Kerriona riodaonsa 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 : 243-244

Kerriona riodaonsa James, Bartz & Brown , sp. nov. ( Fig. 5 a-c)

Holotype. BRPR1852 , one adult, Rio da Onça State Park , Paraná state, Brazil in bromeliad leaf axils, S25.789° W48.534°, 4 m asl. 20 June 2004. G. G. Brown and S.W. James, colls.

Paratypes. BRPR0042 , three adults, same data as holotype .

Etymology. The species name is a phonetic rendering of the name of the river at the collection site, where onça (jaguar or other large felid) is pronounced with a soft c; hence the use of s in this rendering.

Description. Dimensions 70-81 mm by 3.2- 3.4 mm at segment x, 3.0- 3.7 mm at clitellum, 4.0- 4.1 mm at xxx, body flattened ovate, behind clitellum, segments 136-141. Setae widely paired throughout, CD sub-lateral; setal formula AA:AB:BC:CD = 2:1:2.5:1 at x, 3.3:1:3:1 at xxx, DD> ½ circumference. Prostomium epilobous open; segments lacking secondary annulations. Unpigmented, no dorsal pores, spermathecal pores deep within 7/8, 8/9 at B. Ovipores in xiv just behind 13/ 14 in B line; male pores in xviii within straight seminal grooves lateral to B; prostatic pores on elevated turrets at ends of grooves in B in xvii-xix; each turret consists of a short column capped with ovate flat surface broader than a column, with a small rounded notch cut out of the posterior margin of each cap. Setae AB present in xviii, absent in xvii, xix. Clitellum xiii-xxi, annular in xiv-xx, no other genital markings ( Fig. 5a ).

Anterior septa all membranous. Alimentary canal with large pharyngeal glands in iii-vi; lacking gizzard but esophagus enlarged, non-muscular in vi, vii; esophagus valvular in xi, intestinal origin in xii; no typhlosole. Calciferous glands ovate, very large, paired in ix, densely packed with longitudinal, radially-arranged partitions ( Fig. 5b ); each gland with blood vessel from anterior end to extra-esophageal vessel, and blood vessel from posterior face of gland to supra-esophageal vessel. Holonephric, first nephridia in segment iv, tubular throughout and generally small, not reaching full extent of segments, thin peritoneal mantle enclosing tubules but not thick and glandular in appearance; no bladders.

Vascular system with ventral trunk, single dorsal trunk in iv-vi, double dorsal perforated in vii-x or xi, double from xi or xii posteriorly, lateral vessels in iv-ix, latero-esophageal hearts in x-xi.

Fan-shaped ovaries, with funnels in xiii; paired spermathecae in viii, ix, consisting of duct with broad muscular ectal portion containing sperm chambers, narrow non-muscular ental portion joining ampulla; ampulla conical, large ( Fig. 5c ).

Male sexual system proandric, testes and funnels in x enclosed in sac formed by septa 9/10/11, vas deferens superficial on body wall from 10/11, enlarged and muscular from xvi to end at body wall in xviii, where the vas deferens terminates in a small bulb; seminal vesicles in ix small laterally placed on body wall, large and postseptal in xi; slender tubular prostates folded under intestine within xiv-xxii, xxxiii; prostatic ducts muscular, enter muscular low domes of intra-parietal copulatory bursae. Transverse muscle bands within xvi-xxi. No penial setae.

Remarks. Apart from K. davidsonae sp. nov., which has already been discussed, Kerriona riodaonsa sp. nov. is distinguished from other unpigmented Kerriona described here by having a doubled dorsal vessel extending well posteriorly, rather than reverting to single somewhere in the anterior intestinal segments. Differences from K. limae are as described for K. davidsonae sp. nov., plus having differentiated duct and ampulla features in the spermathecae. DNA barcode: GU013965 is a singleton at species level (ASAP/14% calculations).

Figures

FIGURE 5. Kerriona riodaonsa sp. nov.A. Ventral view of male field (mf), scale bar 1 mm; B. Calciferous gland cross section; C. Internal view of calciferous gland (cg), dorsal vessel (dv), pharyngeal gland mass (pgm), spermatheca (sp), seminal vesicle (sv), scale bar 1 mm.