Maternal age, length, and weight influence larval characteristics and viability in the viviparous temperate reef fish Helicolenus percoides

Abstract

Mature age structure has been recognized as an important determinant of fecundity in fish populations. More recently it has been demonstrated that in some species, older, larger females can produce faster-growing and more viable larvae than younger, smaller females. We investigated this effect in sea perch Helicolenus percoides and collected information on fecundity as well as notochord length and oil globule volume (OGV) of larvae on the day of parturition, time to 50% mortality, and rate of change in length and OGV of cohorts of larvae in fed and unfed treatments. Absolute fecundity increased proportionally with maternal age and total length. Older, larger females produced cohorts of larvae with larger OGVs. These cohorts also had faster positive rates of change in length in the fed treatment than did cohorts of larvae produced by younger, smaller females. The OGV was positively correlated with rates of change in length and survival in the fed treatment; however, we did not detect influences on growth or survival in the unfed treatment. Further, cohorts of larvae in the unfed treatment had negative rates of change in length and lower survival compared to cohorts in the fed treatment. The results indicated that the OGV, which was affected by maternal age and size, was an important factor influencing larval growth and viability when external energy sources were available. These data provide insight into the reproductive biology of sea perch and highlight the importance of an old-growth age structure for effective larval viability and growth.