Foviella affinis (Oersted, 1843)

Sluys, Ronald & Kawakatsu, Masaharu, 2005, Biodiversity of marine planarians revisited (Platyhelminthes, Tricladida, Maricola), Journal of Natural History 39 (6), pp. 445-467 : 446-447

Foviella affinis (Oersted, 1843)

( Figures 1–3 )

Synonymy: Procerodes solowetzkianus Sabussow, 1900 .

Material examined

ZMA V.Pl. 948.1, Chupa Bay, White Sea (1986, 1987 or 1988), sagittal sections on four slides; V.Pl. 948.2, ibid., sagittal sections on four slides; V.Pl. 948.3, ibid., sagittal sections on four slides.

Comparative discussion

Since no copy of Sabussow’s (1900) paper was available at the time, Sluys (1989) had to rely on the summaries provided by Wilhelmi (1909) and Böhmig (1906), workers who both pointed to the incomplete and inadequate original description of the species Procerodes solowetzkianus Sabussow, 1900 from the Solovetskiye Islands in the White Sea. When R.S. obtained a personal copy of Sabussow’s paper, no new light was thrown on the enigmatic status of P. solowetzkianus , albeit that thus there was direct access to the drawing of a sagittal section of the copulatory apparatus ( Figure 1 ).

Russian workers continued to report P. solowetzkianus from the White Sea ( Timoshkin 1979; Poljakova 1991) and when finally new material became available it was immediately clear how Sabussow’s account should be correctly interpreted. It turned out that a good deal of misunderstanding had been caused by the fact that Sabussow described as a small, ball-shaped ‘Uterus’ (i.e. copulatory bursa) a structure that actually is the very distal end of the female genital duct, in point of fact the precise point where the oviducts communicate with the genital duct. A copulatory bursa, as present in many maricolans, is actually missing in these animals from the White Sea. Examination of histological sections unequivocally revealed that the specimens are representatives of the species Foviella affinis (Oersted, 1843) . This species is further characterized by: (1) a female genital duct receiving the secretion of penial glands; (2) a well-muscularized penial papilla with a distinct caudally directed bend or with the tip of the papilla curved towards the dorsal body surface; (3) vasa deferentia that expand within the penis bulb to form intrabulbar spermiducal vesicles before uniting to form the ejaculatory duct; and (4) a large lens in each eye cup. All of these features occur in our presumed P. solowetzkianus animals, a finding that we here substantiate by providing a photograph of a sagittal section of the copulatory apparatus ( Figure 2 ) and of an eye cup with a lens ( Figure 3 ).

Sabussow’s (1900) description now turns out to be in close agreement with our findings based on examination of new material, since he depicted the curved nature of the penial papilla (his figures 32–34), the female genital duct receiving the secretion of shell glands (his figure 34) and the intrabulbar spermiducal vesicles (his figure 33).

Figures

Figure 1. Foviella affinis, sagittal section through copulatory apparatus (from Sabussow 1900: pl. III, figure 34; labels adapted according to current terminology).

Figures 2, 3. Foviella affinis. (2) V.Pl. 948.3, sagittal section of the copulatory apparatus. (3) V.Pl. 948.3, sagittal section through eye cup with lens.