On Thursday, October 13, Dr. Lorian Schweikert, Assistant Professor at the University of North Carolina at Wilmington was invited by the Biology department to give a seminar about her work on understanding the evolutionary basis of dynamic camouflage mechanisms in Caribbean hogfish and shrimp species of the Sergestidae family. 

Dynamic camouflage is the capacity of an animal to rapidly change color or appearance to blend into its surroundings in response to environmental cues. Animals that are able to perform dynamic camouflage sometimes have photoreceptors under their skin. In her work with the dynamic camouflage of the Caribbean hogfish, Dr. Schweikert focused her efforts on understanding the functional significance of a new type of photoreceptor identified in the skin of these fish. Photoreceptors are specialized cells that capture light. An increase of photoreceptors also improves the spatial resolution of the animal’s vision. Previous research has shown that dynamic camouflage is often mediated by vision, so the relationship between these newly discovered dermal photoreceptors and the process of dynamic camouflage in the Caribbean hogfish is still unclear. 

In her work with the Sergestidae family of shrimp, Dr. Schweikert focused the discussion on their bioluminescent traits, especially counterillumination, or their ability to use bioluminescence to obscure their silhouette. The Sergestidae family of shrimp shows a large amount of diversity among species in mean depth, diel vertical migration length, habitat, and light organ morphology. Sergestids also display a large variety of eye sizes, with the largest eye sizes relating to the species that have the largest diel vertical migration range. They also exhibit different eye sizes relative to expected eye size for their body, indicating species-level differences in resource investment towards vision. There is also evidence that eye size among Sergestids correlates with specific light organ morphologies. Dr. Schweikert aims to answer the question of why species of shrimp in the Sergestidae family exhibit such diverse light organ patterns when previous experiments have shown that they appear to be incapable of resolving differences in light organ pattern between individuals at close distances.