(Graffia) nicaraoi, Csuzdi & Sherlock, 2011

Sherlock, Emma, Lee, Stewart, Mcphee, Sally, Steer, Mark, Maes, Jean Michel & Csuzdi, Csaba, 2011, The first earthworm collections from Nicaragua with description of two new species (Oligochaeta), Zootaxa 2732, pp. 49-58 : 54-55

Eutrigaster (Graffia) nicaraoi Csuzdi & Sherlock new species

( Fig. 4 )

Material. Holotype. HNHM AF /5475 Nicaragua, Dpto. Rió San Juan, Refugio Bartola (N 10°58.346’, W 84°20.341’) under log. Leg. O. Merkl, N. Bálint & T. Németh, 15– 25.06.2007. Other material. HNHM AF /5476 1 praeadult, locality and date same as that of the Holotype.

Etymology. The specific epithet refers to Cacique Nicarao, an indigenous leader when the Spanish arrived.

Diagnosis. L. 80 mm, D. 5 mm. No. segments: 172. Pigmentation preserved reddish-brown. First dorsal pore in 12/13. Clitellum ½12–20. Ƥ 14 paired, in between a–a. Prostatic pores 17, 19. Spermathecal pores 7/8, 8/9, spermathecae with elongated sac-shaped ampoule, and a duct which ectally bears several small diverticula almost encircling the duct. A prominent proventriculus in 5, gizzards in 6–7, last pair of hearts in 12, meronephridia 7–6 on each side. Penial setae are of two types, larger L. 0.75 mm D. 0.008 mm, tip slightly hooked, ornamentation weak serrations. Smaller L. 0.625 mm D. 0.01 mm, tip slightly spoon-shaped, ornamentation weak serrations.

External charactes. Holotype. Length 80 mm, diameter 5 mm, number of segments 172. Colour reddishbrown preserved, more prominent on dorsum. Prostomium epilobous open with slight furrows running to segment 2. First dorsal pore in 12/13. Setae all ventral, setal arrangement after the clitellum aa:ab:bc:cd:dd=3.5:1:3.25:1:22.5. Clitellum circular extends over segments ½12–20, on 12 slightly developed. Male field oblong, 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 ( Fig. 4 A). Spermathecal pores paired in 7/8, 8/ 9 in the setal line a. Porophores absent.

Internal characters. The first septum 4/5, 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, the first pair somewhat smaller than the others. Excretory system meroic, with 7–8 meronephridia on each side. Paired hearts are present in segments 10–12. Typhlosole small, lamellar, begins in segment 27 and accompanied by a pair of auxiliary typhlosole until 34. The intestine is prominently bulging in 30–34 but due to being filled with debris definite caecum-like organ can not be seen. In the juvenile specimen examined slight caeca were paired in 33–34.

Testes are enclosed in large suboesophageal testis sacs in 10 and 11. Seminal vesicles lacking. Seminal duct is convoluted, its end widening and becoming muscular before discharging in segment 18. Two pairs of prostatic glands are present in 17 and 19 those in 17 are large and highly coiled, in 19 small. Each prostate is provided with a penial setal sack containing two different types of penial setae. The longer one is about 0.75 mm long and 0.008 mm wide with slightly bent tip. Ornamentation consists of weak serrations. The shorter seta is 0.65 mm in length and 0.01 mm in diameter, its tip somewhat bent and slightly spoon-shaped, ornamentation weak serrations ( Fig. 4 D–E). There are two pairs of spermathecae in segment 8 and 9. The first pair is somewhat smaller than the second one. The ampoule is elongated sac-shaped and longer than the muscular duct. The duct ectally bears several bunches of diverticula almost encircling the duct ( Fig. 4 B–C).

Remarks. E. (G.) nicaraoi sp. nov. belongs to the subgenus Graffia due to the presence of penial setae. The new species, regarding the shape of spermathecae is similar to E. (G.) picadoi Michaelsen, 1912 ; however differs from it by presence of two different types of penial setae. It shows affinity to E. (G.) azul sp. nov. by possessing dimorph penial setae but differs from it in the structure of spermathecae and in the morphology of penial setae.

Figures

FIGURE 4. Eutrigaster (Graffia) nicaraoi n. sp. A. Ventral view of the clitellar region, B. Spermatheca, C & D. Photographs of the penial setae. fp = female pores, pp = prostatic pores, mp = male pores.