The Jack Dempsey (Rocio octofasciata) is a species of freshwater fish that is found across North and Central America (from Mexico south to the Honduras). Its common name is likened to that of the famous 1920s boxer Jack Dempsey, because of its strong facial features and aggressive nature. It is found in slow-moving waters, such as areas that are swampy, weedy, murky, and/or warm. It is common in sand-bottom canals, drainage ditches, and rivers. This species has been introduced to Australia, Thailand and the USA.
It can reach up to 10 inches in length. Its coloration changes as it matures from a light gray or tan with faint teal flecks to a dark purple-gray with very bright,iridescent blue, green, and gold flecks. Their colors change under stress. The dorsal and anal fins of mature males have long, pointed tips. Females lack these exaggerated tips. These fish have an anti-predatory characteristic of having fin spines that become erect to avoid being swallowed by other predators. This is common among cichlids.
The Jack Dempsey is carnivorous and feeds on worms, crustaceans, insects and other fish. It can eat other fish when it is three inches long. It is very territorial, especially against its own kind. The fish was once very popular due to its striking appearance and personable mannerisms. It is a popular aquarium fish.
The Jack Dempsey lays its eggs on the substrate (the bottom of the aquarium or pool). Like most cichlids, it shows substantial
parental care; both parents help incubate the eggs and guard the fry when they hatch. Jack Dempseys are known to be attentive parents, pre-chewing food to feed to their offspring. However, it is not uncommon for them to eat their fry when the breeding pair are overly disturbed or something in their environment is wrong.