Meeting Abstract

P1-146   -   Coughing Behaviour Produces Large Pressure Amplitudes in the Gill Chambers of the Spotted Ratfish Kamau-Weng, J*; Farina, S; Northeastern University; Howard University kamau-weng.j@northeastern.edu

Aquatic coughing is a poorly documented and yet ubiquitous behavior among fishes, dating back to at least the emergence of the Gnathstomes. We document coughing in a holocephalan, the spotted ratfish Hydrolagus colliei, using pressure transducers implanted in the parabranchial chambers. Holocephalans have a fleshy operculum extending laterally over the gill chamber, as opposed to other chondrichthyans which possess multiple gill septa. Previous research had recorded extremely low ventilation pressures in the parabranchial chambers of Hydrolagus colliei. Our research indicates Hydrolagus colliei can produce large pressure amplitudes in the parabranchial chambers through a behavior termed as “coughing,” which is a reverse breath that produces a large jet of water out of the mouth. Pressure amplitudes measured during this behavior far exceeded amplitudes produced from regular active breathing. This indicates that the parabranchial chambers are capable of much more forceful compressions than previously observed, likely far exceeding the capacity for parabranchial compression in elasmobranchs with smaller individual chambers.