Caiman c. fuscus is, as its common name suggests, noticeably browner in colour than the common caiman. However, it is difficult to tell the two apart, and to all intents and purposes they are very similar. All subspecies of C. crocodilus possess this bony ridge. Caimans are found naturally in tropical Central and South America. Most species have a wide distribution, and the spectacled caiman occupies a variety of different habitat types from swampy wetlands and isolated pools to major river systems and tributaries.
Caimans tend to prefer freshwater, although some species are tolerant of more saline conditions.
Spectacled caimans are tenacious survivors, and can thrive outside their natural range in suitable environments. There are feral populations of caimans in Cuba, Puerto Rico and also Florida, established primarily through the release of unwanted pets. Such releases are illegal and the colonisation of these caimans outside their natural range can be dangerous both to other crocodilian species and also native species of reptiles and other animals whose ecology is disrupted by an alien species. There seems to be some confusion over the maximum size of Caiman crocodilus . Less reputable or informed pet stores apparently promote the idea that this species doesn't grow more than two to three feet.