Polycystis ali Schockaert, 1982

Artois, Tom J. & Tessens, Bart S., 2008, Polycystididae (Rhabditophora: Rhabdocoela: Kalyptorhynchia) from the Indian Ocean, with the description of twelve new species, Zootaxa 1849, pp. 1-27 : 22-23

Polycystis ali Schockaert, 1982

( Fig. 6 A–B)

Known distribution. Somalia, N of Mogadiscio (Hawadli) ( Schockaert 1982), Mombasa ( Kenya): McKenzie Point, at the mouth of Tudor Creek, on Thalassia hemprichii ( Jouk & De Vocht 1989) . Galapagos, Santa Cruz, Bahia Academy ( Karling 1986).

New localities in the Indian Ocean. McKenzie Point, Mombasa ( Kenya): a short distance past the Four Seasons Restaurant before the second obelisk, algae (mainly Sargassum ) from a vast shallow pool in the lower eulittoral (27/9/1991); same locality: arboriform algae from a shallow tide pool past the second obelisk about 15 m from the roundabout at the Four Seasons Restaurant (01/10/1991); same locality: tufts of brown algae from a shallow tide pool in the lower eulittoral before the fence of the Four Seasons Restaurant (10/10/1991).

Material. Type material and the material of the original description. All material studied by Karling (1986). Several animals from the new localities studied alive and five whole mounted, including that of Jouk & De Vocht (1989). One animal from Kenya serially sectioned.

Remarks. The stylets of the new material are 18–24 µm high (m = 22; n = 4) and distally 31–37 µm wide (m = 34; n = 4). These measurements fit those of Jouk & De Vocht (1989) on their specimen (20 µm high and 41 µm wide). Schockaert’s (1982) measurements on the Somali population were only made on the holotype, which has a stylet of 17 µm high and 28 µm wide. The other whole mounted specimens from Somalia have stylets between 21–24 µm high and 26–31 µm broad. This suggests there is no difference in dimensions of the prostate stylet between the Kenyan and the Somalian population, although such a difference was implied by Jouk & De Vocht (1989).

Discussion. See the discussion after P. e l s a e n. sp.

Figures

FIGURE 6. Polycystis ali Schockaert, 1982 A, Prostate stylet type I, side view (from a specimen from Kenya). B, Prostate stylet type I, view from below (from a specimen from Kenya). Polycystis elsae n. sp. C, Prostate stylet type I (from the holotype).