About Fundulus grandis Baird & Girard, 1853
The Gulf killifish, with the scientific name Fundulus grandis, is one of the largest species in the Fundulus genus. It can grow up to 7 inches (18 cm) in length, while most other Fundulus species reach a maximum length of only 4 inches (10 cm). Because of its larger size, F. grandis is among the biggest minnows hunted as prey by many sport fish, including flounder, speckled trout (Cynoscion nebulosus), and red drum (Sciaenops ocellatus). The genus name Fundulus comes from Latin meaning "bottom," and the species name grandis means "large". This fish is native to the Gulf of Mexico from Texas to Florida, the eastern coast of Florida, and the Caribbean Sea in the Atlantic Ocean. Threats to the Gulf killifish's survival include extreme salinity changes, temperature changes, and toxic events such as Louisiana's hypoxic dead zone and the Deepwater Horizon oil spill. Currently, the Gulf killifish is used in research to test how oil and oil dispersants affect the physiology of marine species exposed to these substances. This research is important for conservation biology, as ongoing extraction of oil and other natural resources from North American waters makes it increasingly critical to understand the risks and consequences of worst-case scenarios like the Deepwater Horizon oil spill, and their long-lasting impacts on marine ecosystems. The Gulf killifish inhabits the Atlantic Ocean, Gulf of Mexico, Caribbean Sea, and the Southeast United States Continental Shelf. Its natural range extends from Texas to Florida's western coast, along Florida's east coast, and throughout the Caribbean. The waters in its range experience frequent changes to water characteristics including temperature, dissolved oxygen, and salinity. These changes can have major impacts on the survival and population size of the Gulf killifish. Populations of F. grandis living in the heavily polluted waters of the Houston Ship Channel have recently been found to have adapted to resist the effects of local pollution. This resistance protects the embryos of these populations from cardiac teratogenesis, which refers to developmental heart deformities, when compared to embryos from reference, uncontaminated populations. In addition, these adapted Gulf killifish populations are also more resistant to pesticides and oxidative stress, and have a higher metabolism. These traits likely developed due to strong natural selection acting on these populations to build resistance to severe contamination. This strong resistance and cross-resistance to multiple stressors shows how adaptation to human-caused contaminants can occur in this species' environment, and similar adaptive events are common across many fish species and populations.
