BIOLOGICAL STUDIES ON SOME SPECIES OF SEA HARES (MOLLUSCA: 0PISTHOBRANCHIA) COLLECTED FROM THE RED SEA, EGYPT

Abstract

A rich mythology was surrounding the sea hares, Ijelated to the belief of their poisoning nature. The sea harehave many populations in the rocky shores of the Red Sealcoast. They stick firmly with their foot on the ventral surfaces1 of the small rocks to protect themselves from direct sunrays, /strong waves and predators. They acquired their popular nae "sea hares" from their unique property, at which they sit likela hare during contraction, and their tentacles much similar to ars of I hares. The sea hares are remarkable widely spread allover the world, where they were recorded from different partof the world, such as Californian coast, west and east Atlantic!ocean, Mediterranean and Red Seas, South African coast, !Indian ocean, Cuba, South Pacific and Hawaiian Island. I The sea hares have a great importance, where they secrete many of natural products from their digestive, opaline,! purple glands, and even from their bodies. In spite oftheiriwidely spread and economic importance, they did not attrhct the I attention of malacologists in Egypt. In the present study, five species of sea hares were collected from different JJcations along the Red Sea coast, from Safaga to Marsa Alatn.They were identifed as Aplysia dactylomela, Aplysia oc lifera, I Aplysia coringera, Dolabrifera dolabrifera and Pe'talifera petalifera. They belong to the genera, Aplysia, Dolabrlfera and Petalifera, which in tum belong to the subfamilies Aplysiinae and Dolabriferinae of the family Aplysiidae. i The present investigation entails, also with the iletailed study of important systems, which are: the reproauctive, digestive and nervous systems for the species Dolbbrifera . ' dolabrifera and Aplysia dactylomela. Also, The toxicij,y of the digestive gland was determined. 'I