Sclerodoris tuberculata Eliot, 1904

Innabi, Julie, Stout, Carla C. & Valdes, Angel, 2023, Seven new " cryptic " species of Discodorididae (Mollusca, Gastropoda, Nudibranchia) from New Caledonia, ZooKeys 1152, pp. 45-95 : 45

Sclerodoris tuberculata Eliot, 1904

Figs 14A , 15A-C , 16A-C

Doris castanea ? Doris castanea Kelaart, 1858: 110. Type locality: Sober Island, Tricomalie [= Trincomalee] harbor, Ceylon [= Sri Lanka].

Sclerodoris tuberculata Eliot, 1904: 381-382. Type locality: Prison Island [= Changuu], Zanzibar harbor, Tanzania.

Sclerodoris minor Eliot, 1904: 381. Type locality: Chuaka [= Chwaka], Zanzibar, Tanzania.

Sclerodoris rubra Eliot, 1904: 382-383. Type locality: reef off the east coast of Zanzibar, Tanzania.

Halgerda rubra Bergh, 1905: 126-127, pl. 4 fig. 2, pl. 15 figs 34-36. Type locality: Bandas [= Banda Islands], Indonesia, 36 m depth.

Material examined.

Pointe de Pandop , Koumac, New Caledonia (20°34.9'S, 164°16.5'E), 7 m depth [Koumac 2.1 stn. KR868], 26 Sep 2018, 1 specimen 44 mm long, dissected (MNHN IM-2013-86197, isolate JI10) .

Description.

Body oval, flattened, with an irregular, coriaceous texture (Fig. 14A ). Branchial and rhinophoral sheaths somewhat elevated, simple, circular. Gill composed of eight short, tripinnate branchial leaves, arranged upright. Rhinophores short, lamellated, with 18 lamellae. Visceral hump clearly elevated over the rest of the mantle, with several lateral protuberances and a conspicuous depression mid-length. Dorsum completely covered with small caryophyllidia. Body color red, with several large, irregularly opaque white patches, mainly on the mantle margin and some white pigment irregularly scattered all over. Rhinophores and branchial leaves are the same color as the dorsum.

Reproductive system (Fig. 15A, B ) with a long, wide, convoluted ampulla with several folds, which connects with the female gland complex and the oval, flattened prostate. The prostate narrows substantially into a long, straight duct, before expanding into the short, wide deferent duct. The penis is armed with triangular spines, varying in size (Fig. 15C ) with thickened bases and sharp cusps. The vagina is elongate, narrow, as wide as the deferent duct, connecting directly to the large, oval bursa copulatrix. The elongate seminal receptacle also connects to the bursa copulatrix next to the vaginal connection, and the short uterine duct that enters the female gland complex (Fig. 15B ). The bursa copulatrix is ~ 4 × as large as the seminal receptable. An accessory gland connects to the genial atrium where the deferent duct and the vagina meet. The accessory gland is granular in texture and approximately as large as the seminal receptable.

Radular formula 38 × 49.0.49 in a 44-mm long specimen (MNHN IM-2013-86197). Rachidian teeth absent. Inner and mid-lateral teeth hamate, having an elongate cusp and lacking denticles (Fig. 16A, B ). Innermost teeth very small in comparison to mid-laterals (Fig. 16A ). The teeth increase in size gradually towards the medial portion of the half-row. Outermost teeth small, decreasing in size gradually, composed of a short, blunt cusp with numerous small denticles (Fig. 13C ). No jaw was observed, labial cuticle smooth.

Biology.

Rare, found under rocks at 7 m depth. Widespread in the Indo-Pacific region. The single specimen was found under a rock while SCUBA diving where it was highly cryptic.

Remarks.

Eliot (1904) described Sclerodoris tuberculata based on one specimen collected in Zanzibar as follows: "Dark brown with sandy spots, exactly like a sponge splashed with sand. Underside clear bright brownish red. Branchial pocket crenulate. The middle part of back covered with conical warts, which form an irregular keel; smaller warts on mantle-edge. Rhinophores red; branchiae eight, voluminous; axes red, tips white. Animal alters shape, sometimes rather high, sometimes quite flat like Platydoris . Consistency quite hard and rather rough. Two depressions with deep black markings as in some species of Trippa ." In the same paper Eliot (1904) introduced two additional species also resembling sponges, Sclerodoris minor Eliot, 1904, and Sclerodoris rubra Eliot, 1904, both synonyms of S. tuberculata . Sclerodoris tuberculata is considered a widespread species in the Indo-Pacific region and is well documented in the literature ( Valdés and Gosliner 2001; Yonow 2008; Gosliner et al. 2018; Nakano 2018). The material here examined is consistent with the original description of S. tuberculata and subsequent records; however, a record of this species from New Caledonia ( Hervé 2010) is probably the closely related species Sclerodoris rubicunda (Baba, 1949).

Eliot (1906) suggested that Doris castanea Kelaart, 1858 was possibly the same species as Sclerodoris tuberculata Eliot, 1904, but indicated the identity of the latter could not be established with certainty based on the type material. Eliot (1906: pl. 42, figs 6, 7) reproduced the original drawing by Kelaart, which clearly resembles a dark specimen of S. tuberculata . Later, Eliot (1908) regarded Sclerodoris rubra Eliot, 1904 as a senior synonym of Halgerda rubra Bergh, 1905.

Allan (1947) reported S. tuberculata from New South Wales, Australia, under the genus name Peronodoris Bergh, 1904 and commented on Eliot’s (1906) proposed synonymy between this species and D. castanea . Allan (1947) indicated that "although the colour sketch of the upper surface of Kelaart’s specimen resembles that of our specimen to a very slight degree," the undersurface is exactly like the color sketch of the New South Wales material of S. tuberculata . Allan (1947) concluded that whether S. tuberculata was eventually to become a synonym of D. castanea remained to be seen, as fresh material from the two type localities needs to be examined before this can be determined.

Rudman (1978) endorsed Eliot’s (1908) decision to synonymize Halgerda rubra Bergh, 1905 with Sclerodoris rubra Eliot, 1904. At the same time Rudman (1978) regarded Sclerodoris rubra Eliot, 1904 and Sclerodoris minor Eliot, 1904 as synonyms of Sclerodoris tuberculata Eliot, 1904, and based on the Principle of First Reviser ( ICZN 1999: Article 24), Rudman (1978) established S. tuberculata as the valid name for this species. Rudman (1978) also commented that the original description of D. castanea by Kelaart (1858) was most inadequate and therefore best to ignore it. In this paper we follow Rudman’s (1978) conclusion and regard Sclerodoris tuberculata Eliot, 1904 as the valid name for this species with the synonymies established above. We also leave the question of the identity of D. castanea as unresolved.

Hervé (2010) reported Sclerodoris tuberculata from New Caledonia but based on the photographs published ( Hervé 2010: 214), it seems that these records correspond to Sclerodoris rubicunda (Baba, 1949). The present study is the first confirmed record of Sclerodoris tuberculata from New Caledonia.

Figures

Figure 13. SEM of the radula of specimens of Rostanga poddubetskaiae sp. nov., MNHN IM- 2013 - 86205 A innermost teeth B mid-lateral teeth C outer lateral teeth.

Figure 14. Photographs of live animals of the genus Sclerodoris Eliot, 1904 A Sclerodoris tuberculata Eliot, 1904, MNHN IM- 2013 - 86197 on black background B-D " Sclerodoris " Sclerodoris dutertrei sp. nov., Holotype (MNHN IM- 2013 - 86193) on black background (B), MNHN IM- 2013 - 86195 on black background (C), MNHN IM- 2013 - 86194 on black background (D) E Sclerodoris faninozi sp. nov., Holotype (MNHN IM- 2013 - 86198) on black background.

Figure 15. Drawing of the reproductive system of specimens of the genus Sclerodoris Eliot, 1904 A-C Sclerodoris tuberculata Eliot, 1904, MNHN IM- 2013 - 86197, general view (A), detail of the bursa copulatrix and seminal receptable (B), penial spines (C) D-F Sclerodoris faninozi sp. nov., Holotype (MNHN IM- 2013 - 86198), general view (D), detail of the bursa copulatrix and seminal receptable (E), penial spines (F) G " Sclerodoris " Sclerodoris dutertrei sp. nov., MNHN IM- 2013 - 86193. Abbreviations: ag, accessory gland; am, ampulla; bc, bursa copulatrix; dd, deferent duct; fg, female gland complex; pr, prostate; sr, seminal receptacle; vg, vagina.

Figure 16. SEM of the radula of specimens of the genus Sclerodoris Eliot, 1904 A-C Sclerodoris tuberculata Eliot, 1904, MNHN IM- 2013 - 86197, innermost teeth (A), mid-lateral teeth (B), outer lateral teeth (C) D-F " Sclerodoris " Sclerodoris dutertrei sp. nov., MNHN IM- 2013 - 86195, innermost teeth (D), mid-lateral teeth (E), outer lateral teeth (F) G-I Sclerodoris faninozi sp. nov., Holotype (MNHN IM- 2013 - 86198), innermost teeth (G), mid-lateral teeth (H), outer lateral teeth (I).