Data from: The genetic structure of Nautilus pompilius populations surrounding Australia and the Philippines

Understanding the distribution of genetic diversity in exploited species
is fundamental to successful conservation. Genetic structure and the
degree of gene flow among populations must be assessed to design
appropriate strategies to prevent the loss of distinct populations. The
cephalopod Nautilus pompilius is fished unsustainably in the Philippines
for the ornamental shell trade and has limited legislative protection,
despite the species' recent dramatic decline in the region. Here, we
use 14 microsatellite markers to evaluate the population structure of N.
pompilius around Australia and the Philippines. Despite their relative
geographical proximity, Great Barrier Reef individuals are genetically
isolated from Osprey Reef and Shark Reef in the Coral Sea (FST = 0.312,
0.229, respectively). Conversely, despite the larger geographical
distances between the Philippines and west Australian reefs, samples
display a small degree of genetic structure (FST = 0.015). Demographic
scenarios modelled using approximate Bayesian computation analysis
indicate that this limited divergence is not due to contemporary gene flow
between the Philippines and west Australia. Instead, present-day genetic
similarity can be explained by very limited genetic drift that has
occurred due to large average effective population sizes that persisted at
both locations following their separation. The lack of connectivity among
populations suggests that immigrants from west Australia would not
facilitate natural recolonization if Philippine populations were fished to
extinction. These data help to rectify the paucity of information on the
species' biology currently inhibiting their conservation
classification. Understanding population structure can allow us to
facilitate sustainable harvesting, thereby preserving the diversity of
genetically distinct stocks.