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

urn:lsid:zoobank.org:act: 965D895F-C83C-46CE-AE1F-7FE9CBEBC16B

(Figs. 13C, 14C–D, 15A)

Type material. Holotype: New Caledonia: North Province: Poum, South Ilôt Yandé (20°4.57'S, 163°49.59'E), 0 m depth [ABC Poum Expedition, stn. ABC58], 20 Jun 2023, 1 specimen 4 mm preserved length (MNHN-IM-2019- 26428, isolate JD113).

Description. Body narrow, elongate, with several low conical tubercles mainly arranged around notal rim, a few on dorsum, velum. Velum differentiated with 12 tubercles, continuing posteriorly into notal rim (Fig. 15A). Color translucent white, tubercles orange-red, thin orange-red line connecting velum tubercles; posterior end of foot translucent. Internal organs visible through body wall as orange, white masses. Rhinophores conical, with 6 lamellae, white stalk, club, with orange tips. Gill inconspicuous, with of 6 small, simple, white leaves, arranged in a circle around anus, opened posteriorly. Foot narrower than notum, opaque white. Oral tentacles small, flattened.

Radular formula 15 × 7.0. 7 in the 4 mm preserved length holotype (MNHN-IM-2019-26428). Innermost lateral teeth large, hook-shaped, with curved smooth cusps (Fig. 13C). Other lateral teeth elongate straight, with short, curved cusps, becoming smaller towards outer edge of half-row (Fig. 13C).

Reproductive system with an elongate, broad, curved ampulla, connecting to female gland complex, prostate (Fig. 14C). Prostate large, tubular, curved around bursa copulatrix, narrowing into a highly convoluted deferent duct, opening into a common atrium with vagina. Vagina long, slightly curved, connecting into bursa copulatrix near seminal receptacle connection. Bursa copulatrix spherical, about 5 times as large as oval seminal receptacle. Penial spines small (about 50 µm long), triangular (Fig. 14D).

Phylogenetic position. The phylogenetic position of Gymnodoris fleuroti sp. nov. is unresolved due to low support values (Fig. 1A).

Etymology. This species is named in honor of Dominique Fleurot, naturalist, author of several floristic treaties, and coordinator of the ABC (Atlas de la Biodiversité Communale) project in Poum, New Caledonia. The ABC project is a large-scale biodiversity census operation centered in Poum, which produced the holotype of Gymnodoris fleuroti sp. nov. and many other species.

Remarks. Gymnodoris fleuroti sp. nov. is externally similar to Gymnodoris mariefranceae sp. nov., but these two species are genetically distinct, recovered in separate groups in the species delimitation analyses. Some differences are visible and appear to be consistent, the orange tubercles of G. mariefranceae sp. nov. are larger and more abundant on the center of the dorsum. Also, G. mariefranceae sp. nov. possesses a branched glandular structure visible at the posterior end of the foot. Internally, the two species are readily distinguishable by the shape of the penial spines, triangular in G. fleuroti sp. nov., elongated in G. mariefranceae sp. nov. The radulae of the two species are similar but G. fleuroti sp. nov. has less lateral teeth, more curve at the tip.