The Everglades, a unique wetland ecosystem, faces challenges from various invasive species. Among these, the “Everglades Bully” is a fish known for its aggressive nature and significant environmental impact. Understanding its identity and characteristics is crucial to recognizing its role.
Unmasking the Everglades Bully
The fish commonly known as the “Everglades Bully” is the Mayan cichlid, scientifically named Mayaheros urophthalmus (formerly Cichlasoma urophthalmus). It is also known by other common names such as Mexican mojarra or orange tiger. These fish typically average around 10 inches in length, though some individuals can grow larger, reaching up to 15 inches and weighing over two pounds.
The Mayan cichlid has an oval-shaped body with spiny dorsal and anal fins, giving it a resemblance to native North American sunfishes. Its coloration is generally olive-brown to beige, featuring six to eight wide, green-black vertical bars along its body. A distinctive “eye-spot” with a silver-blue or turquoise ring and black center on its caudal (tail) fin gives the fish its scientific name, urophthalmus, meaning “tail eye.” This species is native to the Atlantic slope waters of Central America, including southeastern Mexico, Belize, Guatemala, Honduras, and Nicaragua. Non-native populations were first reported in Florida in 1983, likely introduced through aquarium releases or fish farm escapes.
The “Bully” Behavior
The Mayan cichlid’s “bully” moniker stems directly from its highly aggressive and territorial behavior, especially during breeding periods. They actively defend their nests and fry from perceived threats, including other fish species. This aggressive defense can involve chasing, nipping, and displacing native fish from preferred habitats and spawning grounds.
Mayan cichlids are highly competitive for resources and space. Their dominance can lead to a reduction in native fish populations, as they outcompete them for food and territory. Anglers note their aggressive approach to bait and feistiness when hooked, contributing to their reputation as an “atomic sunfish.” This assertive behavior allows them to establish and maintain strongholds within the Everglades.
Life and Thriving in the Everglades
The Mayan cichlid’s remarkable adaptability has allowed it to flourish in the diverse conditions of the Everglades. This species can tolerate a wide range of environmental conditions, including varying salinity levels from freshwater to brackish and even marine environments. They are found in canals, rivers, lakes, marshes, and even mangrove swamps.
Their diet is opportunistic and omnivorous, consisting of small fish, aquatic invertebrates like snails, grass shrimp, and insects, as well as incidental plant matter and detritus. This flexible feeding strategy enables them to utilize readily available food sources.
Mayan cichlids are prolific breeders, typically spawning in the spring and early summer, with peak activity in May and June. Both parents participate in nest construction, often creating shallow depressions in the substrate or among mangrove roots, and then actively guard their eggs and young for several weeks, which enhances the survival rate of their offspring.
Ecological Footprint and Management
The presence of the Mayan cichlid as an invasive species has created a notable ecological footprint in the Everglades. Their aggressive competition for food and space, along with their predatory behavior and consumption of native species’ prey, significantly impacts native fish populations. Studies show an inverse relationship between Mayan cichlid abundance and native species catch, suggesting a displacement effect.
The long-term effects of the Mayan cichlid on the Everglades food web are still being observed, but there is concern that their interactions with native fishes could alter the region’s ecology. While they serve as a food source for some native predators like wading birds and other fish, their overall impact on the ecosystem is considered negative.
Currently, there are no size or bag limits for catching Mayan cichlids in Florida, and anglers are encouraged to keep them, providing a form of population control. Despite these efforts, the species continues to expand its range, posing an ongoing challenge for conservation efforts in the Everglades.