DIE HYDROIDEN DER CIÉNAGA GRANDE DE SANTA MARTA (KOLUMBIEN) UND EINIGES ZU IHRER OKOLOGIE

Abstract

Two brackish water hydroids exist in the Ciénaga Grande de Santa Marta: Calyptospadix cerula Clarke, 1882 and Cordylopbora caspia Pallas, 1771. C. caspia, found so far only in the canal of Los Cocos, is completely developed in a salinity range of 0-10 %o. C. cerula is euryhaline. It is found in a salinity range from 3 %o up to normal marine conditions. Below 3 %o it changes into the menontphase. The change in activity of both species depends on salinity and probably on temperature. C. caspia is fertile during the fresh water period, whereas for C. cerula gonosome have been found from the beginning of June to the end of September. At a salinity of more than about 20 %o other marine hydroids like Laomedea bicuspidata Clarke, 1875 and Laomedea tottoni Leloup 1935 also enter the Ciénaga. For these two species no gonothecae have been observed so far.