TWENTY-THREE NEW RECORDS OF COMMERCIAL FISH SPECIES (ACTINOPTERYGII) FROM THE SOCOTRA ARCHIPELAGO (NORTH-WESTERN INDIAN OCEAN)

. The Socotra Archipelago is recognized globally as a UNESCO World Heritage Site. The unique ichthyofauna of Socotra accumulates fish species from different ecoregions, including commercial species which represent an important part of the local fishery. Positive identification of fish species and knowledge of their distributions are important for management strategies in fisheries and biodiversity conservation. Commercial fish species were collected at sea, taken from fish markets or landing sites, or observed underwater during two field trips in 2018 and 2019. Twenty-three new records of commercial fish species from twelve families are reported from the Socotra Archipelago based on collections and/or photographs: Plicomugil labiosus (Valenciennes, 1836); Epinephelus magniscuttis Postel, Fourmanoir et Guézé, 1963; Epinephelus marginatus (Lowe, 1834); Epinephelus morrhua (Valenciennes, 1833); Epinephelus rivulatus (Valenciennes, 1830); Alectis indica (Rüppell, 1830); Carangoides fulvoguttatus (Forsskål, 1775); Parastromateus niger (Bloch, 1795); Selar crumenophthalmus (Bloch, 1793); Uraspis helvola (Forster, 1801); Gerres oblongus Cuvier, 1830; Etelis coruscans Valenciennes, 1862; Diplodus omanensis Bauchot et Bianchi, 1984; Polysteganus coeruleopunctatus (Klunzinger, 1870); Lethrinus crocineus Smith, 1959; Gymnocranius elongatus Senta, 1973; Gymnocranius sp.; Wattsia mossambica (Smith, 1957); Argyrosomus japonicus (Temminck et Schlegel, 1843); Umbrina robinsoni Gilchrist et Thompson, 1908; Polydactylus plebeius (Broussonet, 1782); Histiopterus typus Temminck et Schlegel, 1844; and Siganus sutor (Valenciennes, 1835). The presence of the following three species are confirmed for Socotra Archipelago: Epinephelus malabaricus (Bloch et Schneider, 1801); Pristipomoides filamentosus (Valenciennes, 1830); and Sphyraena obtusata Cuvier, 1829. The following species represent the first verified records for the Arabian region: Epinephelus magniscuttis , Etelis coruscans , Lethrinus crocineus , Wattsia mossambica , and Gymnocranius sp. Species of two families, Sciaenidae and Polynemidae are reported for Socotra for the first time. Information on each species’ identification and its distribution are provided. Twenty-three commercial species new for the Socotra Archipelago were reported in this study, as a result, a total of about 255 species of fish are considered as exploited in the local small-scale fishery.


INTRODUCTION
The Socotra Archipelago lies in the north-western corner of the Indian Ocean between 53°0′-54°35′E and 12°5′-12°43′N (Fig. 1). The Archipelago includes the main island of Socotra, three smaller islands Darsa, Samha, Abd al-Kuri, and two islets Sabuniya and Kal Farun. The westernmost island Abd al-Kuri is separated from mainland Africa (Somalia) by the Socotra Passage, a narrow strip of water only 95 km wide, and the eastern tip of Socotra Island is separated by a distance of 330 km from the nearest point at mainland Arabia (Yemen, Ras Fartak). The Archipelago is recognized globally for its outstanding universal values, including unique patterns of biodiversity, which led to the designation of the entire island group as a UNESCO World Heritage Site in 2008 (Scholte et al. 2011). Situated at the junction between the Gulf of Aden and the Arabian Sea, the Archipelago forms the center of a region with relatively poorly known coastal and marine faunas.
In the late 19th century, the Socotra Archipelago was the subject of a series of scientific expeditions, led by Balfour in 1880, by Riebeck and Schweinfurth in 1881, by Forbes and Ogilbie-Grant in 1897-1898, and by Paulay and Simony in 1898. Fishes were sampled for the first time on Socotra Island during the German expedition of Riebeck and Schweinfurth in 1881-1882 (Taschenberg 1883). Zajonz et al. (2019) comprehensively summarized all published and their own data and provided a preliminary list of 682 species recorded for Socotra Archipelago and a working list of additional 51 records referred to as Operational Diversity Units (see Zajonz et al. 2019: 104, Annex 2) requiring further confirmation. The total archipelagic richness was estimated by these authors at up to 875 species of coastal fishes.
Fishing used to be the second-most important source of income and food for the islanders after the pastoralist economy (Cheung andDeVantier 2006, Mehring et al. 2017). There are very productive small-scale and industrial-scale fishing activities around the Archipelago that supply both domestic and commercial demand. The small-scale fishery operates from >80 coastal villages (on Socotra, Samha, and Abd al-Kuri) over the continental slope, using either fiber-glass skiffs called 'houri' or larger 'sambuq'. Socotri fishers target shallow demersal and "reef" fishes, rock lobster, and sea-cucumber inshore, and large pelagic fishes, including sharks, and some deep demersal species offshore. The background and the current status of Socotra's commercial fisheries are provided by Zajonz et al. (2016).
Recent field works, one in spring 2018 on the main island Socotra, and one in spring 2019 covering Socotra Island and the three outer islands Abd al-Kuri, Samha, and Darsa, and additional efforts by the second, resident author, yielded additional faunistic records. The present article reports twenty-three species of commercial fishes for the first time from the Archipelago, eight species from Abd al-Kuri Island, and fifteen species from Socotra Island, thus expanding the list of commercial fishes of Socotra substantially. In addition, the occurrence of three commercial species was confirmed.
Information on the source of each new record is provided, as well as species-specific characters for identification, photographs of freshly collected specimens or underwater photographs, and information on the record depth (if available) and the known depth range of the species. In addition, detailed information on the general distribution of the species is included, especially with regard to their distribution in the Arabian region. A map of the marine area of the Socotra Archipelago showing main localities is provided in Fig. 1.

MATERIALS AND METHODS
The majority of the recorded specimens were observed and/or collected during two survey trips to the Socotra Archipelago conducted for the project 'Support to the Integrated Programme for the Conservation and Sustainable Development of the Socotra Archipelago, Yemen', coexecuted by the Senckenberg Biodiversity and Climate Research Centre (SBiK-F) and the Environment Protection Authority of Yemen (EPA) for the United Nations Environment Programme (UNEP) based on funds of the Global Environment Facility (GEF #5347). The EPA also issued the research and export permit. The first fieldwork took place from 23 April to 21 May of 2018 and the second from 21 March to 23 April 2019. Additional records were made by the second author (FNS) who is a resident on Socotra and staff of the same project. The bulk of the collected specimens were preserved in 4-6% formalin and examined by authors at the Senckenberg Field Research Station and the project center in Hadibo, where the material is temporarily stored. It has not yet been possible to export the specimens to the Senckenberg Research Institute and Museum of Nature, Frankfurt am Main, Germany (SMF) due to severe logistic constraints posed by the war in Yemen and the global SARS-Cov-2/Covid-19 crisis. Tissue samples for subsequent genetic analyses were taken for the majority of species before fixation in formalin and readily exported though. Most photographs were taken by the first and third authors (SVB and UZ), while photographs of fresh specimens of Argyrosomus japonicus, Polydactylus plebeius, Histiopterus typus, and Parastromateus niger were taken by FNS. Museum abbreviations follow Fricke and Eschmeyer (2020). The term 'distinctive characters' refers to a combination of species-specific characters based on published and own data which were used for positive identification. The fin-ray counts followed the method of Fricke (1983). Meristic and morphometric methods otherwise followed Hubbs and Lagler (1964). The length of specimens is presented as standard length (SL) measured from the anteriormost point of the upper lip (except for Lethrinidae, measured from anterior tip of snout) to the base of the caudal fin (end of hypural plate), or as fork length (FL) measured from the anteriormost point of the upper lip to the posterior end of the median caudal-fin rays. Counts of pored scales in the lateral line include the anteriormost tubed scale above the opercular margin to the end of hypural plate. In case a scale was partly overlapping the end of the hypural plate, such scale was included in the lateral-line count; additional pored scales on caudal fin were counted separately. Gill rakers counts include developed rakers on the first gill arch, with the raker at the arch's angle included in the lower limb count. Measurements were taken to the nearest 0.5 mm; proportional measurements were rounded to 0.1.
References and genus and species classification follow Eschmeyer's Catalogue of Fishes (Fricke 2020, Fricke et al. 2020, Van der Laan et al. 2020. The Arabian/Persian Gulf is referred to as the 'Gulf'. In reference to the Arabian region, the following areas are included: the Red Sea, inner Gulf of Aden, north-eastern coast of Somalia, Socotra Archipelago, coastal waters of the southern part of the Arabian Peninsula, Gulf of Oman, the Gulf and coast of Pakistan.

RESULTS
A total of twenty-three commercial fish species from twelve families are reported herewith from the Socotra Archipelago Mugilidae Jarocki, 1822 Plicomugil labiosus (Valenciennes, 1836) Thicklip mullet (Fig. 2 Distinctive characters. Plicomugil labiosus is characterized by having a robust body covered with finely ctenoid scales, its depth 3.3-3.7 in SL; upper lip very thick, with a deep fold near its ventral edge, splitting it into lobes, lower lip thin, both lips fringed with small ridges of horny epidermal tissue; preorbital very deeply notched, only its rounded ventral edge serrate, posterior end broad and squarish; posterior part of maxilla slender, curved downward, exposed below preorbital when mouth closed; origin of second dorsal fin below posterior onefourth of anal fin; adipose tissue around eye and pectoralfin axillary scale absent. Meristic values: dorsal-fin spines and rays IV + 8-9; anal-fin spines and rays III,9; longitudinal scale series 32-37; scales in transverse series 11-12; circumpeduncular scales 16. Coloration. Silvery gray dorsally, shading to silvery on sides and ventrally, with a distinct small black spot at upper base of pectoral fins. Distribution. Ranges from the Arabian region south to Madagascar, east to the Marshall and Samoan Islands (Senou 1999). The original description is based on specimens from the Red Sea and from the eastern part of the Arabian Sea (Mumbai). In addition, it is reported in the Arabian region from Gulf of Tadjioura (Lips et al. 2016), Gulf of Oman (Randall 1995), and the Gulf, United Arab Emirates (UAE) (Froese and Pauly 2019). Remarks. The examined specimen matches the morphological and color description of Plicomugil labiosus provided by Senou (1999, as Oedalechilus labiosus). Meristic characters fall within the diagnostic range of values for this species: 8 and 9 rays in the second dorsal fin and anal fin, respectively, 35 scales in longitudinal series, 12 scales in transverse series, and 16 circumpeduncular scales. The examined specimen was obtained from Hadibo fish market without precise collection data on locality and habitat. Elsewhere the species is found in shallow coastal marine waters of variable habitat in the depth range 1-25 m. Usually classified in the genus Oedalechilus together with the eastern Atlantic Ocean species O. labeo (Cuvier, 1829), both species possess a deeply notched preorbital. Ben-Tuvia (1975), who reviewed Red Sea species of the family, placed the species in the monotypic genus Plicomugil, supported by molecular data (Durand et al. 2012). Lavergne et al. (2016) reported ten species of mugilids from estuaries and lagoons in Socotra but no Plicomugil labiosus was mentioned. Additional observations are needed to elucidate the importance of this species in the commercial and subsistence fisheries of Socotra.
The most similar species to Plicomugil labiosus is Crenimugil crenilabis (Forsskål, 1775), sharing a thickened upper lip, but the lip covered with small papillae at edge of lip, no folds on lip, and the lower lip possesses a distinct fringed edge. In addition, C. crenilabis has cycloid scales with crenulate membranous edge, 36-42 in longitudinal series; preorbital weakly concave on serrate anteroventral edge, not kinked; and posterior end of maxilla concealed by preorbital when mouth is closed.  Nakamura et al. 2018, present study). No prior records from the Arabian region are known (Manilo and Bogorodsky 2003). Remarks. A single large grouper was obtained from a fishing boat at Abd al-Kuri Island without collection details. The features of the specimen closely match the diagnostic features of Epinephelus magniscuttis given by Heemstra and Randall (1993) and Craig et al. (2011), including body depth 3.0 in SL, 14 soft rays in dorsal fin, and gill rakers 9 + 16, and the coloration. Elsewhere the species inhabits deep rocky reefs and is reported from depths of 50-300 m. Epinephelus magniscuttis is rare in taxonomic collections, yet not included in IUCN Red List Assessments. Smith and Craig (2007) have proposed to elevate the subfamily Epinephelinae to the family level, followed by Ma and Craig (2018) who based on summarized molecular data maintain the Epinephelidae at the family rank, but it is not accepted by some authors (Betancur-R et al. 2017, Parenti andRandall 2020). Until this taxonomic issue is resolved the present authors prefer to follow Parenti and Randall (2020) and Eschmeyer's Catalogue of Fishes ) who retain the Epinephelinae as well as Anthiadinae and Serraninae within a large family Serranidae. Ma and Craig (2018) also revised the generic classification of groupers based on molecular data and moved several deep-water species of Epinephelus in Mycteroperca. Epinephelus magniscuttis was listed by Ma and Craig (2018)  caudal fin rounded. Meristic values: dorsal-fin spines and rays XI,14-15; anal-fin spines and rays III,8; lateral-line scales 54-64; gill rakers 8-11 + 14-18. Coloration. Light grayish brown, with five slightly oblique broad dark brown bars on body that bifurcate ventrally and which contain pale areas colored like body; head, body and fins with many small black spots. Distribution. Reported from the Arabian region, along the east coast of Africa south to Madagascar, east to southern Japan, Australia (South New Wales) and Tonga (Heemstra and Randall 1993). Reported in the wider Arabian region from the Red Sea (Lieske and Myers 2004), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Arabian Sea coast of Oman and Gulf of Oman (Randall 1995), and Pakistan (Psomadakis et al. 2015). There is a single record from the Gulf in Iraq waters by Al-Mukhtar et al. (2012) based, however, on a photograph of a very low quality which is unsuitable for positive identification. Remarks. Zajonz et al. (2019) tentatively included the species as Epinephelus cf. malabaricus based on visual observation. A single large individual was photographed resting on a large patch of silty sand mixed with scattered small stones in a coral-reef area at Di Hamri at a depth of 5 m. The observed individual closely matches the diagnostic features of E. malabaricus provided by Heemstra and Randall (1993) and Craig et al. (2011), hence its occurrence on Socotra is now confirmed by the present record. The species usually was found from depths of 2-40 m, with the deepest confirmed record for this species in 250 m depth (Heemstra and Randall 1993). Kohno et al. (1988) noted that this grouper is regarded as highly esteemed food fish and most desirable for aquaculture. Epinephelus malabaricus is included in IUCN Red List Assessments and requires conservation management (Samoilys et al. 2018), as underscored by its rarity on Socotra. Epinephelus coioides (Hamilton, 1822) is a very similar species but differs by having orange-red and dark brown spots and lacking white blotches within dark bars. (Lowe, 1834) Dusky grouper (Fig. 3C (Heemstra and Randall 1993). In the Arabian region previously reported only from southern Oman (Randall 1995, Béarez et al. 2020).

Epinephelus marginatus
Remarks. The observed individual closely matched the distinctive characters of Epinephelus marginatus provided by Heemstra and Randall (1993) and Craig et al. (2011). Pollard et al. (2018) doubted the record of the species from southern Oman as waifs or misidentification but the record from southern Oman was confirmed by the collection of two specimens from Salalah fish market (Béarez et al. 2020). A sample of tissue was taken from one large specimen obtained on Hadibo fish market, and the molecular analysis places its sequence of the COI gene within other positively identified specimens from the entire distribution range of E. marginatus (see B. Victor et al., in prep.), thus confirming the presence of the species in southern Arabia. In addition, one individual of this species was photographed under water in a rocky area at Ras Bidou under a deep overhang at a depth of 14 m. The depth range is given by Heemstra and Randall (1993) from shallow water to depths of 50 m, and by Pollard et al. (2018)  Distinctive characters. Epinephelus morrhua is characterized by having a moderately deep body, its depth 2.9-3.1 in SL; interspinous membranes incised; caudal fin moderately rounded. Meristic values: dorsal-fin spines and rays XI,14-15; anal-fin spines and rays III,8; lateralline scales 55-64; gill rakers 8-10 + 15-18. Coloration. Grayish brown with a curving dark yellowish brown band on upper half of head and body which divided into branches below the dorsal fin and small dark brown spots in between, and another oblique dark brown band from eye continuing on ventral half of body (sometimes broken into segments); median fins usually yellowish. Distribution. Reported from the Arabian region, the east coast of Africa and islands of the Western Indian Ocean, east to Mariana and Cook Islands (Heemstra and Randall 1993). In the Arabian region reported from the Red Sea (Heemstra and Randall 1993) and Gulf of Tadjoura (Lips et al. 2016). Psomadakis et al. (2015) included the species in their catalog of fishes of Pakistan, yet without photographic evidence. Remarks. The examined specimen matches the morphological and color description of Epinephelus morrhua provided by Craig et al. (2011). The single specimen was caught by hook-and-line off Abd al-Kuri Island at a depth of ~80 m on a steep slope. It has a robust body with its depth 2.9 in SL, 14 soft dorsal-fin rays, 61 lateral-line scales and 9 + 16 gill rakers. Epinephelus morrhua is included in IUCN Red List Assessments and requires conservation management (Barreiros 2018). The Epinephelus morrhua species-complex includes four deep-water groupers that share essentially the same meristic data and general morphology, including also E. poecilonotus (Temminck et Schlegel, 1842), E. radiatus (Day, 1868) and E. tuamotuensis Fourmanoir, 1971 (see Craig et al. 2011). The former two species are reported from Socotra Archipelago (Zajonz et al. 2019) and can be distinguished as follows. Large adults of E. poecilonotus are grayish brown with two dark brown stripes radiating obliquely behind orbit, outer part of interspinous dorsalfin membranes yellow and posterior margin of caudal fin pale; smaller adults with a dark brown inverted arc on back below spinous portion of dorsal fin and a series of small dark brown spots forming oblique lines on upper part of body. Adults of Epinephelus radiatus are yellowish brown, with five irregular oblique, dark-edged, brown bands that bifurcate ventrally, and small dark brown spots in pale interspaces between bands, and basally on dorsal and caudal fins; head with a dark brown line across upper part of cheek and a faint brown band extending from above middle of upper jaw to margin of opercle. Coloration. Body pale greenish brown with a small pale blue spot on each body scale, and four broad, indistinct, brown bars; head reddish brown with an indistinct brown bar on nape and irregular blue lines and spots; pectoral-fin base with a semicircular dark red or brownish red spot. Distribution. Ranges from the Arabian region south to Madagascar, east to the Marshall and Samoan Islands. In the Arabian region reported from the southern shore of the Arabian Peninsula (Randall 1995); also, was collected from the north-eastern coast of Somalia (e.g., USNM 305326). Remarks. Epinephelus rivulatus is a distinctive species characterized by having a high count of soft dorsal-fin rays, low count of lateral-line scales and certain details of coloration. The examined specimen and the visually observed individual match the morphological and color description of that species provided by Heemstra and Randall (1993) and Craig et al. (2011). The single specimen was taken on Hadibo fish market from a fisherman who caught it from the north-western part of Socotra Island (Mori), with no additional collection data available. The specimen has a body depth 3.0 in SL, 16 soft dorsal-fin rays, 51 lateral-line scales and 8 +15 gill rakers. One individual was photographed under water in algal beds at a depth of 10 m in the southern part of the island. Elsewhere the species occurs in a variety of habitats from coral reefs to algal and seagrass beds at depths of 1-150 m. Epinephelus rivulatus is included in IUCN Red List Assessments and requires conservation management (Fennessy 2018 Distinctive characters. Alectis indica is characterized by having a relatively deep body, its depth 2.7-3.2 in FL; scales minute and embedded, the skin appearing naked; suborbital area broad, its depth 0.8-1.0 in length of upper jaw; bands of villiform teeth in jaws; first dorsal fin not visible in adults and subadults; anterior soft rays of dorsal and anal fins of juveniles extremely long and filamentous, progressively shorter with growth; pectoral fins longer than head length. Meristic values: dorsal-fin spines and rays VII + I,18-20; anal-fin spines and rays II + I,15-17; posterior scutes in lateral line 6-11; gill rakers 8-11 + 21-26. Coloration. Dusky blue-green dorsally, shading to silvery below with a small black spot dorsally at posterior end of opercle. Distribution. Ranges from the Arabian region, the east coast of Africa, and Madagascar, east to the continental waters of Australia and the Indo-Malayan region, and north to southern Japan. Reported in the wider Arabian region from the Red Sea (Golani and Bogorodsky 2010), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015). Remarks. The observed individuals match the description of Alectis indica given by Smith-Vaniz (1999). A small group of five individuals was observed under water in Shuab Bay, western part of Socotra Island, above sand bottom at a depth of 14 m. Alectis ciliaris (Bloch, 1788) is a similar species but differs by a narrower suborbital area, its depth 1.7-3.0 in length of upper jaw, and fewer gill rakers on the lower limb of the first gill arch (12-17). (Forsskål, 1775) Yellowspotted trevally (Figs. 5B and 5C) Scomber fulvoguttatus Forsskål, 1775: 56; no types known; type locality: Red Sea. Material examined. 2 specimens, not preserved [sample of tissue SOC19-482 and 483], 62 and 65 cm FL, Socotra Island, Shuab Bay, 17 April 2019; underwater photographs, Socotra Island, Shuab Bay, 6-12 m depth, 17 April 2019, 6-12 m depth. Distinctive characters. Carangoides fulvoguttatus is characterized by having a moderately elongate body, its depth 3.2-3.8 in FL; no groove before eye; eye distinctly above horizontal line through tip of snout; chest nearly scaleless or rarely interrupted by a scaled zone; small teeth in bands in jaws, vomer and palatines, vomerine tooth patch ovate; first dorsal fin two times lower than second dorsal fin; pectoral fins longer than head length. Meristic values: dorsal-fin spines and rays VIII + I,25-30; analfin spines and rays II + I,21-26; straight part of lateral line with 18-27 scales + 15-21 small scutes; gill rakers 6-8 + 17-21. Coloration. Silvery blue-green dorsally, shading to silvery with iridescence below, with small orange to yellow spots dorsally and series of midlateral blackish blotches (obscured in some individuals); tip of anal fin and lobes of caudal fin white. Distribution. Ranges from the Arabian region, the east coast of Africa, east to Australia (New South Wales), Japan (Ryukyu Islands), Caroline Islands and New Caledonia. Reported in the wider Arabian region from the Red Sea (Golani and Bogorodsky 2010), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015). Remarks. The collected specimens and visually observed individuals match the description of Carangoides fulvoguttatus given by Smith-Vaniz (1999). The larger one of the two collected specimens was examined; it has a body depth 3.6 in FL, 28 soft dorsal-fin rays, 24 soft anal-fin rays, 21 scales + 16 small scutes in straight portion of lateral line, and 6 + 19 gill rakers. A group of individuals was observed in 2018 in midwater over a large sand area in Shuab Bay, western part of Socotra Island, at depths of 6-12 m, and photographed and collected in the same area in 2019. Elsewhere the species is usually seen along outer-reef slopes, and reported from a depth range of 2-100 m (Smith-Vaniz 1999). Carangoides gymnostethus (Cuvier, 1833) is a very similar species and also common on Socotra Archipelago but differs by having a groove before orbit, lower margin of eye at horizontal line through tip of snout, and usually lacking yellow spots on body.  Distinctive characters. Parastromateus niger is characterized by having a deep compressed body, its depth 1.9-2.2 in FL; small conical teeth in jaws in one row; dorsal-fin spines very short, embedded in skin in adults; pectoral fins longer than head length; and no pelvic fins in adults. Meristic values: dorsal-fin spines and rays IV-V + I,41-44; anal-fin spines and rays II + I,35-39; straight part of lateral line with 8-19 small scutes; gill rakers 5-6 + 13-14. Coloration. Adults purplish to brownish gray, sometimes with two or three narrow pale bars visible on body; front of head usually paler; outer margin of median fins blackish to black. Distribution. Known from the Arabian region, the east coast of Africa, east to Australia (Queensland), Japan (Ryukyu Islands), and Papua New Guinea. Reported in the wider Arabian region from the southern Red Sea (Bogorodsky et al. 2014), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015). Remarks. The examined specimen matches the description of Parastromateus niger given by Smith-Vaniz (1999). The examined specimen has a body depth 2.0 in FL, 41 soft dorsal-fin rays, 37 soft anal-fin rays, 12 small scutes in straight portion of lateral line, and 5 + 14 gill rakers. The specimen was taken by hook-and-line in the area of Di Hamd over rocky-sandy bottom at a depth of 10-12 m. The species typically occurs in groups over sand substrata at depths of 15-49 m. (Bloch, 1793) Bigeye scad (Fig. 6B under operculum with furrow and two papillae; first dorsal fin subequal to height of second dorsal fin; pectoral fins subequal to head length. Meristic values: dorsal-fin spines and rays VIII + I,24-27; anal-fin spines and rays II + I,21-23; straight part of lateral line with 0-11 scales and 29-42 scutes; gill rakers 9-12 + 27-31.

Selar crumenophthalmus
Coloration. Silvery blue-green dorsally, shading to silvery with iridescence below, usually with poorly-defined golden yellow stripe on side of body and a blackish indistinct spot at edge of operculum; posterior margin of caudal fin dusky. Distribution. Worldwide in tropical and subtropical seas. Reported in the wider Arabian region from the Red Sea (Golani and Bogorodsky 2010), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015). Remarks. The examined specimen and the visually observed individuals match the description of Selar crumenophthalmus given by Smith-Vaniz (1999 Distinctive characters. Uraspis helvola is characterized by having an oblong and moderately deep body, its depth 2.4-2.7 in FL; naked area at pectoral-fin base and naked part of chest separated by scaled zone; teeth small and pointed, no teeth on vomer and palatines; first dorsal fin in three times lower than second dorsal fin; pectoral fins slightly longer than head length. Meristic values: dorsalfin spines and rays VIII + I,25-30; anal-fin spines and rays II + I,19-22; straight part of lateral line with 23-40 small scutes; gill rakers 5-8 + 13-17. Coloration. Adults dull silvery with iridescence, with a diffuse black blotch on opercle; lining of mouth mainly black; subadults with 5-7 pale bars. Distribution. Widely distributed throughout the Indo-Pacific region to the eastern Pacific. Reported in the wider Arabian region from the Red Sea (Golani and Bogorodsky 2010), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015). Remarks. The examined specimen matches the description of Uraspis helvola given by Smith-Vaniz (1999). It has a body depth 2.6 in FL, 28 soft dorsal-fin rays, 22 soft anal-fin rays, 31 small scutes in straight portion of lateral line, and 7 + 14 gill rakers. The specimen was taken from Hadibo fish market, with no additional collection data available. The very similar Uraspis uraspis (Günther, 1860) is reported from the Gulf of Aden (Lips et al. 2016). It is distinguished by having the ventral naked zone of the chest extending obliquely to the small naked area at the base of the pectoral fin, without a scaled zone in between.
Lutjanidae Gill, 1861 Etelis coruscans Valenciennes, 1862 Deepwater longtail red snapper (Fig. 7A Distinctive characters. Etelis coruscans is characterized by having a moderately elongate body, its depth 3.5-3.8 in SL; premaxilla protrusible, not attached to snout by a frenum; dorsal and anal fins without scales; vomerine teeth in a chevron-shaped patch; dorsal fin with a notch between spinous and soft portions; distance between orbit and angle of preopercle 9.3-12.5 in SL; last ray of dorsal and anal fin only slightly prolonged; upper caudal-fin lobe 1.8-3.1 in SL. Meristic values: dorsal-fin spines and rays X,11; anal-fin spines and rays III,8; lateral-line scales 47-50; gill rakers including rudiments 8-10 + 15-18. Coloration. Head and body deep pink to red dorsally, shading to silvery pink or white on side and ventrally. Distribution. Ranges from the eastern coast of Africa and islands of the Western Indian Ocean, east to Kermadec Islands, Tonga and Hawaiian Islands. Allen (1985) included the Arabian Sea in the distribution range of the species. No voucher specimens in museum collections or published data with references to specimens or photographs exist though supporting this claim. Therefore, the specimen from Socotra Archipelago is the first specimen-based evidence for the occurrence of the species in the Arabian region. Remarks. The examined specimen matches the description of Etelis coruscans given by Allen (1985). A single specimen was caught by hook-and-line off Abd al-Kuri Island at depth of ~150 m on a steep slope. It has a body depth 3.5 in SL, distance between orbit and angle of preopercle 9.3 in SL, upper caudal-fin lobe 2.7 in SL, 11 soft dorsal-fin rays, 49 lateral-line scales and 9 +16 gill rakers. The species is known as inhabitant of rocky bottoms of deepwater slopes and seamounts, from a depth range of 90-400 m. Etelis coruscans is included in IUCN Red List Assessments and requires conservation management (Russell et al. 2016). Two congeners are reported from the Arabian Sea and may be misidentified. Etelis carbunculus Cuvier, 1828 differs by having fewer gill rakers (5-8 + 11-14) and a shorter upper caudal-fin lobe (3.3-3.8 in SL). Etelis radiosus Anderson, 1981 differs by having more gill rakers (11-15 + 20-22), a greater distance between orbit and angle of preopercle (7.1-7.7 in SL) and the last soft dorsal-fin ray distinctly longer than the penultimate ray.
Pristipomoides filamentosus (Valenciennes, 1830) Pink snapper (Fig. 7B) Serranus filamentosus Valenciennes in Cuvier et Valenciennes, 1830: 508; syntypes: MNHN 0000-7033 and 0000-7038; type locality: Réunion. Material examined. SMF uncatalogued [sample of tissue SOC19-316], 1 specimen, 33 cm SL, Socotra Archipelago, Abd al-Kuri Island, 100-120 m depth, 25 March 2019. Distinctive characters. Pristipomoides filamentosus is characterized by having a moderately elongate body, its depth 3.3-3.8 in SL; premaxilla protrusible, not attached to snout by a frenum; dorsal and anal fins without scales; vomerine teeth in a triangular patch; dorsal fin without a notch between spinous and soft portions; last ray of dorsal and anal fin prolonged to filament. Meristic values: dorsalfin spines and rays X,11; anal-fin spines and rays III,8; lateral-line scales 57-62; gill rakers including rudiments 7-8 + 15-18. Coloration. Silvery lavender to silvery pink; top of snout and interorbital space with yellow lines and blue spots; dorsal fin with indistinct yellow spots at base of fin and narrow reddish yellow outer margin. Distribution. Ranges from the Arabian region, the east coast of Africa, and islands of the Western Indian Ocean, east to Australia (New South Wales), Japan, Hawaiian and Society Islands. Reported in the wider Arabian region from the Red Sea (Golani and Bogorodsky 2010), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015). Remarks. Zajonz et al. (2019) listed it as Pristipomoides cf. filamentosus with comment "Also observed by the EPA team, sampling desired". The examined specimen matches the description of P. filamentosus given by Allen (1985), confirming the record from the Socotra Archipelago. A single specimen was caught by hookand-line off Abd al-Kuri Island at a depth of 100-120 m on a steep slope. It has a body depth 3.4 in SL, 11 soft dorsal-fin rays, 60 lateral-line scales and 8 +17 gill rakers. Aphareus furca (Lacépède, 1801) and Aphareus rutilans Cuvier, 1830, also known from Socotra, are both superficially similar to P. filamentosus but can be distinguished by having the premaxilla not protrusible, attached to snout at symphysis by a frenum, and by lacking teeth on the vomer.  Iwatsuki et Kimura, 1998 differs by the second dorsal-fin spine greatly elongate and filamentous, the third anal-fin spine slightly longer than the second spine, a silvery body with indistinct bars and the tips of the second and third dorsal-fin soft ray yellow. Gerres longirostris (Lacépède, 1801) differs by having a deeper body, its depth 2.3-2.8 in SL, usually 5.5 scale rows between lateral line and fifth dorsal-fin spine, a silvery body, with 6-9 vertical series of oblong brownish gray spots on side of body, and the pelvic fins and spinous portion of anal fins yellow. Gerres oyena (Forsskål, 1775) differs by having the second dorsal-fin spine not elongate, the third anal-fin spine longer than the second spine, 3.5 scale rows above lateral line to middle of spinous portion of dorsal fin, and the elevated part of the dorsal fin broadly black-tipped.
Sparidae Rafinesque, 1818 Diplodus omanensis Bauchot et Bianchi, 1984 Oman porgy (Fig. 8A Distinctive characters. Diplodus omanensis is characterized by having a moderately deep body, its depth 2.0-2.3 in SL; interorbital space scaleless; series of 4-5 pairs of incisiform teeth at front of jaws, side of jaws with 2-3 rows of small molariform teeth; pectoral fins reaching to above third anal-fin spine. Meristic values: dorsal-fin spines and rays XI,12; anal-fin spines and rays III,10-11; lateral-line scales 61-63; scale rows between lateral line and fourth dorsal-fin spine 6.5; gill rakers including rudiments 9-10 + 8-10. Coloration. Body silvery white with four broad black bars and additional four short black bars ventrally; head with a black bar through eye, snout partly yellow; dorsal, anal and pelvic fins black. Distribution. Restricted to the north-western Indian Ocean where it previously was only known from southern Oman (Randall 1995) and Pakistan (Amir et al. 2013). Remarks. The observed individuals match the description of Diplodus omanensis given by Randall (1995). A pair of individuals was observed under water in a rocky area with sand bottom at Ras Bidou, western part of the island, at a depth of 12 m. The species is distinctive in coloration and easily distinguished from other sparid fishes in the region. Only one congener is known from Socotra, Diplodus kotschyi (Steindachner, 1876) which differs by its entirely silvery body and by having a black spot on the caudal peduncle. interorbital space scaly; series of 2-3 pairs of canine teeth at front of jaws, side of jaws with row of conical teeth; pectoral fins reaching to above spinous portion of anal fin. Meristic values: dorsal-fin spines and rays XII,10; anal-fin spines and rays III,8; lateral-line scales 51-52; scale rows between lateral line and fourth dorsal-fin spine 5.5-6; gill rakers including rudiments 7-8 + 11-13. Coloration. Silvery tan, silvery red to silvery pink dorsally, silvery ventrally, with a small iridescent blue spot on each scale; lateral-line conspicuous. Distribution. Reported from the Arabian region from the Red Sea (Golani and Bogorodsky 2010) and Somalia only (Sommer et al. 1996), also reported from Kenya (Iwatsuki and Heemstra 2015). Remarks. The examined specimen matches the distinctive characters of Polysteganus coeruleopunctatus given by Iwatsuki and Heemstra (2015). The large single specimen was caught by hook-and-line off Abd al-Kuri Island at a depth of 100-120 m on a steep slope. It has a body depth of 2.2 in SL, 52 lateral-line scales, 6 scale rows between lateral line and fourth dorsal-fin spine and 7 +12 gill rakers. The species is known as inhabitant of rocky bottoms of deepwater slopes or deep coral areas, in a depth range of 50-450 m.

Polysteganus coeruleopunctatus
Lethrinidae Bonaparte, 1831 Lethrinus crocineus Smith, 1959 Yellowtail emperor (Fig. 9A and pectoral fins yellow, margin of spinous portion of dorsal fin dark orange, pelvic fins white. Distribution. Ranges from Mozambique, Seychelles, Madagascar and South Africa (Natal), east to Sri Lanka and Andaman Sea. There are no published data on the occurrence of the species in Arabian region. A single specimen of 183 mm SL (USNM 349335) was collected off the north-eastern coast of Somalia but not mentioned in publications. Therefore, two specimens from the Socotra Archipelago represent the first published record of the species in the Arabian region.
Remarks. The collected specimens match the distinctive characters of Lethrinus crocineus given by Carpenter and Allen (1989). The larger one of the two collected specimens was examined; it has a body depth 2.3 in SL, 47 lateral-line scales, 15 scales between lateral line and anal-fin origin, and 5.5 scale rows between lateral line and fifth dorsal-fin spine. Two specimens were collected from off Abd al-Kuri Island, with no additional collection details available. Elsewhere the species occurs in coastal areas and coral reefs at depths of 20-150 m. It is distinctive by the combination of morphological characters provided above and its unique coloration, featuring pale orange lips and yellow dorsal, anal, caudal, and pectoral fins, with the margin of the spinous portion of dorsal fin dark orange. Senta, 1973 Elongate emperor (Fig. 9B cheek with scales; side of jaws with row of conical teeth; outer surface of maxilla smooth; caudal fin distinctly forked. Meristic values: dorsal-fin spines and rays X,10; anal-fin spines and rays III,10; lateral-line scales 46-48. Coloration. Light silvery gray, scales dorsally on body with darker edges, with 5-6 irregular narrow, indistinct, blackish bars on body; cheek sometimes with a blackish bar below eye; caudal fin grayish brown, posterior margin bright reddish orange to reddish. Distribution. Ranges from the Arabian region, the east coast of Africa, east to southern Japan, northern Australia, and Solomon Islands. Known in the Arabian region from the southern Red Sea, based on several specimens trawled off Jizan, southern Saudi Arabia (Bogorodsky et al., in prep.) and from Somalia (Sommer et al. 1996), from the north-eastern coast of which also voucher specimens exist (e.g., USNM 306039) and should be examined. Remarks. The examined specimen matches the distinctive characters of Gymnocranius elongatus given by Carpenter and Allen (1989). It was caught by hook-and-line over a shallow slope with moderate current at Roosh, north-eastern part of Socotra Island, at a depth of 120 m. One individual was photographed in midwater over a coral area in Medina, north-western part of the island, at a depth of 12 m. Carpenter and Allen (1989) noted that the species occurs mainly over sandy substrata of lagoons and seaward slopes from depths of 50 to 100 m. The record from Socotra thus extends the known depth range.

Gymnocranius sp.
Plain emperor (Fig. 10A dorsal-fin spines and rays X,10; anal-fin spines and rays III,10; lateral-line scales 48-49. Coloration. Light silvery gray without markings, the scale edges slightly darker; fins grayish. Distribution. Known from few specimens originating from Socotra Archipelago (Abd al-Kuri Island and Socotra Island), Kenya and South Africa. Remarks. The two examined specimens from Socotra Archipelago match generic features of Gymnocranius, yet could not be assigned to any described species of the genus. One specimen was caught by hook-and-line off Abd al-Kuri Island at a depth of 100-120 m on a steep slope; the second specimen was caught by hook-and-line off Mori, north-western part of Socotra Island, at a depth of 80 m. Chen and Borsa (2020) investigated the diversity and phylogenetic relation in the Monotaxinae and recognized 15 species in Gymnocranius, four of which are undescribed. Sequences of the Socotra specimens were included in a preliminary phylogenetic analysis which revealed them as nesting within Gymnocranius sp. F sensu Chen and Borsa (2020). The species is currently being described by the present authors and Philippe Borsa. The species differs from two congeners also known from Socotra by its uniformly gray head, and its body and fins without markings. In contrast, G. elongatus possesses a body with 5-6 irregular, indistinct, blackish bars, a cheek usually with a blackish bar below eye and a caudal fin with a reddish posterior margin. Gymnocranius grandoculis (Valenciennes, 1830) differs by having a cheek with undulating blue lines, opercle and preopercle with pale blue spots and fins often yellow distally. Another species G. griseus (Temminck et Schlegel, 1843) reported from southern Oman by Jawad et al. (2011) exhibits dark bars on body and a bar below eye. (Smith, 1957) Mozambique seabream (Fig. 10B) Gnathodentex mossambicus Smith, 1957e: 122; holotype: SAIAB 439; type locality: Mozambique. Material examined. SMF uncatalogued [sample of tissue SOC19-320], 1 specimen, 27 cm SL, Socotra Archipelago, Abd al-Kuri Island, 100-120 m depth, 25 March 2019.

Wattsia mossambica
Distinctive characters. Wattsia mossambica is characterized by having a relatively deep, somewhat rhomboid body, its depth 1.9-2.2 in SL; no scales on inner surface of pectoralfin base; cheek with scales; side of jaws with a row of conical teeth; outer surface of maxilla with a longitudinal denticulated ridge; caudal fin moderately forked, with broadly rounded lobes. Meristic values: dorsal-fin spines and rays X,10; analfin spines and rays III,10; lateral-line scales 48-49. Coloration. Light silvery gray, the scale edges darker, often with a dark brown spot on scales dorsally on body; cheek with undulating blue lines; opercle and preopercle with pale blue spots; fins yellow distally. Distribution. Ranges from the east coast of Africa, east to southern Japan, northern Australia, and Marshall Islands. The species has not been known from the Arabian region and the present record thus extends its distribution range.
Remarks. The examined specimen matches the distinctive characters of Wattsia mossambica given by Carpenter and Allen (1989). It was caught by hook-andline off Abd al-Kuri Island at a depth of 100-120 m on a steep slope. In other areas is the species occurs usually solitary over sandy or rocky substrata of seaward slopes at depths between 100-180 m.  Distinctive characters. Argyrosomus japonicus is characterized by having a body depth of 3.3-4.0 in SL; mouth nearly terminal; jaws with small conical teeth in two rows; dorsal profile of head nearly straight; chin with 3 pairs of pores, no barbel. Meristic values: dorsal-fin spines and rays XI,25-30; anal-fin spines and rays III,7; pectoral-fin rays 15-17; lateral-line scales 50-53; gill rakers 4-5 + 10-12. Coloration. Silvery gray, fins colored like body, dorsal-fin spines and rays pale gray; a blackish spot at upper base of pectoral fins. Distribution. Ranges from the Arabian Sea, south to South Africa, east to the Philippines and Japan. Reported from the wider Arabian region from the Gulf of Tadjoura (Lips et al. 2016, as Argyrosomus regius (Asso y del Rio, 1801)), Oman (Randall 1995, as A. hololepidotus (Lacepède, 1801), and Pakistan (Psomadakis et al. 2015). Remarks. The observed individuals and the collected specimen match the description of Argyrosomus japonicus given by Griffiths and Heemstra (1995). A small group of individuals was photographed under a large rock overhang in a sand area mixed with rocks at Ras Bidou, western part of Socotra Island, at a depth of 14 m. The species is known to usually inhabit sand and mud bottoms from depths of 12 to 150 m; it may also occur in estuaries . The single specimen was taken from Hadibo fish market, and caught in the area of Delisha over rocky habitat at 25 m depth according to the fishermen. It matches the species-specific characters given above including the dentition, and by having 27 soft rays in dorsal fin, 51 lateral-line scale, and 5 + 11 gill rakers. Griffiths and Heemstra (1995) stated that A. hololepidotus (Lacepède, 1801), reported from Oman (Randall 1995), is an endemic to Madagascar, and differs by having more appendages on the swimbladder (34-36), fewer gill rakers (4-5 + 9), and a broader suborbital distance (8.3-9.1 in SL). However, two specimens from Madagascar nested in a molecular phylogenetic analysis within specimens of A. japonicus from its entire distribution range (present authors' unpublished data). More specimens from Madagascar are needed for an expanded combined molecular and morphological study. Furthermore, specimens from Australia are genetically distinct and may represent another species, and referred to the available name A. antarcticus (Castelnau, 1872). Another similar species Argyrosomus heinii (Steindachner, 1907) known from Oman differs by having more soft rays in the dorsal fin (32-33) and 9 gill rakers on lower limb, and should be included in forthcoming studies. The population from Socotra is referred to A. japonicus until a revision of the genus. Argyrosomus japonicus is included in IUCN Red List Assessments as endangered species and requires conservation management . Populations of the species are greatly reduced in most areas due to overfishing in combination with its very slow reproductive cycle, maturing at age 5-6 years only . Argyrosomus japonicus may be confused with externally similar species of Otolithes. For example, Lin et al. (2019) in using an integrative taxonomic approach described O. arabicus from the Gulf and recognized two lineages from the Gulf as potentially undescribed species, all previously misidentified as O. ruber (Bloch et Schneider, 1801). Species of Otolithes might be found on Socotra and can be easily distinguished from Argyrosomus by having large canine teeth at front of each jaw. Gilchrist et Thompson, 1908 Slender baardman (Fig. 11C) Umbrina robinsoni Gilchrist et Thompson, 1908: 182; holotype: SAM 9966; type locality: KwaZulu Natal, South Africa. Material examined. underwater photographs, Socotra Island, Ras Bidou, 14 m depth, 17 April 2019. Distinctive characters. Umbrina robinsoni is characterized by having a body depth of 2.8-3.8 in SL; mouth inferior; jaws with small villiform teeth; dorsal profile of head evenly convex; chin with 2 pairs of pores, and pored at its tip barbel. Meristic values: dorsal-fin spines and rays XI,22-27; anal-fin spines and rays III,7; pectoral-fin rays 17; lateral-line scales 48-54; gill rakers 4-6 + 6-10. Coloration. Silvery dark gray with irregular short and moderate pale gray vermiculations on head and body; pelvic and median fins blackish. Distribution. Ranges from the Arabian region, south to Madagascar and South Africa. Reported in the wider Arabian region from Oman (Randall 1995, as U. ronchus), the Gulf (Eagderi et al. 2019, as U. ronchus), and Pakistan (Psomadakis et al. 2015, as U. canariensis Valenciennes 1843. Remarks. The observed individuals match the description of Umbrina robinsoni given by Hutchings and Griffiths (2005). A pair of individuals was photographed under water above a silty sand bottom in an area mixed with rocks at Ras Bidou, western part of Socotra Island, at a depth of 14 m. The species is known to usually inhabit open sand areas, but also coral and rocky reef areas, at depths of 1-40 m. Hutchings and Griffiths (2005) resurrected U. robinsoni from synonymy of U. ronchus and noted that the latter can be distinguished by an almost straight dorsal profile of the head between orbit and nape, then steeply convex above preopercle, a longer distance between nostril and anterior margin of orbit (11.8-12.8 in head length versus 14.5-41.5 in head length in U. robinsoni) and by lacking a pale vermiculate pattern. Polynemidae Rafinesque, 1815 Polydactylus plebeius (Broussonet, 1782) Striped threadfin (Fig. 12A) Polynemus plebeius Broussonet, 1782: 35; neotype: FMNH 108655; type locality: Tahiti, Society Islands. Material examined. 2 specimens, 22 and 25 cm SL, Socotra Island, Haleh, 10-15 m depth, 2 July 2020. Distinctive characters. Polydactylus plebeius is characterized by having a body depth of 3.1-4.0 in SL; jaws, palatines and vomer with villiform teeth; pectoral fins low on body, distinctly below lateral line; lateral line simple, extending to posterior margin of upper part of lower caudal-fin lobe. Meristic values: dorsal-fin spines and rays VIII + I,12-13; anal-fin spines and rays III,11-12; pectoral-fin rays and filaments 16-18 + 5; lateral-line scales 60-68; gill rakers 9-14 + 13-18. Coloration. Silvery whitish, with series of longitudinal dusky stripes following the scale rows; first and second dorsal fins blackish distally. Distribution. Ranges from the Arabian region, the east coast of Africa and South Africa, east to southern Japan (Miyazaki), eastern Australia (New South Wales), and French Polynesia. Reported in the wider Arabian region from southern Oman and Pakistan (Motomura 2002). Remarks. The examined specimens match diagnostic characters of Polydactylus plebeius given by Motomura (2002) and the combination of distinctive characters provided above including coloration, i.e., having dusky stripes along side of body and lacking black blotch anteriorly on lateral line. Both specimens were examined and photographed from Hadibo fish market and caught in the area of Haleh over rocky and sandy habitat at 10-15 m depth according to the fishermen. Specimens from the Arabian Sea slightly differ in some details from elsewhere (H. Motomura, pers. comm.) and additional study involving genetic analysis is needed to determine the status of the populations from the area. As yet no polynemid fishes had been reported, and P. plebeius represents the first record of the family for Socotra Archipelago. Distinctive characters. Histiopterus typus is characterized by having a body depth of 1.3-1.9 in SL; head covered with naked, striated bones, except for a broad patch of ctenoid scales on cheek, and a small patch above eye and on opercle; mouth slightly oblique, the upper jaw reaching to below posterior nostril; jaws with a band of short conical teeth, the outer row largest, no teeth on vomer; third dorsal-fin spine longest and much stouter than other spines. Meristic values: dorsal-fin spines and rays IV,23-29; anal-fin spines and rays III,8-10; pectoral-fin rays usually 16-18; lateral-line scales 58-70; gill rakers 3-6 + 14-16. Coloration. Head and body with four broad dark brown bars, the first on nape, second bar narrower than other; lips pinkish; pelvic fins dark brown to black. Distribution. Reported from scattered Indo-Pacific localities, including the Arabian region, South Africa, Comoro Islands, Réunion, New Britain (Papua New Guinea), the Philippines, and Japan. Reported in the wider Arabian region from the Red Sea (Klausewitz 1980), Gulf of Oman (Randall 1995), Iraqi waters of the Gulf (Jawad et al. 2018) and Pakistan (Psomadakis et al. 2015). Remarks. The examined specimen matches the distinctive characters of Histiopterus typus given by Hardy (1983), including 25 soft rays in dorsal fin, 16 pectoral-fin rays, 66 scales in lateral line, and 4 + 14 gill rakers. The single specimen was taken from Hadibo fish market, and caught in the area of Delisha over rocky habitat at 45 m depth according to the fishermen. The species is commercial but rare in catches because it occurs solitary and in moderately deep water, making the record from Socotra an interesting finding.

Siganidae Richardson, 1837
Siganus sutor (Valenciennes, 1835) Shoemaker spinefoot (Fig. 12C Distinctive characters. Siganus sutor is characterized by having a body depth of 2.2-2.6 in standard length; dorsal fin with slender spines, the fourth to eighth longest, 1.6-2.0 times longer than last spine; caudal fin forked. Meristic values: dorsal-fin spines and rays XIII,10; anal-fin spines and rays VII,9; scale rows above lateral line 27-32. Coloration. Usually greenish to sandy brown dorsally, paler ventrally, with scattered small pale blue spots, some about three-fourths to equal orbit diameter; opercular membrane dark brown; dorsal and anal fins dark gray or yellowish-gray marbled with brown. Distribution. Ranges from the Arabian region and the coast of Somalia south to South Africa and Madagascar. Reported in the wider Arabian region from the Gulf of Aden and Oman (Randall 1995), the Gulf (Carpenter et al. 1997), and Pakistan (Psomadakis et al. 2015, as S. canaliculatus (Park, 1797). Woodland (1990) demonstrated that S. sutor is restricted to the coast of East Africa and islands of the Western Indian Ocean. But previous records of S. canaliculatus from Oman and the Gulf are based on misidentification of S. sutor. It is supported by unpublished genetic data, with the inclusion of our own examined material from the Gulf and Socotra which nested in one lineage with positively identified specimens of S. sutor from the Western Indian Ocean (Bogorodsky, Zajonz and Victor, in prep.). The records from the Gulf of Aden require confirmation. Woodland (1990) did not examine specimens and just noted that the species perhaps occurs in the Gulf of Aden. Lips et al. (2016) included four photographs from the Gulf of Tadjoura but their upper photograph represents Siganus rivulatus Forsskål et Niebuhr, 1775 which is characterized by having obvious yellow stripes on the ventral side of body, and the lower three photographs represent S. luridus (Rüppell, 1829) which is distinguished from other species by having a truncate caudal fin. Remarks. The two examined specimens match distinctive characters of Siganus sutor given by Woodland (1990). They were collected in an area of mixed coral, stone and seagrass habitats at Delisha, northern part of the Socotra Island, at a depth of 5-6 m. Zajonz et al. (2019)  Distinctive characters. Sphyraena obtusata is characterized by having a slender body, its depth 6.2-8.3 in SL; maxilla not extending posteriorly to a vertical at anterior margin of eye; a single row of scales in the suborbital groove covered with skin; origin of first dorsal fin posterior to vertical at rear base of pelvic fins; caudal fin forked. Meristic values: dorsal-fin spines and rays V + I,9; anal-fin spines and rays II,9; lateral-line scales 78-85; scale rows above lateral line 5-7.5; scales on the line from posterior margin of eye to preopercular edge 5-7; gill rakers 1 + 1. Coloration. Dark grayish green dorsally, silvery on side and ventrally, with about 15, vertically-elongated, sometimes obscured, blackish spots along lateral line; an indistinct dusky yellowish stripe from upper pectoral-fin base continuing along side of body at level of dorsal edge of pectoral-fin base joining lateral line about halfway between rear end of second dorsal fin and caudal-fin base. Distribution. Ranges from the Arabian region to South Africa (KwaZulu-Natal), Madagascar and the Mascarene Islands, east to Japan (Shizuoka Prefecture, Honshu), Australia (New South Wales) and Fiji. Reported in the wider Arabian region from the Red Sea (Doiuchi and Nakabo 2005), Gulf of Tadjoura (Lips et al. 2016), Somalia (Sommer et al. 1996), Oman (Randall 1995), Pakistan (Psomadakis et al. 2015), and the Gulf (various records summarized by Eagderi et al. (2019)). Many previous records in the Arabian region were initially attributed to Sphyraena flavicauda Rüppell, 1838, placed in synonymy with S. obtusata by Doiuchi and Nakabo (2005) who reviewed the S. obtusata species group. Remarks. The examined specimen and observed individuals match the distinctive characters of Sphyraena obtusata given by Doiuchi and Nakabo (2005). The small examined specimen has 81 scales in lateral line, 6.5 scales above lateral line, and 1 + 1 gill rakers. A small group of individuals was observed over a large sand patch in a coral-reef area in Di Hamri, the north-eastern part of Socotra Island, at a depth of 3 m. Zajonz et al. (2019) listed the species in Annex 2 as requiring confirmation. Sphyraena chrysotaenia Klunzinger, 1884 is a similar species, mistakenly placed in synonymy with S. pinguis Günther, 1874 by Doiuchi and Nakabo (2005). It might be found on Socotra because it is also known from the Arabian region. It differs by having smaller scales, lateralline scales 80-94, scales above lateral line 7.5-9.5, a single row of scales in the suborbital groove not covered with skin, and longitudinal dusky yellow stripe running on body above level of dorsal edge of pectoral-fin base.

DISCUSSION
The present article adds 23 bony fish species to the known coastal fish fauna of the Socotra Archipelago (Zajonz et al. 2019). The occurrence of three additional species is confirmed which were listed by these authors as requiring confirmation. The article presents species which are commercially relevant in the local small scale fishery, being marketed locally or regionally or at least consumed domestically. Additional new records and descriptions of new species, unrelated to the local fishery, are subjects of several forthcoming publications by the present authors. Lavergne et al. (2016) included a comprehensive taxonomic account as part of an ecological study of the estuarine fishes of the Archipelago. Among a total of 65 species in 32 families, they listed 19 species which are highly important and 19 species which are moderately important in the local fishery. Zajonz et al. (2016) provided a comprehensive summary of the current state of knowledge about the diversity and ecology of the fish assemblages, fish biomass productivity, and local fisheries in the Archipelago, using both historical information and the results of field surveys conducted over the past 20 years. During visual underwater counts of the fish communities at permanent monitoring transects, Zajonz et al. (2016)  bohar (Forsskål, 1775) were the most abundant commercial species. The review was considered timely given the severe political and humanitarian crisis in Yemen which has been putting increasing pressure on living marine resources on both the mainland and the Socotra Archipelago over the past decade. It has been especially pivotal in demonstrating severely declining catch trends associated with other clear signs of overfishing and highlighting the root causes for this development, i.e., increased numbers of men turning to fishing as a means to feed their families, weak national fishery and enforcement authorities, and increased, unrecorded regional export of catch production by internal and external players taking advantage of Yemen's situation as a failed state. Documenting the "fishery biodiversity" is therefore critical to foster the correct identification of commercial species and improve the statistics of catches and landings as a key prerequisite to close the existing eminent gaps in fishery management. With the twentythree additional species herein reported a total of about 255 species of fish are considered as exploited in the local smallscale fishery and will be included in the forthcoming book 'Atlas to the Commercial Fishes of Socotra Archipelago' (Zajonz et al., in prep.). Among the newly recorded species all but Carangoides fulvoguttatus are relatively rare species which likely reflects at least in part the high fishing pressure. Five species, Epinephelus magniscuttis, Etelis coruscans, Lethrinus crocineus, Wattsia mossambica, and the undescribed species of Gymnocranius represent first records for the Arabian region.
All observed groupers (Serranidae) of the genus Epinephelus are targeted species and rare on Socotra Archipelago, largely due to heavy fishing; only E. undulosus (Quoy et Gaimard, 1824) is still moderately common. Among the groupers of the genus Cephalopholis two species are most frequent in catch and landings, C. miniata (Forsskål, 1775) and C. sonnerati (Valenciennes, 1828). The archipelagic species richness of the subfamily Epinephelinae is high, containing at present 34 recorded species, including 24 species of Epinephelus, with the presence of E. indistinctus yet to be corroborated by additional observations. By comparison, there are 27 species (16 species of Epinephelus) in the Red Sea (Golani and Bogorodsky 2010), 34 species (21 species of Epinephelus) in the Gulf of Tadjoura and inner Gulf of Aden (Lips et al. 2016, Zajonz et al. 2019 in press * ), 32 species (22 species of Epinephelus) in Oman waters (Randall 1995, Zajonz et al. 2019 in press * ) and 19 species (16 species of Epinephelus) in Pakistan waters (Psomadakis et al. 2015).
Jacks, amberjacks, trevallies, scads, and allies is another group of fishes of high commercial interest. The recorded species richness of the family Carangidae for the Archipelago is less than in neighboring areas and at present contains 26 species. In contrast, there are 37 species in the Red Sea (Golani and Bogorodsky 2010), 45 species in the Gulf of Tadjoura (Lips et al. 2016), 42 species in Somalia (Sommer et al. 1996), 44 species in Oman (Randall 1995), 42 species in the Gulf (Carpenter et al. 1997), and 53 species in Pakistan (Psomadakis et al. 2015). The relatively low diversity of the family is somewhat surprising, considering the substantially higher species richness of all adjacent regions and given that the Archipelago biogeographically is a sink for fish diversity. Four species are most targeted in the local fishery, Carangoides fulvoguttatus, Carangoides gymnostethus, Caranx heberi, and Caranx sexfasciatus Quoy et Gaimard,

1825.
Snappers of the family Lutjanidae is another group of fishes of high commercial value. The species richness of the family for the Archipelago is high and at present contains 24 recorded species. In contrast, there are 21 species in the Red Sea (Golani and Bogorodsky 2010), 31 species in the Gulf of Tadjoura (Lips et al. 2016), 26 species in Oman (Randall 1995), 15 species in the Gulf (Carpenter et al. 1997) , and 33 species in Pakistan (Psomadakis et al. 2015). During the field works in 2018 and 2019 three species of snappers were most common in the catches of fishermen, Aprion virescens Valenciennes, 1830, Lutjanus bohar and L. rivulatus (Cuvier, 1828).
Emperors of the family Lethrinidae is another group of fishes of high commercial interest and some species are most abundant in catches. Among the 15 species now recorded from the Archipelago, three species Lethrinus borbonicus, L. microdon Valenciennes, 1830, andL. nebulosus (Forsskål, 1775) are most commonly observed on fish markets and landing sites. In adjacent areas, there are fewer species than reported from the Socotra Archipelago, with 13 species in the Red Sea (Golani and Bogorodsky 2010), 14 species in the Gulf of Tadjoura (Lips et al. 2016), 9 species in Oman (Randall 1995), 8 species in the Gulf (Eagderi et al. 2019), and 9 species in Pakistan (Psomadakis et al. 2015).
No sciaenid or polynemid fishes had hitherto been observed by the authors during their long-term study of the fishes of Socotra, or reported otherwise. Two species of Sciaenidae and one species of Polynemidae reported in the present article thus represent the first records of these families from the Archipelago. Interestingly, no species of Polynemidae are known from the Red Sea and the Gulf of Aden whereas two species are reported from the Gulf and six species from Pakistan waters (Psomadakis et al. 2015, Eagderi et al. 2019). Among the Sciaenidae, only one deepwater species Atrobucca geniae Ben-Tuvia et Trewavas, 1987 is known from the Red Sea and three species from the Gulf of Aden (Argyrosomus japonicus, Atrobucca alcocki Talwar, 1980 and Otolithes sp.). In contrast, the north-eastern part of the wider Arabian region is richer with 14 species reported from the Gulf and 24 species from Pakistan (Psomadakis et al. 2015, Eagderi et al. 2019. The Socotra Archipelago lies in a unique zoogeographical area (Kemp 1998, Zajonz et al., in press * ), and numerous new and unexpected records of species of fish, including additional commercial species will no doubt be found in the future.