Nudibranchia (Mollusca: Gastropoda) from San Matías Gulf, Northern Argentine Patagonia Cetra, Nicolás Roche, Andrea Zootaxa 2023 2023-02-22 5244 5 455 473 5WK3R 1287632 Muniain & Ortea, 1999 Muniain & Ortea 1999 [151,755,1579,1606] Gastropoda Aeolidiidae Berghia Animalia Nudibranchia 11 466 Mollusca species rissodominguezi  ( 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 mdepth.   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. rissodomingueziin the San Matías gulf. 4035853315 2017-02-23 Argentina Rio Negro Caleta Los Hornitos 11 466 1