Philine cerebralis, Malaquias & Ohnheiser & Oskars & Willassen, 2017

Malaquias, Manuel António E., Ohnheiser, Lena T., Oskars, Trond R. & Willassen, Endre, 2017, Diversity and systematics of philinid snails (Gastropoda: Cephalaspidea) in West Africa with remarks on the biogeography of the region, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 180 (1), pp. 1-35 : 12-16

PHILINE CEREBRALIS SP. NOV.

( FIGS 2A–O, 3A–E )

Diagnosis: Shell internal, translucent, elongate-oval in shape, with chain-like sculpture in transverse lines. Body white. Rachidian tooth absent, one curved inner lateral tooth with sharp, developed denticulation along inner edge, one outer lateral tooth. Gizzard surrounded by muscle fibres, contains three equal chitinous spindle-like gizzard plates. Prostate highly lobate, emerging from tubular penial sheath.

ZooBank registration: urn:lsid:zoobank.org:act:D3FC6EEC-729D-477D-AEAE-D3022BC6C154

Etymology: The name of this species stems from the shape of the prostate, which is highly lobate, resembling a vertebrate brain.

Type locality: Off Nikine , Senegal, 12 ° 33 0 53.28 ″ N , 017 ° 21 0 18.36 ″ E.

Material examined: Off Nikine , Senegal, 12 ° 33 0 53.28 ″ N, 017 ° 21 0 18.36 ″ E, 1 spec. (holotype), dissected, ZMBN 105812 , H = 3.6 mm .

Shell ( Fig. 2D–G): Maximum H = 3.6 mm. Internal, thin; translucent; elongated-oval cylindrical in shape, aperture wide with thin whitish parietal callus, outer lip scalloped, apex obtuse, not umbilicated; sculpture visible through mantle, consisting of transverse lines of pits connected to form chains.

Animal ( Fig. 2A–C): Body white in preserved specimen, mantle thin. Cephalic shield indented, median groove present. Larval kidney not visible through shell.

Radula ( Fig. 3A–D ): Radular formula 17 9 1.1.0.1.1. Rachidian tooth absent. Inner lateral teeth with broad base, curved; inner edge with sharp and developed denticulation. Outer lateral teeth straight, with broad base.

Gizzard ( Fig. 2H–O): Gizzard elongate cylindrical, surrounded by muscle fibres, contains three equal chitinous spindle-like plates with two longitudinal depressions on ventral surface. Dorsal surface inside the gizzard of amber colour, ventral surface more whitish, surrounded by translucent margin. Microsculpture on ventral surface, dorsal surface with crystalline needles.

Male reproductive system ( Fig. 3E ): Obvious separation between long, thin, lobate brain likeshaped prostate and elongate tubular penial sheath.

Figures

Figure 3. Philine cerebralis sp. nov. (ZMBN 105802, H = 3.6 mm, holotype). A, radula (SEM). B, detail of radula (SEM). C, outer lateral tooth (SEM). D, detail of denticles (SEM). E, male reproductive system. ga, genital aperture; pr, prostate; ps, penial sheath. Scale bars: A = 50 lm; B = 30 lm; C = 10 lm; D = 5 lm; E = 250 lm.