Lucania goodei: The Bluefin Killifish
Lucania goodei, also known as the bluefin killifish, is a small yet fascinating species of fish that belongs to the topminnow family, Fundulidae. Notable for its upturned mouth designed for gulping air at the surface, and striking color combination with a bold zigzag black stripe from the snout to the caudal fin base, this species is a native of the southeastern United States and has a notable presence in Florida, Alabama, and South Carolina.
Distinguishing Features
The bluefin killifish is named after its distinctive red-orange caudal fin contrasting with its silver/grey body etched with iridescent blue/green highlights. Characterized by its compressed body and small upturned mouth, the adult species measures from 0.6 to 1.7 inches (16 to 42 mm), with a maximum recorded length of up to 6 cm. This species can live up to 2 years and prefers to swim well below the water surface.
Unraveling the Habitat
Bluefin killifish frequent various aquatic habitats that are heavily vegetated, such as sloughs, ditches, ponds, lakes, and pools. They have adapted well to survive in moderate salinity and low oxygen environments and are often found in sites with organic debris and cypress knees. The species favors spring habitats in shallow vegetated margins, marking its distribution across peninsular Florida, Gulf slope drainages up to the lower Choctawhatchee River, and the Ogeechee River drainage in Georgia among others.
Tracing the Distribution and Invasion History
The indigenous home of the bluefin killifish includes water bodies in parts of Georgia and the Florida peninsula. Their adaptability has allowed them to establish populations in North Carolina, South Carolina, Texas, and California. This is likely due to aquarium fish releases or the unintended transportation of eggs via aquatic plants. Established populations have spread across various environments on both the East and West Coasts, even including sightings outside their native range, such as in Los Angeles County and the San Dieguito River lagoon in California.
Breeding Biology and Diet
The bluefin killifish breeds from spring through late summer, with spawning pairs depositing up to 20 eggs per day on vegetation or algae. This species feeds on small insects, crustaceans, and plant material, evidencing an omnivorous diet.
Human Interaction: Aquarium Care and Breeding
Beyond their natural habitat, bluefin killifish are well-suited for life in community aquariums due to their peaceful nature. These fish thrive in densely planted tanks with access to floating plants, and their proper care involves setting up a breeding tank with fine-leaved plants or spawning mops for the protection of eggs and fry. Proper feeding practices and tank setup are integral for maintaining the health of bluefin killifish in captivity.
Lucania goodei: Discovery and Significance
Described first in 1880 by David Starr Jordan, the species name goodei honors American ichthyologist George Brown Goode, who contributed significantly to its discovery. Further recognitions of the species were noted, such as its presence in the Arlington River, Florida.
Rounding up the Species: Conservation Status and Further Research
While the impact of this species in its newly invaded ranges is yet to be fully understood and studied, researchers continue to monitor the spread of the bluefin killifish in these environments. Despite its wide distribution and varying environments, recent studies suggest shared transport events, implying the possibility that isolated populations may have common areas of refuge.
