Phaenocora foliacea Bohmig 1914

Phaenocora foliacea Böhmig, 1914

(Figs 1 B, C, 9)

Phaenocora foliacea Böhmig 1914: 87 –92, Figs 1 –4; Meixner 1924: 114; Beauchamp 1940: 323; Marcus 1946: 72, 81–82, 166; Marcus 1955b: 101 –103, Figs 1–2; Marcus 1955a: 4 –7, Figs 1–3; Weir 1969: 100; Young & Young 1976: 93, 101; Young 1976: 423.

Derostoma foliaceum Böhmig 1914: 87 –92, Figs 1 –4.

Phaenocora chappuisi Beauchamp 1936: 148 –151, Fig. 5; Ruebush 1939: 53; Beauchamp 1940: 323; Marcus 1946: 72, 166; Young & Young 1976: 101.

Derostoma foliacea Young & Young 1976: 101.

Known distribution: Cape Peninsula (South-Africa), several locations: Lange vlei, pond between Fishhoek and Chapmans bay, Plumstead, Fishhoek (Böhmig 1914); Mount Elgon (Kenya) at 4000 m altitude, lake Naivasha (Kenya) at 1900 m altitude (Beauchamp 1936); Congo (Beauchamp 1940); Kruger National Park, Leeupan 24 km North-East of Skukuza (South-Africa) (Marcus 1955b); Garamba National Park (Congo) (Marcus 1955a); Hwange National Park (Zimbabwe) (Weir 1969).

New localities: Hluhluwe Game Reserve (Memorial Gate, South Africa; 28°04'03.18"S, 32°08'29.22"E), temporary pond fringed with Leersia hexandria on clay; 10 December 2009 (TYPE LOCALITY).

Mayem lake (Goa, India; 15°34’32.8”N, 73°56’31.8”E), relatively high waterweed-like submersed vegetation; 0 1 December 2008.

Material examined: Two sagitally-sectioned specimens from Hluhluwe Game Reserve (South-Africa) (sections of one specimen located on two slides: HU nos VI.3.38–VI.3.39), one of which is designated neotype (sections of one specimen located on two slides: SMNH Type-8673a and Type-8673b), three sagitally-sectioned specimens from Mayem lake (India) HU nos VI.3.40–VI.3.42).

Diagnosis: Largest animals up to 3 mm long, without pigmented eyes. Body pigmentation absent. Zoochlorellae sometimes present. Male copulatory system is of the simplex-type. Female genital system is of the UNIPUNCTATA - type. Oviduct opens in the distal part of the female genital canal.

Descriptive notes: The studied animals are about 1–1.5 mm long (measured on sagitally-sectioned specimens). Eye pigmentation and body pigmentation absent. Zoochlorellae sometimes present. All individuals from South Africa with zoochlorellae, indian specimens without zoochlorellae.

The inferior genital atrium (Fig. 9: iga) is lined with the same epithelium as the epidermis, albeit with less cilia. The superior genital atrium (Fig. 9: sga) is lined with a nucleated epithelium and receives the male copulatory system and the female genital system through its dorsal wall.

The male copulatory organ is of the simplex-type (see GENERAL MORPHOLOGY section). The studied specimens all have two vasa deferentia, which unite at the point of entrance into the copulatory organ.

The female genital system is provided with an intestinal bursa (Fig. 9: bi), a genito-bursal duct (Fig. 9: dgb) and a female genital canal (Fig. 9: fgc). Although the intestinal bursa is situated near to the gut in the studied specimens, a connection between the intestinal bursa and the gut was not observed (see remarks). The intestinal bursa is lined with a low epithelium, which is thickened at each place where a nucleus occurs. The genito-bursal duct is lined with a high nucleated epithelium and a muscular sheath, which consists of an outer longitudinal and a strong inner circular muscle layer. The oviduct (Fig. 9: od) is short and lined with a high, nucleated epithelium. It opens into the female genital canal somewhat distally from the junction of the genito-bursal duct and this canal, which gives the impression of a small dilatation (Fig. 9: dil) as was described by Marcus (1955b). The exact place where the vitelloduct opens could not be clearly assessed.

Remarks: Marcus (1955b) provided a very exhaustive description of P. foliacea. However, there are some small differences between her description and that of Böhmig (1914) and our new material.

First, Marcus (1955b) described two vasa deferentia, which unite at the level of the gonopore, to form a single vas deferens before entering the male copulatory organ. In the original description of Böhmig (1914) and in our observed specimens, the two vasa deferentia unite at the point of entrance into the copulatory organ. Second, Marcus (1955b) also specifically mentioned and illustrated a connection between intestinal bursa and gut, which we could not see on the studied specimens.

New material consistent with that of Marcus is needed to ascertain whether or not these differences are significant enough to warrant splitting the species. For the sake of taxonomical stability we assume these small differences are because of intraspecific variation. Nevertheless, our material matches the original description of Böhmig (1914) and therefore all qualifying conditions for neotype designation are met (ICZN 1999: Art. 75).