Pontoscolex (Nulloscolex) hugoi, Hernandez-Garcia & Sousa, 2023

Hernández-García, Luis Manuel, Sousa, Sandriel Costa, Pereira, Natália Jovita, Rousseau, Guillaume Xavier & Ferreira, Carmen, 2023, Additions to earthworms (Annelida, Crassiclitellata) from Aragua and Miranda states, Venezuela, Zootaxa 5255 (1), pp. 171-182 : 179-180

Pontoscolex (Nulloscolex) hugoi, Hernandez-Garcia & Sousa , n. sp. ( Figs. 5 A-G)

Holotype. MBUCV-XIII 0311 one adult, complete, bean crop, Santa María settlement, San Casimiro County, Aragua, Venezuela, 10°2’15.56’’S, 67°2’15.09’’W, 950 masl. June 2010. Hernández-Garcia, L.M., and García, J. D. colls.

Paratypes. MBUCV-XIII 0312 four adults, same locality as holotype. June 2010. Hernández-Garcia, L.M., and García, J. D. colls .

Etymology. The species is named in honor of Hugo Hernández, owner of the land where earthworms were collected.

Description. Dimensions: holotype 115 mm in length by 5.0 mm in width at X; 5.2 mm at clitellum and 5.1 mm at XXX; 505 segments; paratypes complete 85–108 mm in length by 5.1–5.2 mm at X; 5.4–5.6 mm at clitellum and 4.9–5.0 mm at XXX; 303–344 segments. Body cylindrical, unpigmented. Setae ab commence on II and cd commence on III in all types; only A line is regular, B and CD lines are irregular all over the body. Prostomium prolobic. The prostomium and the first segment are grooved longitudinally. The first 12 segments are wider than the others. Clitellum in XVIII–XXXII, annular. Tubercula pubertatis absent ( Fig. 5A ). Common setae slightly sigmoid, 250–270 μ m in length, jagged shaped at the apex ( Fig. 5B ). Intra-clitellar genital setae ab 680–720 μ m in length, straight and ornamented at the sub-apical concave part with excavations, irregularly arranged and cuneiform ( Fig. 5C ). Globular papillae are surrounding the a setae of XI and XII and the ab setae of XIII. Microscopical male and female pores not recognized externally. Spermathecae pores are present near the posterior inter-segmental lines of VI, VII, and VIII in C line. Nephropores are just near the anterior inter-segmental lines, sphincteric and aligned with C line; the first sphincteric nephropore is visible in VII.

Septa are highly muscular in 6/7, 7/8, 8/9, 9/10, septa slightly muscular in 10/11, 11/12, intra-clitellar and posterior septa membranous. Gizzard in VI, 2.0 mm in width and 2.9 mm in length, highly muscular; intestinal origin in XVIII. Typhlosole is lamellar-shaped in XXXIII extended to CCXL, occupying approximately 15% of the intestinal diameter. Three pairs of tiny calciferous glands in VII–IX are finger-shaped ( Fig. 5D ) and tubular in structure ( Fig. 5E ). Some tubes became irregularly dichotomous at the medial area. Glands are oriented dorsoventrally.The dimensions are 0.2–0.3 mm in wide versus 0.9–1 mm in length. Three pairs of fine lateral blood vessels are present in VII–IX. Two pairs of large lateroesophageal hearts are in X–XI. Moniliform supra-esophageal vessel runs dorsally to the intestine, thicker in XVI–XXXII; those of XVI–XXIV are thicker. Holonephridial system: three loops were recognized in the postclitellar nephridium. The smallest, a quarter of the bladder length, is connected with the nephrostome. The others, similar in length, run over half of the bladder length. The connection between the tubes and the bladder is mediated by a rough tube with different quantities of nematodes ( Fig. 5F ).

One pair of ovaries in XIII. Female pores open in segment 15/16 near the A line. Three pairs of long spermathecae are filled with spermatozoa, in VI–VIII; the duct is 0.15–0.25 mm in width and 1.2–1.7 mm in length; the saccular ampulla is 0.6–0.9 mm in width and 2.3–3.3 mm in length ( Fig. 5G ). Spermathecae pores open near the intersegmental lines 6/7, 7/8, and 8/ 9 in CD line, at the posterior part of the segments; seminal chambers absent. Paired of testes sacs, filled with spermatozoa, in XI. Paired long seminal vesicles in XII, extended to segment CL-L. Deferent ducts go through the B line and open into 26/27.

Remarks. The new species P. (Nulloscolex) hugoi n. sp. is assigned to Pontoscolex due to the presence of three pairs of calciferous glands in VII–IX, and the metandric male sexual system. The main differences with the subgenera are the size (<400 µm in diameter) and structure of calciferous glands, which is tubular simple in our specimens and tubular-dichotomous in other species of the subgenera. Furthermore, this new species is the only one lacking both the tubercula pubertatis and intra-clitellar genital markings.

Figures

FIGURE 5. Pontoscolex (Nulloscolex) hugoi n. subgen., n. sp. A. Ventral view of clitellum. B. Right common a seta of segment XXX. C. Right genital b seta of XXIV. D. View in cross-section of the right calciferous gland of IX. E. Dorsal view of ental and ectal in cross-section of the right calciferous gland of IX. F. View in cross-section of right post-clitellar nephridium. G. Dorsal view of right spermathecae of VIII. npt: nephrostome. ne: nematode. np: nephropore.