Gymnodoris nigricolor Baba, 1960

(Figs. 7A–B)

Gymnodoris nigricolor Baba, 1960: 72, pl. 5, figs. 1A–B. Type locality: Misaki, Sagami Bay, Japan.

Material examined. New Caledonia: North Province: Koumac, East of Karembé (20°39.6'S, 164°17.5'E), 2–5 m depth [Koumac 2.1 Expedition, stn. KR636, sandy bottom], 27 Sep 2018, 1 specimen 5 mm preserved length (MNHN IM-2019-26208, isolate JD67). New Caledonia: North Province: Koumac, Channel between Tangadiou Islet and Magone (20°33.9'S, 164°13.2'E), 7–8 m depth [Koumac 2.1 Expedition, stn. KR224, compact mud bottom, sandier near the reef], 20 Sep 2018, 1 specimen 6 mm preserved length, dissected (MNHN IM-2019-26209, isolate JD27).

Description. Body elongate, smooth, lacking tubercles (Figs.2A–B).Velum and notal rim hardly distinguishable; posterior end of foot narrowing into a pointy “tail.” Body color velvet black, with blurry neon-blue lines visible on mantle margin under certain light conditions. Rhinophores and branchial leaves with same color as dorsum. Rhinophores short, triangular, fused together at base. Rhinophoral club occupying entire visible length, with six transverse lamellae. Gill composed of 10–11 simple leaves, arranged in a circle.

Phylogenetic position. Gymnodoris nigricolor is sister to G. nagoensis (PP: 1, MLB: 100) and appears to be closely related to G. boussionae, but this relationship is not supported (PP: 1, MLB: <50) (Fig. 1A).

Remarks. This species has been recently re-described and characterized by De Souza-Canal et al. (2025).