Gymnodoris deniseae De Souza-Canal & Valdés, 2025

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

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( Figs. 15J–O View FIGURE 15 , 16B View FIGURE 16 , 17A–B View FIGURE 17 )

Type material. Holotype: New Caledonia: North Province: Poum, Mouac Is. ( 20°12.84'S, 164°0.61'E), 0 m depth [ABC Poum Expedition, stn. ABC46 ], 18 Jun 2023, 4 mm preserved length (MNHN-IM-2019-26463, isolate JD136) GoogleMaps . Paratypes: New Caledonia: North Province: Poum, Mouac Is. ( 20°12.84'S, 164°0.61'E), 0 m depth [ABC Poum Expedition, stn. ABC46 ], 18 Jun 2023, 1 specimen 3 mm preserved length (MNHN-IM-2019-26464, isolate JD103); 1 specimen 3 mm preserved length (MNHN-IM-2019-26465, isolate JD111); 1 specimen 3 mm preserved length (MNHN-IM-2019-26466, isolate JD116) GoogleMaps . New Caledonia: North Province: Poum, Mouac Is. ( 20°13.02'S, 164°1.4'E), 0 m depth [ABC Poum Expedition, stn. ABC63 ], 21 Jun 2023, 1 specimen 4 mm preserved length (MNHN-IM-2019- 26467, isolate JD109); 1 specimen 3 mm preserved length (MNHN-IM-2019-26468, isolate JD101) GoogleMaps .

Description. Body narrow, elongate, with numerous, small conical tubercles. Velum distinct with 10 irregular protuberances/tubercles; notal rim absent, velum fuses with dorsum posteriorly ( Figs. 15J–O View FIGURE 15 ). Color translucent dirty-white to yellow, tubercles opaque yellow-orange with blurry edges, faint yellow orange line edging velum; posterior end of foot translucent grey. Internal organs hardly visible through body wall as orange, white masses. Rhinophores bulbous, with 9–10 lamellae, orange-brown. Gill with 10 small, simple, translucent leaves with opaque white bases, arranged in circle around anus, opened posteriorly. Foot wider than notum, opaque white. Oral tentacles small, blunt.

Radular formula 10 × 8.0. 8 in a 4 mm preserved length specimen (MNHN-IM-2019-26468). Lateral teeth slightly curved, with pointed, long, smooth cusps, broad bases ( Fig. 16B View FIGURE 16 ). All teeth similar in size. ( Fig. 16B View FIGURE 16 ).

Reproductive system with an elongate, slightly curved ampulla, connecting to female gland complex, prostate ( Fig. 17A View FIGURE 17 ). Prostate tubular, convoluted, narrowing into a highly convoluted deferent duct, opening into a common atrium with vagina. Vagina very long, slightly curved, connecting into bursa copulatrix near seminal receptacle connection. Bursa copulatrix spherical, about four times as large as ovoid seminal receptacle. Penial spines triangular to elongate (about 60–80 µm long), with relatively broad bases ( Fig. 17B View FIGURE 17 ).

Phylogenetic position. Gymnodoris deniseae sp. nov. is sister to Gymnodoris subornata Baba, 1960 (PP: 0.99, MLB: 99) but the position of this clade in the overall phylogeny of Gymnodoris is uncertain ( Fig. 1A View FIGURE 1 ).

Etymology. Denise Azuelos, educator, author, and outstanding collector, who found most of the specimens here studied and provided enormous help processing specimens during the Ouvéa and Poum “quinzaines.”

Remarks. Gymnodoris deniseae sp. nov. is sister to Gymnodoris subornata Baba, 1960 , but these two species were recovered as distinct in the species delimitation analyses based on the material examined by Knutson & Gosliner (2022). Externally, G. subornata resembles G. deniseae sp. nov. by having an elongate orange body with small conical tubercles and a distinct velum ( Baba, 1960). The radula of the two species is also similar, with elongate teeth with broad bases, but whereas in G. subornata Baba, 1960 the innermost teeth are much smaller than the rest in G. deniseae sp. nov. they are all similar in size.