Kerriona apadaserraensis James, Bartz & Brown, 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 : 244-245

Kerriona apadaserraensis James, Bartz & Brown , sp. nov. ( Fig. 6 a-d)

Holotype. BRRS0020 , 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; 27 January 2012, S.W. James, S.K. Davidson, G.G. Brown and H. Yong, colls.

Paratype. BRRS0402 , one preclitellate individual, same data as holotype .

Etymology. The species name is a contraction of the name of the park where the earthworms were collected: Aparados da Serra.

Description. Dimensions 116-118 mm by 3.5-3.6 mm at segment x, 4 mm at clitellum, 3.6-4 mm at xxx, body cylindrical, segments 128-144. Setae closely paired throughout, CD sub-lateral; setal formula AA:AB:BC: CD = 3:1:3.5:1 at x, 3.3:1:4:1 at xxx, DD> ½ circumference. Setae AB of last 20 or so segments enlarged with 90 degree bend, nearly hooked. Prostomium epilobous open; segments lacking secondary annulations. Unpigmented, no dorsal pores, spermathecal pores within 7/8, 8/9 approximately centered in AB; with tumid lips wider than AB. Ovipores in xiv just behind 13/ 14 in B line; male pores equatorial in xviii within seminal grooves; grooves in B line slightly curved and concave laterally; prostatic pores on (or near?) elevated turrets at ends of grooves, lateral to B in xvii-xix; each turret consists of a short column capped with a round flat surface broader than a column, and small crossed furrows on each cap; small pore could be at intersection of these furrows. Setae AB present unmodified in xviii, absent in xvii, xix. Clitellum ½ xiii-xx, saddle in xiv-xx, no other genital markings ( Fig. 6a ).

Anterior septa 5/6 nearly fused into pharyngeal musculature, this musculature in broad bands from iii, iv back to body wall of vii and merge with septum 6/7; septa 6/7/8/9 very strong and elongate, 9/10/11/12 decreasingly muscular; 12/13 and remaining all thin. Alimentary canal lacking gizzard; esophagus elongate, folded in v, shorter but still elongate vi-viii; valvular in xii, intestinal origin in ½ xii; no typhlosole; prominent blood sinuses in intestinal wall in xii-xxii; intestinal walls of xii-xix thicker with longitudinal corrugations and deep segmental pouches. Calciferous glands large, paired in ix, partitioned into multiple lumens by 4 or 5 complete dividing lamina; shorter lamina filling space of each partition ( Fig. 6b ); each gland with blood vessel from anterior end to extra-esophageal vessel, blood vessel from duct of gland to supra-esophageal vessel. Holonephric, first nephridia in segment viii, tubular throughout from B to above D with upper part above CD apparently a bladder, or thin peritoneal mantle attached to uppermost tubule.

Vascular system with ventral trunk, single dorsal trunk in iv-viii, dorsal vessel perforated in ix, forming O-rings in x-xii, xiii; otherwise single; lateral vessels in v-ix, latero-esophageal hearts x-xi. In intestinal segments, small segmental vessels from dorsal vessel to body wall normally with branches within one intestinal segment, but those of xiv receive branches from xiii-xv.

Large ovaries, with funnels in xiii; paired spermathecae in viii, ix, consisting of a large muscular duct widening ectally, with 6 inner folds; narrowing conical ampulla smaller in length and volume than duct ( Fig. 6c ).

Male sexual system proandric, testes and funnels in x enclosed in thin membranous sac not composed of septa, vas deferens superficial on body wall from 10/11, joins body wall in xviii where vas deferens terminates in a small muscular bulb; seminal vesicles in ix large laterally placed on body wall, large and post-septal in xi. Slender tubular prostates folded under intestine within xvii-xxxiv, gland diameter about same as ducts; prostatic ducts 2 to 3 segments long, muscular, entering muscular domes of low copulatory bursae; bursal chambers entirely intraparietal containing the bases of the prostatic pore turret bodies. No penial setae. Transverse muscle bands of male field in xvii, xviii, xix with more in the first and third of these segments.

Remarks. Compared to other unpigmented Kerriona with turrets in the prostatic pore openings, Kerriona apadaserraensis sp. nov. has the least extensive doubling of the dorsal vessel, because the vessel is not doubled except to a limited extent in segments ix, x-xii, and xiii. The calciferous glands have more (4 or 5 vs. 1 or 2) complete partitions than the other species, and the spermathecal ampullae are smaller than the ducts. These characters distinguish it from other Kerriona . Unfortunately, no DNA barcode data is available for this species.

Figures

FIGURE 6. Kerriona apadaserraensis sp. nov. A. Composite ventral view with male field (mf), spermathecal pore (sp); B. Cross section of calciferous gland; C. Internal view with calciferous gland (cg), spermatheca (sp) and seminal vesicle (sv), scale bars 2 mm.