The Webb lab investigates the development and evolution of cranial sensory systems in fishes. In particular, we are interested in the development and evolution of the mechanosensory lateral line system. Over the years, we have focused on a variety of teleost fish taxa (butterflyfishes, zebrafish, flounders, cichlids, greenlings). Each of these taxa has interesting and unique attributes, which has allowed us to ask fundamental questions about evolution, patterns and mechanisms of development and functional morphology of the lateral line system. New projects are being added to our lab as new students and post-docs join our lab group.
1) Development and Evolution of an Adaptive Phenotype in the Mechanosensory Lateral Line System of Cichlid Fishes - (supported by NSF grant IOS- 0843307) - 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 generally. However, species that have widened canals and that are suitable for laboratory studies are rare. 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. This project has three goals: 1)
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. 2) 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 (work of graduate student Juleen Dickson) and 3) the role of widened canals in the detection of sand-dwelling prey will be analyzed using a behavioral assay and video analysis (work of graduate student Margot Bergstrom). 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. Collaborations with Drs. Karen Carleton and Tom Kocher at U. Maryland (cichlid genetics), Dr. Matt McHenry at UC Irvine (biomechanical modeling of neuromasts), and Dr. Jim Miller at URI Ocean Engineering (design of stimulus delivery apparatus), will provide new interdisciplinary training opportunities for students. This funding will enhance research infrastructure in Rhode Island, an EPSCoR state with a research focus in marine life sciences.
Development of the Lateral Line System in Elasmobranch Fishes - Graduate student Insley Haciski is studying the pattern and timing of development of the lateral line system in a skate and a shark. This taxonomic comparison will address how developmental patterns are related to changes in body form. Using these data we will explore how patterns of lateral line development evolved at the divergence of the elasmobranchiomorph and osteichthyan fishes.
Graduate student Molly Moore (Villanova. U.) used histochemical assays for osteoblasts and osteoclasts to detail cell-level patterns of lateral line morphogenesis and growth in post-embryonic zebrafish in order to discover the way in which lateral line canals are developmentally integrated into cranial dermal bones of the osteichthyan skull.
4) The Laterophysic Connection in Butterflyfishes - We have described the comparative anatomy, development and systematic significance of the laterophysic connection, a unique swim bladder-lateral line linkage in butterflyfishes in the genus Chaetodon. Ongoing field work (Tricas Lab, U. Hawaii) is investigating sound production, hearing capabilities and the significance of the laterophysic connection in the social behavior of butterflyfishes in the field and in the lab. Supported by NSF grants to JFW and TCT. [ Link to Butterflyfish Project site ]
Other projects:
-- MicroCT and MR imaging of the lateral line system of fishes in collaboration with the Orthopedics Research Lab at RI Hospital and Brain Institute at Brown University.
-- Anatomy of the lateral line canals on the trunk of teleosts.
-- The relationship of water flow patterns and the placement of lateral line canals on the head and trunk of teleost fishes (in collaboration with Jim Miller, URI Ocean Engineering).
Jacqueline Webb
Dept. of Biological Sciences/CBLS
120 Flagg Road
University of Rhode Island
Kingston, RI 02881-0816
Tel: 401-874-2609 (Dr. Webb)
Fax: 401-874-4256 (Dept. Bio. Sci.)
eMail: jacqueline_webb@mail.uri.edu |
