Sea slug night fever: 39 new records of elusive heterobranchs in the western Mediterranean (Mollusca: Gastropoda) Salvador, Xavier Fernández-Vilert, Robert Moles, Juan Journal of Natural History 2022 2022-05-18 56 5 - 8 265 310 4J8LF (Schmekel, 1965) Schmekel 1965 [391,924,1148,1174] Gastropoda Piseinotecidae Piseinotecus Animalia Nudibranchia 21 286 Mollusca species sphaeriferus  ( Figure 4(f))   Material examined   Punta del Romaní, l’Escala, Girona (Catalunya), 42°6 ʹ53.088”N, 3°10 ʹ6.765”E,  8 November 2014, 1 spc.;  Le Ponton, Étang de Thau, Sète( France), 43°25 ʹ28.5”N, 3°42 ʹE,  20 May 2018,  0.4 mdepth, 1 spc., adult, L = 13 mm.  External morphology Body elongate, narrow, background colour transparent white. Rhinophores and oral tentacles smooth, translucent with white spots. Cerata smooth, background colour white or beige, base with a green iridescent sphere at their base; first and second row of cerata connected with a dark line.   Ecology The singleton specimen was found on the hydrozoan  Obeliasp.at night. Distribution  Ghana( Edmunds 1977); Portugal( Cervera et al. 2004); Italyand Adriatic Sea ( Zenetos et al. 2016); Spain: Canary Islands( Ortea et al. 2003), Catalonia(GROC 2009–2021; Ballesteros et al. 2016); France(this study).   Remarks This elusive species is easily diagnosed by an iridescent green sphere at the base of the cerata ( Ortea et al. 2003). Family TRINCHESIIDAE F. Nordsieck, 1972 Genus  TenelliaA. Costa, 1866 3819588320 2014-11-08 42.114746 Punta del Romani 1 3.168546 21 286 1 3819588376 2018-05-20 Le Ponton & Sete France 4 43.424583 Etang de Thau 672 3.7 21 286 1