Rhinodrilus Perrier, 1872

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 : 175

Genus Rhinodrilus Perrier, 1872 .

Diagnosis: after Righi (1985).

Four pairs of setae arranged in eight longitudinal lines, rarely one or more irregular series at tail. Intra-clitellar tubercula pubertatis. Gizzard in VI. Three pairs of calciferous glands in VII–IX, tubular-dichotomous, tubularpaniculate or tubular-composite structure, sometimes with a medial wide lumen. Exceptionally trabecular (Feijoo, Peña-Venegas & Zuluaga 2020). Male sexual system holandric, testes and funnels enclosed in sacs, and metagynous. Seminal vesicles in general are short and limited to the segment of origin. One pair, or sometimes two pairs, of intra-clitellar male pores, paired. Structures similar to prostate glands or copulatory chambers can be present. Intra-coelomic spermathecae, rarely intra-parietal, in one or more segments. Spermathecal chambers are sometimes present (modified from Righi 1985).

Type species. Rhinodrilus paradoxus Perrier, 1872

Rhinodrilus fuenzalidae Cordero 1944 . ( Figs. 3 A-F)

Material MBUCV-XIII 0310 five adults, complete, Rodríguez Farm, La Cortada, Urdaneta county , Miranda, Venezuela, 66°57'0.25"W, 10°2'25.29"N, 600 masl. June 2010. Hernández-García, L.M. & Rodriguez, L.N. colls .

Description. Dimensions: length 83–110 mm; width 4.8–5.0 mm in X; 4.0– 4.8 mm at clitellum, and 4.5–5.0 mm at XXX; 242–290 segments. Body cylindrical, pigment absent. Setae ab and cd commence on III, closely paired. Setal arrangement average aa:ab:bc:cd:dd = 3.0:1.0:3.5:0.5:30.0 at XXX. Setae b irregular at tail. Prostomium prolobic. Clitellum in XVII–XXIV saddle-shaped. Tubercula pubertatis in XX–XXIII band-shaped, limited to BC line ( Fig. 3A ). Common setae are straight, smooth, and slightly curved at apical part, 350–400 μ m in length. Posterior setae become larger, straighter, smoother and tapered in form, 1100 μ m in length ( Fig. 3B ). Longitudinal ornamentation, 200 μ m in length, is present in the middle area. Paired genital markings are observed as protruding papillae in XI–XIX on AB line; setae ab visible within these papillae. Genital setae of XX–XXIII in AB line, 800- 900 μ m in length, straight and ornamented at the sub-apical region by four longitudinal series of 9–10 semilunar excavations ( Fig. 3C ). Nephropores just on the anterior part of segment near the intersegmental limit, sphincteric type and aligned with CD line, first nephropores visible in XII–XIII. Microscopical male and female pores are not recognized externally.

Highly muscular and conical septa are in 6/7, 7/8, 8/9, slightly muscular septa in 10/11, 11/12; intraclitellar and further septa membranous. Gizzard in VI, 3.0 mm in width and 2.5 mm in length, with strong musculature; intestinal origin in XIV, typhlosole sigmoidal-shaped in XXVII extended to CCXXIV occupying approximately 20% of the intestinal diameter. Three pairs of lobulated laterodorsal calciferous glands in VII–IX, 1 mm in width, and 2.1 mm in length ( Fig. 3D ). The calciferous glands tubular-paniculate type. Holonephridial system, postclitellar nephridia with a small nephrostome, connected to a fine tube running in two loops extended three-quarters of the bladder length. The loops continue to connect with a thick rough tube that opens to the bladder ( Fig. 3E ). The vascular system with ventral trunk, single dorsal trunk, three pairs of lateral blood vessels in VII–IX, parallel to calciferous glands. Two pairs of bulky lateroesophageal hearts, kidney-shaped, in X–XI. Supraesophageal vessel on the dorsal side of the esophagus.

One pair of ovaries in XIII, ovules extended in a fine line. Female pores open in segment XIV near the A line. Three pairs of spermathecae in VI–VIII: seminal chambers absent. Spermathecal pores open on the posterior region of the segment, near the intersegmental limits of 6/7, 7/8, and 8/ 9 in CD line. The spermathecal duct and the ampulla are well-differentiated, the duct measures 0.2 mm in width and 1 mm in length; the ovoid ampulla measures 1 mm in length and 0.6 mm in width ( Fig. 3F ). Two pairs of large testes sacs in X and XI. Two pairs of short lobed-shaped seminal vesicles in XI and XII. Deferent ducts go on the B line and open in 19/20.

Remarks. The previous description of Rhinodrilus fuenzalidae ( Cordero 1944) lacked some recent standard measures needed for accurate comparison as well as other characteristics used for analysis of functional traits ( Pey et al., 2014). Herein we re-describe this species based on our specimens and with new illustrations, not reported previously. Differences with the original description include: the setae arrangement in XXX, which is aa:ab:bc:cd: dd = 1.7:1.0:2.0:0.5:- in Cordero (1944) vs. aa:ab:bc:cd:dd= 3.0:1.0:3.5:0.5:30.0 in our samples. The male pore was dubiously described originally in 21/ 22 in AB line ( Cordero 1944); herein we have reported it in 19/ 20 in BC line. The spermathecae pores were originally described as opening into 6/7-8/ 9 in D line ( Cordero 1944); we found it in the CD line. The intestinal origin in our samples in XIV while in Cordero (1944) was reported in XVIII.

Figures

FIGURE 3. Rhinodrilus fuenzalidae.A. Ventral view of clitellum. B. Posterior a setae of the segment CCXL. C. Right genital b seta of XIX. D. Dorsal view of transversal cut of the right calciferous gland of IX. E. Cross-section view of left post-clitellar nephridium. F. Dorsal view of right spermathecae of VIII. npt: nephrostome. np: nephropore.