High connectivity among locally adapted populations of a marine fish (Menidia menidia)

Abstract

Abstract. Patterns of connectivity are important in understanding the geographic scale of local adaptation in marine populations. While natural selection can lead to local adaptation, high connectivity can diminish the potential for such adaptation to occur. Connectivity, defined as the exchange of individuals among subpopulations, is presumed to be significant in most marine species due to life histories that include widely dispersive stages. However, evidence of local adaptation in marine species, such the Atlantic silverside, Menidia menidia, raises questions concerning the degree of connectivity. We examined geochemical signatures in the otoliths, or ear bones, of adult Atlantic silversides collected in 11 locations along the northeastern coast of the United States from New Jersey to Maine in 2004 and eight locations in 2005 using laser ablation inductively coupled plasma mass spectrometry (ICP-MS) and isotope ratio monitoring mass spectrometry (irm-MS). These signatures were then compared to baseline signatures of juvenile fish of known origin to determine natal origin of these adult fish. We then estimated migration distances and the degree of mixing from these data. In both years, fish generally had the highest probability of originating from the same location in which they were captured (0.01-0.80), but evidence of mixing throughout the sample area was present. Furthermore, adult M. menidia exhibit highly dispersive behavior with some fish migrating over 700 km. The probability of adult fish returning to natal areas differed between years, with the probability being, on average, 0.2 higher in the second year. These findings demonstrate that marine species with largely open populations are capable of local adaptation despite apparently high gene flow.

You Better Repeat It: Complex CO2 × Temperature Effects in Atlantic Silverside Offspring Revealed by Serial Experimentation

“…An additional source of CO 2 tolerance may arise from local adaptation. Despite being an annual fish with high population connectivity, Atlantic silversides exhibit local adaptation for traits involved in growth and environmental sex determination [77], which are likely maintained through the continuous selection of locally suited genotypes [78]. As previously demonstrated, early life survival under high CO 2 conditions is a heritable trait in this species, suggesting that CO 2 tolerance could evolve [63].…”

Acidification increases sensitivity to hypoxia in important forage fishes

“…These species have been used extensively as model organisms in studies of fundamental concepts of evolution and ecology (Billerbeck et al 2000, Clarke et al 2010 and to examine chemical toxicity and the resilience of an ecosystem to abiotic stressors (Fuller et al 2004, Brander et al 2013, Stefansson et al 2013. Previous work has shown that they are sensitive to acidification and hypoxia during early life stages (Baumann et al 2012, Murray et al 2014, and that acidification could make them more sensitive to hypoxia (DePasquale et al 2015), though the sensitivity of adults to these stressors is unknown.…”

Geographic coupling of juvenile and adult habitat shapes spatial population dynamics of a coral reef fish

“…However, the coral reef supports low juvenile densities as well (Nagelkerken 2007), and due to its much larger surface area compared to sea grass nurseries it may therefore prove to subsidize a significant number of juveniles to local adult populations. The island of Curac¸ao is an oceanic pinnacle, separated from other islands by deep waters (.1.5 km), which provides a true opportunity to study an enclosed demersal population, something that is extremely difficult in the marine environment where sedentary animals can move over hundreds of kilometers along continental shelves (Clarke et al 2010).…”