Austinograea hourdezi Guinot & Segonzac 2018

Austinograea hourdezi Guinot & Segonzac, 2018 Austinograea hourdezi Guinot & Segonzac, 2018: 880, figs 3A; 4A-E; 5A-H; 6A-E; 7A-H. — Lee et al. 2019a: fig. 1B, D. — Chabert 2021: table 2. MATERIAL EXAMINED. — 3 ♀ 28.0 × 44.1 mm, 28.6 × 44.6 mm, 25.0 × 38.6 mm; Lau Basin, Tow Cam; PL730 – Panier; 20°19.080’S, 176°8.264’W; 2710 m; 26.IV.2019; CHUBACARC 2019 cruise; Hourdez det. Austinograea; MNHN-IU-2024-6023. REMARKS The Tow Cam Site in the Lau Basin is the type locality of Austinograea hourdezi, a widespread species in the southwestern Pacific, found in numerous vent fields of the Lau and North Fiji Back-Arc Basins (Guinot & Segonzac 2018: 80). In a still from the video 190527174907236_15_1080 https://video.ifremer.fr/index) of the La Scala vent Field, PL738 (Fig. 8A), A. hourdezi is easily recognised by the thick patch of setae on the inner surface of the chelipedal palm: its presence is confimed in the Woodlark Basin at the La Scala vent Field, where it coexists with A. chubacarc n. sp. Chabert (2021: table 2), using a barcode approach with the cytochrome c oxidase subunit I (COI) gene, identified Austinograea aff. hourdezi in the Woodlark Basin, and A. hourdezi in the North Fiji. In addition, she identified A. aff. williamsi in the Manus and Lau Basins, but we cannot determine which species they correspond to. S. Hourdez plans to carry out the correspondence between these genetic results and the different bythograeid species, after the publication of this paper (pers. comm.). We did not identify A. williamsi among the bythograeids collected during the CHUBACARC 2019 cruise, and so far the species appears to be endemic to the Mariana Trough, a back-arc basin in the northwest Pacific (Fig. 1) (Kojima & Watanabe 2015). Lee et al. (2019a), who determined the COI sequence of Austinograea hourdezi from three hydrothermal vent regions in the North Fiji Basin, found that all were identical. Lee et al. (2019b: 10, tables 3, 4, S1 table) obtained sequences of two mitochondrial genes (COI and 16S rDNA) of the species.