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

urn:lsid:zoobank.org:act: 6AFB4172-390A-4BEE-A6B7-C5A76341EA8C

(Figs. 16C–D, 17C–D, 18A)

Type material. Holotype: New Caledonia: South Province: St. Vincent Bay (21°59.5'S, 166°4.2'E), 6 m depth, 26 Jul 2022, 1 specimen 4 mm preserved length [rocky reef] (MNHN-IM-2019-26451, isolate JD149), leg. Y. Thévenet.

Description. Body narrow, elongate, with numerous, small conical to elongate tubercles of varying sizes. Velum distinct with 6 irregular protuberances/tubercles; notal rim absent, velum fuses with dorsum posteriorly (Fig. 18A). Color translucent dirty-white, tubercles red, red line edging velum; posterior end of foot translucent grey. Internal organs visible through body wall as orange, white masses. Rhinophores bulbous, with 8 lamellae, white with red tips. Gill with 12 small, simple, translucent leaves with opaque white bases, arranged in row anterior to anus. Foot narrower than notum, opaque white. Oral tentacles small, blunt.

Radular formula 11 × 12.0.12 the 6 mm preserved length holotype (MNHN-IM-2019-26451). Innermost lateral teeth small, hook-shaped, with curved, smooth cusps, broad bases (Fig. 16C). Other lateral teeth elongate, with narrow bases, long, slightly curved cusps (Fig. 16D).

Reproductive system with an ovoid, straight ampulla, connecting to female gland complex, prostate (Fig. 17C). Prostate large, flattened, curved around bursa copulatrix, narrowing into a convoluted deferent duct, opening into a common atrium with vagina. Vagina short, slightly curved, connecting into bursa copulatrix near seminal receptacle connection. Bursa copulatrix ovoid, about eight times as large as spherical seminal receptacle. Penial spines elongate (about 50–80 µm long), with very narrow bases (Fig. 17D).

Phylogenetic position. Gymnodoris bricei sp. nov. is the most basal member of a clade (PP: 1, MLB: 99) also including Gymnodoris cf. alba and Gymnodoris sp. X, which are sister to one another (PP: 1, MLB: 98). (Fig. 1A). This larger clade is sister (PP: 1, MLB: 99) to a monophyletic group (PP: 0.97, MLB: 79) including Gymnodoris sp. Y and Gymnodoris sp. 31. Other closely related species include Gymnodoris sp. 23, Gymnodoris sp. W, and Gymnodoris aurita, which were recovered in more basal positions of the same overall clade (PP: 0.95, MLB: 97) (Fig. 1A).

Etymology. This species is named after Brice De Souza-Canal, father of the first author of this paper, in appreciation for sharing his passion for the marine world as well as his curious and scientific mindset, which helped in the development of critical thinking and detail-oriented skills in the first author, leading her career path.

Remarks. Gymnodoris bricei sp. nov. is most similar to G. sp. Y as described by Knutson & Gosliner (2022), both species have elongate bodies with orange red spots and a line bordering the velum anteriorly. Differences include a conspicuous orange patch on the posterior end of the foot in G. sp. Y, absent in G. bricei sp. nov. Moreover, these two species were recovered in different groups in the species delimitation analyses and did not form a monophyletic group in the phylogenetic analyses.