MEPS 357:185-194 (2008)  -  DOI: https://doi.org/10.3354/meps07301

ABSTRACT: Marine species have a wide range of reproductive strategies that are considered to influence genetic structuring and connectivity between populations. Generally, species without planktonic larvae have reduced dispersal and gene flow between populations compared to species with free-living pelagic larvae. Further divisions exist within non-planktonic species including those exhibiting viviparity and oviparity. Although dispersal potential and population connectivity patterns of these 2 reproductive modes are considered similar, there is little supporting evidence. I examined genetic structuring and gene flow between oviparous and viviparous gastropod populations separated at the same spatial scales (at the same sites). Population genetic structure (using microsatellite data) was compared between island–mainland, mainland–mainland and island–island populations for an egg-laying (Nucella lapillus: oviparous) and a brooding (Littorina saxatilis: ovoviviparous) gastropod species. N. lapillus generally had lower levels of genetic differentiation between populations (R_ST ranged between 0.01 and 0.20; F_ST ranged between 0.01 and 0.17) than L. saxatilis (R_ST ranged between 0.02 and 0.21; F_ST ranged between 0.02 and 0.19); these differences were small for all site comparisons. Significant correlations were found between genetic structuring and gene flow patterns for the 2 species, indicating similar dispersal routes and population connectivity patterns. This study shows that it may be possible to generalise connectivity patterns (i.e. dispersal routes) across species lacking pelagic larvae, which may be important for Marine Protected Area network planning.

KEY WORDS: Connectivity · Dispersal · Nucella lapillus · Littorina saxatilis · Oviparity · Viviparity · Islands · Marine Protected Area