Comparative allometric growth of the gastrointestinal tract of two sympatric congeners, copper rockfish (Sebastes caurinus) and quillback rockfish (S. maliger)

Allometric growth of the stomach, intestine, and caeca was compared between two sympatric congeners, the copper rockfish ( Sebastes caurinus ) and the quillback rockfish ( S. maliger ), to examine the species-specific differences in their gut tract in relation to their general feeding habits. The intestine of copper rockfish was shorter and its mass less than the intestine of quillback rockfish. Copper rockfish also had a greater stomach mass and, on average, a greater number of pyloric caeca than quillback rockfish. The differences in the gut allometry between the species were consistent with differences in their general food habits as copper rockfish consume proportionally more fish and larger crustaceans than quillback rockfish.