Assessing multiple mating and reproductive skew in three species of clinid fishes (Blenniiformes: Clinidae: Clinini), in reference to multiple mating in viviparous teleosts

This study investigated multiple mating in three species of intertidal klipfishes (family Clinidae): super klipfish <i>Clinus superciliosus</i>, bluntnose klipfish <i>Clinus cottoides</i>, and nosestripe klipfish <i>Muraenoclinus dorsalis</i>. These species display the rare reproductive mode of female vivipary with superfetation, a phenomenon where offspring at various stages of development are found within the female. Three or four microsatellite loci were used to genotype 25–30 adults of each species, as well as embryos of 131 <i>C. superciliosus</i> from six broods, 103 <i>C. cottoides</i> from six broods, and 63 <i>M. dorsalis</i> from five broods. The presence of multiple mating by females was assessed by maximum-likelihood sibship reconstruction implemented in the program COLONY, and the non-random distribution of reproductive success among individuals (reproductive skew) within broods was tested using the binomial skew index. Multiple mating by females was pervasive and observed in 83%, 100% and 80% of the broods of <i>C. superciliosus</i>, <i>C. cottoides</i> and <i>M. dorsalis</i>, respectively. The mean number of sires per brood was 4.3, 3.0 and 3.2, and, correspondingly, 5/5, 5/6 and 1/4 of multiply-sired broods showed significant reproductive skew in <i>C. superciliosus</i>, <i>C. cottoides</i> and <i>M. dorsalis</i>, respectively. The presence of pronounced reproductive skew may indicate post-copulatory processes taking place that bias paternity. We compared our results on multiple mating within the klipfish family, and with four other fish families that have vivipary with superfetation, and found the klipfish patterns were among those of live-bearing vertebrate groups with the highest average numbers of sires per brood.