Alluroides brinkhursti abyssinicus Jamieson 1968

Jamieson, Barrie G. M. & Fragoso, Carlos, 2024, A monograph of the Oligochaete family Alluroididae, Zootaxa 5529 (3), pp. 401-435 : 415-416

Alluroides brinkhursti abyssinicus Jamieson 1968 (see Fig 6 )

Alluroides brinkhursti abyssinicus Jamieson 1968: 77 , Fig. 9–11 , 14 ; Brinkhurst & Jamieson 1971: 712–713, Figs 4.1B, C, D , 14.3B .

Length 45 mm, width 1.6 mm, segments 144. Zygolobous. Body form slender, tapering uniformly to the somewhat pointed tail end; cylindrical throughout. A lateral line visible as a conspicuous white line running the length of the body on each side slightly above mid– bc and commencing at the lower limits of the peristomium. Ventral setal couples absent from XIII. Clitellum annular, over XII–XV but its limits not determinable with certainty; best developed in XII–XIV. Male pores one on each side in the setal arc of XIII immediately below the lateral line and thus almost exactly lateral. Each pore at the depressed centre of a very protuberant, transversely elliptical porophore which extends forwards to intersegmental furrow 12/13 and is preceded by a small tumescent crescent in XII. Female pores one on each side, each a small but conspicuous transverse slit, with minute elliptical lips, in intersegmental furrow 13/14 which is deflected posteriorly; slightly more ventrally located than the male pores. Spermathecal pore, a conspicuous unpaired mid–dorsal slit immediately in front of the posterior border of VII, with obvious but only slightly tumid lips which are surrounded by a transversely oval pale field. This field extending anteriorly almost to the setal arc and posteriorly impinging slightly on VIII.

Septa 4/5–12/13 fairly strong, with the exception of 10/11 which is very thin and is evaginated posteriad to form a bulbous seminal vesicle; 7/8–9/10 the thickest; 3/4 imperfect and very delicate; 13/14–15/16 thin but not as delicate as the succeeding septa. 13 /14 is deflected posteriad by the atria so as almost to touch 14/15 and is prolonged backwards to XVIII as the (unpaired?) ovisac. Chromophil glands extend posteriorly to the posterior wall of VII. The first nephridia with recognizable lumina in XVI, but peritoneal masses in XV and some more anterior segments possibly represent nephridia. The alimentary canal widens in XIII, but not until XV, which may be the segment of intestinal origin, is enlargement pronounced. Dorsal and ventral blood vessels well developed; subneural vessel absent. Sperm morulae in X form a compact mass suggesting the presence of a testis–sac and also contained in a narrow stalked seminal vesicle formed by backward evagination of septum 10/11 into XI which it almost fills. The sperm funnel situated in the spermatogenic mass at the neck of the seminal vesicle and directed dorsally so as to serve both X and the seminal vesicle. Atria each a bulbous tube with narrow lumen, restricted to XIII, with lining epithelium of eosinophil glandular cells surrounded in turn by a thick sheath of predominantly circular muscle and a layer of similar width and several cells thick of unicellular gland cells: total width of muscular tube (external surface) 0.38 mm, narrowing to 0.195 mm ectally. Ovaries and funnels in XIII. The ovisac almost occluded at the intersegmental septa but bulging dorsally to the gut in each segment and posteriorly containing large oocytes full of large eosinophil yolk granules. Spermatheca unpaired; a simple, narrow, blind tube, 0.14 mm wide, recurving at the ental third, widening ectally before opening, via a narrower section at its pore dorsally in VIII.

Distribution. Ethiopia: Stream at 10,500 feet (3,200 m) in Choke Mts (Mt. Tab). Senan District, Goj jam Province.

Figures

FIGURE 4. Alluroides brinkhursti brinkhursti Jamieson (1968). Longitudinal section of the holotype. Abbreviations: br, brain; bv, blood vessel; m, mouth; msh, muscular sheath of atrium; oe, oesophagus; oo, oocyte: os, ovisac; ph m, pharyngeal musculature; pr c, prostatic cells; sep, septum; sep gl, septal gland; sp p, spermathecal pore; s. ves, seminal vesicle; sp, spermatheca; sp f, sperm funnel; tes, testis; vd, vas deferens; v n, ventral nerve cord. Adapted from Jamieson (1968).

FIGURE 6. Alluroides brinkhursti abyssinicus Jamieson (1968). Longitudinal section of holotype. Abbreviations: epi, epithelium of atrium; gl sh, glandular sheath of atrium; m, mouth; msh, muscular sheath of atrium; oe, oesophagus; oo, oocyte: ph m, pharyngeal musculature; s.ves, seminal vesicle; sp, spermatheca; vbv, ventral blood vessel; vd, vas deferens; v n, ventral nerve cord. Slightly modified from Jamieson (1968).

FIGURE 9. Alluroides ruwenzoriensis Brinkhurst 1964. Atrium and vas deferens entering at midlength. From Brinkhurst (1964).

FIGURE 10. Brinkhurstia americanus. (Brinkhurst 1964). Spermatheca opening mid–dorsally in the anterior of IX. Abbreviations: a, ampulla; cv, commissural vessel. From Omodeo & Coates (2001), reproduced with permission.

FIGURE 11. Brinkhurstia donaldi Omodeo and Coates (2001).A. Scheme showing arrangement of genital organs and vascular commissures. B. Cross section through spermathecal duct. C. Cross section of the muscular sac ensheathing penial seta. D. Section through ental part of prostate. E. Cross section of prostatic duct. F. Dorsal view of the arrangement of the penial setae within IX–XIII. Abbreviations: a, spermathecal ampulla, cv, commissural vessels, d, spermathecal duct, di, spermathecal diverticulum, e, egg, if‚ female funnel, md, male duct, pc, penial seta, pr, prostate. From Omodeo & Coates (2001), reproduced with permission.

FIGURE 14. Lacandodrilus paludosus Fragoso & Rojas 2023. A. External view of the anterior ventral region of a clitellate adult. B. Internal view of the anterior region of an adult. C. Spermatheca. Abbreviations: a, ampulla: clit, clitellum; d, duct; dv, dorsal vessel; gg, genital glands (prostates?); img, internal male gonoducts; mf, male funnels; n, nephridia; oe, oesophagus; sg, septal glands. Modified from Fragoso & Rojas (2023).