Eulodrobia spirula Zhang 2019, n. sp.
Creators: name: Zhang, - H.
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Tateidae
Eulodrobia
Eulodrobia spirula

description: Eulodrobia spirula n. sp.
Jardinella n. sp. uncoiled Perez et al. 2005: 547 (incorrectly cited as C.400131 = 400133).
Material examined. Holotype: Queensland, Yowah Creek Springs, on Bundoona Station, 27° 57' 08" S, 144° 46' 12" E, in flowing water, at spring head and outflow, up to 15–20 cm from spring head, W.F. Ponder & C. Lydeard, 2 May 2001, C.479945. Paratypes: Same data, C.400133, 20+; QM MO85765, 5. Other material examined: Queensland, Yowah Creek Springs, on Bundoona Station, main spring, head of spring, 27° 57' 07" S, 144° 46' 08" E, on wet sand, mostly out of water flow, W.F. Ponder, J.H. Waterhouse & A.C. Miller, 4 Apr 2002, C.421807, 6; area around head of spring, 27° 57' 07" S, 144° 46' 08" E, mostly on thick wet mud, out of water flow, W.F. Ponder, J.H. Waterhouse & A.C. Miller, 4 Apr 2002, C.421809, 11; main flow area, 27° 57' 07" S, 144° 46' 08" E, seepage/ flow areas of spring, short sedges and duck weed, W.F. Ponder, J.H. Waterhouse & A.C. Miller, 4 Apr 2002, C.421812, 8.
Shell (Fig. 2 G–I, 3F). Flat-spired, spire outline moderately convex, coils markedly disjunct, opaque. Length 0.8–1.5 mm (mean 1.0 mm), width 2.2–2.4 mm (mean 2.3 mm). Protoconch of about 1.2–1.3 whorls, with distinct irregular pitting on most of first whorl, last part with fine pitting crossed by a few broad axial grooves and ridges; sometimes a few spiral folds (Fig. 3F). Teleoconch whorls strongly convex, evenly rounded to weakly keeled, total number 2.5–2.7 (mean 2.6). Umbilicus wide. Sculpture of growth lines and some subobsolete spiral scratches on periphery. Aperture circular, inner lip narrow, thin, widely separated along entire length of parietal wall, outer lip thin. Periostracum moderately developed, yellow-brown.
Operculum (Fig. 4 K–L). Translucent, yellow-brown or brown, slightly concave, nucleus central. Inner side lacking pimple or white smear, simple.
Head-foot and external body. Snout unpigmented or pigmented, tentacles, neck and opercular lobes pigmented, dorsal and lateral foot unpigmented, mantle roof and visceral coil weakly pigmented.
Mantle cavity. Ctenidium well-developed, filaments 17–20, broadly triangular, apex right edge. Osphradium narrowly oval, towards posterior end of ctenidium, length relative to gill 0.25–0.32. Hypobranchial gland moderately developed, or thin (poorly developed). Rectum with U-shaped bend, anus behind mantle collar. Kidney extends for about quarter of length into mantle cavity roof. Renal gland transverse. Pericardium extends for about quarter of length into mantle cavity roof, overlapping posterior end of ctenidium or abutting posterior end of ctenidium.
Radula (Fig. 5 M–N). Central teeth with cusp formula 2–3+1+2–3, basal cusps 2+2; median cusp very broad to spathulate, about 3 times as long as adjacent cusps. Lateral teeth with cusp formula 3–4+1+1–2, main cusp broad to spathulate, about 3 times longer than adjacent cusps. Inner marginal teeth with 21 small, sharp cusps, proximalmost about 1.5 x length of adjacent cusp. Outer marginal teeth with about 21–24 small, sharp cusps.
Female reproductive system (Fig. 6I, L). Ovary simple sac. Renal oviduct with weak to absent initial arch; forms near circular loop to anterior end of bursa copulatrix. Seminal receptacle absent; orientated sperm in renal oviduct and/or bursal duct. Bursa copulatrix overlapping albumen gland on left, round or pyriform, shorter than albumen gland, bursal duct enters bursa mid anteriorly or antero-ventrally, bursal duct joins coiled oviduct little behind posterior mantle cavity wall. Albumen gland behind posterior mantle cavity wall. Capsule gland with two or three distinct glandular zones, medium thickness in cross section, markedly indented by rectum. Anterior vestibule small, opening terminal or subterminal, intermediate in size.
Male reproductive system (Figs. 7F, 8F). Prostate gland less than half in mantle roof, oval, medium in cross section. Posterior pallial vas deferens straight, anteriorly slightly undulating. Penis behind right eye or towards middle of head, intermediate or well down neck, distal end tapering, terminal papilla long, small non-glandular lobe present.
Etymology. Spirula—Latin, small spiral—shell somewhat like that of the cephalopod genus Spirula.
Distribution and habitat. Known only from the main spring, Yowah Creek Springs, on Bundoona Station about 36 km NW of Eulo (Fig. 1), where it lives in clean, rather coarse sediment in very shallow spring outflow. This outflow has well oxygenated, clean water and coarse sediment.
Remarks. This species lives together with Eu. carinata. It differs from that species in its smaller size, loosely coiled shell, flatter spire and weak to absent peripheral angulation. No other species is similar and the uncoiled shell is unique in described Australian tateids.
This species was not included in our molecular analysis but in the COI analysis of Perez et al. (2005), it was sister to Eu. carinata and these two species formed a subgroup within Eulodrobia. They are distinguished from other species of Eulodrobia by their small size, flattened shell (which often bears a carina) and a thicker, near circular operculum with a central to near central nucleus. The protoconch is also distinctive in having the last part bearing distinct axial ridges. In anatomy, however, they are similar to other species of Eulodrobia.
description: Published as part of Zhang, - H., 2019, New taxa of Tateidae (Caenogastropoda, Truncatelloidea) from springs associated with the Great Artesian Basin and Einasleigh Uplands, Queensland, with the description of two related taxa from eastern coastal drainages, pp. 1-67 in Zootaxa 4583 (1) on pages 21-22, DOI: 10.11646/zootaxa.4583.1.1, http://zenodo.org/record/2637603