The King of Tampa Bay’s Killifish

By Joseph Post

The Tampa Bay watershed is home to a wide variety of fish species, many of these being killifish. There are a total of 10 ‘killifish’ species that call Tampa Bay their home. Fundulus grandis, the gulf killifish, is the largest of these species, maxing out at a whopping 7 inches while most Fundulus typically only grow to 3-4 inches. 

The gulf killifish plays numerous important roles in the Tampa Bay ecosystem, often feeding on algaes that can overrun the habitats they call home. Gulf killifish are also used in lab research to measure the effects of oil and oil dispersants on the physiology of marine life. This fish has become ever important in this testing as oil spills continue to be a pertinent issue throughout the Gulf of Mexico. 

One of the most fascinating characteristics of the gulf killifish is its extremely wide range of tolerance. Range of tolerance refers to the amount of environmental pressures an animal can handle within its habitat, such as pollution, oxygen levels, and salt levels. This fish can be found in nearly any body of water from salty ocean water to freshwater areas within estuaries. The gulf killifish has the widest tolerance of any other fish found within the bay, capable of surviving in bodies of water as small as puddles! Due to an increase in industrial shoreline development, the gulf killifish is at risk of habitat loss. Although resilient, this fish, like many other shore dwelling species, is heavily threatened by this habitat loss. 

The gulf killifish along with two other species of killifish are featured in our ornate diamondback terrapin enclosure here at the Discovery Center. On occasion the male gulf killifish will display their gorgeous spawning colors with hues of dark gold and black.