The Pupfish Family – Cyprinodontidae

There are currently FOUR members of the Pupfish or Cyprinodontidae Family, all from Mexico’s freshwater systems, presented in this website:

FROM MEXICO’S FRESHWATER SYSTEMS (4):

The Pupfish of Cyprinodontidae Family has one hundred three members that have been placed in nine genera of which thirty-three are found in the freshwater systems of Mexico. They are a small group of killifish that received their common name from their mating habits of the males that resemble puppies at play. They are known in Mexican fishing waters as cachorritos.

The Pupfish have moderately deep and chubby bodies with flattened heads that have short blunt snouts with wide oblique protrusible mouths that are equipped with compressed teeth, and large eyes. They have one anal fin that has 8 to 13 rays and is located well behind the pectoral fins; their caudal fin is bluntly rounded; they have one short dorsal fin that has 0 to 1 spine and 10 to 18 rays that are found mid-body originating before the anal fin; the pelvic fins are found abdominally. They largest Pupfish is 22 cm (8.7 inches). Reproduction is oviparous and involves external fertilization. They have poorly developed gill rakers. They are covered with large scales. They do not have a lateral line.

The Pupfishes are found in fresh, brackish and rarely in coastal marine environments. They are found in tropical and warm temperate waters in the United States, Middle America, West Indies, northern South America, northern Africa, and the Mediterranean Anatolian region are especially noted for being found in extreme and isolated locations. Most species are ovoviviparous with diets consisting of algae, decaying vegetation, and insects. They are capable of surviving extreme conditions including very high salinities, very low oxygen levels and water temperatures between 0^oC (32^oF) and 45^oC (114^oF).

The Pupfish are of scientific interest due their rapid adaptive morphologically diversification and ability to survive in extremely hot water. Some are utilized by the aquarium trade. They date to the middle Tertiary Oligocene Period with a large number of their family now being extinct or facing extinction in the wild.