Exotic Fish Rediscovered

On September 26, 2012, Biological Science Technician Darren Pecora trapped 17 croaking gourami, Trichophsis vittata, while inventorying the Cypress Swamp for fish species.

Darren Pecora sets a minnow trap Darren Pecora (USFWS) sets a minnow trap in a canal adjacent to Refuge waters.

This species had not been seen before by current Refuge staff, so Darren referenced the Comprehensive Conservation Plan for more information. The species was listed as “Breeding Status Unknown”. He looked through the species list for the Refuge, researched local species accounts online, and identified the fish as the croaking gourami, an exotic freshwater fish from Southeast Asia.

A positive identification was made by the Florida Museum of Natural History through Pam Schofield’s lab (USGS) in Gainesville. The Florida Fish and Wildlife Conservation Commission had declared the species extirpated from the region, and the fish has not been collected in over 15 years. Historical accounts placed the fish in a Palm Beach County drainage canal only a few miles from the Refuge.

Agency teams gather Agency teams gather on the morning of the Gourami Blitz to receive a briefing from Pam Schofield (USGS)

The croaking gourami is broadly distributed throughout Southeast Asia, and can grow up to six or seven centimeters. They are capable of breathing atmospheric air using a specialized labyrinth organ. During reproduction, they produce a croaking-like noise using their pelvic fins and place eggs in bubble nests that they build. They prefer to inhabit weedy shallow slow moving waters with lots of cover. The life history traits associated with this species make it a great candidate for establishment in areas like the Refuge’s Cypress Swamp.

A long-standing partnership between USFWS and USGS has been established within the Refuge, and an event called the Gourami Blitz was formed. This quick response to an invasive exotic species is an example of the Early Detection Rapid Response program, and how it works to find and locate an invasive exotic species after a sighting has been confirmed. The idea behind the “Blitz” was to sample water bodies adjacent to where the fish was initially found in order to determine the geographic range of the fish, and to collect any other exotic fishes.

Exotic croaking gourami An exotic croaking gourami, Trichophsis vittata, captured from the Refuge Cypress Swamp, can grow up to seven centimeters.

A fun-filled day of sampling was arranged to survey the area (both inside and outside the Refuge), and get a better understanding of the spread of this species. Gear provided by the various partners included minnow traps, dip nets, seines, and an electrofishing boat. All native fishes were immediately returned to the wild, while all non-native fishes were euthanized and retained as voucher specimens at the Florida Museum of Natural History. A total of 14 biologists participated in the Gourami Blitz, including USFWS, USGS, FWC, South Florida Water Management District, and Florida International University. The group was broken up into teams and was assigned different geographic areas to sample. At the end of the day teams gathered to compare their findings. Several croaking gourami were captured in a drainage ditch near the Refuge’s border in waters not previously documented. Several other exotic fish species were captured and cataloged by all teams, rendering the event a success.