Can Larvae of a Deep-Sea Gastropod, Thalassonerita naticoidea, Swim to the Surface to Find Food in the Gulf of Mexico?

For larvae of benthic organisms living in the deep-sea, the location where they begin their dispersal influences their vector of travel because ocean currents affect larval dispersal when the larvae are in the water column during a possible vertical migration. The deep-sea is food-poor when compared to the food-rich surface waters, but planktotrophic (feeding) larval development of deep-sea benthic organisms is common. Despite the potential need for planktotrophic larvae of deep-sea organisms to access more nutrient-rich food sources and knowing a larva's position in the water column can impact larval transport, we have very little understanding of where in the water column the larvae of deep-sea organisms develop. In this work I used Thalassonerita naticoidea larvae, to study deep-sea larval migration potential by modeling the expended energy of larvae while vertically swimming. This study examined how the swimming rates and metabolism of T. naticoidea larvae are influenced by water temperature. The model predicted that a larva swimming vertically from a depth of 650.8 meters to 87.7 meters at a constant mean velocity of 1.43 ± 0.06 m h-1 will expend 52.7 mJ in 13.5 days to reach the photic zone (200 meters). As the larvae vertically migrate up to the surface, they have access to food like dissolved organic materials and bacteria. Once at the surface, they have access to phytoplankton which they can eat to continue their development. Migration through a 650-meter water column will expose larvae to dynamic currents that influence their dispersal and population connectivity.