Yagansia traful, Csuzdi & Mischis, 2010

Csuzdi, Csaba & Mischis, Catalina C., 2010, Earthworms from Argentinean Patagonia with description of two remarkable new species (Oligochaeta: Acanthodrilidae, Lumbricidae and Megascolecidae), Journal of Natural History 44 (1 - 2), pp. 31-40 : 34-37

Yagansia traful sp. nov.

( Figures 3–6 )

Material examined

Holotype. HNHM/5240 , Argentina, Prov. Neuquén, Traful Ville , 40°40′S; 71°21′W, 965 m, under log, coll. C. Mischis, 10 January 2008.

Paratypes. HNHM/5249 two ex., Argentina, Prov. Neuquén, Traful Ville , 40°40′S; 71°21′W, 965 m, under log, coll. C. Mischis, 10 January 2008 .

Derivatio nominis

The species is named after the type locality Traful Ville.

Diagnosis

L. 70–85 mm. D. 4–5 mm. No. segments 119–123. Colour dark brown-violet on dorsum, pale from setal line cd. First dorsal pore in 17/18. Clitellum ½13–16, ½ 17 saddle-shaped. Prostatic pores paired on 17. Penial setae dimorph, smaller setae 3 mm long its tip spoon-shaped, longer setae 4 mm with club-shaped tip. Muscular gizzard in 6, calciferous glands and lamellae lacking. Last pair of hearts in 12. Spermathecal pores 8/9 ab. Spermathecae with a wide duct and an oval ampoule. Diverticulum large, semicircular with sperm chambers arranged in double arch.

External characters

Holotype. L. 85 mm, D. 5 mm, No. segments 121.

Paratypes. L. 70–76 mm, D. 4 mm, No. segments 119–123. Colour dark brown-violet on dorsum sharply changing to pale in the setal line cd. Prostomium tanylobous, first dorsal pore occurs in the intersegmental furrow 17/18. Setae are closely paired, setal formula after the clitellum aa:ab:bc:cd:dd = 6:1:8:1:20. Clitellum not fully developed, extends over segments 1/2 13–16, 1/2 17 saddle-shaped, provided with a trapezoid male field ( Figure 3 ). Prostatic pores paired on 17, male pores externally not visible, they are on segment 18, at the end of the seminal groves running from the prostatic pores. Female pores paired on 14, close each to other in between setae a-a. Single pair of spermathecal pores present in furrow 8/9 near to the setae b. Nephridiopores aligned in setal line c. Unpaired porophores on 16, 19, 20 in between setae a-a.

Internal characters

Septa 9/10–11/12 somewhat thickened, others membranous. Oesophageal gizzard large in 6. Calciferous glands and lamellae lacking. Intestine begins in segment 17. Excretory system holoic, nephridial bladders biscuit-shaped. Paired hearts present in segments 10, 11 and 12. Septa 9/10 and 10/11 dorsally fused forming a cavity where the testes and sperm funnels are enclosed. Two pairs of seminal vesicles present in 9, 11. Those in 9 somewhat smaller than those in 11. A pair of racemose ovaries pendent from the posterior face of the septum 12/13. Seminal duct discharging in segment 18. The single pair of prostatic glands is moderately large occupying three or four segments. Each prostate accompanied by a penial setal sac containing two different adult and several replacement setae. The longer seta 4 mm in length and in the middle 0.06 mm wide, the tip club-shaped. Ornamentation consists of densely arranged serrated bars ( Figure 5 ). The smaller seta 3 mm long and in the middle 0.1 mm wide. The seta is slightly curved and the spoon-shaped tip is reclinate. Ornamentation similar to that of the longer seta but somewhat stronger and denser ( Figure 6 ). Single pair of spermathecae present in segment 9. It consists of a wide duct and an oval ampoule. Diverticulum large, semicircular, with sperm chambers arranged in double arch ( Figure 4 ).

Remarks

Using the key provided by Zicsi (1989), Y. traful n. sp. is most closely related to Y. hajeki but differs from it in the larger size, the structure of the spermathecae as well as the length, shape and ornamentation of the penial setae ( Figure 7 ). Owing to the male pore on 18 and the closely paired setae, the new species appears to be close also to Y. lajaensis Zicsi and Csuzdi, 2001 but differs in several characters, for example in the length and shape of penial setae ( Figure 8 ) and shape of spermathecae.

Figures

Figure 5. Yagansia traful sp. nov. longer penial seta. (a) Full seta; (b) tip of the seta; (c) ornamentation.

Figure 6. Yagansia traful sp. nov. smaller penial seta. (a) Full seta; (b) tip of the seta; (c) ornamentation.

Figure 7. Yagansia hajeki Zicsi 1989. Smaller penial seta of the paratype HNHM/AF667. (a) Tip of the seta; (b) ornamentation.

Figure 8. Yagansia lajaensis Zicsi and Csuzdi, 2001. Penial setae of a paratype HNHM/ AF4280. (a) Tip of the smaller penial seta; (b) ornamentation of the smaller penial seta; (c) tip of the larger penial seta; (d) ornamentation of the larger penial seta.

Figures 3–4. Yagansia traful sp. nov. (3) Ventral view of the clitellar region; (4) spermatheca. Notes: pp, prostate pore; mp, male pore.