Eulodrobia eulo ( Ponder & Clark, 1990 )

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, Zootaxa 4583 (1), pp. 1-67 : 8-11

Eulodrobia eulo ( Ponder & Clark, 1990) and Eulodrobia cf. eulo .

Jardinella eulo Ponder & Clark, 1990: 342 , figs. 6C, 31A, B, 32, A, B, 33C, D, 34D, F. Jardinella eulo Perez et al. 2005: 547 (C.400135); Jardinella sp. Commonwealth of Australia, 2014: 37 (= Eulodrobia cf. eulo ).

Material examined. Eu. eulo . Queensland, Massey Spring (=Rocky Springs), Granites Springs, near Mt Francis

ca 52 km SW of Eulo, 28° 18' 00" S, 144° 32' 00" E, on small-leaved plants, W.F. Ponder & P.H. Colman, 7 Sep 1984 (holotype, C.156778, and paratypes, C.156779). Additional material from same locality, C.410724, C.479953.

Eu. cf. eulo ‘Unnamed spring’ (=Tunga Spring) at Tunga Bore, Queensland, 28° 13' 00" S, 144° 38' 00" E, 6 Sep 1984, W.F. Ponder & P.H. Colman, spring flows into boulder strewn creek, C.156780 (designated as paratypes of Eu. eulo ). Other material from same locality 28 Aug 2000, R. J. Fensham, artesian spring with flow enhanced by bore head, on mud and plant surfaces, C.410643 (SEM material), 20+; C.479952, 1; 2 May 2001, W.F. Ponder & C. Lydeard, in shallow muddy habitat at head of spring, C.400135 (molecular sample).

Shell ( Fig. 2B, C , 3B ). Ovate, spire outline slightly convex, normally coiled, opaque. Length 1.44–2.43 mm (mean 2.4 mm), width 1.5–2.3 mm (mean 1.9 mm). Protoconch of 1.5 whorls, minutely and irregularly pitted ( Fig. 3B ). Teleoconch whorls moderately convex, evenly rounded, total number 3.5–4.3 (mean 3.6). Umbilicus moderate. Sculpture of close growth lines, often raised into weak riblets. Aperture ovate, inner lip narrow, thick, slightly separated along whole length of parietal wall, outer lip medium thickness. Periostracum moderately developed, yellow-brown to reddish or orange-brown.

Operculum ( Fig. 4C, D ). Translucent, yellow-brown, slightly concave, nucleus acentric. Inner side lacking white smear, simple except for low rounded thickening at nucleus.

Head-foot and external body. Snout black, tentacles dark grey; dorsal and lateral parts of foot and opercular lobes pigmented, mantle roof and visceral coil black.

Mantle cavity. Ctenidium well-developed, filaments 24–28, broadly triangular, apex towards right. Osphradium narrowly oval, towards posterior end of ctenidium, length relative to gill 0.29–0.31. Hypobranchial gland thin. Rectum with U-shaped bend, with longitudinal to oblique pellets, anus behind mantle collar. Kidney extends for about one third to one half of length into mantle cavity roof. Renal gland longitudinal. Pericardium extends for about one third to one half of length into mantle cavity roof, overlapping posterior end of ctenidium.

Radula ( Fig. 5 C–E). Central teeth with cusp formula 3+1+3, basal cusps 2+2; median cusp narrow, pointed, about 3 times longer than adjacent cusps (note: worn in Fig. 5E ). Lateral teeth with cusp formula 2–3+1+2–3, main cusp narrow, blunt or pointed, about twice as long as adjacent cusps. Inner marginal teeth with 12–16 cusps. Outer marginal teeth with 17–21 cusps.

Female reproductive system ( Fig. 6C, F ). Ovary weakly lobed. Renal oviduct with single ( Fig. 4 ) or double ( Ponder & Clark 1990, fig. 34E) U-shaped arch. Seminal receptacle oval, duct very short. Bursa copulatrix behind albumen gland, pyriform to oval, shorter than albumen gland, bursal duct enters bursa anteroventrally, bursal duct joins coiled oviduct well behind posterior mantle cavity wall. Albumen gland partly in mantle cavity. Capsule gland with two distinct glandular zones apparent in some, medium thickness in cross section, slightly indented by rectum. Anterior vestibule small, opening terminal.

Male reproductive system ( Figs. 7B , 8B ). Prostate gland less than half in mantle roof, bean-shaped, medium in cross section. Posterior pallial vas deferens slightly undulating to (usually) coiled, anteriorly slightly undulating. Penis behind right eye well down neck, distal end broad, terminal papilla absent, two non-glandular lobes present.

Distribution and habitat. Restricted to Massey Spring, Granites Spring group, a small spring on Granite Springs Station, Eulo Supergroup ( Commonwealth of Australia 2014) ( Fig. 1 ). This species was absent in a few other nearby small springs which occur in the Granites Spring group. A similar taxon occurs in Tunga Spring (see Remarks). Massey Spring and Tunga Spring are about 11 km apart and on two different local drainage systems, although both are tributaries of the Paroo River system. These populations can be formally distinguished by referring to them as Eulodrobia eulo (from Massey Spring) and Eu. cf. eulo (from Tunga Spring).

Remarks. This species was originally recorded from both Massey Spring (= Granite or Rocky Springs) and Tunga Spring (at Tunga Bore). Molecular data for both populations (see Fig 31 ) shows some differentiation suggesting that separate species-group status may eventually be necessary. Although the Tunga Spring population has not been examined anatomically, its shell, opercular and radular characters are very similar to those of specimens from Massey Spring. Also, the operculum in both populations has the same raised nipple-like thickening at the nucleus. However, a discriminant function analysis separated most specimens of the two forms, as detailed below in the Remarks under the next species.

The spring at the type locality (Massey Spring) is a medium-sized spring ( Commonwealth of Australia 2014) about 52 km SW of the village of Eulo while the other known population lives in a tiny spring next to Tunga Bore, which is located near Mt Tunga, about 45 km WSW of Eulo, south-western Queensland. Other springs near both these springs have substantially decreased in flow ( Commonwealth of Australia 2014), and none contain these snails.

Figures

FIGURE 1. Map of the spring supergroups associated with the Great Artesian Basin (GAB) in Queensland, showing the main non-town locations mentioned in the text (squares) and some of the towns in the area (ovals). The pale grey shading is the discharge part of the GAB, the dark grey the recharge part. The inset map of Australia shows the area illustrated. The approximate location of Conondale is indicated by a triangle and Nundle by a star. The spring supergroups are outlined with dotted lines and are as follows: A, Mulligan River; B, Springvale; C, Flinders River; D, Hughenden; E, Barcaldine (see inset at upper right for details); F, Springsure; G, Eulo.

FIGURE 2. Shells of species of Eulodrobia n. gen. A. Eulodrobia fenshami n. sp., holotype, spring at Town Common, Eulo (C.479950). B. Eulodrobia eulo (Ponder & Clark, 1990), paratype, Massey Spring (C.156779). C. Eulodrobia cf. eulo (Ponder & Clark, 1990), Tunga Spring (C.410643). D. Eulodrobia ovata n. sp., holotype, Yowah Springs, Bundoona Station (C.479944). E. Eulodrobia bundoona n. sp., holotype, Yowah Springs, Bundoona Station (C.479943). F. Eulodrobia carinata n. sp., holotype, Yowah Springs, Bundoona Station (C.479942). G–I. Eulodrobia spirula n. sp., Yowah Springs, Bundoona Station. G. dorsal view of holotype (479945). H, I. apertural view of paratypes (C.400133). Scale bars 1 mm.

FIGURE 3. Protoconchs and protoconch microsculpture of species of Eulodrobia n. gen. A. Eulodrobia fenshami n. sp., paratype, spring at Town Common, Eulo (C.410721). B. Eulodrobia eulo (Ponder & Clark, 1990), paratype, Massey Spring (C.156779). C. Eulodrobia ovata n. sp., paratype, Yowah Springs, Bundoona Stn (C.400130). D. Eulodrobia bundoona n. sp., paratype, Yowah Springs, Bundoona Stn (C.400132). E. Eulodrobia carinata n. sp., paratype, Yowah Springs, Bundoona Stn (C.400131). F. Eulodrobia spirula n. sp., paratype, Yowah Springs, Bundoona Stn (C.400133). Scale bars 100 µm (lowpowered images [left]), 10 µm (high-powered images [right]).

FIGURE 4. Opercula of species of Eulodrobia n. gen., external and internal views of each species. A, B. Eulodrobia fenshami n. sp., paratype, spring at Town Common, Eulo (C.410721). C, D. Eulodrobia eulo (Ponder & Clark, 1990), paratype, Massey Spring (C.156779). E, F. Eulodrobia ovata n. sp., paratype, Yowah Springs, Bundoona Stn (C.400130). G, H. Eulodrobia bundoona n. sp., paratype, Yowah Springs, Bundoona Stn (C.400132). I, J. Eulodrobia carinata n. sp., paratype, Yowah Springs, Bundoona Stn (C.400131). K, L. Eulodrobia spirula n. sp., paratype, Yowah Springs, Bundoona Stn (C.400133). Scale bars 500 µm.

FIGURE 5. Radulae of Eulodrobia n. gen. A, B. Eulodrobia fenshami n. sp., paratype, spring at Town Common, Eulo (C.410721). A, half rows, B, detail of lateral tooth. C–E. Eulodrobia eulo (Ponder & Clark, 1990), paratype, Massey Spring (C.156779), C, half rows, D detail of lateral tooth, E, detail of central tooth. F–H. Eulodrobia ovata n. sp., paratype, Yowah Springs, Bundoona Stn (C.400130). F. Detail of central tooth. G. Detail of inner marginal tooth. H. Detail of outer lateral teeth. I–K. Eulodrobia bundoona n. sp., paratype, Yowah Springs, Bundoona Stn (C.400132). I. Part of tooth row. J. Detail of lateral teeth. K. Detail of inner marginal tooth. L.Eulodrobia carinata n. sp., paratype, Yowah Springs, Bundoona Stn (C.400131), half rows. M. N. Eulodrobia spirula n. sp., paratype, Yowah Springs, Bundoona Stn (C.400133), half rows. Scale bars 10 µm.

FIGURE 6. Female reproductive system of species of Eulodrobia n. gen., shown from left side. A, B. Eulodrobia fenshami n. sp. (C. 410721). C, F. Eulodrobia eulo (Ponder & Clark, 1990) (C. 410724). D, E. Eulodrobia ovata n. sp. (C. 400130). G, H. Eulodrobia bundoona n. sp. (C.400132). I, L. Eulodrobia spirula n. sp. (C.400133). J, K. Eulodrobia carinata n. sp. (C.400131). Abbreviations: ag—albumen gland; bc—bursa copulatrix; cg—capsule gland; ga—opening of oviduct; pwposterior wall of mantle cavity; ro—renal oviduct; sr—seminal receptacle; v—vestibule; vc—ventral channel. Scale bars 500 µm.

FIGURE 7. Prostate and vas deferens of species of Eulodrobia n. gen. Each species is shown with anterior at left and posterior at right, with line indicating position of posterior pallial wall. A. Eulodrobia fenshami n. sp. (C. 410721). B. Eulodrobia eulo (Ponder & Clark, 1990) (C. 410724). C. Eulodrobia ovata n. sp. (C.400130). D. Eulodrobia bundoona n. sp. (C.400132). E, Eulodrobia carinata n. sp. (C. 400131). F. Eulodrobia spirula n. sp. (C.400133). Abbreviations: avd—anterior vas deferens; pw—position of posterior wall of pallial cavity; ve—posterior vas deferens. Scale bars 200 µm.

FIGURE 8. Penis and vas deferens of species of Eulodrobia n. gen. A. Eulodrobia fenshami n. sp. (C. 410721). B. Eulodrobia eulo (Ponder & Clark, 1990) (C. 410724). C. Eulodrobia ovata n. sp. (C. 400130). D. Eulodrobia bundoona n. sp. (C.400132). E, Eulodrobia carinata n. sp. (C. 400131). F. Eulodrobia spirula n. sp. (C.400133). Abbreviations: ngl—non-glandular lobe; pd—penial duct; vd—vas deferens. Scale bars 200 µm.

FIGURE 31. Phylogram of Australian tateid spring taxa and selected outgroups with Bayesian posterior probability values (shown above nodes) and RAxML bootstrap support values (shown below nodes). Posterior probability values below 0.85 and bootstrap support below 70% are not shown, and asterisks indicate optimal support. Two parallel diagonal lines on branches indicate those branches have been shortened. Bayesian tree is shown. The grey box indicates the clade encompassing all Queensland spring taxa, the monotypic Nundalia from New South Wales, and the coastal, riverine genus Jardinella from northern Queensland. All taxa included in this clade are illustrated to the right and where possible aligned with their respective placement in the phylogram. Abbreviations: C—Carnarvoncochlea; E. (B.)—Edgbastonia (Barcaldinia); E. (E.) -Edgbastonia (Edgbastonia); NQ—North Queensland (coastal); NSW—New South Wales; S—Springvalia. Names of imaged taxa are indicated, next to the illustrations, by the three first letters in their species (or subspecies) name, or, when identical, the four first letters. For details of superscript numbers 1–40, see Table 20.