Greenland sharks (Somniosus microcephalus) are long-lived marine predators that have endured various harvesting pressures, yet their conservation is hindered by little knowledge of their populations. Given the technical constraints of observing these deep-dwelling sharks, molecular genetic methods can be used to reveal intraspecific genetic variation and identify patterns across their distribution, including population structure and connectivity. To accomplish this, 13 novel microsatellite markers were developed and used to genotype 212 S. microcephalus individuals from 6 locations spanning their known distribution.
Results/Conclusions
Each locus produced observed heterozygosity between 0.05 to 0.71, three to nine alleles and no significant departures from HWE or linkage equilibrium following Bonferroni correction. Bayesian clustering analyses suggest the presence of at least two populations, with substructure likely occurring within a priori (site-based) designations found in the Canadian Arctic. Significant site-level differentiation was evident for Svalbard compared with sites from the Canadian Arctic (Grise Fjord: FST = 0.025, Maxwell Bay: FST = 0.015, and Scott Inlet: FST = 0.020). These markers also provide multi-locus genotyping suitable for parentage and population studies in the Pacific sleeper shark (Somniosus pacificus), emphasizing their utility in describing genetic variation for both species.