Eutrigaster (Graffia) georgei, Sherlock & Csuzdi, 2013

Sherlock, Emma & Csuzdi, Csaba, 2013, Two new earthworm species from Belize (Oligochaeta: Acanthodrilidae), Journal of Natural History (J. Nat. Hist.) 47 (29 - 30), pp. 1911-1919 : 1915-1918

Eutrigaster (Graffia) georgei sp. nov.

( Figures 3–5 )

Material examined

Holotype. NHMUK 2012.64 . Belize, Las Cuevas (16 ◦ 44 ′ N, 88 ◦ 59 ′ W) Leg. A. Hayward, June 2001.

Paratypes. HNHM AF / 5558–5559 and NHMUK 2012.65 – 71 . Belize, Las Cuevas (16 ◦ 44 ′ N, 88 ◦ 59 ′ W). Leg. A. Hayward, June, 2001 .

Etymology

Named after the nephew of the first author, George Reader. This worm after preservation is distinctly blond in colour, as currently is George.

Diagnosis

L. 48–58 mm, D. 4–5 mm. Number of segments: 104–174. Pigmentation unknown alive, pale preserved. First dorsal pore in 12 / 13. Clitellum 1 / n 12, 13 –20. Female pores 14 paired between a–a. Prostatic pores 17, 19. Spermathecal pores 7 / 8, 8 / 9, spermathecae with sac-shaped ampoule, and a duct which ectally bears several small diverticula almost encircling the duct. A large proventriculus in 5, two gizzards in 6–7. Last pair of hearts in 12, meronephridia 8 on each side. Penial setae of two types, larger L. 1.3 mm D. 0.09 mm, tip hooked, ornamentation small serrations. Smaller seta L. 0.6 mm D. 0.07 mm, tip spatulate with delicate dentations on the rim, ornamentation prominent serrations.

External characters

Holotype. Length 52 mm, diameter 4 mm, number of segments 104 (tail regenerated). Paratypes. 48–58 mm in length, 4–5 mm in diameter, number of segments: 150–174. Colour alive unknown, pale yellow preserved, darker on dorsum. Prostomium epilobous. First dorsal pore in 12 / 13. Setae all ventral, setal arrangement after the clitellum aa:ab:bc:cd:dd =4:1.2:3.5:1:40. Clitellum circular, extends over segments 1 / n 12, 13 –20, on 12 and 13 slightly developed. Male field barbell-shaped, prostatic pores paired on 17, 19 in the setal line a. Male pores clearly visible on 18, in the seminal groves. Female pores paired on 14 in between setae a–a ( Figure 3A ). Spermathecal pores paired in 7 / 8, 8 / 9 in the setal line a.

Internal characters

The first septum 3 / 4, septa 11 / 12–13 / 14 slightly thickened. A voluminous proventriculus in segment 5 and two oesophageal gizzards in 6 and 7. Three pairs of calciferous glands open separately in segment 15–17, their size slightly increasing backwards. Excretory system meroic, with eight meronephridia on each side. Paired hearts are present in segments 10–12. Typhlosole present, lamellar, but due to the poor preservation of the intestine its beginning cannot be determined. Two pairs of dorsal protuberances of the intestine present in 33, 34. Sperm funnels 10, 11 in seminal sacs. Seminal vesicles lacking. Sperm duct convoluted, ectal end muscular, open in 18. Two pairs of prostatic glands present in 17 and 19, those in 17 are larger. Each prostate provided with a penial setal sack containing two different types of penial setae. The longer one about 1.3 mm long and 0.09 mm wide in the middle and 0.025 mm just under the hooked tip. Ornamentation consists of small but strong serrations ( Figure 4 ). The smaller seta 0.6 mm long, diameter 0.07 mm in the middle, 0.037 mm just under the tip. The tip spatulate with delicate dentation on the rim, 0.054 mm wide. Ornamentation large serrations. ( Figure 5 ). Two pairs of spermathecae present in segment 8 and 9. The ampoule irregular sac-shaped, and as long as the muscular duct. The duct ectally bears several bunches of diverticula accompanied by some singular ones almost encircling the duct ( Figure 3B ).

Remarks

The new species, regarding the shape of spermathecae is similar to both E. (G.) azul Sherlock and Csuzdi, 2011 described from Nicaragua and E. (G.) picadoi Michaelsen, 1912 from Costa Rica but differs from them primarily by the shape and ornamentation of the penial setae. Eutrigaster (G.) georgei sp. nov. possesses dimorphic penial setae of which the smaller one bears a spatulate tip with small dentations on the rim. This character is extraordinary in the subfamily Benhamiinae .

Figures

Figure 3. Eutrigaster (Graffia) georgei sp. nov. (A) Ventral view of the clitellar region. fp = female pores, mp = male pores, pp = prostatic pores; (B) spermatheca.

Figure 4. Eutrigaster (Graffia) georgei sp. nov. (A) Larger penial seta; (B) ornamentation of the larger penial seta; (C) tip of the larger penial seta.

Figure 5. Eutrigaster (Graffia) georgei sp. nov. (A) Smaller penial seta; (B) ornamentation of the smaller penial seta; (C) tip of the smaller penial seta.