The ascidian fauna of a Jamaican lagoon: Thirty years of change

Abstract

The information on which this paper is based was obtained by visual surveys conducted by swimming along the shoreline, supplemented by collecting. The principal surveys were in April 1963, April 1966, April 1968, August 1977, Match 1984, Match 1987, May/June 1991 followed by regular monitoring from June 1991 to June 1992. Twenty-five species of ascidians have be recorded from the Fort Rocky Lagoon; three of these as follows are considered no further. Didemnum conchyliatum (Sluiter, 1898) is recorded from only the northern entrance to the lagoon over the entire period and is not considered as a component of the main lagoon. Polyandrocarpa tineta (Van Name, 1902) was recorded only once on a piece of floating bamboo carried into the lagoon as an adult colony. Styela plicata (Lesueur, 1823) was recorded once only (1963) as a single specimen and was not a normal component; at that time it was common elsewhere in Kingston Harbour. Of the remaining twenty-two (22) species eight (8) have disappeared since 1963 and two additional species have colonised; four other species have shown change in status. These changes are outlined below.