Acanthodrilus barrierei, Csuzdi & Pearlson & Pavlíček, 2017

Csuzdi, Csaba, Pearlson, Oren & Pavlíček, Tomás, 2017, New Acanthodrilus species from New Caledonia (Clitellata, Megadrili, Acanthodrilidae), Journal of Natural History (J. Nat. Hist.) 51 (31 - 32), pp. 1899-1912 : 1900-1902

Acanthodrilus barrierei sp. nov.

( Figure 1 )

Type material

Holotype. HNHM / AF5683 , clitellate adult, complete specimen. New Caledonia, Blue River Provincial Park (22.15° S, 166.73° E), rainforest, 31 January 2014, leg. T. Pavlí Č ek . Paratypes: HNHM / AF5684 , two clitellate adult ex ., locality same as that of holotype.

Etymology

The new species is named in honour of Frédérique Alain-Barrière for her generous help during the collecting trip to New Caledonia.

Diagnosis

L. 90 mm. D. 2 mm. Average weight 0.6 g. Colour yellowish. First dorsal pore in 12/13. Clitellum ½13–½17, circular. Prostatic pores paired in 17, 19. Penial setae L. 3.5 mm, D. 0.07 mm, ornamentation group of spines. Spermathecal pores 7/8, 8/9 b. Muscular gizzard in 6, calciferous glands lacking. Last pair of hearts in 13. Spermathecae with long narrow duct and a somewhat shorter oval ampoule joining the duct at a right angle. The duct entally bears a small diverticulum filled with sperm-chambers. Genital setae present.

Description

Holotype. L. 90 mm, D. 2 mm, No. segments 165.

Paratypes. 44–46 mm in length, 2 mm in diameter, No. segments 92, 117, tail missing. Colour yellowish, pigmentation lacking. Prostomium tanylobous, the first dorsal pore occurs in the intersegmental furrow 17/18. Setae closely paired, setal formula after the clitellum aa:ab:bc:cd:dd = 8.9:1.1:6.4:1:28.6. Setae ab of segment 9 modified to genital setae. The clitellum extends over segments ½13–17, clearly saddle-shaped, reaching ventrally the setal line a ( Figure 1a ). Prostatic pores paired on small papillae in 17, 19. Male pores externally clearly visible on segment 18, in the curly bracket-shaped seminal grooves. Female pores paired on 14, small slits anterior to setae b-b. Spermathecal pores large in furrows 7/8, 8/ 9 in setal line b. Nephridiopores aligned in setal line cd. Paired oval porophores in 9/10, 10/11 aligned with setae ab, and unpaired ventral median porophores in segment 17–19, 21/22–22/23.

Internal characters

All septa membranous. Oesophageal gizzard large in 6. Calciferous glands lacking, the intestine commences from segment 23. Typhlosole lamellar, moderately sized, beginning around segment 30. Excretory system holoic, nephridial bladders sack-shaped ( Figure 1b ). Paired hearts present in segments 10–13. Testes are in 10, 11 free. Two pairs of seminal vesicles present in 11, 12. A pair of small ovaries in segment 13. Two pairs of prostates present in 17, 19. The glands are moderately long, reaching up to segment 22. Each prostate accompanied by a penial setal sac containing an adult and several replacement setae. The adult seta 1.5 mm in length and the middle 0.05 mm wide. The seta forms almost a halfcircle, tip pointed, ornamentation consists of small serrated bars ( Figure 1c ). The genital seta is almost straight, 1.1 mm long and in the middle 0.037 mm wide. Its tip rounded, ornamentation consists of small serrated scales ( Figure 1d ). Two pairs of spermathecae present in segments 8 and 9. Each consists of a narrow and duct and an equally long, oblong ampoule. The ampoule joins the duct almost in a right angle. The ental part of the duct forms a protruding elbow containing several small sperm chambers ( Figure 1e ).

Remarks

The new species with its medium size, lack of pigmentation and vesicles in 11, 12 seems to be most close to A. foanus Michaelsen, 1913 . However, it differs from the latter in the presence of genital setae, in the size and ornamentation of the penial setae (1.5 mm with pointed tip vs. 4.5 mm with a blunt tip) and the form of the spermathecae.

Figures

Figure 1. Acanthodrilus barrieri sp. n. (a) ventral view of the clitellar region; Fp, female pore; Gp, genital papillae; Gs, genital setal papilla; Mp, male pore; Prp, prostate pores; St, spermathecal pores; scale bar, 1 mm. (b) nephridial bladder from the postclitellar segments. (c) penial seta; scale bar, 0.05 mm. (d) genital seta; scale bar, 0.03 mm. (e) spermatheca.