Development and Evolution of an Adaptive Phenotype in the Mechanosensory Lateral Line System

University Of Rhode Island, Kingston RI

Investigators

Abstract

The mechanosensory lateral line system is a structurally diverse sensory system present in all fishes that is responsible for detection of water flow (hydrodynamic) stimuli and is of critical importance in a variety of behavioral contexts. It is composed of sensory organs located on the skin and in bony lateral line canals that are contained in a subset of bones in the skull. One of the four types of canals, widened canals, are quite sensitive to hydrodynamic stimuli and is considered to be an adaptation for the non-visual detection of prey, which is of great ecological importance for fishes. Two genera of Lake Malawi (Africa) cichlid fishes (Aulonocara [widened canals], and Tramitichromis [narrow canals]), will be used for a study that uses comparative anatomical, developmental and behavioral approaches to address fundamental issues in fish sensory biology. First, the convergent evolution of widened canals will be assessed among cichlids and among fishes more generally to more precisely define common features of its anatomy. Second, the pattern and timing of development of widened and narrow canals and the sensory organs contained within them will be analyzed quantitatively to determine the developmental basis for evolutionary change in the lateral line canal system. Finally, the role of widened canals in the detection of sand-dwelling prey will be analyzed using a behavioral assay and video analysis. This work will have important implications for our understanding of the evolution of feeding habits of cichlids in the African Rift Lakes, and of marine and freshwater fishes that feed on benthic prey, especially those in disturbed habitats in which non-visual predators may have an ecological advantage. The PI will integrate research and education by involving undergraduates and graduate students in all aspects of this project. Collaborations with colleagues (re: genetics, biomechanical modeling, microCT imaging, design of stimulus delivery apparatus), will enhance the interdisciplinary nature of the PI's research program and provide new training opportunities for students. This funding will enhance research infrastructure in Rhode Island, an EPSCoR state with a research focus in marine life sciences.