Glossoscolex riograndensis subsp. riograndensis, 2018

Bartz, Marie L. C., James, Samuel W., Steffen, Gerusa P. K., Antoniolli, Zaida, Steffen, Ricardo B. & Brown, George G., 2018, New species-group taxa of Glossoscolex (Clitellata: Glossoscolecidae) from Rio Grande do Sul, Brazil, Zootaxa 4496 (1), pp. 548-561 : 550-552

GlossosColex (GlossosColex) riograndensis riograndensis Bartz & James , n. sp.

( Figures 1A,B , 2A,B )

Holotype. COFM BRRS0038 one adult, fragment of natiVe forest, Rosário do Sul , Rio Grande do Sul, Brazil, 30°02'07,7''S 54°34'51,8''O, 105 masl. 0 9 NoVember 2011, G.P.K. Steffen & R.B. Steffen colls.

Paratype. COFM BRRS 0039 one adult. Same locality and collecting data as holotype.

Other material. COFM BRRS0040 one adult and 2 subadults, fragment of natiVe forest, Rosário do Sul, Rio Grande do Sul, Brazil, 30°02'07,7''S 54°34'51,8''O, 105 masl. 0 9 NoVember 2011, G.P.K. Steffen & R.B. Steffen colls . COFM BRRS0041 fiVe adults and one subadult, fragment of natiVe forest, Rosário do Sul , Rio Grande do Sul, Brazil, 30°02'07,7''S 54°34'51,8''O, 174 masl. 0 9 NoVember 2009, G.P.K. Steffen & R.B. Steffen colls . COFM BRRS0042 fiVe adults and one subadult, black acacia plantation, Rosário do Sul , Rio Grande do Sul, Brazil, 30°05'50,7''S 54°37'53,4''O, 151 masl. 0 9 NoVember 2009, G.P.K. Steffen & R.B. Steffen colls. 17 specimens altogether.

Etymology. The species is named due it occurrence in the State of Rio Grande do Sul, Brazil.

Description. Dimensions: Holotype 54 mm by 3.7 mm at x, 4.0 mm at clitellum, 3.5 mm at xl, 195 segments; paratype 53 mm by 4.1 mm at x, 4.2 mm at clitellum, 3.7 mm at xl, 125 segments. Other material ranges from 41 to 72 mm in length, With 132–188 segments. Body cylindrical. Setae closely paired throughout starting in iV; setal formula aa:ab:bc:cd:dd = 7.8:0.3:1.0:0.2:11.2. Setae not Visible before clitellum. Prostomium prolobous. Unpigmented/Whitish. OVipores in a on xiV. Male pores 2.8 mm apart on xVii Within paired round eleVations (like a mound); clitellum saddle, xV–xxiii and Ventrally until to xxii, in other material (5 specimens) the clitellum extends dorsally to 3/4 xxii ( Fig. 1A,B ). Nephropores near b.

Septa 6/7–10/11 equally thick and muscular. Alimentary canal With barrel-shaped gizzard in Vi; esophagus With high cheVron-patterned lamellae Vii–xi, ValVular in xii; intestinal origin xiii; typhlosole origin xiV, in xiV–xxV zig-zag With Ventral edge bent oVer to form pockets, xxVi–xlii straight lamina in Z form occupying half of the diameter of the intestine, after xliii gradually becoming simple S form lamina. Calciferous glands paired xii, heartshaped, pedunculated, composite-tubular type; blood Vessels to gland include large branch of dorsal Vessel to approximate center of each gland. Holonephric, Vesiculate; ducts to body Wall near leVel of b; nephridia in xii, xiii full of sperm (iridescent material) in both specimens type ( Fig. 2A,B ).

Vascular system With Ventral trunk, single dorsal trunk, lateral Vessels in Vii–ix, esophageal hearts in x–xi, last pair (xi) free. Extra-esophageal Vessel from pharyngeal glands, along Ventral–lateral face of gizzard, esophagus back to calciferous glands; supraesophageal Vessel in x–xi.

OVaries, oVarian funnels free in xiii. Male sexual system metandric, testes and funnels in U shaped sac in xi, occupying part of xii; seminal Vesicles tubular, pass through xii–xiii connected lateral-Ventrally to the testis sacs, after xiV seminal Vesicles dorsally and tubular With lobulated edges ranging posteriorly along intestine farther than lxii; Vasa deferentia long, looped from testis sacs in xi, form dense zig-zag on body Wall on route to middle-anterior face of muscular round to oVal copulatory bulbs (1.3–1.7 mm diameter); bulbs extend oVer xVi–xViii. Copulatory bulbs With thin muscular outer layer, dense, delicate corrugated glandular inner surface With small lumen leading to male pore at approximate center of bulb connection to body Wall; no transVerse muscle bands crossing oVer bulbs, under face of bulb attached to body Wall.

Remarks. Glossoscolex (Glossoscolex) riograndensis riograndensis is close to Glossoscolex (G.) minor Zicsi & Czusdi, 1999 considering the small body size—all other described species of this subgenus are considerably larger (comp. Table 1). The differences betWeen G. (G.) r. riograndensis and G. (G.) minor are as folloWs, With the characteristics of the latter in parentheses: length 41–72 mm (24–45 mm), number of segments 125–195 (198– 231), clitellum saddle (annular), clitellum extension xV–xxiii (xiV–xxiii), testis sacs U shaped sac in xi–xii (unpaired in xi), seminal Vesicles long tubular With lobulated edges until lxii (band until l), copulatory bulbs round to oVal (elongated). ( Table 1).

For comparison of G. (G.) r. riograndensis n. ssp. With G. (G.) r. pollulus n. ssp. and G. (G.) r. nativus n. sp., see beloW.

The presence of sperm cells in some post- and pre-clitellar nephridia of this species is highly unusual in knoWn Glossoscolex and the closely related Fimoscolex . Both genera are athecal, i.e. Without spermatophores, and yet nearly all species shoW tremendous inVestment in sperm production and storage, With extremely long and WelldeVeloped seminal Vesicles. All haVe large muscular ejaculatory structures; the copulatory bursae empty Via the male pores. Among the hundreds of specimens that We haVe examined none shoWs signs of parthenogenetic reduction of the male gonads. Only G. sp.1 (see beloW) is aVesiculate but eVen in that species the male anatomy looks otherWise normal. GiVen the large inVestment in the male reproductiVe apparatus one should expect bisexual reproduction Via mutual sperm exchange during copulation, but in fact We can only speculate What is going on in the many Glossoscolex and Fimoscolex species Where We haVe not Validated the presence of sperm in unusual locations. Prior to this study We haVe reported on strong deVelopment of unusually White spots and tiny pockets on enlarged septa in the region of segments xiii–xiV in G. (Praedrilus) itaguajensis , G. (P.) lutoculus , G. (P.) uliginosus , G. (G.) mariarum , G. (G.) primaensis and G. (G.) sanpredoensis (Bartz 2012) , and We suspected possible sperm storage in those cases. In the case of G. riograndensis it appears that sperm receiVed in copulation, perhaps by high-pressure injection into nephropores, is stored in the nephridia.

Figures

FIGURE 1. Glossoscolex (Glossoscolex) riograndensis n. sp.. A, B. Glossoscolex (Glossoscolex) riograndensis riograndensis. C, D. Glossoscolex (Glossoscolex) riograndensis nativus n. ssp. E, F. Glossoscolex (Glossoscolex) riograndensis pollulus n. ssp. FM = female pOres; MP = male pOres; NF = nephridial pOres.

FIGURE 2. Sperm-filled nephridia Of Glossoscolex (Glossoscolex) riograndensis n. sp., histOlOgical sectiOns. A, B. Glossoscolex (G.) riograndensis riograndensis n. sp., segment xii (A) and xiii (B). C, D. Glossoscolex (G.) riograndensis pollulus n. ssp., segments Vi (C) and Vii (D).