|The ascidians of Tossa de Mar (NE Spain) 2. Biological cycles of the colonial species|
Turon, X. (1988). The ascidians of Tossa de Mar (NE Spain) 2. Biological cycles of the colonial species. Cah. Biol. Mar. 29(3): 407-418
In: Cahiers de Biologie Marine. Station Biologique de Roscoff: Paris. ISSN 0007-9723, more
The ascidians from a locality on the Spanish NE coast were sampled from November 1984 until January 1986, with the aim of studying their biological cycles. Only the results concerning the colonial species are presented here. The samplings were performed twice a month, and the relative abundance, reproductive state and presence of resistance forms of the compound ascidian species were evaluated. Many species feature seasonal variations in abundance and even disappear from the samples in an unfavourable season. The reproductive periods are always restricted to a certain time of the year and they are strongly correlated with the biogeographical distribution of the species. The temperature appears as the main factor controlling ascidian reproduction.