Proandricus lesothoensis ( Reinecke & Ryke, 1969 )

Plisko, Jadwiga Danuta, 2009, Pre-testical spermathecal pores and unusual setal arrangement in the South African endemic microchaetid earthworms of presumed Gondwanan origin (Oligochaeta: Microchaetidae), African Invertebrates 50 (2), pp. 237-237 : 240

Proandricus lesothoensis ( Reinecke & Ryke, 1969)

Fig. 2

Geogenia lesothoensis: Reinecke & Ryke 1969: 516 ; Reynolds & Cook 1976: 127.

Microchaetus lesothoensis: Zicsi & Pajor 1992: 129 (for Proandricus pajori ).

Proandricus lesothoensis: Plisko 1992: 355 ; 1993: 202; 1994: 229; 2003: 295.

Type locality: Lesotho: Butha-Buthe District (approx. 28 ° 50'S: 28 ° 30'E) , at ca 3300 m. This species is known from the central Drakensberg mountain range, in Lesotho .

Material examined: Lectotype NMSA /Olig.01402 and 3 paralectotypes NMSA /Olig.01403.

This species’ external and internal characters are in accord with their description ( Reinecke & Ryke 1969) and redescription (Plisko 1993). Re-examination of setae confirms their closely paired arrangement in four pairs, although on several pre-clitellar segments they are difficult to trace and some of ab are irregularly misplaced. In clitellar area ab are sporadically uplifted dorsally to cd pairs. No constant pattern was observed in four examined individuals. Usually, the discrepancies occur on four to six segments, where ab setae are shifted dorsally to leave the other ab pairs on neighbouring segments in even, regular rows. Setae cd always in regular rows, not misplaced. Spermathecae in 9 and 10, variable in shape and size in the same individual; usually ampulla spherical with elongated duct. Number of spermathecae one or two, in one segment. Spermathecal pores in 9/10 and 10/11. Anterior spermathecae usually empty. Presence of sperm in posterior thecae confirms activity of spermathecal pores 10/11; lack of sperm in the anterior spermathecae in the same specimen suggests that pores 9/10 might be not active during mating.

P. lesothoensis , identified more than three decades after Michaelsen (1933) described timmianus , exhibits the possible occurrence of the spermathecae in pre-testicular segments observed on histological slides, and some irregularities in the arrangement of setae in clitellar segments. However, no comparative study between these two species was undertaken at the time of the species’ description, or during the revision of the lesothoensis type material by Plisko (1994), because of the lack of timmianus type material, and this has obscured the taxonomic position of both species. Although lesothoensis was first accredited to the timmianus species-group, later a lack of timmianus type material made this invalid. Later, when pre-testicular spermathecal location was observed in other proandric species, with some irregularities in the arrangement of setae, the species-group was proposed, and the name given after lesothoensis .

Present examination verifies the lesothoensis relationship with the small group of species having spermathecae anterior to the testicular segment, supposedly in the process of variation or evolutionary change.

Figures

Figs 2–5. Habitus and enlarged clitellar area of Proandricus species: (2) P. lesothoensis, (3) P. pajori, (4) P. bourquini, (5) P. sani. Scale bars = 1 cm.