Mating system of the rockfish, Sebastiscus marmoratus as revealed by DNA fingerprinting

Abstract

The mating system of the viviparous rockfish, Sebastiscus marmoratus was studied using aquarium mating experiments and paternity testing by DNA fingerprinting. Individually specific DNA fingerprints were produced and the paternal relationships determined with the use of the restriction enzyme HinfI and the DNA probe (CAC)₅. Two types of mating experiments, multiple-male and single-male, were set up to investigate the effect of male sizes on their mating success, as determined by number of females fertilized. Male size was positively and significantly related to mating success in the multiple-male situation in which male–male interaction was present, but not in the single-male situation in which no male–male interaction was involved. Females produced one to seven batches of larvae, and all batches from individual females had identical paternity. Most females were fertilized by a single male but one case of multiple paternity was detected. The laboratory study suggested the principal mating system of S. marmoratus to be promiscuity, although multiple mating by females was uncommon.