I am currently researching the defensive adaptations of planktonic invertebrate larvae in Steven Morgan‘s lab at the UC Davis Bodega Marine Lab. These larvae are subject to extremely high mortality rates as they develop as members of the plankton community and have evolved some very interesting adaptions in response. However, in some cases these anti-predator adaptions increase the vulnerability of larvae to other stresses resulting in evolutionary trade-offs or compensation.
Anti-predator defenses, trade-offs, and compensation in marine larvae
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Anti-predator adaptations in crustacean larvae
Crustacean larvae are some of the most well-defended members of the plankton community. I have conducted a systematic review of the anti-predator adaptations of these larvae as well as the predators that consume them in order to better understand how the predation threats these larvae face has driven the evolution of their morphology and behaviors.
Left: Crab (Gecarcinus ruricola) zoea.
Right: Shrimp zoea
Coloration of crab larvae
Tropical crab larvae can exhibit extraordinary colorations, or remain mostly transparent. It is thought that pigments may protect larvae from ultraviolet radiation but make them more visible to visual predators. At the Smithsonian Tropical Research Institute Galeta Marine Laboratory in Panama, I investigated the countervailing effects of ultraviolet radiation (UVR) and predation pressure on the coloration of crab larvae. The objective of this research is to understand the costs and benefits of larval coloration and how it may lead to inter- and intra-specific variation in coloration.
Biogeography, environment, life history strategies, phylogeny, and crab larval morphology
With the assistance of volunteers and technicians, I am compiling information on the morphology and life history characteristics of all 800+ species of described crab larvae. This project will improve our understanding of the drivers and constraints of larval morphology in crabs and more broadly the relationships among morphological defenses, life history strategies, and biogeographic/environmental influences. The results will have applications for constructing keys to identify crab larvae from the plankton, improving our understanding of the evolution of marine larval forms, and predicting environmental influences on larval survival and dispersal for diverse species under current and future climate scenarios.
Impacts of fluctuating salinity on the behavior and protein expression of echinoderm larvae
At Friday Harbor Laboratories in Washington State I worked with Sophie George to research the effects of low salinity on the swimming behavior (Bashevkin et al. 2016) and protein expression of sand dollar (Dendraster excentricus) and sea star (Pisaster ochraceus) larvae.
Top left: Field site for collecting sand dollars at Orcas Island, WA. Top middle: Sea star bipinnaria larva. Top right: Sand dollar 4-arm pluteus larvae. Middle right: Gel with bands of proteins from an experiment investigating the effects of low salinity on protein echinoderm larvae. Bottom: Experimental setup to investigate the swimming behavior of sea star larvae.
Environmental impacts on the early development of a marine snail
At Tufts University I worked with Jan Pechenik to study the marine snail Crepidula fornicata. I looked at the desiccation tolerance of young juveniles with (then) graduate student Casey Diederich (Diederich et al. 2015) and then investigated the effects of temperature and salinity on the larval and juvenile life stages, and how stresses in the larval stage carry over to affect juvenile fitness (Bashevkin and Pechenik 2015).
Left: C. fornicata juvenile deformed by salinity stress. Right: Normal C. fornicata juvenile