Belladrilus (Belladrilus) browni James & Bartz, 2023

James, Samuel W., Bartz, Marie L. C. & Brown, George G., 2023, New Ocnerodrilidae genera, species and records from Brazil (Annelida: Crassiclitellata), Zootaxa 5255 (1), pp. 235-269 : 254-256

Belladrilus (Belladrilus) browni James & Bartz sp. nov. ( Fig. 12 a-c)

Holotype. BRRS0054 , one adult, Aparados da Serra National Park , Cambará do Sul, Rio Grande do Sul state, Brazil, S29.17234°, W50.11646°, 932 m asl., in wetland adjacent to forest; 27 January 2012, S.K. Davidson, G.G. Brown, H. Yong, and S.W. James, colls.

Paratypes. BRRSDNA0245-0247, three adults, same data as holotype, one in each vial .

Etymology. The species is named for George G. Brown, a co-discoverer of the worm and a leader of earthworm research in Brazil.

Description. Dimensions 45-50 mm by 1.0 mm at segment x, 0.8 mm at clitellum, 0.9 mm at xxx, body cylindrical, segments 120-139. Setae closely paired throughout, CD above lateral; setal formula AA:AB:BC:CD = 4:1:5:1 at x, 5:1:5:1 at xxx, DD <½ circumference. Prostomium epilobous open; segments lacking secondary annulations and dorsal pores. Unpigmented, spermathecal pores in 8/9 about 0.1 mm below C. Ovipores in xiv just lateral to B between equator and 13/14; male pores pre-equatorial in xviii at end of seminal grooves; prostatic pores equatorial in xvii within circular collars at anterior ends of seminal grooves; male field pores and seminal grooves on flat surfaces of large oval pads extending from 16/17 to equator of xviii. Setae AB present in xvii-xix, B of xvii within oval pads. Clitellum from xiv-xix, annular; no other genital markings ( Fig. 12a ).

Septa 5/6-9/10 muscular, others not. Alimentary canal with gizzard in vii; septal glands in v, vi; esophagus valvular in xi, intestinal origin in xii, no typhlosole. Calciferous glands oblong with blunt anterior ends, paired in ix with duct to dorsal-lateral esophagus, and solid thick walls surrounding small central lumen which is semi-lunate or bifurcate in cross section ( Fig. 12b ); each gland with blood vessel from anterior end to extra-esophageal vessel, blood vessel from posterior end of gland to supra-esophageal vessel. Holonephric, first nephridia in segment xi, attain full size and regular morphology in xii; reach dorsally to ½ BC or up to D; tubular throughout, no bladders.

Vascular system with ventral trunk, single dorsal trunk, lateral vessels in vi-ix, latero-esophageal hearts in x-xi with long connective vessels from supraesophageal vessel to hearts; supraesophageal vessel in ix-xi.

Fan-shaped ovaries with funnels free in xiii; paired large spermathecae in ix, consisting of long muscular duct, duct nearly as long as segment ix, ovate to pyriform ampulla ( Fig. 12c ).

Male sexual system proandric, testes and funnels free in x, vas deferens superficial on body wall from 10/11 to xviii where it has a small terminal expansion; seminal vesicles only in xi, large, post-septal; slender tubular prostates folded under intestine within xvii-xviii, xx; prostatic ducts slightly muscular about the length of two segments.

Remarks. Belladrilus (B.) browni sp. nov. has the largest and most elevated male pore zone of any known species in the subgenus. Like B. (B.) riparius sp. nov., it has more posterior first nephridia than the older species. On the other hand it shares the character state of seminal vesicles only in xi and spermathecae in ix with the following species: B. (B.) jimi , B. (B.) pocaju, B. (B.) arua, and B. (B.) vaucheri. With spermathecal pores in line C and differentiated spermathecal ducts vs. ampulla, it most closely resembles B. (B.) arua, which is smaller (19 vs. 45 mm, has fewer segments (84 vs. 128), male field pads L-shaped vs oval, intestinal origin in xiii vs xii, and folded prostates occupying xvii-xxiv vs. xvii-xviii. We were unable to obtain DNA barcode data for this species.

Figures

FIGURE 12. Belladrilus browni sp. nov. A. Ventral view with male pore (mp) and spermathecal pore (sp), scale bar 1 mm; B. Cross section of calciferous gland (cg); C. Spermatheca (sp).