Holoscolex alatus Hernández-García, Burgos, Rousseau & James, 2018

Hernández-García, Luis Manuel, Burgos-Guerrero, Jesús Enrique, Santos, Bianca Tamires Silva Dos, Rousseau, Guillaume Xavier & James, Samuel Wooster, 2018, Three new species of Holoscolex (Clitellata, Glossoscolecidae) from the Gurupi Biological Reserve, last forest remnant of the Belém Endemism Area, Eastern Amazon, Zootaxa 4496 (1), pp. 459-471 : 463-464

Holoscolex alatus Hernández-García, Burgos, Rousseau & James sp. nov.

( Figure 3 )

Holotype. MPEG.ANL 0 0 0 310 one adult, clitellate, fragmented. Gurupi Biological Reserve , logged primary forest, Centro Novo do Maranhão, Maranhão, Brazil, 3°41'27.19"S 46°45'6.91"W, 209 masl. 26 March 2015, Hernández- García, L.M. & Rousseau G.X. colls.

Paratypes. MPEG.ANL 0 0 0 313, two adults, clitellate, fragmented, Gurupi Biological Reserve , logged primary forest, Centro Novo do Maranhão, Maranhão, Brazil, 3°41'16.35"S 46°45'34.74"W, 175 masl. 24 March 2015 . MPEG.ANL 0 0 0 315, one adult clitellate fragmented, Gurupi Biological Reserve , logged primary forest, Centro Novo do Maranhão, Maranhão, Brazil, 3°41'10.76"S 46°45'56.54"W, 158 masl. 28 March 2015 . MPEG.ANL 0 0 0 314 one adult, clitellate, fragmented. Gurupi Biological Reserve , logged primary forest, Centro Novo do Maranhão, Maranhão, Brazil, 3°41'11.71"S 46°45'34.91"W, 189 masl. 23 March 2015. Hernández-García, L.M. & Rousseau G.X. colls.

Other Material. MPEG.ANL 0 0 0 312, three adults, clitellate, fragmented, Gurupi Biological Reserve , logged primary forest, Centro Novo do Maranhão, Maranhão, Brazil, 3°40'50.07"S 46°46'12.95"W, 154 masl. 24 March 2015 . MPEG.ANL 0 0 0 311, two adults, clitellate, fragmented, Gurupi Biological Reserve , logged primary forest, Centro Novo do Maranhão, Maranhão, Brazil, 3°41'20.33"S 46°46'1.16"W, 172 masl. 28 March 2015. Hernández- García, L.M. & Rousseau G.X. colls.

Description. Dimensions: holotype 64 mm long and 2.7 mm wide at X, 3.2 mm at clitellum, 2.2 mm at XXX, 129 segments; paratypes 53–79 mm by 2.5–2.8 mm at X, 2.8–3.1 mm at clitellum and 2.4–2.9 mm at XXX, 188– 297 segments. Body cylindrical and slightly flattened. Setae AB commence on VI, and, CD on VIII, but setae are sporadic until clitellum. Setae AB widely paired and CD narrowly paired. Setal arrangement aa:ab:bc:cd:dd = 2.0:1.0:0.4:0.1:2.8 at XXX, dd <1/2 circumference throughout. Prostomium pro-epilobous. Two pairs of spermathecal pores are in 7/8 and 8/9 opening on very small gaps in intersegmental area at B line. Ovipores aligned to the ventral edge of genital markings on XIV, 0.8 mm apart; male pores in 20/21 inside tubercula pubertatis; clitellum slightly beige color in XVI–XXIV, saddle shaped. Wing-flat shaped tubercula pubertatis are present on XIX–XXII in B line, protruding from body wall ( Fig. 3A ). Small genital markings with genital setae are present in some specimens on segments VIII and IX at AB line. Other paratypes have slight genital markings on segments XI–XIV on A line, with genital markings of XIV bigger and near the female pore and large and protuberant genital markings with genital setae or internal atrial glands on the left side of XXII, sometimes on the right side. Common setae are sigmoid shape and smooth with 150µm in length, while genital setae are smooth and slightly more straight at the apical region ( Fig. 3B,C ). Nephropores in setal line C with very small stomata like valves seen on external body wall.

Septa 6/7–9/10 equally thick and muscular, 10/11 thinly muscular, other septa membranous. Alimentary canal with large cylindrical gizzard in VI; intestinal origin in XIV; typhlosole origin in XIV, disk-shaped, concave folds in XXXV–XL, then a simple lamina which ends in CV–CXL. Calciferous glands paired in XII, extending to XV, pedunculated sacs with a glandular region of composite-tubular type and ovoid shape, distal part membranous and with a calcium carbonate reservoir ( Fig. 3D ). Open vesiculated holonephridia; nematodes were found inside the bladder ( Fig. 3E ); two thin loops recognized in pre-septal region ending in an area with cell aggregation near the bladder. Semi-lunar valve with micro-sphincters present at nephropores, nephridia enlarged in IV–VI. Vascular system with ventral trunk, single dorsal trunk, lateral vessels in VII–IX and latero-esophageal hearts in X and XI. Supra-esophageal vessels from X, connected to latero-esophageal hearts and running along dorsal region of intestine.

Ovaries not recognized. Ovarian funnels at 13/14. Spermathecae in VIII and IX at B line; 2.6–2.9 mm long, elongate with rounded tip and iridescent interior, ducts conical and very narrow at base ( Fig. 3F ). Male sexual system holandric, testes and funnels free in X and XI. Two pairs of seminal vesicles with a lobulated form in XI– XII, with those of XII penetrating septa and extending posteriorly along intestine to XVII–XVIII; vasa deferentia on body wall, extending along B to enter body wall in 20/21.

Etymology. The species name is derived from the winged shape of the tubercula pubertatis.

Remarks. Holoscolex alatus sp. nov. resembles Holoscolex caramuru Righi, 1975 and Holoscolex nemorosus tacoa Righi et al., 1978 by the presence of two pairs of spermathecae in VIII and IX, the presence of tubercula pubertatis and the beginning of the clitellum on segment XVI. They are however separated by the following differences ( H. alatus sp. nov. vs. H. nemorosus tacoa and H. caramuru ): i) length of tubercula pubertatis, XIX– XXII vs. XIX–XXI; ii) male pores in 20/21 vs. XX; iii) spermathecal pores in B line, vs. BC line in H. nemorosus tacoa and B line for H. caramuru . Moreover, H. alatus sp. nov. has alate tubercula pubertatis, unusual for this genus, protruding from the body wall and looking like a flat wing. H.alatus sp. nov. also has a distinctive setal arrangement, widely paired ventrally and narrowly paired laterally. More details of compared characters among species of the genus are listed in Table 1.

Figures

FIGURE 3. Holoscolex alatus sp. nov. (holotype). A. Ventral view of anterior region. B. Common seta on right A line of XXX. C. Genital seta on right A line of XXII. D. Dorsal view of right calciferous glands. G, glandular region; M, membranous region. E. Frontal view of left post-clitellar nephridium. np, nephropore; npt, nephrostome; V, nepridium vesicle; Nm, Nematoda; Bd, bladder. F. Dorsal view of right spermatheca of VIII.