Biogeographic and phylogenetic data on the deep-sea isopod family Ilyarachnidae (Paraselloidea) d... more Biogeographic and phylogenetic data on the deep-sea isopod family Ilyarachnidae (Paraselloidea) document its origin and evolutionary radiation in the deep sea. The distribution of eyes among paraselloidean families suggests an in situ evolution for all those families which have primarily deep-sea distributions. Presentday distributions of paraselloidean isopods provide no hints to their ultimate sources in shallow water. These findings contrast to recent suggestions in the literature that the deep-sea isopod fauna has been derived from shallow Antarctic waters.
NEMATODA ABSTRACT - Although it has been proposed that tail shapes could be used as DEEP-SEA BENT... more NEMATODA ABSTRACT - Although it has been proposed that tail shapes could be used as DEEP-SEA BENTHOS the basis for ecologically useful functional groups of nematodes, the proposition has not been tested. We used data from three sites in the deep North Atlantic for such a test. In a pretest, we found that nematode functional groups based on buccal morphology differed significantly in their proportional representation among the sites, indicating that for nematodes the sites differed ecologically. Results of similar tests involving tail-shape groups were significant, indicating that there is ecological information in the tail-shape groups, and a further test revealed that the information in the shape of the tail was not a simple reflection of information in the buccal- morphology groups. Distribution of functional groups formed by combining tail shape and buccal morphology also differed significantly among sites. We conclude that both the tail-shape and buccal-morphology-by-tail-shape ...
Biogeographic and phylogenetic data on the deep-sea isopod family Ilyarachnidae (Paraselloidea) d... more Biogeographic and phylogenetic data on the deep-sea isopod family Ilyarachnidae (Paraselloidea) document its origin and evolutionary radiation in the deep sea. The distribution of eyes among paraselloidean families suggests an in situ evolution for all those families which have primarily deep-sea distributions. Presentday distributions of paraselloidean isopods provide no hints to their ultimate sources in shallow water. These findings contrast to recent suggestions in the literature that the deep-sea isopod fauna has been derived from shallow Antarctic waters.
NEMATODA ABSTRACT - Although it has been proposed that tail shapes could be used as DEEP-SEA BENT... more NEMATODA ABSTRACT - Although it has been proposed that tail shapes could be used as DEEP-SEA BENTHOS the basis for ecologically useful functional groups of nematodes, the proposition has not been tested. We used data from three sites in the deep North Atlantic for such a test. In a pretest, we found that nematode functional groups based on buccal morphology differed significantly in their proportional representation among the sites, indicating that for nematodes the sites differed ecologically. Results of similar tests involving tail-shape groups were significant, indicating that there is ecological information in the tail-shape groups, and a further test revealed that the information in the shape of the tail was not a simple reflection of information in the buccal- morphology groups. Distribution of functional groups formed by combining tail shape and buccal morphology also differed significantly among sites. We conclude that both the tail-shape and buccal-morphology-by-tail-shape ...
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