Gymnodoris sp.

Souza-Canal, Jade De & Valdés, Ángel, 2025, The genus Gymnodoris Stimpson, 1855 (Mollusca, Nudibranchia) in New Caledonia, with descriptions of eleven new species, Zootaxa 5710 (1), pp. 1-73 : 53

Gymnodoris sp. 51

( Fig. 12G )

Material examined. New Caledonia: North Province: Koumac ( 20°41.1'S, 164°16.5'E), 10 m depth [Koumac 2.3 Expedition, stn. KS517 ], 20 Nov 2019, 1 specimen 4 mm preserved length (MNHN-IM-2019-26481, isolate JD73) .

Description. Body oval to elongate, dorsum irregular, lacking true tubercles ( Fig. 12G ). Velum slightly differentiated smooth, tapering anteriorly, continuing posteriorly into notal rim. Posterior end of foot broad, tapering into blunt “tail.” Color dirty-white, with irregular opaque white pigment, various irregular yellow spots, flecks. Rhinophores bulbous with 9 transverse lamellae, club yellow antero-distally, opaque white postero-proximally, stalk translucent white. Gill with 6 bipinnate, translucent white leaves, with yellow rachises, arranged in transverse row. Foot narrower than notum, translucent white. Oral tentacles small, blunt, edged in yellow.

Phylogenetic position. The phylogenetic position of Gymnodoris sp. 51 is poorly supported ( Fig. 1A ).

Remarks. This widespread species is highly variable in color (from yellow to red), and characterized by a white patch between the rhinophores as well as a series of opaque white pustules and longitudinal red-orange lines ( Gosliner et al., 2018). Reported from Malaysia and Papua New Guinea by Knutson & Gosliner (2022).

Figures

FIGURE 1. A. Bayesian consensus phylogenetic tree of the concatenated dataset including PP above branches and MLB below branches. Branches fully supported (PP: 1, MLB: 100) marked with asterisks. New species described in this paper highlighted in red font and illustrated; other species reported from New Caledonia in this study highlighted in blue font. Clades are collapsed according to the results of the ASAP and bPTP species delimitation analyses. B. Histogram representing the distance plot from the ASAP analysis using the COI gene showing pairwise p-distances (Kimura 2 model) among candidate species. The dashed line represents the distance threshold provided by the lowest ASAP score for species delimitation.

FIGURE 12. Gymnodoris sp. 15, Gymnodoris sp. 16, Gymnodoris sp. 34, Gymnodoris sp. 51, and Gymnodoris knutsonae sp. nov., photographs of live animals showing color variation. A. G. sp. 15, specimen from Nouméa, New Caledonia (MNHN-IM- 2019-26462, isolate JD86). B. G. sp. 16, specimen from Koumac, New Caledonia (MNHN-IM-2019-26430, isolate JD45). C. G. sp. 16, specimen from Koumac, New Caledonia (MNHN-IM-2019-26429, isolate JD34). D. G. sp. 34, specimen from Koumac, New Caledonia (MNHN-IM-2019-26453, isolate JD163). E. G. sp. 34, specimen from Nouméa, New Caledonia (MNHN-IM- 2019-26454, isolate JD145), photo Y. Thévenet. F. G. sp. 34, specimen from New Caledonia: Loyalty Is.: Ouvéa, (MNHN-IM- 2019-26517, isolate JD184). G. G. sp. 51, specimen from Nouméa, New Caledonia (MNHN-IM-2019-26481, isolate JD73). H. G. sp. 53, specimen from Nouméa, New Caledonia (MNHN-IM-2019-26414, isolate JD79). I. G. knutsonae sp. nov., paratype, Koumac, New Caledonia (MNHN-IM-2019-26382, isolate JD64). J. G. knutsonae sp. nov., paratype Koumac, New Caledonia (MNHN-IM-2019-26380, isolate JD53). K. G. knutsonae sp. nov., holotype, Koumac, New Caledonia (MNHN-IM-2019- 26381, isolate JD60).