One Fish, Two Fish

Submitted by: Margaret A Malone

Program: Biological Sciences, PhD

The Labridae (wrasses) are one of the largest and most diverse groups of fishes, with 82 genera and over 600 species. Like many coral reef fishes, wrasses exhibit a complex life history. Larvae and juveniles have very similar morphologies and trophic positions, while adult wrasses have disparate morphologies and trophic positions. Much is known about the ecological and evolutionary patterns of adult wrasses, yet few studies address variation in ecomorphology throughout ontogeny. My research investigates the ontogeny of wrasse functional morphology within a genus that demonstrates diverse and novel adult feeding: Thalassoma and its close relatives.

To study changes in functional morphology I utilize a process called clearing and staining of larval and juvenile fishes, where bones is dyed red and cartilage blue. This process reveals the ossification of cranial bones allowing for anatomical study. The resulting fishes are quite beautiful after this process. In this image I have a "school" of moon wrasse, Thalassoma lunare cleared and stained, and ready for analysis.