Preliminary study on the ecomorphological signification of the sound-producing complex in Carapidae

Carapidae can be classified in four ecological groups : pelagic, dermersal, commensal and parasitic. Carapidae display otophysic structures associated with the anterior part of the swim bladder and highly modified labyrinths, which suggest particular acoustic performances. The commensal and parasitic species have the best developed sound-producing features and also the thickest sagitta within the largest otic cavity, and surrounded by the thinnest cranial wall. However, these features do not necessarily imply a direct relation between the sound emission and reception in a given species but suggest a selective pressure lying in the habitat use of the species. The structures involved in sound-production and hearing are seemingly adapted to match the loss of energy of the sonic vibrations when travelling through the host tissues.