Kerriona davidsonae 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 : 241-242

Kerriona davidsonae James, Bartz & Brown , sp. nov. ( Fig. 4 a-c)

Holotype. BRSP0139 , late aclitellate juvenile, Intervales State Park , Itapeúna , Eldorado county, S„o Paulo state, Brazil, S24.305°, W48.3651°, 818 m asl., in bromeliad leaf axils; 7 February 2009, S.W. James, S.K. Davidson, M.L.C. Bartz, and G.G. Brown, colls.

Paratype. BRSP0919 , late aclitellate juvenile, same data as holotype .

Etymology. The species is named after our colleague and collaborator Seana Davidson, a pioneer in researching the bacterial symbionts living in earthworm nephridia.

Description. Dimensions 60-69 mm by 2.5-3.0 mm at segment x, 3.3 mm at xxx, 151 segments; body cylindrical throughout, posterior gradually tapered to tail, posterior-most segments shorter. Setae paired throughout, CD sub-lateral; setal formula AA:AB:BC:CD = 2.4:1:3:1.2 at xxx, DD> ½ circumference. Prostomium epilobous open; segments without secondary annulations. Unpigmented, no dorsal pores, spermathecal pores in 7/8, 8/9 at B. Ovipores not seen; male pores in xviii just lateral to B; prostatic pores adjacent to elevated penial bodies at ends of grooves in B in xvii-xix; each penial body consists of a short column capped with an ovate flat surface broader than a column, and a small rounded triangular notch cut out of the posterior margin of each cap ( Fig. 4 a,b ). Setae AB present unmodified in xvii-xix. Clitellum not developed, no other genital markings.

Anterior septa thin but not membranous. Alimentary canal with strong pharyngeal muscles in iv-vii ( Fig. 4c ); lacking gizzard; esophagous valvular in xi, intestinal origin in xii; no typhlosole; intestine with lateral pouches in xiii-xx. Calciferous glands elongate an ovate, very large, paired in ix, densely packed with longitudinal partitions; each gland with blood vessel from anterior end to extra-esophageal vessel, blood vessel from posterior face of gland to esophageal wall and supra-esophageal vessel. Holonephric, tubular nephridia without bladders; beginning in vii or viii ( Fig. 4c ).

Vascular system with ventral trunk, single dorsal trunk iv-ix, double dorsal vessel x and posteriorly ( Fig. 4c ), lateral vessels in vii, viii, lateral hearts in ix-xi.

Ovaries, funnels in xiii; paired spermathecae in viii, ix, immature and very small ( Fig. 4c ).

Male sexual system proandric, testes and funnels in x enclosed in sac made by fusion of septa 9/10/11, vas deferens superficial on body wall from 10/11 to enlarged muscular end at body wall in xviii; seminal vesicles in ix small laterally placed on body wall, large and post-septal in xi; slender tubular prostates folded under intestine within xvii-xxii; prostatic ducts slender, enter 0.7 mm diameter muscular domes. No penial setae.

Remarks. The proandric testes enclosed in sacs is a feature of all the unpigmented Kerriona species we report on here, plus K. limae . This character excludes K. garbei , K. luederwaldti , and K. bocainensis sp. nov. in which the testes are free, dorsal vessels single, and prostatic pores unaccompanied by turrets. Kerriona garbei differs from all other Kerriona known previously or described here by having a single pair of spermathecae, and by its much larger body size. The closest relationship of K. davidsonae sp. nov. is with those species bearing the doubled dorsal vessel and small turrets at the prostatic pores, of which we describe several in the following pages. Although the specimens of K. davidsonae sp. nov. are juveniles, sperm has matured and gathered on the funnels so maturity is close at hand. They differ from K. riodaonsa sp. nov. by having more posterior start of doubling of the dorsal vessel, more widely paired setae, thicker anterior septa, a pouched intestine in xii-xix, AB setae present in all male field segments, and a muscular termination of the vas deferens. Another possible distinction is that the muscular surroundings of the prostatic duct terminations are clearly coelomic in this species and more intraparietal in K. riodaonsa sp. nov., despite the latter being more fully mature. Kerriona davidsonae sp. nov. has many more lamellae in the calciferous glands and a more extensively doubled dorsal vessel than K. apadaserraensis sp. nov., K. vilavelhaensis sp. nov., and K. clivedwardsi sp. nov. It differs from K. limae by having more widely paired setae, calciferous glands more densely packed with lamellae, and muscular copulatory pouches around the prostatic pores.

DNA barcodes: HQ562639, HQ562640, HQ562641. These are separated from all other Kerriona DNA barcodes as a species-level taxon by ASAP ( Puillandre et al. 2020) and the 14% criterion.

Figures

FIGURE 4. Kerriona davidsonae sp. nov. A. Lateral view of male field; B. Ventral view of male field; C. Internal view, with doubled dorsal vessel (dv), copulatory pouches (cp), pharynx (Ph), and spermatheca (s).