May 1, 2006
From: Cristian Magnani
Recently we witnessed a massive presence of a nudibranch that was identified as Onchidoris neapolitana by Lucas Cervera ( thanks Lucas for your help!)
Since I wasn't able to find any picture of this animal I thought it would be nice to share these ones with other enthusiasts. They are easily found on their food bryozoan, as shown in pictures
Locality: Numana, 10 metres, Italy, Adriatic sea, 15 April 2006, Shipwreck. Length: 5 - 10 mm. Photographer: Cristian Magnani.
Magnani C., 2006 (May 1) Onchidoris neapolitana from the Adriatic Sea. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/16434
Thanks for this new species for the Forum. It looks a bit like a red variety of Onchidoris depressa. Your animals have certainly been eating through this red bryozoan colony and are filling the white spaces with their eggs. The white spaces are areas of the colony where the nudibranch has eaten off all the red animal tissue leaving only the calcified skelelton. Ros (1975) lists quite a few species of bryozoans as their food, including species of Chorizopora, Cribrilaria, Escharina, Microporella, Parasmittina, Schismopora, Schizobrachiella, Schizomavella, Schizoporella, Smittoidea and Tubulipora.Sanchez-Santos (2005) reports it feeding on the red bryozoan Schizobrachiella sanguinea, which is possibly the bryozoan in your photos.
It's good to get the photos of the egg ribbons.
Ros, J. (1975). Opistobranquios (Gastropoda: Euthyneura) del litoral ibérico. Investigación Pesquera (Consejo Superior de Investigaciones Cientificas, Patronado Juan de la Cierva, Barcelona ), 39(2): 269-372, pls. 1-4.
Sanchez-Santos, A. (2005) Onchidoris neapolitana (Delle Chiaje, 1844) (Gastropoda: Nudibranchia: Onchidorididae): una nueva especie de molusco para la fauna andaluza. Iberus, 23: 43-48.