Gymnodoris sp.

Gymnodoris sp. X

( Fig. 9K View FIGURE 9 )

Material examined. New Caledonia: North Province: Poum, East of Ilôt Yandé ( 20°2.57'S, 163°49.73'E) [ABC Poum Expedition, stn. ABC61, island slopes], 20 Jun 2023, 1 specimen 1 mm preserved length (MNHN-IM-2019- 26423, isolate JD108) GoogleMaps .

Description. Body narrow, elongate, with several low, conical tubercles ( Fig. 9K View FIGURE 9 ). Anterior end of notum with distinct velum having 12 small tubercles; notal rim absent, velum merges with notum behind rhinophores. Posterior end of foot broad, tapering into pointy “tail.” Color translucent white, tubercles opaque yellow; posterior end translucent. Internal organs visible through body wall as brown, white masses. Rhinophores conical with 7 lamellae, with same color as body, yellow tips. Gill with 7 short, simple leaves, translucent white, opaque white bases, arranged in circle around anus, opened posteriorly. Foot narrower than notum, translucent yellow. Oral tentacles small, blunt.

Phylogenetic position. Gymnodoris sp. X is sister to Gymnodoris cf. alba (PP: 1, MLB: 98) and nested in a well-supported clade (PP: 1, MLB: 99) also including Gymnodoris bricei sp. nov. ( Fig. 1A View FIGURE 1 ).

Remarks. Gymnodoris sp. X is similar to the preceding species ( Gymnodoris sp. V) but lacks the glandular structure posterior to the gill and has larger tubercles and yellow rhinophoral tips.

Knutson & Gosliner (2022) illustrated as Gymnodoris sp. X the same specimen identified as Gymnodoris alba in Gosliner et al. (2018). This specimen, however, appears somewhat different from the material here examined, which was recovered as conspecific with Gymnodoris sp. X in the species delimitation analyses. Differences include larger tubercles and branchial leaves in the specimen illustrated by Gosliner et al. (2018) and Knutson & Gosliner (2022) in comparison to the material here examined.