Patterns of Resource Partitioning in Searobins (Pisces: Triglidae)

Eight species of searobins are common on the West Florida Shelf between Tampa and Fort Myers. All have the same mouth shape; the principal differences between species are relative mouth size and adult body size. Cluster analysis of searobins based on prey similarity indicated two principal species groups corresponding, in part, to inshore and offshore distribution patterns. Searobins showed two adult feeding modes based on prey size utilization. A scitulus mode was shown by Prionotus scitulus, Bellator militaris, P. martis and P. roseus, in which at least 70% of the adult diet was made up of prey 10 mm or smaller. A tribulus mode was shown by P. alatus, P. tribulus, P. ophryas and P. salmonicolor, in which prey larger than 10 mm made up 66% of the adult diet. Scitulus mode predators had significantly greater percent relative abundances than tribulus mode predators. The dominant method of resource partitioning was macrohabitat partitioning. At high levels of overlap there was evidence of partitioning by prey size.