Effects of Maternal Growth on Fecundity and Egg Quality of Wild and Captive Atka Mackerel (Pleurogrammus monopteyrius)

Tradeoffs in energy allocation between growth and reproduction can result in variation of the reproductive potential in fish with differing growth patterns.  We examined variation in the reproductive potential of Atka mackerel (Pleurogrammus monopterygius) by studying the effect of differential growth and condition patterns on fecundity, atresia, and egg energy.  Fecundity and egg energy were determined from two geographic areas in the Aleutian Islands, Alaska: Seguam Pass and Amchitka Island, and compared to those of fish held in captivity.  Atka mackerel showed distinct growth and condition differences with weight at length and length at age being the highest for captive fish, intermediate at Seguam Pass, and smallest at Amchitka Island.  For wild fish, potential and realized fecundity at length or age were significantly higher at Seguam Pass than at Amchitka whereas the fecundity at weight, atresia, and batch fecundity did not differ by area.  Egg dry weight of captive fish was higher than for wild fish, whereas batch order did not significantly affect egg dry weight. Increased potential fecundity, realized fecundity, and egg quality in Atka mackerel females was strongly related to body size, indicating that growth differences and maternal feeding success impact fecundity and egg quality of Atka mackerel.