Chapter 19 Integumentary Sensory Organs in Crocodilians

Crocodilians, which include alligators and crocodiles, have a tough exterior with scales covering their dorsal and ventral surfaces. Living on earth before the dinosaurs, these reptilians have evolved a structure that has helped them adapt to the changing environment of earth. This structure is called an integumentary sensory organ (ISO). Integumentary is a term, which refers to the skin surface of organisms. In the case of crocodilians their skin possess many tiny ISOs that look like tiny protuberances on the crocodilian scales. The ISOs location on their skin allows them to gather information on their environment. The ISO distribution across crocodilians vary in location, but are similar in morphology and function. Historically, these tiny sense organs of crocodilians have been observed by earlier researchers but were not well understood and mainly just observed and suggested as a possible tactile sensitivity organ. Yet, they are now known to serve as a sensory organ, which includes tactile sensitivity. ISOs as a sensory organ can function for water disturbance detection (track prey or avoid predator), mating, reproduction, and osmo-regulation. ISOs have been referred to as many different terms in the past depending on the research being done and the findings from that research. Water surface dis-