Peer Review #2 of "Life histories predict genetic diversity and population structure within three species of octopus targeted by small-scale fisheries in Northwest Mexico (v0.2)" [peer_review]

2018 unpublished
The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to date the specific composition of the catch has been ignored. With at least three main species targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological information about the distribution, metapopulation size and structure of each species could impede effective fisheries management to avoid overexploitation. We tested if different life histories of three
more » ... stories of three species of octopus could help predict observed patterns of genetic diversity, population dynamics, structure and connectivity and how this information could be relevant to the sustainable management of the fishery. We sequenced two mitochondrial genes and genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 locations from the Gulf of California and the west coast of the Baja California peninsula. We tested five hypotheses derived from population genetic theory based on differences in the fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides with low fecundity and direct development (without a planktonic phase) had lower average effective population size and genetic diversity, but higher levels of kinship, population structure, and richness of private alleles, than the other two species. These features indicated limited dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher fecundity and planktonic phase as paralarvae had higher effective population size and genetic diversity, and overall lower kinship and population structure than O. bimaculoides. These observations supported higher levels of gene flow over a larger geographical scale. O. bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal potential had differences in the calculated parameters possibly associated with increased PeerJ reviewing PDF | Manuscript to be reviewed connectivity. We propose O. bimaculoides is more susceptible to over exploitation of small, isolated populations and could have longer recovery times than the other two species. This species may benefit from distinct fishery management within each local population. O. bimaculatus and O. hubbsorum may benefit from fishery management that takes into account metapopulation structure over larger geographic scales and the directionality and magnitude of larval dispersal driven by ocean currents and population connectivity among individuals of each locality. The distribution of each species and variations in their reproductive phenology is also important to consider when establishing marine reserves or seasonal fishing closures. PeerJ reviewing PDF | ABSTRACT 20 The fishery for octopus in Northwest Mexico has increased to over 2,000 tons annually, but to 21 date the specific composition of the catch has been ignored. With at least three main species 22 targeted by artisanal fisheries in the region with distinct life histories, the lack of basic biological 23 information about the distribution, metapopulation size and structure of each species could 24 impede effective fisheries management to avoid overexploitation. We tested if different life 25 histories of three species of octopus could help predict observed patterns of genetic diversity, 26 population dynamics, structure and connectivity and how this information could be relevant to 27 the sustainable management of the fishery. We sequenced two mitochondrial genes and 28 genotyped seven nuclear microsatellite loci to identify the distribution of each species in 20 29 locations from the Gulf of California and the west coast of the Baja California peninsula. We 30 tested five hypotheses derived from population genetic theory based on differences in the 31 fecundity and dispersal potential for each species. We discovered that Octopus bimaculoides 32 with low fecundity and direct development (without a planktonic phase) had lower average 33 effective population size and genetic diversity, but higher levels of kinship, population structure, 34 and richness of private alleles, than the other two species. These features indicated limited 35 dispersal and high local recruitment. In contrast, O. bimaculatus and O. hubbsorum with higher 36 fecundity and planktonic phase as paralarvae had higher effective population size and genetic 37 diversity, and overall lower kinship and population structure than O. bimaculoides. These 38 observations supported higher levels of gene flow over a larger geographical scale. O. 39 bimaculatus with the longest planktonic paralarval duration and therefore larger dispersal 40 potential had differences in the calculated parameters possibly associated with increased 41 connectivity. We propose O. bimaculoides is more susceptible to over exploitation of small, PeerJ reviewing PDF | Manuscript to be reviewed 42 isolated populations and could have longer recovery times than the other two species. This 43 species may benefit from distinct fishery management within each local population. O. 44 bimaculatus and O. hubbsorum may benefit from fishery management that takes into account 45 metapopulation structure over larger geographic scales and the directionality and magnitude of 46 larval dispersal driven by ocean currents and population connectivity among individuals of each 47 locality. The distribution of each species and variations in their reproductive phenology is also 48 important to consider when establishing marine reserves or seasonal fishing closures. PeerJ reviewing PDF |
doi:10.7287/peerj.4295v0.2/reviews/2 fatcat:symvaoxjbrhqtkow7dl4qb34ry