Righiodrilus gurupi Hernández-García, Rousseau & James, 2017

Santos, Bianca Tamires Silva Dos, Bartz, Marie Luise Caroline, Hernández-García, Luis Manuel, Rousseau, Guillaume Xavier, Martins, Marlucia Bonifácio & James, Samuel Wooster, 2017, New earthworm species of Righiodrilus (Clitellata, Glossoscolecidae) from eastern Amazonia, Zootaxa 4242 (2), pp. 392-400 : 393-394

Righiodrilus gurupi Hernández-García, Rousseau & James , n. sp.

( Figure 1 )

Holotype. MPEG.ANL 0 0 0 286, adult. Centro Novo , PPBio Gurupi Norte, Maranhão, Brazil, primary forest, 3°41'S 46°45'W, 189 masl. 20 March 2015, Hernandez-Garcia, L.M. & Rousseau G.X. colls.

Paratypes. MPEG.ANL 0 0 0 294 one adult, MPEG.ANL 0 0 0 290 two adults, primary forest, MPEG.ANL 0 0 0 287 two adults, MPEG.ANL 0 0 0 288 three adults, MPEG.ANL 0 0 0 289 one adult, MPEG.ANL 0 0 0 291 one adult, MPEG. ANL 0 0 0 292 one adult, primary forest disturbed, same locality as holotype. MPEG . ANL 0 0 0 296 one adult, mature forest, MPEG.ANL 0 0 0 295 two adults, secondary forest, Alcântara , Maranhão, Brazil, 2°21'56.3''S 44°27'10.5''W, 54 masl, 19 May 2015. Hernandez-Garcia, L.M., Burgos J.E & Rousseau G.X. colls.

Etymology. The species is named for the region where it was found, Gurupi .

Description. Holotype 65 mm by 3.0 mm at x, 3.4 mm at clitellum, 3.0 mm at xxx, 273 segments; paratypes 59–72 mm by 2.0– 2.9 mm at x, 3.0– 3.8 mm at clitellum and 2.0– 2.9 mm at xxx, 205–267 segments. Body cylindrical and slightly flattened in clitellar region. Setae commence on ii. Setae widely paired throughout; setal formula aa:ab:bc:cd: dd = 0.6:0.6:0.5:0.4:0.8 at xxx. Prostomium prolobous open. Unpigmented. Clitellum saddle to just above b, xvi–xxiii, tubercula pubertatis xvii–xxi ( Fig. 1 A). Ovipores equatorial just medial to a setae and 0.9 mm apart on xiv; male pores 2.8 mm apart on xviii/xix within paired bands of tubercula pubertatis with slight long groove and associated to genital setae ( Fig. 1 C). Drawings of setae ( Fig. 1 B,C) show the size difference between somatic and genital setae, there is no difference in structure or their surface. Nephropores just above b setal line.

Septa 6/7 membranous, 7/8–10/11 equally thick and muscular, others membranous. Alimentary canal with large cylindrical gizzard in vi; esophagus with high lamellae in chevron pattern vii–ix, valvular in xiv, intestinal origin xv; typhlosole origin xvi, xvii–xxix cupped folds, transformed to bifid lamina near xxx, completly flat bifid by xxxiv and non-bifid by cxxx. Calciferous glands paired in xii, under seminal vesicles, composite-tubular type, oval; supra-esophageal blood vessels running to the calciferous gland from basal to anterior part ( Fig. 1 D). Calcium carbonate reservoir conical and latero-dorsal ( Fig. 1 D: "M"). Holonephric, vesiculate ( Fig. 1 F); nephridial ducts to body wall near level of b setae. Vascular system with ventral trunk, single dorsal trunk, lateral vessels in vii–ix, latero-esophageal hearts in x–xi, last pair (xi) enclosed in testis sacs. Extra-esophageal vessel from pharyngeal glands, along ventral-lateral face of gizzard; supraesophageal vessel in x–xi. Ovaries, ovarian funnels free in xiii; four pairs of small lenticular spermathecae sacs are present near b setal line in xiv–xvii, 350x500 µm in size ( Fig. 1 E). Male sexual system metandric, testes and funnels in single midventral subesophageal sac in xi; seminal vesicles expanded in xii, penetrate septa and range posteriorly along intestine to xiv; seminal vesicles lobulated occupying xi to xiv; vasa deferentia on body wall at b setal level en route to enter body wall in segment xviii/xix.

Remarks. R. gurupi sp. nov. differs from other members of the genus in the presence of four pairs of posttesticular spermathecae in xiv–xvii. Spermathecae are pre-testicular in species with 1, 2 or 3 pairs, or spermathecae are absent. The only other Righiodrilus species with more than 3 pairs of spermathecae is R. sucunduris ( Righi, Ayres & Bittencourt, 1976) with six pairs in ix–xi, 2 pairs per segment.

Figures

FIGURE 1. Righiodrilus gurupi n. sp. A. Ventral view of clitellar region. B. Somatic setae A of xxi. C. Genital setae A of xvii. D. Ventral view of calciferous gland of xii; m: membranous region; g: glandular region. E. Ventro-lateral view of spermathecae. F. Nephridium as seen in xiv – xvii.