Howascolex madagascariensis Michaelsen, 1901

Csuzdi, Csaba, Razafindrakoto, Malalatiana & Hong, Yong, 2016, The second species of the endemic Malagasy earthworm genus Howascolex Michaelsen, 1901; Howascolexfarafangana sp. n. (Clitellata, Megadrili), African Invertebrates 57 (2), pp. 83-91 : 86

Taxon classification Animalia Haplotaxida Acanthodrilidae

Howascolex madagascariensis Michaelsen, 1901

Howascolex madagascariensis Michaelsen, 1901: 202, Pickford 1937: 605, Julka 1988: 344.

Diagnosis.

Length 90-100 mm diameter 4-6 mm. Colour pale, pigmentation lacking. First dorsal pore in 12/13. Clitellum 13-19. ♀ 14 paired, presetal in a–a. Prostatic pores 17, 19. Spermathecal pores on the rim of 8 and 9, spermathecae with elongated oval ampoule, and a small duct bearing an acinous diverticula almost encircling the duct. Gizzard large in 5 or 6, last pair of hearts in 13. Calciferous glands large intramural encircles the oesophagus in 16. Excretory system holoic? before clitellum and meroic with 5-6 meronephridia and a stomate ventralmedian megameronephridium per side. Penial setae present. Ectal third highly bent, tip somewhat spoon-shaped. Length 2 mm diameter 0.04 mm, ornamentation small scattered teeth.

Material examined.

ZMUH V5616 Howascolex madagascariensis syntypes 8 ex. S. Madagaskar, Andrahomana in Höhlen. Leg. Sikora.

HNHM/AF5667 1+1 juvenile ex., HNHM/AF5668 1 ex. Madagascar, Vatovavy Fito Vinany Region, Farafangana District, Tsararafa, Ankazomafaitsa 22°38'42"S, 47°50'04"E, 63 asl, Legit: Y. Hong & M. Razafindrakoto.

Remarks.

We had the possibility to examine the syntypes of Howascolex madagascariensis housed in the Zoological Museum of the University of Hamburg (ZMUH). The specimens are softened but all the inner structures are clearly seen. The nephridial system is completely identical with that of described in Michaelsen (1901). In the praeclitellar segments there is a pair of highly coiled stomate, exoic and avesiculate tubular holonephridium. In the postclitellar region the larger nephridia (megameronephridia) are accompanied by several smaller highly coiled meronephridia.

Our specimens agree well with the syntypes but their nephridia are not so well preserved and it seems that the praeclitellar holonephridium consists of 2-3 interconnected more compact regions which became separated after the clitellum to form 4-6 normal meronephridia. The shape of the spermathecae, the penial setae, and the distribution of the characteristic genital papillae are identical in the syntypes and the new material.