鳄雀鳝 · Alligator Gar

Overview

A giant freshwater fish capable of living well beyond fifty years, Atractosteus spatula is unsuitable for home aquaria. Juveniles in the trade represent only the beginning of an exceptional space and time commitment. Very large public facilities are the appropriate scale.

Distribution & habitat

Native range covers central and southeastern parts of the United States and northern to central Mexico, with losses from much of the former northern range. Remaining distribution centers on the lower Mississippi and Gulf Coast toward Veracruz. It uses fresh and brackish water, favoring large rivers and floodplains rather than fast currents.

Aquarium setup

Only very large public installations are appropriate. Avoid strong current and bright lighting, while recognizing that these simple preferences do not lessen the enormous adult housing requirement.

Diet & feeding

Gar-feeding practice centers on aquatic animal foods, using suitably sized frozen shrimp and fish before progressing to whole fish for larger specimens. Juveniles are fed daily, with adult meals reduced to once or twice weekly.

Conversion to dead food can be difficult. Any brief withholding requires adequate body condition. Where live fish are temporarily necessary, quarantine and condition them for at least two weeks before use, then work toward alternatives; this does not eliminate pathogen risk. Mammalian and avian meats are inappropriate.

Behaviour & compatibility

Keep it alone, or only with similarly sized, nonaggressive fish safely beyond swallowing size in sufficiently large facilities.

Sexual dimorphism

Females are thought to grow larger, but this is not a confirmed reliable sexing distinction.

Breeding

Wild spawning takes place in temporarily flooded habitat during spring. A female may mate with several males, placing eggs among submerged vegetation at different depths. Hatching follows in about 48–72 hours, with larvae attached to submerged surfaces for another 5–10 days while yolk is absorbed.

The eggs are toxic to humans, crustaceans, and other nonfish vertebrates and must not be eaten. This describes natural reproduction rather than a home-aquarium method.

Notes

A vascularized swim bladder allows gars to supplement aquatic respiration with air breathing. Hybrids also occur in the trade, so similarly worded common names do not guarantee a pure species identity.