Meeting Notes

September, 2009

Bob Bock, "Tropical Fish Collecting in Florida"

Bob Bock began collecting in Florida after his wife's parents retired there. The condo was next to a pond. Like most ponds in the area, it drained to a culvert, which drained to one of the state's numerous canals, which typically drain to the Everglades or the ocean. Bob described Florida as "an incubator for released species." The Sunshine State's network of artificial waterways provide a habitat for many exotic terrestrial animals like iguanas and Muscovy ducks. They also have many introduced fish species.

Some of the introduced fish are put in the canals and ponds on purpose. Large Mouth Bass and Sunfish, native to the Great Lakes, were stocked by wildlife officials. Most exotics, however are released by human beings who encountered problems caring for them. Hurricanes and tropical fish farms also account for a small proportion of the exotic fish species that establish in Florida.

Exotic Cichlids with established breeding populations in the state:

Mayan Cichlid

Most of these cichlids are bi-parental, substrate spawners. To collect fish from the canals, Bob uses a dip net, running the net through the plants at the shoreline to catch fish. He prefers not to wade into the water, as encountering alligators is always a possibility.

Bob gave specific information on the fish he showed in the program:

Spotted Tilapia: Illegal to keep in Florida, but the law was too late. This species is probably the most numerous large fish in the state. Bob has found them in nearly every collecting site he visited, sometimes catching 50-100 young in a single scoop of the dip net.

Peacock Bass: Intentionally introduced by the Florida Fish and Wildlife Conservation Commission the Peacock Bass grows to 18 inches. Bob said that the strategy of "introducing an exotic to control an exotic" was controversial.

Blue Tilapia: Native to North Africa, they were originally released to control aquatic vegetation. The species is a rarity among the state's introduced cichlid species. A maternal mouthbrooder, the male digs a nest for spawning, after which the female picks up the eggs and carries the eggs in her mouth until they hatch.

Midas Cichlid: Originally from Nicaragua and Venezuela, they are throughout the southern portion of the state. Bob collected them in the Hillsboro Canal outside Fort Lauderdale, Florida among the non-native water lettuce. A lovely, bright colorful fish, the babies feed on the body slime of the parents, but only when their food source is low.

Mayan Cichlid: An aggressive and mean fish that is native to Central America. They live in a variety of water types - fresh, up to full seawater.

Jaguar Cichlid: Bob found a "mystery fish" in a Fort Lauderdale canal in 2008. The fish was only a couple of inches long and resembled a baby smallmouth bass. Members of an Internet forum identified the fish as a baby Jaguar Cichlid. Bob described it as a "neat fish - shy, and not too aggressive."

Yellow Belly, or Salvini, Cichlid: Found naturally from Mexico to Guatemala. Under 7 inches long and on the shy side and likes to hide. This fish would benefit from a good dither fish. Unfortunately, they're so territorial and aggressive that they would probably kill any dither fish you put in the tank. The parents are tough on each other. Bob says that if you "start with six young, then they will form a pair and spawn in temperatures in the high 70's to low 80's. If you see teeth marks on the fishes' upper jaw you know that they're getting ready to pair up."

Black Acara

Black Acara: Found in stagnant water low in oxygen, like agricultural canals. Bob said the Black Acara is an easy keeper which gets along well with other fish. They're slow and stately, like an angelfish, but their coloration is drab.

North African Jewelfish: An African fish found in southern Guinea to southern Liberia, they are also found in Florida canals from Fort Lauderdale down to Miami. Non spawning individuals are also drab, principally gray with flecks of green. Spawning individuals however become bright crimson on the flanks and belly. They are not fussy about water conditions, and will live in anything from soft, acid water to brackish water. In their native habitat, they are known to spawn after heavy rains. Large water changes in the aquarium might also stimulate spawning.

Non-Native CATFISH found in Florida:

Pleco

Walking Catfish: Breath air and crawl on their stomach to reach new water. Bob has never encountered them, but the fish received a lot of media attention a few years ago. Highly predacious, experts feared they would overpopulate the state and reduce local fish populations. Despite concerns, the population apparently crashed. Bob said that his friends who live in the area haven't seen any in years. State regulations also prohibit transporting live walking catfish.

Brown Hoplo: From South America. Lives in fresh to brackish water. The fish builds a bubble nest on the water's surface, like an anabantid.

Plecos: Bob found huge sailfin plecos from casting a net in a pond. Plecos abound in the ponds and canals of Florida.

Other Non-native Fish:

Bullseye Snakehead
Pike Killifish
Swamp Eels

Pike Livebearer: The pike livebearer is the only member in its genus. It grows up to 8 inches and is related to guppies and mollies. Citing an article by PVAS member John Mangan, Bob said the key to success with them is to keep them well fed. If they get too hungry, Pike livebearers will eat each other.

Bob said it was reasonable to ask whether or not Florida's exotic fishes have caused harm to the environment. In other parts of the world, introduced non-native species have spread diseases to native fish populations, compete with native species for food and territory, and in some areas, have caused the extinction of native species. No definitive studies have been conducted on the impact of Florida's many introduced species on local fish populations. However, one reference Bob cited hypothesized that the flux of seasons may help to keep exotic fish populations in check. In fall and winter, the dry season brings cold weather and large cichlids species may have trouble surviving. Because the canals are not subject to seasonal drying, and because they're deeper than Everglades marshes, the canals provide a more stable environment, offering a sanctuary for the many exotics. Because of their interconnectedness, and because most feed into the Everglades, the canals are like "highway system for exotics to move around the state," said Bob.

Bob went on to explain that Florida is not a closed system like an island or a desert spring. Rather, the state is an open system, with native predators like gar, bowfins, and warmouth sunfish, which feed on the native small fish species. Because these smaller native species have developed the ability to cope with native predators, the introduction of cichlids and other exotic predators may not have had a major impact on their populations. Bob speculated that, instead, the native predators may experience a greater impact from the introductions, as they now must compete with the exotic predators for food and resources.

Further along in his presentation, Bob offered some rules for avoiding alligator hazards and then described his field trip along the Tamiami trail, which connects Miami with Tampa. Along the way, Bob stopped in Little Havana to buy a Cuban shirt, ate in a Cuban restaurant, encountered feral chickens, and toured Everglades National Park. Fifteen miles into the everglades, Bob encountered all kinds of wildlife from alligators to aquatic birds, to fish.

Bob also described the native fish species he encountered through the years:

Bluefin Killifish

Bluefin Killifish: All over Florida and into South Carolina. A small fish, reaching no more than an inch and a half, with a black lateral band. Florida populations may have blue or red dorsal fins.

Florida Flagfish: Found only in Peninsular Florida. The flagfish eats hair algae and can be a bit aggressive. Provide a tank with a lot of plants and hiding places. The best set up is a 20 long with one male and several females.

Golden Ear Topminnow: Up to 3 inches long. Aggressive, especially with members of its own species. One male to 3-4 females in a well planted tank. Females have green spots, males have red spots.

Swamp Darter: These bottom dwellers breed in mops in the home aquarium. They were very numerous during Bob's last trip to Florida.

Native Livebearers

Mosquitofish
Least Killifish
Sailfin Molly

Centrarchids - Indiginous Sunfishes:

Spotted Sunfish: 8-10 inches, requires a large tank. Males dig a large circular nest in the substrate. Interesting fact: out of the water they are green, when in the water they are purple!

Bluespotted Sunfish: About the size of a silver dollar. Will not wreck a tank, but need live food. They have been found at Little Hunting Creek in the Washington D.C. area.

Sherry Mitchell