Lipid class composition of the viviparous yellowtail rockfish over a reproductive cycle

Abstract

Triacylglycerols (TAG) were the dominant lipids in liver tissue of both sexes of the viviparous yellowtail rockfish Sebastes flavidus during the spring and summer when greatest feeding occurred. Significant declines in liver TAG during the winter corresponded to increased concentrations of polar lipids (PL), the main component of cell membranes. Elevated PL in female livers relative to those of males preceded the period of ovarian enlargement and may be attributed to the production of vitellogenin. During late vitellogenesis and gestation, ovaries contained significantly elevated concentrations of PL, TAG, and cholesterol. Since yellowtail rockfish are highly fecund and viviparous, large quantities of ovarian PL are required for proliferation of the cell membranes in developing larval tissues. TAG accumulated in ovaries in lower concentrations than PL and were likely metabolized as the main source of energy during gestation. This pattern of ovarian PL concentrations exceeding those of TAG and the presence of oil globules, may be unique to highly fecund, viviparous teleosts and signify an alternative profile to those previously documented for oviparous species. Testes at maximum I G were only 7% of maximum ovarian size, composed of mainly PL, and lacked a defined lipid dynamic pattern across the reproductive cycle. 1999 The Fisheries Society of the British Isles

Body lipid and fatty acid composition in male gilthead seabream broodstock at different stages of the reproductive cycle: effects of a diet lacking n-3 and n-6 HUFA

“…In the present study, liver TAG were particularly elevated during spermatogenesis and declined at the end. This confirms the role of the liver as the major storage site of lipids in gilthead seabream, with data similar to those obtained in other teleosts such as cod ( Gadus morhua ) (Tocher & Harvie 1988) or yellowtail rockfish ( Sebastes flavidus ) (Norton & MacFarlane 1999). The high accumulation of fatty acids in liver NL between November and March and their subsequent decrease in June when spermatogenesis is complete indicates the importance of these fatty acids not only as a source of energy to meet the energy demands of the gonad during spermatogenesis, but also as a structural reserve.…”

“…1984), Arctic charr ( Salvelinus alpinus ) (Jorgensen et al. 1997), herring ( Clupea harengus ) (Henderson & Almatar 1989) and yellowtail rockfish ( Sebastes flavidus ) (Norton & MacFarlane 1999). The results show that in fish fed the control diet (diet C) and those fed the HUFA‐deficient diet (diet D), the lipid content of the gonad was high between November (pre‐spermatogenesis) and March (spermatogenesis).…”

Seasonal changes in haematology and metabolic resources in the tench

“…data). Similar results have been published for the yellowtail rockfish Sebastes flavidus (Ayers) (Norton & MacFarlane, 1999). The liver gains mass during postspawning, when intensive food intake generally occurs in male and female tench, similar to the pattern observed in Arctic charr (Jobling et al ., 1998).…”

Seasonal changes in reproductive and physical condition, sexual dimorphism, and male mating tactics in the jewelled blenny Salarias fasciatus

“…To examine seasonal variation in physical condition and the relationship between reproduction and physical condition, Fulton's condition factor (K) was calculated as: K = (BM -VM)/SL 3 . In fish, the liver is an important organ for storage of proteins and lipids and synthesis of vitellogenin, the precursor of oocyte yolk, and seasonal variation in liver mass is associated with reproductive effort (e.g., Htun-Han 1978;Podroschko et al 1985;Santos et al 1996;Norton and MacFarlane 1999). To examine seasonal variation in liver mass, the hepatosomatic index (HSI) was calculated according to the following formula: HSI = LM/(BM -VM ?…”