are of great value for species identification. Characteristic for the microchaetids and lumbricids. gizzard (crop): a part of the digestive system, usually muscularised; however, in some species may be weakly muscularised or not at all. Its location in segments is an important generic and species character. Glossoscolecidae: a family name. Downloaded From: https://bioone.org/journals/African-Invertebrates on 11 Apr 2020 Terms of Use: https://bioone.org/terms-of-use hearts: the enlarged segmental pulsating connectives of the blood system between the ventral and dorsal trunks (or sometimes between ventral and supraoesophageal vessels). hermaphrodite: having both male and female reproductive organs in one individual. Earthworms are hermaphroditic. holandric: a condition characterised by the presence of two pairs of testes and their funnels occurring successively in segments 10 and 11 (cf. proandric and metandric). holandric condition: when testes and male funnels occur in segments 10 and 11. holandry: a state of being holandric. holoic: refers to the excretory system when the nephridia (stomate, exoic) are paired in segments (with the exception of the first and last segment, and in some species also omitting some of the segments). A state of the excretory system. A replacement for a term 'meganephridial' or shortened for 'holonephridial' (used in some papers) (cf. meroic). indigenous: belonging naturally to the area; native, endemic; not imported or introduced. intersegmental furrow: a division of segments; a border between two following segments where the epidermis is thinnest. intestine: part of a digestive system. Commencement of intestine is an important character in all earthworm groups. In some species a folding occurs (named the caecum) on the dorsal part of the intestine. introduced: brought from a place other than the native area; foreign, exotic, alien. juveniles: not mature; individuals with no recognisable external feature indicating maturity, such as clitellum or tubercula pubertatis. Lumbricidae: a family name. lumbricine arrangement or 'setae lumbricine': refers to eight setae per segment. male funnels: the ental ends of the sperm ducts initiated at testes. Sometimes in older papers named 'spermiducal funnels'. Temporarily aggregated sperm in male pores may reveal its presence by iridescence (very useful observation for the funnels' location). male pores (sing. male pore): the external openings of vasa deferentia through which the sperm are discharged during mating; may be simple opening, or with some glandular swellings (tumescens) around pores, or expanding on neighbouring segments. Important generic and species character. megadrile: the term used for the description of terrestrial Oligochaeta larger than 20 mm, as opposed to the description of microdrile (smaller than 20 mm). Megascolecidae: a family name. megascolecine (Fig. 4A, 4B): the term indicates that the single pair of prostates, tubular or racemose, open their pores in segment 18 together with the ducts of male pores. In South Africa megascolecid species the prostates are of 'racemose' structure; the lobulation may be not be obvious superficially; however, within glands a prostate duct branches repeatedly. meroic: refers to the excretory system when the nephridia are minute, multiple in one segment, and formed by fragmentation of the embryonic original single nephridial pair. Their number and shape are some of the most important characters in earthworm taxonomy (cf. holoic). metandric: refers to a condition characterised by the presence of a single pair of testes and their funnels in segment 11 (cf. holandric and proandric). metandric condition: when testes and male funnels occur in segment 11. metandry: a state of being metandric. microdrile: the term used for the description of small, usually limnic or aquatic Oligochaeta smaller than 20 mm (or slightly larger), in opposition to description of megadrile (larger than 20 mm, terrestrial). microscolecine: refers to a state of microscolecine arrangement of the male, prostatic and spermathecae pores in acanthodrilids. microscolecine arrangement: refers to a reduction of a pair of prostatic pores, some of the spermathecal pores, with the presence of male pores in segment 17 or 18, or they may be absent. The reduction is observed in the species with acanthodriline male reproductive organs. In various species prostates may be one pair with opening in 17 or 19, or may be absent; spermathecae may be single pair, with pores in 7/8 or 8/9, or 7/8 and 8/9 or may be absent; male pores may occur in segment 17 or 18, or may be be absent (Fig. 3). nephridium -(pl. nephridia): excretory organs: large, paired in one segment are referred to as holoic; small, multiple in segment are meroic. Their shapes are one of the most important characters in earthworm taxonomy. nephropore: the external opening of a nephridium. Ocnerodrilidae: a family name. oesophagus: a portion of the digestive organ between pharynx and crop, ending in an oesophageal valve. ovaries: the organs producing ova (eggs). In megadrile usually in segment 13. oviduct: the duct carrying the ova (eggs) from the coelomic funnel to the exterior (female pores). papillae: occurring on various segments as swollen, raised areas; circular, oval or of other various shapes. It is of different taxonomic value in different families, and is often a problematic character. penial setae: specialised setae, associated with male or prostatic pores. perichaetine arrangement or 'setae perichaetine': refers to numerous setae occurring on one segment. Characteristic for Megascolecidae. peristomium: the first part of the body supporting the prostomium and the mouth; first segment containing mouth; it is asetal. proandric: refers to a condition characterised by the presence of a single pair of testes and their funnels in segment 10 (cf. holandric and metandric). proandric condition: testes and male funnels occur only in segment 10. prolobous: a shape of prostomium with tongue not dividing peristomium (see other shapes of prostomium: epilobous, tanylobous, zygolobous). prostates (sing. prostate): the paired glands, producing fluid supporting the transport of sperm during copulation; associated with vasa deferentia that extend to the exterior through male pores; each consists of a prostatic gland, muscular prostatic duct and prostatic pores (Fig. 6A, 6B). Prostates are absent in indigenous Microchaetidae and Tritogeniidae and in introduced lumbricidae and Glossoscolecidae. In Acanthodrilinae, Benhamiinae, Ocnerodrilidae and Eudrilidae they are of a tubular structure (Fig. 6B).
In Megascolecidae they are of a lobular structure, i.e. 'racemose' (Fig. 6A). prostatic duct: extended part of prostatic gland, usually muscular; its ectal part opens into the prostatic pore. prostatic gland: glandular part of prostate; may be confined to one segment or extended through several segments.
prostatic pores (sing. prostatic pore): the ectal parts of prostatic ducts, open near male pores or fused with them; occur at ventral part of the body in the area of segments 17-19 (Acanthodrilinae, Benhamiinae and Ocnerodrilidae), or are combined with male pores in front of intersegmental furrow 17/18 covered by ventral part of clitellar tissues (Eudrilidae). prostomium: the anterior part of the body (a lobe) projecting above the mouth. The shape of the prostomium is species specific and used broadly for species classification. Types of prostomium: 1. zygolobous: when anterior lobe is just like extended little part of peristomium (Fig. 7A). 2. prolobous: a shape of prostomium with tongue not dividing peristomium (Fig. 7B). 3. epilobous: when a tongue partly divides the peristomium, may be open or closed (Fig. 7C). 4. tanylobous: when a tongue completely divides peristomium (Fig. 7D). There may not be clear lines dividing the peristomium, making the prostomium open or closed. quincunx: a pattern involving the location of setae in a peculiar set-up; refers to species -Pontoscolex corethrurus (Müller, 1857) of the family Glossoscolecidae. racemose: (Fig. 6A) the lobular kind of prostate with a central lumen from which short branches pass out. This type of prostate occurs in species accredited to Megascolecidae. regeneration: a regrowth of an organ or part of the body that has been lost. Common in earthworms, although only the part of the body that does not consist of reproductive organs may be fully regenerated. Partially injured reproductive organs may be regenerated. reproduction: the biological process by which new individual organisms are produced. In earthworms the following types of reproduction may occur: 1. biparental (e.g. sexual reproduction, when the development of a new individual occurs after two mature individuals exchange sperm during mating). 2. parthenogenetic (e.g. when an individual develops from a female gamete (ovum) without being fertilised by a male gamete (sperm). 3. self-fertilisation: the union of female and male gametes produced by the same individual. saddle-shaped: refers to clitellum (Fig. 5B) when tissues cover the body only dorsolaterally, sometimes extending ventrally, although they are not connected. secondary annulation (Fig. 8A): external demarcations of the segment occurring between intersegmental furrows and marking the segments. The term used to describe a loss of the uniformity in internal-external division in the preclitellar part of the body, something which occurs commonly in the two South African indigenous families: Microchaetidae and Tritogeniidae. Usually occurs on the anterior segments in front of the clitellum. The lack of uniformity creates difficulty in establishing the segment number and the position of internal and external characters, and special attention is therefore required during external observation and dissection. segment (metamere): portion of the body externally divided by intersegmental furrows, internally separated by septa; a primary unit of segmentation. It may be a 'simple' part, internally divided by septa and externally demarcated by intersegmental furrows (as it is in acanthodrilids and megascolecids), or a primary unit superficially demarcated by shallow external furrows (as it is in microchaetids) when it is commonly termed 'secondary annulation' and sometimes a 'ringlet'. segmentation (Figs 8A-8C): repeated transverse metameric internal and external divisions along the longitudinal axis, externally clearly marked by intersegmental furrows and internally by septa; simple (Fig. 8B). (See also a secondary segmentation (Fig. 8A)). semimature: an individual having partly developed some of the sexual characters in progress to maturity but with no external sexual features, such as clitellum, tubercula pubertatis or other maturity glands. seminal grooves: external elongated depressions connecting prostatic pores and male pores. seminal vesicles: the storage sacs for an individual earthworm's own sperm. septum (pl. septa): an internal partition between segments, dividing and supporting internal organs; usually delicate, thin, although in some segments much thickened to varying degrees. It is an important specific character in all earthworm groups. seta (pl. setae): small, solid bristles to aid locomotion located at each segment (excluding only peristomium and last segment with anus). They are of several types, shapes, and functions: simple, genital, penial, associated with male pores, or genital papillae or certain other parts of the body. Each state has a particular taxonomical value at family, genus and species level.
2. More than eight setae on each segment is termed a 'perichaetine arrangement' or 'setae perichaetine' (Fig 9D) as it occurs in Megascolecidae. setal formula: a measurement of the distance between the setae allocated on segments. If they are only eight setae, they may be paired in four rows: closely paired, or widely paired, or separated in eight rows. They are marked by the letters: a b c d, at the right and left side of the body, starting from the ventral part of the body with 'a', then 'b', then 'c' and dorsal is'd'. If they are in pairs, it is expressed as 'ab' and 'cd'. The distance between the setae is usually measured between aa, ab, bc, cd, dd; and is expressed as a ratio, e.g. aa:ab:bc:cd:dd: 7:3:5:2:18. Exceptions are some species from the family Glossoscolecidae, where at the caudal part of the body the setae are in a peculiar setup, e.g. quincunx. If there are more than eight setae on each segment, it is important to count the number of setae, and note the distance between them. To identify a species to species-group it is necessary to know the number of setae located on the segments.  sperm: a male cell fertilising eggs during reproduction. spermatheca (Figs 10A-10D) (pl. spermathecae): a male genital organ into which sperm from the partner is deposited during copulation, and stored until release for reproduction, when laying the cocoon. Shape, size and location are important for species recognition. They may be simple (in Lumbricidae, Microchaetidae and Tritogeniidae) A Downloaded From: https://bioone.org/journals/African-Invertebrates on 11 Apr 2020 Terms of Use: https://bioone.org/terms-of-use or with diverticulae (in Acanthodrilidae and Megascolecidae). In Eudrilidae they are combined with an ovarian duct, forming a specific organ. tanylobous: a shape of prostomium when a tongue completely divides peristomium (see also other shapes of prostomium: epilobous, prolobous, zygolobous). testis (pl. testes): male organ for sperm production. May occur only in one segment: 10 (proandric condition) or 11 (metandric); or in two segments, 10 and 11 (holandric). testis sac: sac containing one testis or a pair of testes. Tritogeniidae: a family name. tubercula pubertatis (sing. tuberculum): the paired glandular swellings located near the ventro-lateral margins of the saddle-shaped clitellum. They are of various sizes and shapes; on immature species they may not be completely developed, or may be absent. typhlosole: a longitudinal fold in the gut projecting into its lumen; shape and commencement are species features. vas deference (pl. vasa deferentia): the ducts from the male funnels to the exterior of the male pores. vascular system: the arterial and venous vessels forming a network for the transport of blood. zygolobous: a shape of prostomium where the lobe is just like the extended little part of the peristomium. (cf. epilobous, prolobous, tanylobous).

TAXONOMY
The South African indigenous earthworm species of Acanthodrilinae, Microchaetidae and Tritogeniidae often occur together with the introduced taxa of Benhamiinae, Eudrilidae, Glossoscolecidae, lumbricidae, Megascolecidae and Ocnerodrilidae, and may be externally distinguished by the presence or absence of prostatic pores (and internally by the presence or absence of prostates). When prostatic pores and prostates are present, the species may be distinguished according to the degree of the prostates' advancement and the arrangement of the male reproductive organs. The families' distinction and subsequent generic separation in the keys are based on the prostates' structure, which may be tubular or non-tubular (e.g lobular, also termed 'racemose'). The Acanthodrilidae have their male reproductive organs assembled as an acanthodriline, microscolecine, or balantine arrangement, while the Megascolecidae have a megascolecine arrangement. A fusion of the male (spermathecae) and female (ovaries and oviducts) genitalia occurs in Eudrilidae. The introduced species of the lumbricidae and Glossoscolecidae have no prostates and prostatic pores. The indigenous Microchaetidae and Tritogeniidae families also do not have prostates and prostatic pores. The taxonomic characters applied in part I of the key below, refer to features separating individuals at a family or subfamily level. The keys assembled under the chosen family should be used for identification of the genera and species. These may differ in distinct families due to different characters used in species description and identification and a number of the recorded species. It should be considered that some species (in various families) reproduce biparentally and parthenogenetically, creating morphs, in which the mature characters indicated in the key are not sufficient for these specimens' identification. In this case it is necessary to seek more completely developed representatives of the taxon. Description: Body length from small to very long: 30 mm to 2 m 60 cm; elongated. Pigmented or unpigmented. Setae closely paired, sometimes somewhat irregularly distanced. Clitellum on some of the segments 10-32, 33. Tubercula pubertatis on some of the segments 13-23. Male pores in varying intersegmental furrows between 13/14-20/21, with tumescens or with no tumescens. Calciferous glands oesophageal, stalked or not stalked. Dorsal blood vessel simple through the body length or double in some preclitellar segments, simple when passing septa. Holandric, proandric or metandric. Spermathecae in varying segments, some of the segments 9-16, 17, paired or multiple. Seminal vesicles confined to one segment or extended backwards to two or more segments. Genital papillae and glands often present. Notes: Four genera: Microchaetus Rapp, 1849; Geogenia Kinberg, 1867;Proandricus Plisko, 1992;Kazimierzus Plisko, 2006. All genera and species indigenous; occur in the whole of South Africa and are known from Lesotho and Swaziland. Autotomy observed in some species (M. microchaetus, stuckenbergi, vernoni). Indigenous.
-One gizzard in segment 6-7, or two gizzards: one in 6-7 and the second in 9.  (Kinberg, 1867) recorded in RSA. Vermicomposting species. Nearly 45 genera are known from tropical Africa south of the Sahara, with one species, Eudrilus eugeniae, introduced to other tropical areas. This species in recent years started to be used in vermiculture production. Four other species (from two other genera), namely Eudriloides durbanensis Beddard, 1893, Nemertodrilus kellneri Michaelsen, 1912, N. kruegeri Zicsi & Reinecke, 1992 and N. transvaalensis Zicsi & Reinecke, 1992, are probably native to South African soils (Plisko 2010), and are not included in this paper. Notes: Twenty-one genera are known from Africa and American tropical and subtropical areas, and possibly also from adjacent regions (Christoffersen 2008;Brown & Fragoso 2007). Terrestrial, although prefer moist, limnic or even aquatic environments. A few species transported intentionally or accidentally by humans (Rota 2013). In RSA five known species of four genera: Eukerria Michaelsen, 1935;Nematogenia Eisen, 1900;Ocnerodrilus Eisen, 1878;and Pygmaeodrilus Michaelsen, 1890. From these only Eukerria saltensis (Beddard, 1895b) may be accepted as introduced taxa. The other species reported by Plisko (2010) need taxonomic revision to establish their original identity. Some of them may be of African origin, or possibly indigenous to South Africa. Their inclusion in the present key is purely to indicate the differences observed between macrodriles and microdriles.
PART II Family Acanthodrilidae Claus, 1880 emend. Csuzdi, 2010 At present ca. 768 Acanthodrilidae taxa are described (Csuzdi 2012). Three subfamilies are distinguished: Acanthodrilinae Claus, 1880, Benhamiinae Michaelsen, 1897emend. Csuzdi, 2010and Octochaetinae Michaelsen, 1900; of which the first two are known to occur in South Africa. In both these subfamilies numerous taxa are indigenous for certain parts of the world. Some of them may occur broadly, or have been transported to other regions, and have adapted under new environmental conditions. The representatives of Acanthodrilinae consist of 107 species indigenous to RSA, accredited to five genera: Chilota Michaelsen, 1899 (12 species), Eodriloides Zicsi, 1998 (17), Parachilota Pickford, 1937 (65), Udeina Michaelsen, 1910 (11), Microscolex Rosa, 1887 with one indigenous species, and two introduced species. Only two introduced species of the genus Microscolex (namely M. phosphoreus (Dugès, 1837) and M. dubius (Fletcher, 1887)) are recorded from South African soil, and five species from the subfamily Benhamiinae  (Beddard, 1893)) are inserted in the present key. These species are known from many parts of the world and their occurrence in RSA was summarised by Plisko (2010). The key presented in this paper is designated for the identification of the species introduced to RSA; therefore, no indigenous acanthodrilids are included. The generic and species characters applied in the key are based on data given by the authors. It should be admitted that some of the species descriptions have been limited, or the species erroneously identified were afterwards transferred to synonyms. Finally, the descriptions were enhanced with additional, presently observed taxonomic characters, making available identification. The improvement in descriptions for the Microscolex species was taken from Pickford (1937); enlarged descriptions for Benhamiinae species are based on Csuzdi (2010).
Subfamily Acanthodrilinae Claus, 1880 Characterisation of Acanthodrilinae species (considering the indigenous and introduced ones in RSA; after Pickford (1937)): Prostates tubular, with a central duct (two pairs, or one pair, or absent). Calciferous glands absent (in all South African species). Male reproductive organs acanthodriline, microscolecine or balantine. Gizzard oesophageal, variably developed, present or absent. Excretory system holoic; nephridia vesiculate or avesiculate. Holandric or some proandric. Spermathecae present or absent; if present, two pairs or one pair; diverticulate. Male pores present or absent; if present, paired, in 17 or 18 or 19. Prostatic pores two pairs, each pair in 17 and 19, or 18 and 20, respectively; or one pair in segment 17, 18 or 19. Clitellum saddle-shaped or ring-shaped. Setae lumbricine, paired variably: closely or not quite, sometimes changing the dividing distance on some segments. Body cylindrical, size variable; length 20-370 mm. Pigmentation present or lacking.
Notes: Representatives of the subfamily are predominantly from Central and South America and parts of the western and southern African continent. However, a number of the family species are recorded widely throughout the southern hemisphere (Blakemore 2010). On the African continent they occur in the western, central and eastern regions, and in RSA indigenous representatives of the five genera, Chilota, Eodriloides, Parachilota, Udeina, with one indigenous species, and two broadly distributed species of the genus Microscolex Rosa, 1887, are known.
Genus Microscolex Rosa, 1887 emend. Pickford, 1937 (based on species occurring in RSA) Description: Length 10-102 mm.  (Fletcher, 1887) Description: Body length ca. 30-102 mm. Nephridial pores at each segment in c setal line, laterally. Fe male pores anterior to setae a. Male pores in ab, with circular porophores. Clitellum on 13-17. No genital markings. Septa 6/7-13/14 thickened. Gizzard small in 5. Salivary glands extend backwards over gizzard to segment 5 or 6. Oesophagus extends to 13, intestine widens between 16 and 18. Excretory system holoic, with 'ocarina'-shaped bladders. Seminal vesicles in 10, 11, 12. Prostates single pair in 17, small, bent into L-shape with short ducts. Typhlosole absent. Notes: A synantropic species, distributed worldwide. Abundant in moist soils, noted in drains. In RSA recorded from various localities in EC and WC, summarised by Plisko (2010). Occasionally found together with the introduced lumbricid Aporrectodea rosea and the indigenous Proandricus timmianus (Michaelsen, 1933). Various authors expected common distribution of this species; however, no new material has been reported (Plisko 2010 (Dugès, 1837) Description: Body length ca. 10-55 mm. Nephridial pores from 4/5 slightly median to c lines. Male pores on 17 in a small longitudinal furrow near setae ab. Spermathecal pores in 8/9 near a setae. Clitellum on 12, 13-1/n17, 17 with clear setae and intersegmental furrows. Genital markings present, at central depression in 17/18 and posterior to 17. Septa 5/6-11/12 weak, 12/13-15/16 membranous. Gizzard rudimentary in 5. Salivary glands extend into 7/8. Intestine initiates in 16. Seminal vesicles two pairs, occurring from septa 10/11 and 11/12 and extend to 11 and 12 respectively. Prostates in one or two segments; prostatic gland thick, tubular, slightly curved. Penial setae present. Notes: Synantropic. Cosmopolitan; broadly distributed by humans. Common in pastures, moist plots, gardens, drains, glasshouses, pot plants; found also in native bushes, in soil rich in humus. Noted in variable biotopes (Csuzdi 1986). In RSA recorded by a number of authors from lP, FS, KZN, EC, WC and NC provinces, with its occurrence indicated by Plisko (2010). Pickford (1937) found this species in native forest (Soutpansberg) and in a number of other sites in various provinces, and predicted its broad distribution, suggesting a common occurrence in South Africa. However, during the past decades only one specimen has been added to the NMSA collection (Plisko 2010). According to Gates (1972) the discharged luminescence observed in this species when an individual is disturbed is produced either by symbiotic bacteria or by luciferin-luciferase reactions. The opalescent glandular masses noted around pharynx or oesophagus in 4-6 may be acting in this phenomenon.
Subfamily Benhamiinae Michaelsen, 1897emend. Csuzdi, 1996 The Benhamiinae subfamily was established by Michaelsen (1897a) within the Megascolecidae family with no precise definition. Csuzdi (1996) revised and redefined the superfamily Megascolecoidea and defined Megascolecidae and Acanthodrilidae. Further, the Acanthodrilidae was separated into three subfamilies: Acanthodrilinae, Octochaetinae and Benhamiinae (Csuzdi 2010). Although the taxonomical position of the Benhamiinae is under discussion (Blakemore 2005(Blakemore , 2006(Blakemore , 2010James & Davidson 2012), it is accepted for the present key confined to species introduced in the soils of RSA. The most distinctive characters of the Benhamiinae are: a presence of the tubular prostates with a central duct, excretory system meroic, and extramural, stalked calciferous glands (2-3 pairs, commencing in or near segment 14). Multiple gizzards may occur.
Known from tropical and subtropical areas in South America, West Africa, India, Burma and some Indonesian islands. In RSA noted only in a few localities in KZN (Plisko 2010).
4 Spermathecae paired, in 8 and 9 respectively, small; both parts of subdivided ampulla similar in size and shape, with short diverticulum bearing one unilocular ball (Fig. 10B) (Kinberg, 1867) is known as anthropochorous and has become cultured in many parts of the world. At present it is one of the common earthworm species in West African soils and it is widely distributed in many parts of the world. Primarily imported to RSA for a specific experimental study (Reinecke & Viljoen 1988Reinecke et al. 1992;, it is adapting to habitats in this country. Being a tropical species it has the ability to survive under customary South African environmental conditions. It is a composting species used in the commercial production of compost, at vermicomposting farms, and in worm production for various uses. Other eudrilids (Eudriloides durbanensis Beddard, 1893, Nemertodrilus kellneri Michaelsen, 1912, N. kruegeri Zicsi & Reinecke, 1992 and N. transvaalensis Zicsi & Reinecke, 1992) reported by Plisko (2010) for RSA as introduced species are probably native to South African soils and are not included in this paper.
Notes: This species is biparental, characterised by internal fertilisation. Successful cocoon production by adult worms was reported by Reineke and Viljoen (1988), who indicated a mean of 2.7 hatchlings per cocoon with an 84 % hatchling success rate.
Notes: In this family seven genera display an irregular arrangement in the setal rows (Moreno 2004); amongst them is the genus Pontoscolex Schmarda, 1861. In RSA only one species of this genus is found and the comprehensive description is given below.
Notes: The species extends over a large part of the tropical/subtropical zone, mainly due to anthropogenic dispersal. Its great adaptability to variable ecological conditions has allowed it to spread in the tropics, especially near the coastal zone. In RSA the species occurs in the subtropical northeastern areas, in the coastal zone and in the hinterland along the Indian Ocean, south of the tropic, extending to 31ºS latitude (Plisko 2001). The majority of the samples (ca. 70 %) came from agricultural environments, to which the species was directly or indirectly introduced. Passive transport of the species has been observed, and Van Bruggen (1964) has noted this kind of infestation in South African soils. This species is commonly used in agriculture practices for crop improvement in a number of countries (Avendaño-Yáñez et al. 2014), although this practice has not yet been introduced in this country.

Family lumbricidae Rafinesque-Schmaltz, 1815
Sixty-three genera with approximately 163 valid species accredited to the family Lumbricidae (Csuzdi 2012) are recorded from various terrestrial or semi-terrestrial and limnic biotopes. Of these, 33 species are cosmopolitan (Blakemore 2010), of which nineteen (species with subspecies) were recorded in RSA. The characters presented in the key are based on those observed at their collection; however, they are enriched by some other features noted in species during advanced study by Blakemore (2004bBlakemore ( , 2010, Csuzdi & Zicsi (2003),  and Plisko (1973), and observation based on the material gathered in the NMSAD. To better understand the terminologies in the species decriptions, it is advised to refer to the Glossary. The key presented below refers to species recorded from South Africa to date. Specimens' external characters may indicate assignment to a species; however, dissection and internal study are advised to confirm the identifications. For further diagnostic characters and data on some other species possibly found in RSA, see Blakemore (2010), Csuzdi and Zicsi (2003), Stephenson (1930) and Michaelsen (1900).
The main characters of species known from RSA attributed to the family Lumbricidae: Body cylindrical, elongated for the entire length of the body, with some variability occurring at its posterior part, which may be flattened (Lumbricus) or square-shaped (Eiseniella). Body length from 20-150 mm, diameter 1.5-7 mm. Segmentation simple along the whole body (Fig. 8C), sometimes dorsally slightly marked superficially, transversally. Setae lumbricine (Fig. 9A-C) (e.g. eight setae at each segment with the exception of the prostomium and anal segment; variably located at segments: setae may be closely, moderately or widely paired in four rows, or distantly separated in eight lines). Prostomium (Fig. 7C, 7D) epilobous or tanylobous. Dorsal pores present; location of first pore variable, distinct for species. Spermathecal pores present or absent; if present, paired, in intersegmental furrows 9/10 and 10/11 or in 9/10, 10/11, 11/12. Female pores paired (frequently inconspicuous) in 14 above setae b (exception Eiseniella where they are ventrally to setae a). Male pores paired, in segment 15 or exceptionally in 13 (Eiseniella tetraedra), with variably swollen glands around pores (exception Lumbricus rubellus and Lumbricus castaneus, where these appear as clear pores, with no swollen glands around). Clitellum saddle-shaped (Fig. 5B), appearing on some of the segments 22-36; a number of segments covered by clitellar tissues and their position is the taxonomic species character. Tubercula pubertatis present, (Fig. 8C) variably shaped, from band-like, ridge-like, knob-shaped to sucker-like tubercles, with location on some of the segments 24-35; it is an important, exclusive species character. Holandric condition (two pairs of testes; each with male funnels in segment 10 and 11 respectively). Spermathecae present or absent; if present: adiverticulate, paired, in segment 9 and 10 respectively, or in 9, 10, 11. Seminal vesicles paired, in four segments 9-12, or in three 9, 11, 12, or in two 11, 12. Excretory system holoic. Crop intestinal in 15-16. Gizzards intestinal in 17 or 17-18. Calciferous glands oesophageal, present; with or without lateral pouches. Intestinal caeca absent. Prostates absent. Notes: It should be noted that Lumbricus terrestris Linneaus, 1758 does not occur in RSA as had been previously indicated (Ljungström 1972;Plisko 2010).

Keys to the introduced species of Lumbricidae genera
Genus Eiseniella Michaelsen, 1900 Only one species E. tetraedra Savigny, 1826 is known from RSA. Description: Body length 25-75 mm. Colour yellowish brown. First dorsal pore in intersegmental furrow 4/5. Nephropores alternate, irregular between b and d. Male pores in 13 or 14 or 15 with large glandular tumescens. Clitellum on 22, 23-27, at ventral side less developed. Tubercula pubertatis on 24-25. Calciferous glands in 10, as lateral pouches. Excretory system holoic. Notes: Palearctic origin, known from the whole of Europe and many parts of the world; transported by natural forces, coincidentally or intentionally by humans. Amphibiotic, limicolous. In RSA known from various provinces, mainly from limnic biotopes with high decomposing organic matter Plisko 2010). May be found in various moist to saturated soils in areas of natural inland watercourses, or artificial lakes, and other biotopes with decaying organic matter. Transported by natural courses (river flow) or by humans.
Genus Aporrectodea (Örley, 1885) Four species: rosea, longa, caliginosa and trapezoides; all described under numerous synonymic names. Occur in variable biotopes, with easy adaptation to wide-ranging environmental conditions. 1 First dorsal pore in intersegmental furrow 4/5, often expelling yellowish white coelomic fluid (not smelly). In life slightly red ................... A. rosea Savigny, 1826 Description: Body length 25-120. The openings of male pores between setae b and c variably sized, with large semi-circular glandular tumescens, frequently extending to neighbouring segments. Spermathecal pores present or absent; if present, in 9/10 and 10/11 between lines cd. Clitellum on 24, 25-32, 33. Tubercula pubertatis as continuous bands on 29-31. Seminal vesicles in four segments 9-12 or in two segments 11 and 12. Excretory system holoic, with nephridial bladders U-shaped. Notes: A synantropic species distributed worldwide. Subsoil, endogeic. Daily cast production of this species was estimated as 71, 85 mg dry mass per 1 g of living mass of the individual (Csuzdi & Zicsi 2003). Various experimental studies conducted in agricultural production confirmed the beneficial improvement in soil productivity in the presence of A. rosea (Stephens et al. 1994). In RSA recorded under various synonymic names from various provinces (Plisko 2010), and occurs abundantly in variable biotopes: pastures, grasslands, forests and agricultural fields. Common in gardens and in cultivated fields. Occurs with other introduced earthworm species of various families. Also found together with indigenous acanthodrilids and microchaetids. Under unfavourable conditions the species may be found in an aestivation state. Bisexual and parthenogenetic reproduction commonly observed.  (Savigny, 1826) Description: Body length 40-150. In life whitish grey, dorsally dark. Male pores with variably shaped tumescens (Fig. 8C). Seminal vesicles in four segments, 9-12. Excretory system holoic, with nephridial bladders S-shaped, twisted backwards. Notes: Palearctic, synantropic, most widely distributed, described under a number of synonyms. Reproduces biparentally, and in parthenogenesis, with morphs common. Recorded broadly in RSA, although it is less common than the dominant trapezoides. Commonly occurs in various biotopes, but is found predominantly in agriculture fields and disturbed environments. Species has adapted widely to a variety of ecosystems. Subsoil.  (Dugès, 1828) Description: Body length 50-150 mm. Excretory system holoic with S-shaped nephridial bladders. Notes: Synantropic, described under numerous synonyms, often as a subspecies or a form of caliginosus, from which it differs in the shape of the tubercula pubertatis. Subsoil. In RSA it is the dominant lumbricid, and has been recorded over one hundred times from various biotopes.  (Ude, 1885) Description: Body length 120-150 mm. In life dorsally dark. Male pores with prominent glands extending to neighboring segments. Septa 5/6-10/11 thickened. Seminal vesicles in four segments, 9-12. Excretory system holoic with nephridial bladders J-shaped. Notes: Native to Palearctic, widely distributed worldwide. Synantropic, anecic. Occurs in pastures, gardens and forests. Found only twice in RSA, in garden soil in two distant localities of GP and WC (Plisko 2010).
Genus Allolobophoridella Mršić, 1990 Only two species known from RSA: Allolobophoridella eiseni (Levinsen, 1884) and A. parva (Eisen, 1874), both morphologically similar, but differ in the histology of the muscles. No histological study has been done on the material collected in RSA. It is possible that after histological and molecular analysis the species may be classified with a more precise description, as pointed out by Plisko (2010). Possibly these species are parthenogenetic morphs of a species not yet identified. At present, if similar specimens are found, they should be identified using the following description of the genus.
Notes: Both species are regarded as being of Atlantic origin, and have spread widely over many parts of the world. However, because of their frequent erroneous identification, their distribution has possibly been produced incorrectly. These forms are possibly parthenogenetic reproductions of the non-established original species. In RSA a collection record also can not be confirmed because both were recorded under various synonyms with a lack of complete descriptions. Both species may be found in patches of foreign plantations, under decaying bark and moist litter, in gardens, under pot plants in greenhouses, and in any other biotopes where human interaction is expected. However, it should be said that the taxonomical position of these species with their various generic accreditations, their numerous synonymic names, and the lack of a completed new study, suggest the need for a species revision on the accessible new material. Inclusion of histological and molecular studies should be considered and Genbank should be searched for molecular data.
Genus Eisenia Malm, 1877 Two species, E. fetida (Savigny, 1826) and E. andrei Bouché, 1972, are morphologically and anatomically alike but differ at a molecular level. Both species occur in RSA and may be identified using the following description of the genus.

Notes:
The original range of both species may be attributed to a forested-steppe area in the Caucasus, as suggested by Perel (1997). At present widely distributed; synantropic. Well known all worldwide as the manure earthworm. Common in composting heaps, decaying organic matter and damp rotting vegetation, and in nurseries and around barns. In recent decades has been widely distributed worldwide in the compost trade, and in vermicomposting farms for various uses. In RSA they are common in various biotopes and in vermicomposting. E. andrei has been used for various laboratory studies (Reinecke & Kriel 1981;Venter & Reinecke 1987;Reinecke & Vijoen 1991). The recognition of E. andrei is still under discussion (Blakemore 2010). Voua Otomo et al. (2013) checked selected vermicomposting farms in RSA using molecular tools and concluded that there was no evidence of the presence of E. fetida in all the locations studied. E. fetida material at the NMSA was also investigated by Voua Otomo using molecular tools to check whether these belonged to E. fetida or E. andrei, but the investigation was inconclusive because of the material's previous exposure to formalin; therefore, the two species are kept as separate species, as indicated by Pérez-Losada et al. (2005). However, because their distinction may be apparent only at a molecular level, the species identification should be based on the external characters described at the generic level.
Genus Dendrodrilus Omodeo, 1956 One species, Dendrodrilus rubidus (Savigny, 1826), with subspecies D. rubidus rubidus (Savigny, 1826) and D. rubidus subrubicundus (Eisen, 1873). Notes: The validity of the subspecies is in question (Csuzdi & Zicsi 2003). Both reproduce parthenogenetically in variable morphs and have been described under numerous synonyms. Palearctic origin, distributed occasionally or intentionally by humans. Frequently reported from numerous localities in RSA (Plisko 2010) under various synonyms. Epigeic, occur under bark of fallen trees, in the litter and between the roots of plants in grasslands and various plantations. Common in gardens and occur abundantly in natural and cultivated environments, from various altitudes. Present separation into two subspecies is based on documented data by Csuzdi and Zicsi (2003), and Blakemore (2010), and Genbank may be searched for molecular data.  (Savigny, 1826) Description: Body length 26-50 mm. Spermathecal pores in 9/10 and 10/11 or absent. Seminal vesicles in three segments 9, 11, 12, or in 11, 12; usually first pair located in 9 much smaller that the others. Notes: In RSA is more frequent than subrubicunda. Occurs abundantly in natural and cultivated fields, at sea level and at high altitudes in the Drakensberg mountains. Recorded from KZN, FS, GP, EC, WC. Epigeic. Found together with various species of indigenous microchaetids, tritogeniids and acanthodrilids, and also with other introduced lumbricids and megascolecids (Plisko 2010). A great consumer of organic matter (Csuzdi & Zicsi 2003), it may compete for food with other invertebrates and possibly its distribution and developing populations within a country should be controlled, as indicated by Plisko (2010 (Eisen, 1873) Description: Body length 30-65. Spermathecal pores in 9/10 and 10/11. Seminal vesicles in three segments, 9, 11, 12. Notes: In KZN less frequent than rubidus rubidus although the need for control of its growing populations is emphasised.
Notes: Palearctic species, broadly distributed worldwide. Reproduces biparentally and parthenogenetically, with high morphological variations, and variable morphs. Epigeic. In RSA occurs commonly in plantations and forests into which foreign plants or trees have been introduced. Nearly thirty records refer to protected areas (Plisko 2010 Description: Body length 35-100 mm. First dorsal pore in 5/6. Male pore glands slightly protruding onto neighbouring segments. Spermathecal pores in 9/10 and 10/11. Septa 7/8-9/10 thickened. Spermathecae in 9 and 10. Seminal vesicles in 9, 10, 11, or 11 and 12. Calciferous glands in 10-12, with no lateral pouches. Excretory system holoic, with small nephridial bladders. Notes: Origin in East Mediterranean area; spread to other European countries and also to other continents in tandem with the developing vermicomposting industry. Synantropic. In RSA it is recorded from garden soil and composting heaps (Plisko 2010). Common in vermicomposting. Muyima et al. (1994) studied the species' adaptability for vermicomposting production.  (Michaelsen, 1903) Description: Body length 35 mm. Violet to light red dorsally, light ventrally, sometimes iridescent. Setae widely spaced, in pairs. Dorsal pores absent. Spermathecae absent. Seminal vesicles in 11, 12.
Calciferous glands in 11-13, with lateral pouches in 11, 12. Excretory system holoic; nephridial bladders in postclitellar segments bilobate. Notes: Palearctic origin. Its distribution is not well known. The initial species Descriptions were possibly based on a parthenogenetic morph, and its small size has put the species' validity in question for nearly a century. The species' taxonomical position was discussed by Csuzdi and Zicsi (2003) and a species revision was suggested. Blakemore (2010) synonymised D. cognettii with a few other controversial species, which together probably form a highly polymorphic parthenogenic species-complex. In RSA the species was found only in the Cape Peninsula (WC) in the litter of a pine plantation that has been integrated into the indigenous Newlands Forest.  (Michaelsen, 1890) Description: Body length 70-125 mm. Setae in eight rows with distance between ab and cd shorter than bc. First dorsal pore in 5/6. Male pores with moderate glandular tumescens protruding onto neighbouring segments. Spermathecal pores present, in 9/10 and 10/11. Septa 7/8-9/10 thickened. Spermathecae in 9 and 10. Seminal vesicles in 9, 10, 11, or 11 and 12. Calciferous glands in 11-13, lateral pouches lacking. Holandric. Excretory system holoic, nephridial bladders sausage-shaped. Notes: Known from Central and Western Europe, distributed over Europe and other continents mainly in connection with the vermicomposting industry. Synantropic, occurs in manure, composting heaps or any litter rich in decaying organic matter. In RSA it is recorded from garden soil and composting heaps (Plisko 2010 (Savigny, 1826) Description: Body length 7-145 mm. Unpigmented, grey. Setae at anterior part closely paired, post clitellum distant. First dorsal pore in 11/12. Male pores with small tumescens not extending to neighbouring segments. Spermathecal pores in 9/10 and 10/11. Calciferous glands in 10-11. Holandric. Excretory system holoic, nephridial bladders ocarina-shaped. Notes: Native to Palearctic, transported broadly to many parts of the world. Kuu and Ivask (2010) observed the species' quick adaptation to new environmental conditions. Endogeic. In RSA it has been found only twice; once in a garden between the roots of imported plants in EC, and a recent new record in WC. Description: Body length 30-145 mm. Unpigmented, grey. Setae at anterior part paired more closely than at posterior. Male pores with tumescens slightly extending to neighbouring segments. Spermathecal pores in 9/10 and 10/11. Calciferous glands in 10-11 with lateral diverticula in 10. Notes: Palearctic origin, broadly distributed worldwide. Described under various synonyms. In RSA common in moist-to-wet biotopes, and in rich organic matter in forests, grasslands and gardens. Endogeic. Reproduces bisexually and parthenogenetically. The small, 30-45 mm morphs produced via parthenogenetic polyploid reproduction create abundant communities. Under the favourable climatic conditions found in RSA, the species occurs in large populations in wet biotopes, and has spread to cultivated and natural fields. Control of its growing population is advised.
Family Megascolecidae Rosa, 1891 Megascolecidae is a second family belonging to the superfamily Megascolecoidea (compare notes for Acanthodrilidae), and is the largest group of megadrile, accounting for around 2000 taxa recorded into various ranks and various generic/family statuses (Csuzdi 2012;Easton 1979Easton , 1982Blakemore 2002). From these, nearly 30 species are known to be distributed worldwide and to adapt easily under various conditions in new biotopes. These species have been described/re-described under numerous synonyms in various genera, creating a long list of names. , Easton (1982) and Blakemore (2004aBlakemore ( , 2010 have eliminated a number of the synonyms and have grouped some of the accepted names into species-complexes. Species known from RSA have also been reported under various synonyms. Some of them have been positively accredited to valid species and their recorded presence in the country has been summarised by Plisko (2010). However, a large portion of the material collected in this country and accessioned in the NMSA has also been recorded under various synonyms, or simply marked as 'Pheretima-group', possibly referring to a presently unidentified species. This paper includes only those species which have been positively identified and assigned to a 'species group', as indicated by  or Blakemore (2004a), and have been found in RSA. In the case of specimens that differ from those placed in the key, it is necessary to consult other literature (Michaelsen 1900;Stephenson 1930;Gates 1972;Blakemore 2002Blakemore , 2010 and newly described megascolecid species. In RSA 12 species of three genera are known: Amynthas (Kinberg, 1867) -eight species; Metaphire Sims & Easton, 1972 -two species; Perionyx Perrier, 1872 -one species. Pontodrilus litoralis (Grube, 1855), assigned to Megascolecidae by Plisko (2010), is placed separately in the Appendix of this paper. The megascolecids recorded in this key were introduced to RSA at different times, either naturally, or intentionally or coincidentally by humans, by means of one of the various mechanisms of species introduction hypothesised by Ljungstöm (1972). Their appearance in RSA has been summarised by Plisko (2010).
The species are terrestrial, occurring in cultivated fields (mostly in sugar cane plantations); in parks and gardens; in natural biotopes to which they were transported along with introduced bushes and other plants; in experimental plots; on riverbanks; and in other moist areas. They are often found in polluted spots, and are common in composting heaps, vermiculture farms, nurseries and pot plants.
All the species reproduce bisexually, although parthenogenetic reproduction is frequently noted. In parthenogenetic morphs the prostates and spermathecae may be degraded or aborted, and the male pores malformed or absent. Ljungström (1972) found that in a majority of A. diffringens the prostates and spermathecae were degraded or aborted. In the material collected from a polluted field in the Pietermaritzburg area (KZN) it was also found that the prostates were greatly deformed, although the spermathecae were present and well developed (personal observation).
A practical/shortened characterisation of the megascolecids occurring in RSA soils may be given as follows: Body cylindrical, segments clear, not marked externally by furrows. Length 20-150 mm. May be pigmented or not. Setae perichaetine (numerous setae distributed around the body at each segment). Prostomium epilobous (Fig 7C). Dorsal pores present (there are external intersegmental openings to the coelomic cavity in some of the intersegmental furrows). Female pore single, in 14 (a single pore is characteristic for South African megascolecids). Male reproductive organs megascolecine (the term megascolecine indicates that the single pair of prostates open their pores in segment 18, together with the ectal part of the male ducts, in male pores). Male pores paired, in 18, postclitellar, (parthenogenetic morphs may lack male pores or these may be degenerated). Spermathecal pores paired, in some of the intersegmental furrows 4/5-8/9; the number of pores and their location are specific characters. Clitellum annular (Fig. 5A). Gizzard in 8-10. Intestinal caeca can be present. Ovaria paired in 13. Holandric (testes restricted to segment 10 and 11). Excretory system meroic (minute, numerous nephridial tubules in each egment) or holoic (a single pair of large nephridium in each segment). Prostate racemose (with no central canal) (Fig. 6A). Spermathecae paired, in pre-testicular segments. Copulatory pouches (invagination of the male pores) present or absent. Calciferous glands absent.
Notes: The species of this genus are broadly dispersed around the world and appear in variable biotopes. In RSA are common and were recorded from numerous localities, summarised by Plisko (2010). Ljungström (1972) provided extensive information on their possible introduction to this country. Athecate species present in this genus are listed under minimus group = Amynthas illotus species-group (Blakemore 2010).
short, muscular with slender ental region. Spermathecae in 8 and 9; ampulla and duct similar length; diverticulum slender with convoluted end. Notes: Known from Pacific Islands (see Blakemore 2010: 305). Recorded in RSA from agricultural fields in the KZN area (Dlamini 2002), and from parks and in various locations (Plisko 2010). May occur also in various locations that are rich in organic matter. It is a variable species that has been recorded under a number of synonyms, and revised and re-described by  and Blakemore (2010). Sims and Easton (1972: 234) assigned it to the 'aeruginosus species-group'.
Notes: It is a variable species described under a number of synonyms. It is very widely distributed, and has been recorded from temperate and tropical regions throughout the world. In RSA it occurs mostly in sugar cane plantations, and in cultivated lands with various plantations; it has been recorded at experimental plots at Cedara Agriculture College (KZN). Found also in natural biotopes, in parks and gardens in conjunction with introduced bushes and plants. Parthenogenetic morphs may be observed.
-Spermathecae with diverticulum slightly longer than duct; duct rather thick and shorter than the ampulla; ampulla triangular with a broad ental portion, becoming increasingly bigger and more compressed backwards. Spermathecal pores paired, in 5/6-8/9, superficial, minute ............. A. diffringens (Baird, 1869)  Notes: Parthenogenetic reproduction appears in many populations, especially in those from chemically polluted fields. Various degrees of prostatic gland degeneration are observed in various sized morphs. This is a topsoil species, and is always found in the upper layer of the soil. It is most abundant in sugar cane fields, in naturally decomposed leaf litter, and in composting heaps. Used in composting and vermiculture production. Indicated as a 'diffringens' species-group (Sims & Easton 1972: 235).
Ocnerodrilidae Beddard, 1891 Currently ca. 181 species are described and located in 21 genera (Blakemore 2010;Csuzdi 2012). Ocnerodrilinae occur mainly in tropical/subtropical South America and Africa, with some species extending into the temperate zone of Central and North America, and the European northern hemisphere, while Malabarinae are restricted to India and the Seychelles Islands. Christoffersen (2008) recorded 70 Ocnerodrilidae (with no family subdivision) species in South America, with South American endemics accounting for 86 % of the taxa. A small ratio of them was assigned to a group distributed accidentally or intentionally by human actions. However, only two of these, Eukerria saltensis (Beddard, 1895) and Ocnerodrilus occidentalis Eisen, 1878, are pantropical, extending also to the temperate zone of the northern hemisphere (Rota 2013). Important characters: Prostates tubular, variable, could be paired or 3 pairs with pores between 16-21. Male pores paired in 17 or 18, associated with openings of prostates, at ventral part of clitellum. Setae lumbricine, paired. Clitellum annular but does not cover the body completely on the ventral side, separated by seminal grooves (clitellum may be seen as saddle-shaped). Tubercula pubertatis absent. Gizzard present or absent. Spermathecae present or absent; if present, paired, in front of testis segments. Intestinal origin in 12. Calciferous glands oesophageal or absent. Seminal vesicles present. Last pair of hearts in 11. Holandric or proandric. Excretory system holoic, avesiculate. Intestinal caeca absent. Unpigmented. Notes: Twenty-one genera are known from African and American tropical and subtropical areas and possibly also from adjacent regions (Christoffersen 2008;Fragoso & Rojas 2009). Individuals are small, usually shorter than 130 mm, living in moist to semi-aquatic biotopes; they may be terrestrial, although they prefer moist, limnic or even aquatic environments. A few species have been transported intentionally or accidentally by humans (Rota 2013). In RSA four species of four genera are known: Eukerria Michaelsen, 1935;Nematogenia Eisen, 1900;Ocnerodrilus Eisen, 1878;and Pygmaeodrilus Michaelsen, 1890. From these only Eukerria saltensis (Beddard, 1895) may be accepted as an introduced taxa. The other species reported by Plisko (2010) need taxonomic revision to establish their original identity although they are included in the present paper. Some of them may be of African origin, or possibly indigenous to South Africa. The recent opinion of a few researchers (Christoffersen 2008;Rota 2013) is that the Ocnerodrilidae form a homogeneous taxon and according to the classical phylogeny compose the most recent off-shoot from the ancestral root-genus of all megascolecoid forms.
Genus Eukerria Michaelsen, 1935 Only Eukerria saltensis is known to occur in RSA.