Nudibranchia (Mollusca: Gastropoda) from San Matías Gulf, Northern Argentine Patagonia Author Cetra, Nicolás Escuela Superior de Ciencias Marinas (ESCiMar), San Martín 247, San Antonio Oeste, Río Negro, Argentina. Author Roche, Andrea Escuela Superior de Ciencias Marinas (ESCiMar), San Martín 247, San Antonio Oeste, Río Negro, Argentina. & Centro de Investigación y Transferencia Tecnológica en Recursos Marinos Almirante Storni (CIMAS), Güemes 1030, San Antonio Oeste, Río Negro, Argentina. text Zootaxa 2023 2023-02-22 5244 5 455 473 http://dx.doi.org/10.11646/zootaxa.5244.5.3 journal article 54187 10.11646/zootaxa.5244.5.3 bca5397b-9bb5-4b55-a9e0-302523ff937c 1175-5326 7663830 21F87739-7A95-4A6C-8887-A8E22A40120A Berghia rissodominguezi Muniain & Ortea, 1999 ( Figures 6A, 6B , 7A ) Material examined . Argentina , Río Negro , Caleta Los Hornitos , two specimens , intertidal, 23/02/2017 (ESCM-Ma-37) . Description . Length up to 30 mm . Body elongated, translucent white color, with oblique bright orange lines at the base of the cerata and rhinophores. Translucent cerata with white tip and a small, terminal cnidosac. Oral tentacles long, distal portion yellow. Rhinophores yellow ( Figure 6B ). Radular formula 25 x 0.1.0 (ESCM-Ma-37). Rachidian teeth bicurved with up to 45 denticles on each side of the central triangular cusp ( Figure 7A ). Geographic distribution and depth range . Western Atlantic, from Florida to San Jose gulf, Argentina ( Muniain & Ortea 1999 , Padula et al. 2011 ). Found in soft and intertidal bottoms under rocks up to 15 m depth. Biology . The white egg mass is a cylindrical belt with up to four complete turns in a spiral. The egg mass is deposited on rocks ( Figure 6B ). Remarks. This species was described and illustrated by Muniain & Ortea (1999) . It is a warm water species that extends its distribution to the Magallanes Province . This is the first record of the B. rissodominguezi in the San Matías gulf.