Gymnodoris boiteuxi De Souza-Canal & Valdés sp. nov.

urn:lsid:zoobank.org:act: 9C2462CA-8D11-4238-BBC0-7B5A4264AAD0

(Fig. 18L, 20E–F, 21B)

Type material. Holotype: New Caledonia: North Province: Koumac (20°40.2'S, 164°13.8'E), 3 m depth [Koumac 2.3 Expedition, stn. KS1069], 23 Nov 2019, 1 specimen 2 mm preserved length (MNHN-IM-2019-26469, isolate JD69).

Description. Body oval to elongate, covered with few, low, conical tubercles arranged in low density irregular pattern; velum distinct with three lateral tubercles on each side, continuing posteriorly into inconspicuous notal rim (Fig. 18L). Color dirty white, tubercles orange, small opaque white irregular lines/flecks all over dorsum. Interior organs visible through body wall as cream, white masses. Posterior end of foot translucent grey. Rhinophores bulbous, with 8 lamellae, clubs light brown, bases translucent white. Gill underdeveloped, with of 5 short, inconspicuous, opaque white, simple leaves.

Radular formula 6 × 7.0.7 the 2 mm preserved length holotype (MNHN-IM-2019-26469). Radular teeth hook-shaped, elongate with no denticles. Inner lateral teeth thinner and longer, becoming shorter and wider towards outer edge of half-row (Fig. 21B).

Reproductive system with an elongate, slightly curved ampulla, connecting to female gland complex, prostate (Fig. 20E). Prostate large, flattened, partially covering bursa copulatrix, narrowing into a highly convoluted, long deferent duct, opening into a common atrium with vagina. Vagina short, slightly curved, connecting into bursa copulatrix next to seminal receptacle connection. Bursa copulatrix spherical, about 10 time as large as pyriform seminal receptacle. Penial spines straight, elongate, with narrow bases (Fig. 20F).

Phylogenetic position. Gymnodoris boiteuxi sp. nov. is nested in a well-supported clade (PP: 1, MLB: 94) containing several other undescribed species: Gymnodoris sp. 17, Gymnodoris sp. 38, Gymnodoris sp. U and Gymnodoris sp. V, but the relationships among members of this clade are not fully resolved (Fig. 1A).

Etymology. This species is named in honor of Benoît Boiteux in appreciation for his help and support during the Koumac 2.3 expedition, when the holotype of this species was collected.

Remarks. Gymnodoris boiteuxi sp. nov. is a distinct species having few orange tubercles, a very small white gill and large bulbous rhinophores. Externally it is very different from other members of its clade, including Gymnodoris sp. 17, Gymnodoris sp. 38, Gymnodoris sp. U and Gymnodoris sp. V, not of which have this combination of characters.

Gymnodoris boiteuxi sp. nov. is similar to Gymnodoris fleuroti sp. nov., but the bulbous brown rhinophores of the former are very different from the conical, white and orange of the latter. Also, the general body shape and the radular morphology is very different, G. boiteuxi sp. nov. has a more rounded anterior end of the body and lacks the large, curved innermost lateral teeth characteristic of G. fleuroti sp. nov.