Potosi pupfish

Scientific name: Cyprinodon alvarezi

Country: Mexico

Continent: North America

Diet: Herbivore

Food & feeding: Filamentous algae

Habitats: Freshwater

Conservation status: Extinct in the wild

Relatives: Other pupfish

Description: Potosi pupfish have a classic pupfish body form; just 5 cm long with a large head and eyes, an extendable mouth with many teeth and large silver-blue scales.

Lifestyle: Very little is known about its ecology. However, males have been seen defending a breeding territory in the thick swamp vegetation, with heavy aggregate spawning occurring down to 2 metres.

Family & friends: This fish will defend its territory, showing aggression towards other males of the same and different species.

Keeping in touch: The common name is said to derive from the male’s courtship dance, which resembles puppies at play.

Growing up: Females can carry eggs from at least February to April. Once these eggs are laid, the fry hatch out after 5-6 days gestation and are mature at 6 months. It seems these fish may be capable of repeated reproduction over long periods of time.

Conservation news: These fish once inhabited the fresh water springs and swamps on the arid plateaux of the El Potosi region of Mexico. Their limited habitat appeared to be the remnants of a large Pleistocene lake. None of this habitat remains and this fish is now extinct in the wild. Potosi pupfish are part of a captive breeding programme at Bristol Zoo Gardens.