Meeting Abstract
Goldfish, Carassius auratus, are a model system due to popularity and ease of obtaining. However, while there are several functional studies on the feeding mechanisms of the common goldfish, there are no functional studies on those goldfish varieties exhibiting ornamentation. Goldfish, a member of Cypriniformes, use a unique mode of premaxillary protrusion during feeding. Differences in eye and fin configurations, as well as body shape, from the common goldfish are known as ornamentation. This ornamentation may include: lateral protrusions of the eye region (“telescope eye”) often filled with lymph (“bubble-eye”), hyperplasia of epithelial tissue on the head (a “hood” or “wen”), and even a complete loss of dorsal fin. We investigated several different varieties of goldfish exhibiting ornamentation (black moor, oranda, lionhead, bubble-eye) to find the effects of this ornamentation on feeding. We document the modifications of the musculoskeletal morphology of the feeding apparatus in ornamental goldfish. Analysis of high-speed video allowed us to test our functional hypotheses. Specifically, we tested whether certain varieties rely more on ram vs. suction feeding modes for prey capture. We expected the wen might inhibit premaxillary protrusion and thus have an effect on suction feeding, while the loss of a dorsal fin would impact swimming (and thus ram feeding), requiring these varieties to rely more on suction. We found that underlying musculoskeletal anatomy varied only slightly despite wide variation in ornamentation but that certain ornamental morphologies affected function in aspects unrelated to skeletal anatomy. This suggests overall conservation of important musculoskeletal traits associated with suction feeding, despite widely varying external appearance.
