Temperature and Maternal Effects on Hatch Rate and Length at Hatch of Hybrid Bass (White Bass × Striped Bass) Larvae

Abstract

AbstractBroodstock selection is an approach that could improve aspects of hybrid bass (white bass Morone chrysops × striped bass M. saxatilis) production. We examined incubation temperature and maternal effects on modal period of incubation (h), hatch rate, and length at hatch. Gametes from three to four white bass dams and one striped bass sire were used to produce hybrids each week for 4 weeks. Eggs from each dam were incubated at 14, 16, 18, and 20°C. The period of incubation, hatch rate, and length at hatch were determined for larvae from each dam × temperature combination. The relationship between incubation period and incubation temperature was exponential, and warmer temperatures resulted in progressively shorter incubation periods and less‐variable hatching duration (i.e., the period from first hatch to last hatch). The effects of incubation temperature and dam explained approximately equal amounts of the variability in length at hatch. Dam weight did not explain a significant amount of variability in modal incubation period, hatch rate, or average length at hatch. Selection for increases in length at hatch could offer improvements to the hybrid bass industry by improving survival in ponds or by eliminating the need for rotifers at first feeding in tanks. The benefits of producing larvae that are larger at hatch should be compared with the effort and cost of a breeding program that selects for length at hatch.