Octochaetus kenleei Blakemore

Boyer, Stephane, Blakemore, Robert J. & Wratten, Steve D., 2011, An integrative taxonomic approach to the identification of three new New Zealand endemic earthworm species (Acanthodrilidae, Octochaetidae: Oligochaeta), Zootaxa 2994, pp. 21-32 : 27

Octochaetus kenleei Blakemore sp. nov.

Material examined. Museum of New Zealand Te Papa Tongarewa W.002910 (Holotype). From the tussock grassland of “Happy Valley” (Upper Waimangaroa Valley, Buller Region, West Coast, New Zealand). Collected by S. Boyer, 2010. Mature, complete, fixed in ethanol 98% and placed in propylene glycol.

Etymology. In patronymic tribute to the foremost earthworm eco-taxonomist of New Zealand, Dr Kenneth Earnest Lee (1927–2007).

External characters. Body circular but posterior slightly square. Pigment lacking and generally fair. Length 220 mm with 270 segments. Prostomium prolobous. Setae lumbricine, 8 per segment, evenly spaced. Clitellum not well marked, perhaps in some or all of 14–20. Dorsal pores from 14/15, small. Nephropores not clear, some possibly in c and d lines or rather irregular. Spermathecal pores segmental, lateral to b lines on 8 and 9 on small mounds. Female pores just anterior to setae a on 14. Prostatic pores at b on 17 and 19. Male pores within concave seminal grooves lateral to b. Genital markings as small lens-shaped hollows paired in 8/9 and 9/10 near b lines and in 15/ 16 in a lines with a unilateral marking in 18/19lhs; area bb in 19/20–22/23 tumid. Genital and penial setae not found.

Internal morphology. Pharyngeal mass anterior to 4/5. Septa 8/9–10/11 with some thickening. Gizzards muscular in 5 and 6. Dorsal blood vessel appears single on gizzards but is doubled from 7 posteriorly. Heart paired in 10–13. Nephridia meroic as a few (ca. 4 per side) small tufted clusters in each segment. Spermathecae in 8 and 9 saccular each with small discrete and interlocular diverticula (inseminated) ringing exit. Testes free, posterio-ventrally in 10 and 11. Seminal vesicles large finely racemose anterio-dorsally in 11 and 12. Ovaries composed of several strings of largish eggs in 13; ovisacs absent. Prostates tubular in 17 and 19 exiting through narrow ducts. Vasa deferentia exits in 18. Oesophagus dilated as annular calciferous gland in 17 with several internal lamellae but not especially vascularized. Intestinal origin in 20 (valval in 19). Typhlosole large inverted T-shape developing from 21. Gut contains colloidal soil with a few quartz grits and woody fragments.

Ecology. Specimen was found under 10 to 20 cm of soil. Large size, pale colouration and gut contents suggest subsoil geophagy. This species is likely to be endogeic.

Remarks. The current species is compared to Octochaetus thomasi Beddard, 1892 , widespread in the Canterbury Plains, that is the only other congener known to have gizzards in 5–6. As with all other members, it has spermathecal pores in 7/8/9 and on this character alone the current species is differentiated. Neodrilus campestris (Hutton, 1877) from Dunedin has segmental spermathecal pores (on 8) but differs, not least, by qualifying for inclusion in Acanthodrilidae due to its holoic nephridia.