Eukerria adecarvalhoi 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 : 237-238

Eukerria adecarvalhoi James, Bartz & Brown , sp. nov. ( Fig. 1 a-c)

Holotype. BRSE0014 , one adult, Fazenda Haras Chamusca , Lagarto, Sergipe state, Brazil, S11.033611°, W37.648528°, 137 m asl., degraded area on the banks of a small stream; 25 May 2012, André de Carvalho coll.

Paratypes. BRSE0015 , two adults, same data as holotype .

Other material. BRSE0006 , 8 adults, 4 juveniles, same data as holotype . BRSE0010 , 4 juveniles and 2 adults, same data as holotype .

Etymology. The species is named after the collector of most of the specimens, by contracting his first and family names.

Description. Dimensions 35-53 mm by 1.3-1.7 mm at segment x, 1.1-1.6 mm at xxx, 1-1.5 mm at clitellum; body cylindrical throughout, segments 110-140. Setae paired throughout; setal formula AA:AB:BC:CD = 2.5:1:4:1.3 at xxx, DD <½ circumference. Prostomium short zygolobous; segments without secondary annulations. Unpigmented, no dorsal pores, spermathecal pores in 7/8, 8/ 9 in line C; mated worms have copulatory plugs in spermathecal pores. Ovipores just behind anterior edges of xiv in line B; male pores in xviii deeply invaginated pits within seminal grooves; prostatic pores on small papillae within ends of grooves in B in xvii-xix; grooves with two curves concave medially, within raised sub-alate pad extending from xvii-xix ½ BC-A; cleft transverse oval papillae on xvii, xix respectively anterior, posterior to seminal grooves. Setae AB present unmodified in xvii-xix. Clitellum ½ xiii-½ xx, saddle-shaped reaching to ½ AB, no other genital markings ( Fig. 1a ).

Septa 6/7-11/12 thin but not membranous. Alimentary canal with variable degree of pharyngeal muscles in iv, v; weak barrel-shaped gizzard in vii; esophagous valvular in xi, intestinal origin xii; no typhlosole or other differentiation of intestine. Calciferous glands ovate, paired in ix, composed of radial lamellae with very small central lumen ( Fig. 1b ); each gland with blood vessel from anterior end to extra-esophageal vessel, blood vessel from duct of gland to esophageal wall becoming supra-esophageal vessel. Holonephric, tubular nephridia lacking bladders, present from segment xi or xii, occupying space from mid-BC ventrally.

Vascular system with ventral trunk, dorsal trunk, these connected by lateral vessels in vii, viii; lateral hearts in ix-xi; dorsal trunk in xi doubled with each side connecting to lateral heart of that segment.

Ovaries, with funnels in xiii; paired spermathecae in viii, ix, each an elongate sac or with pronounced swelling at ampulla end, no diverticulum; sperm chambers visible within duct near body wall ( Fig. 1c ).

Male sexual system proandric, testes and funnels free in x, vas deferens superficial on body wall from 10/11 to xviii; seminal vesicles small, parietal in ix, large post-septal in xi ( Fig. 1c ); tubular prostates with very long glandular portion folded under and along sides of intestine within xvi-xx, xxii; prostatic ducts more muscular at body wall, generally slender and long, gradually narrowing towards junction with glandular part. No penial setae.

Remarks. Of the 32 nominal species, some are from far-flung locations, and might be synonyms of the peregrines E. kuekenthali (Michaelsen, 1908) or E. saltensis (Beddard, 1895) . In the former group Blakemore (2006) includes E. peguana Gates, 1942 from Myanmar and E. selangorensis (Stephenson, 1931) from Malaysia. Junior synonyms of E. saltensis include at least E. gunningi Michaelsen, 1913 , E. nichollsi Jackson, 1931 and E. sydneyensis Jackson, 1931 ( Blakemore, 2006) . Eukerria . hortensis (Stephenson, 1931), E. limosa (Stephenson, 1931) , E. pascuorum (Stephenson, 1931) and E. rubra (Friend, 1916) may also be synonyms of these or other species, e.g., E. eiseniana ( Rosa, 1895) , but have not been adequately evaluated ( Blakemore 2006). Species described after the publication of Righi (1968), which includes a key to all the known species of Eukerria (at that time) are the following: E. cuca Righi, 1984 , E. emete Righi & Guerra, 1985 , E. guamais Righi, 1971 , E. mucu Righi, 1988 , E. taisa Righi, 1983 , and E. santafesina Lungstr ̂m, 1972. All of these publications were consulted in diagnosing the new species of Eukerria described here.

The widely-distributed peregrine E. saltensis is epilobous, has an annular clitellum, is much more slenderbodied, the spermathecal pores are more ventral, the male field grooves are straighter and lack the oval genital markings at the ends of the grooves, as well as lacking the deep pits containing the male pores. Its calciferous gland is usually described as a solid mass with a small central lumen, and only by Gates (1942) as having radial lamellae extending into a large lumen. The same external characters distinguish E. adecarvalhoi sp. nov. from E. kuekenthali . The spermathecal pores of E. eiseniana are above the level of setal row D, its seminal grooves near the level of C, and there is no evidence of sperm production. However it appears to have radial lamellae in the calciferous glands. The present species is diagnosed by the following combination of character states: clitellum saddle shaped ending in xx, calciferous glands with parallel lamellae projecting radially inwards from the gland wall (cf. Righi 1968), spermathecal pores at the C setal row level, lacking genital markings, 2 pairs of prostate glands, prostate glands opening with copulatory bursae (interpreting the deep pits as such), double dorsal vessel in xi, and spermathecal duct shorter than the ampulla.

In the new species the calciferous glands’ radial lamellae appear to meet, or almost meet, in the center of the gland, but it is difficult to tell if the sometime appearance of a small lumen is an artifact of making sections by hand, or a real feature of the gland. The specimens from BRSE006 were slightly larger and had less muscularity in the prostatic ducts but more in the pharynx area, compared to those of BRSE0010. External characters are in complete agreement between the two sites. Unfortunately, no DNA barcode data is available for this species.

Figures

FIGURE 1. Eukerria adecarvalhoi sp. nov. A. Composite ventral view with male pore (mp) and spermathecal pores (sp); B. Cross section of calciferous gland; C. Internal view with seminal vesicle (vs) and vas deferens (vd), scale bars 1 mm.