Reproductive and Overwintering Adaptations in Northern Pike (Esox lucius L.): Balancing Essential Fatty Acid Requirements with Dietary Supply

Autor: Karl Schwalme
Rok vydání: 1994
Předmět:
Zdroj: Physiological Zoology. 67:1507-1522
ISSN: 0031-935X
DOI: 10.1086/physzool.67.6.30163909
Popis: In northern pike, ovarian recrudescence and membrane lipid restructuring occur during winter and may thereby create physiological requirements for essential fatty acids (EFAs) that surpass dietary EFA intake. Seasonal changes in the fatty acid composition of pike ovary and whole-body lipids and mass balance comparisons were used to identify mechanisms that during winter help balance physiological requirements for EFAs with the dietary supply. Mature ovaries of pike exhibited a polar lipid:neutral lipid ratio (70:30; based on the weight of fatty acids) much greater than that of somatic tissues (30:70), yet the fatty acid compositions of ovarian and somatic total lipids were quite similar. This similarity resulted from an adaptive reduction in the percentage of n-3 EFAs in ovarian neutral and polar lipids to levels lower than those typical of somatic lipids. Adaptive features of ovarian fatty acid composition, combined with significant reductions in the n-3 EFA content of somatic neutral lipids during winte...
Databáze: OpenAIRE