Ostracod Communities Research Articles

Repeated samples from a deep midwater planktonic ostracod community

Ten repeated horizontal hauls with a modified Indian Ocean net fitted with a catch dividing device were taken at a depth of 550 m off Fuertaventura. The planktonic ostracods from these hauls have been examined. Thirty-one species were identified, eleven in average numbers of 10/haul. Coefficients of variation were higher for the individual species than for the total ostracods. The coefficients of variation were substantially reduced if the percentage species compositions were analysed, suggesting that the patchiness of the constituent species is related in part to the patchiness of the overall population. Analyses showed that the distributions were non-random, but it was considered that too few samples had been taken to fit contagious distributions. Correlation coefficients showed that the ostracods were divided into three main groups of species which were inter-correlated at the 1% level. Species diversity indices indicated that the population showed a very close fit to MacArthur's ‘broken stick’ model, which suggests that, despite the effects of diurnal vertical migration, the community was ecologically highly organized and stable. Spearman Rank tests on the order of species abundance in each haul showed that the order of species abundance was a significantly consistent measure of the community sampled. Order of species abundance may, therefore, prove a useful method of analysing plankton communities, even from single plankton samples.

Preliminary notes on the Ostracoda of the Mediterranean coast of Israel : Lerner-Seggev Ruth, 1965. Israel J. Zool., 13 (4): 145–176.

ABSTRACT The present work is the first study on the Ostracoda of the Mediterranean coast of Israel. The first part includes the description of 9 species, two of which: Cytherella pori n.sp., and Bairdia incognita n.sp., are new to science. In the second part, preliminary notes are given on the Ostracod communities of the different biotopes, from the eulittoral down to the bathyal.