Aspects of the Natural History of the Harpacticoid Copepods of San Diego Trough

Abstract

In samples from San Diego Trough (32 35.75' N, 117 29.00' W, 1,220-m depth), there were significantly more sig- nificant correlations between pairs of harpacticoid copepod species than expected by chance. Of these, significant positive correlations were significantly more frequent than negative correlations. By sum- ming the per station abundances for pairs of significantly positively correlated species, it was shown that these correlations appear to be shared responses to five classes of biogenous structures. Also, species with morphological features suggesting that they were functionally similar were combined into groups, i.e., a sediment-covered group, an interstitial group, and a burrowing group. There was no evidence to suggest that the per-core abundance of these functional groups covaried with the per-core volume of classes of biogenous structures. However, the existence of large, apparently surface-dwelling species from three families that covered their dona with mud suggested that these species had adapted to a strong selective pressure. The mud covering seems capable of minimizing predation by particle-by- particle feeders, implying that selective predation is an important ecological force acting on deep-sea harpacticoids. Of the models proposed to explain diversity maintenance in the deep sea, those that Contribution number 17 from Expedition Quagmire