Proandricus oresbiosus Plisko, 2003

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 : 244-246

Proandricus oresbiosus Plisko, 2003

Fig. 8

Proandricus oresbiosus: Plisko 2003: 299 .

Type locality: South Africa: KZN, Royal Natal National Park , north side of Devil’s Hoek River (28 ° 41'S: 28 ° 53'E). Known from a few sites in the central Drakensberg mountain range .

Material examined: Holotype NMSA /Olig.02440; 3 cl paratypes NMSA /Olig.02434 from Bergville area (28 ° 42'S: 29 ° 22'E). New material: NMSA /Olig.03878, 2 cl Free State: ca 70 km north of Mont-aux-Sources , on extended grassland, slightly below 2500 m (28 ° 38'10.62"S: 28 ° 57'39.84"E).

External and internal characters are in accord with the species description. However, it should be added that the intestine in segments 21–27, 28 is covered by twisted, paired folds, similar to those observed in adami . Setae, although minute on type material, are slightly larger in the clitellar area on the newly examined specimens, but their irregular shifting on the few segments is difficult to locate. Spermathecae in all dissected specimens are minute, ampullae oval, ducts elongated on bulbous basis. Two pairs of spermathecae are located in the anterior and posterior parts of segment 9; always smaller than the pair in 10. Ectal parts of anterior pair of 9 enter the body wall intrasegmentally between segmental ringlets, or in intersegmental furrow 8/9, with pores not noted externally. Spermathecal pores of the posterior pair of 9 open intersegmentally in 9/10. Pores of spermathecae located in 10 are in 10/11.Although examined individuals reveal external and internal maturity, having well developed clitella, tubercula pubertatis and spermathecae, iridescence was observed in tiny parts of the ampullae in only two individuals. This species, having three pairs of spermathecae, of which two pairs are in one segment opening intrasegmentally and intersegmentally, differs markedly from others.

The Mont-aux-Sources area, located in the northern part of the central Drakensberg, is adjacent to the Royal Natal National Park, and the new collecting site lies in the neighbourhood of the species’ type locality. Both sites are located in the area of the water source for the Vaal, Orange and Thukela rivers, which descend west to the Atlantic Ocean, and east to the Indian Ocean respectively. It is possible, that, in addition to other factors, the distribution of this species is correlated with rainfall and plunged rivers.

Holandric species:

Figures

Figs 6–8. Habitus and enlarged clitellar area of Proandricus species: (6) P. adami, (7) P. amphius, (8) P. oresbiosus. Scale bars = 1 cm.