Geogenia benhami ( Rosa, 1891 )

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 : 246

Geogenia benhami ( Rosa, 1891)

Fig. 9

Microchaeta benhami: Rosa1891: 382 ; Beddard 1895: 673.

Microchaetus benhami: Michaelsen 1891: 382 ; 1900: 451; 1913: 538; 1918: 316; Pickford 1975: 2; Reynolds & Cook 1976: 77; Plisko 1992: 342; 1993: 235; 1995: 46 [designation of lectotype, deposited in ZMH]; 2003: 288.

Geogenia benhami: Plisko 2006: 43 .

Type locality unknown. Type material declared as “ typus amissus ” by Reynolds and Cook (1976). Lectotype designated by Plisko (1995) on the material deposited in ZMH, collected in: South Africa, Western Cape, Bergvleit near Constantia (34 ° 01'S: 18 ° 27'E). Material examined: 7 mature and 5 semimature specimens deposited in USNM, with no. 52.831, lectotype with no V 183, deposited in ZMH, 1 deposited in NMHW with no. 4811, and 2 mature specimens NMSA / Olig.03925 collected recently in Western Cape, Stellenbosh area .

Although the locality was not indicated at the time of the species description, Michaelsen (1891) and Pickford (1975) reported its occurrence in the Western Cape: the Constantia area, Cape Town, and Stellenbosch, and some of the collected material is deposited in ZMH and USNM. In examined specimens, the anterior spermathecae and their pores occur in intersegmental furrow 10/11, with the following in 11/12, 12/13, 13/14, 14/15, 15/16. Spermathecae in this species are multiple in one segment, usually being more than three, sometimes five or six. Setae are arranged in four even pairs, showing no discrepancy. Although the anterior spermathecal pores in this species are not located anterior to the testicular segment, their unusual position is of great interest. Only mkuzi is similar to this species, though it differs anatomically and in distribution.

Considering this species’ holandric condition, the presence of spermathecae in both testicular segments (10 and 11), and also the numerous spermathecae posterior to testes in segments 12, 13, 14, 15, and the regular arrangement of setae, no similarity to the species accredited to lesothoensis species-group has been found. Its distant occurrence from the sites of species distributed in the Drakensberg mountain range confirms its exclusion.

From verbal information provided by Frana Fourie who deposited new material in the NMSA, the species occurs in the Stellenbosch area in large populations. Recorded from natural, not disturbed sites, and also from an arable cultivated field.

Figures

Figs 9, 10. Habitus of Geogenia benhami (9) and G. mkuzi (10). Scale bars = 1 cm.