Cyprinodon brontotheroides · Durophage Pupfish

Overview

Specialized for hard-shelled prey, Cyprinodon brontotheroides has a protruding nasal region and shortened upper jaw that support forceful shell crushing. Its natural setting is hypersaline lakes, so ordinary freshwater-pupfish husbandry should not be assumed to apply.

Distribution & habitat

It is endemic to six hypersaline lakes on San Salvador Island, Bahamas. Fish use littoral habitat and can be common in aquatic-grass patches, without showing a clear dependence on one vegetation type.

Diet & feeding

A specialized durophage, it chiefly targets shelled invertebrates, especially gastropods and ostracods. Modified jaws permit powerful closure to crush their protective shells.

Sexual dimorphism

Mature males have metallic blue speckling toward the front of the back and a black tail margin. Breeding males sometimes develop orange below. Females and juveniles carry a black-and-white dorsal eyespot.

Breeding

Males defend breeding territories in midwater. Reproduction has been observed throughout the year but appears most frequent in spring. These field observations do not establish an aquarium breeding protocol.

Notes

Related island species coexist while exploiting different food resources, providing the ecological setting for this fish’s unusual anatomy. Introduced fishes in local waters have prompted concern for these endemic assemblages.