High genetic differentiation in the edible cannonball jellyfish (cnidaria: Scyphozoa: Stomolophus spp.) from the Gulf of California, Mexico

Abstract

Studies of population genetic structure in relation to ecological and evolutionary processes are crucial for conservation genetics and particularly for sustainable management of fisheries. However, such knowledge is not always available for the management of fisheries, as is the case of the edible cannonball jellyfish Stomolophus spp. fishery in the Gulf of California, Mexico. The aim of this study is describe the population genetic structure of cannonball jellyfish in the Gulf of California. We used sequences of cytochrome oxidase I (COI) and microsatellite markers in five locations within the Gulf of California and the southern Pacific coast. Both COI and microsatellite markers corroborated the presence of two differentiated genetic lineages in the fishing areas, which diverged around 1.17 Mya: Stomolophus sp.1, distributed in the Golfo de Santa Clara; and Stomolophus sp.2, in the southern region of the Gulf of California and the Pacific coast of the Baja California peninsula. In addition, significant differentiation between the four locations within the lineage Stomolophus sp.2 was found (mean FST: 0.56 and 0.12 for COI and microsatellites respectively). Our results are consistent with the endemism and phylogeographic break hypotheses proposed for the northern region of the Gulf of California. We proposed that the historical geology and complex oceanography of the Gulf of California might be responsible of this species-level differentiation. Conversely, the population structure within Stomolophus sp.2 could be more related to the life cycle, and particularly due the short larval dispersal stage of cannonball jellyfish in the Gulf of California.