Allozyme polymorphisms permit the identification of larval and juvenile rockfishes of the genus Sebastes

Abstract

ManySebastes larvae lack distinguishing morphological characteristics, particularly in the size range of 8–12 mm. Complete descriptions are available for only about 12 of the 72 northeastern Pacific species. Allozyme analysis has been very useful in the identification of adultSebastes, and our objective was to determine whether it could be equally useful in the identification of larvae and juveniles. Individually dissected tissues (muscle, liver, eye, heart) were assayed fromSebastes juveniles (>30 mm total length (TL)). The allozyme activity and resolution from the juveniles for 33 loci were indistinguishable from those obtained from adults. Larvae (5–12 mm TL) were prepared whole, and their allozyme expression varied by individual size and locus. A total of 32 loci were resolved from the larger (9–12 mm TL) larvae, but the allozyme activity was reduced in smaller (5–8 mm TL) larvae. Adequate resolution from the smaller larvae was obtained for 28 loci, a sufficient number to identify individuals to species. Allozyme analysis is a valuable technique to identify the species ofSebastes larvae and to aid in developing morphological and meristic descriptions. Other DNA-level techniques will likely further increase our ability to identifySebastes larvae.