Life cycles of Phialella zappai n. sp., Phialella fragilis and Phialella sp. (Cnidaria,Leptomedusae, Phialellidae) from central California

The life cycles of three species of Philadella from central California (Phialella zappai n. sp., P. fragilis and P. sp.) are described. The three species have similar hydroids, with similar ecology. The medusae are very distinctive in both morphology and biology. Phialella sp. is delicate and difficult to rear; P. fragilis has a limited growth; and P. zappai shows precocious gonad maturation and continuous growth, with the possibility of becoming sexually mature more than once in its life. An interpretation of these phenomena suggests that the hydroids are basic, less varied, larval stages, as the medusae are the adults.