| Morphological differences associated with sex or stage, together with total lipids and carotenoids, were studied in Euphausia superba as possible indicators of physiological condition. E. superba displays sexual dimorphism during growth. A group of mature males, called Males II herein, has a greater abdominal length, suggesting that they are faster swimmers, a feature implying higher metabolic rates and a higher demand for protecting pigments like carotenoids. Mature Males II have proportionally lower lipids but higher total lipid-soluble carotenoids, a counterintuitive finding. Males II also have bigger eyes. Significant regressions with carotenoids were found for wet weight, abdominal length, and eye diameter. On a spatial analysis, population... |
