Proandricus sani, Plisko, 2002

Plisko, Jadwiga Danuta, 2002, Nine new earthworm species of Proandricus Plisko, 1992 from South Africa and Lesotho (Oligochaeta: Microchaetidae), African Invertebrates 43, pp. 183-204 : 185-186

Proandricus sani sp. n.

( Fig. 1 )

Etymology: Named after the type locality, Sani Plateau.

Material examined: LESOTHO: Holotype NMSA /Olig.02715 mature, clitellate, Sani Plateau (29º35'S:29º16"E) [in summit area of Drakensberg, near South African border] at ca. 2906 m, under rock, 12 February 1998, M. Hamer & K. Martens leg.

Description based on holotype.

External characters:

General: Body cylindrical, compact. Colour: In life probably violet on whole length of body; alcohol-preserved anteriorly dorsally violet, postclitellarly only in a strip parallel with dorsal blood vessel, ventrally whitish-grey. Dimensions: Preserved and slightly contracted 70 mm long, at segment 10 and at tubercula pubertatis 6 mm wide. Segment number: Holotype 98 with partly regenerated segments 64–67. Prostomium: Prolobous, moderate. Segmentation: Secondary annulation present on preclitellar segments; segment 1 simple, with irregular longitudinal grooves; 2 and 3 simple; 4–8 with two simple ringlets similar in size and appearance; 9 with two simple ringlets, second shorter than first. Setae: Minute; preclitellarly and on some clitellar segments ab are irregularly shifted to cd position; postclitellarly in regular lumbricinae arrangement. Nephridial pores: Conspicuous; in cd setal lines. Female pores: In 14, laterally, slightly below cd setae. Male pores: Externally not observed, probably in intersegmental furrow 16/17, where vasa deferentia enter body wall. Spermathecal pores: Externally not observed; position of first pair of spermathecae, observed during dissection, indicates the furrow between two ringlets of segment 9; the second pair located in segment 10 has its pores in intersegmental furrow 10/11.

Clitellar region: Clitellum ( Fig. 1 ): Not well developed, segmented, whitish-grey, extends over segments 12–21; anterior border not well marked, posterior border distinct; ventral borders along cd setal lines, weakly marked. Tubercula pubertatis: Probably also not fully developed, on 16–19, extending slightly onto segment 20; between cd and ab setae, with elevated rims, consisting of four separated transverse pads; a shallow groove divides each pad into two parts; on segment 20 only half of a pad. Papillae: Moderate swellings, paired, on segments 11, 12, 19 around ab setae.

Internal characters:

Septa: 4/5 5/6 6/7 not thickened, thin, firm; 7/8 and 8/9 thickened moderately, muscular, thick, similar in size and appearance; other septa thin, firm. Gizzard: Short, muscular, soft posteriorly. Calciferous glands: In 9, small, globular, distinctly separated dorsally and ventrally. Intestine: In 12 slightly enlarged, in 13 large, folded tube. Typhlosole: Commences in segment 21, terminates in 55. Dorsal blood vessel: In 5–7 thin, double in large part, close together; in 8 double, separated; in 9 enlarged, double, cordiform; in 10 and the following segments enlarged and simple. Paired dorsoventral vessels: In 5– 8 thin vessels, in 9–11 enlarged, moniliform. Nephridia: Meganephridia ; coiled loops and extended, V-shaped caeca.

Reproductive organs: Spermiductal funnels: Proandric arrangement (in segment 10); one pair of large, iridescent funnels closely connected at posterior septum of segment 10 with seminal sacs. Vasa deferentia: Distinct single ducts commence at dorsal parts of spermiductal funnels and run backward at each side of body to segment 16, where they enter body wall. The extended parts of the ducts in segment 16, and their connections with male pores are probably at intersegmental furrow 16/17. Seminal vesicles: Pair of composite sacs commence at septum 10/11 and extend into segment 11; both sacs consist of elongated lobes, variable in shape and size, each communicating with their base, connected with spermiductal funnels. Spermathecae: Variable in shape and size, in segments 9 and 10; anterior pair of elongated thecae enter body wall at furrow between two ringlets of segment 9; posterior pair of round ampullae with long ducts run into intersegmental furrow 10/11. Ovaries: Not observed. Genital glands: Two pairs in segments 11, 12 and 19 associated with papillae; all glands flat, two- or three-lobed, moderate in size.

Biological notes: Known from a single specimen found at a high altitude of nearly 3000 m in the Drakensberg, on the Lesotho side, near the KwaZulu-Natal border, on a mountain path under stone. This species is probably restricted to high altitudes.

Discussion: Locations of spermathecae in segments 9 and 10 suggest assignation to the lesothoensis species-group. However, sani differs clearly from the other species of this group, having an anterior pair of spermathecal pores between two ringlets of segment 9; this condition is not observed in any other known microchaetid species. In the other known species of this group, the spermathecal pores are in intersegmental furrows 9/10 and 10/11 ( lesothoensis and bourquini ), or only in 10/11 ( pajori ).

Figures

Fig. 1. Proandricus sani sp. n. Clitellar part of body, ventral view. [C = clitellum.]