Pseudoveronicella (Hoffmannia) zootoca tanzaniensis, Rowson, Ben, Paustian, Megan & Goethem, Jackie Van, 2017

Rowson, Ben, Paustian, Megan & Goethem, Jackie Van, 2017, New species and records of terrestrial slugs from East Africa (Gastropoda, Urocyclidae, Veronicellidae, Agriolimacidae), ZooKeys 723, pp. 11-42 : 12

Pseudoveronicella (Hoffmannia) zootoca tanzaniensis subsp. n. Figs 1-2, 21, 27-29, 45-49

Material.

TANZANIA: Holotype NMW.Z.2003.001.00030: 1 ad., Mt. Mwanihana FR (7.82°S, 36.83°E), Udzungwa Mts. NP, Kilombero District, forest at 1050 m alt., leg. BR, PT, MBS & CFN, 29 Jan. 2003 (sample 1050 misc). Paratype 1 NMW.Z.2003.001.00031: 1 ad., data as previous but 1200 m alt. (sample 1200P). Paratype 2 NMW.Z.2003.001.00032: 1 ad., data as previous but 1695 m alt. (sample 1695S).

Comparative material of P. (Pseudoveronicella) liberiana (Gould, 1850): UGANDA: 17 ads., Jubiya FR (0.27°S, 31.97°E), Masaka District, forest at 1180 m alt., leg. PT, BR, & FE, 3 Feb. 2007.

Description.

External appearance (Figs 1-2, 45). Medium-sized slugs (notum length 33-39 mm), notum weakly mottled grey-brown or grey-green, evenly speckled with small dark grey speckles, which continue onto the lighter-coloured hyponotum. Tentacles dark grey. Conspicuous anus in the form of a crescent-shaped slit with strongly flaring lips. Female genital opening just anterior to the mid-point of the right hyponotum. Juveniles not known.

Jaw and radula (Figs 21, 27-29). Similar to other African Veronicellidae : jaw of overlapping plates, accompanied by chitinous (?) bristles forming rows along the upper lip and two patches at the margins of the lower lips. Radula with central tooth and 47 teeth in a half-row. Central tooth small, rounded, stump-like; laterals simple, unicuspid and triangular; marginals subtriangular, becoming increasingly elongate and irregular in outline.

Genitalia (Figs 46-49). Penial sheath thin-walled, smooth, incorporating a verge and the conical tip of the "penial gland" of Forcart (1953). Verge small, lacking thorns or spines, basally swollen and with a single rim around the glandular, glans-like tip, which is symmetrical and lacks a fringe around its opening. Penial gland in the form of a smooth cone with an opening at its pointed tip. Five long, tangled digitiform glands enter the penial sheath near one another at the muscular base of the cone. Embryos not found; a single soft spheroidal mass (perhaps an egg) present in the uterus of one individual.

Etymology.

From Tanzania.

Distribution and habitat.

Apparently endemic to forest in the Udzungwa Mts. Pseudoveronicella is a West and Central African genus previously known in eastern Africa only from western Uganda and a single occurrence in Ethiopia ( Forcart 1953, Verdcourt 2006, Wronski and Hausdorf 2010). It is easily recognised by the slit-like anus. Using Forcart (1953), all other Tanzanian Veronicellidae examined key to Laevicaulis Simroth, 1913, a genus widespread in eastern Africa ( Forcart 1953, Herbert 1997, Verdcourt 2006), while the Ugandan material keys to P. liberiana . The Udzungwa specimens thus extend the range of the genus Pseudoveronicella far to the southeast, providing further evidence of western affinities among the endemic and other molluscs of these mountains ( Rowson and Van Goethem 2012).

Remarks.

In Forcart (1953) the Udzungwa specimens key to Pseudoveronicella subgenus Hoffmannia . This differs from Pseudoveronicella s. str. (examined from Uganda) in having a verge that is glandiform rather than utricular, with an opening that is not surrounded by fringes. It then keys to P. (H.) zootoca , whose verge lacks thorns and has a glans-like tip. The shape of the tip differs between the two subspecies recognised by Forcart: P. (H.) z. zootoca , widespread in West Africa from Tamassadou to Leopoldville, and P. (H.) z. aethiopica Forcart, 1953 described from Sidamo, southern Ethiopia, at 2500 m. The Udzungwa slugs resemble P. (H.) z. aethiopica more closely than P. (H.) z. zootoca in their larger body size, and in not containing embryos (Forcart, 1953). However they do not confirm exactly to either: the verge has a much more strongly swollen base than either subspecies, while the glans is not hoof-like as in P. (H.) z. aethiopica . In light of the morphological differences and the greatly disjunct distributions, we follow Forcart (1953) in ascribing the material to a new subspecies of P. (H.) zootoca .