Alligator gar
Atractosteus spatula
— Where the name comes from
Atractosteus is “arrow bone”, from átraktos, the spindle or dart, and ostéon: the body is tapered and rigid as a shaft. Spatula describes the broad short snout, unlike the slender one of the other gars. The common name comes from the double row of teeth and the snout, which really do suggest an alligator.
— Facts
- Group
- Fish · Actinopterygii · Chondrichthyes
- Order
- Gars
- Habitat
- Large slow rivers, bayous, brackish estuaries
- Range
- The Mississippi basin and the Gulf of Mexico coasts
- Size
- 1.8–2.4 m, up to 3 m; 45–140 kg
- Diet
- Fish, waterfowl, turtles, carrion
- Lifespan
- 50 years, females over 90
— Characteristics
- 01
Its ganoid scales are so hard that Native Americans used them as arrowheads.
- 02
It breathes air and survives in water nearly devoid of oxygen.
- 03
Its eggs are toxic to people and to most predators.
— What sets it apart
Its armour is studied in materials engineering laboratories. Each scale is made of two layers — very hard enamel above, tougher bone below — bonded across a wavy interface that stops cracks propagating, and the result withstands bites that would break bone: experiments have shown that not even an alligator’s teeth pierce it. It is the same principle as modern composite materials, arrived at a hundred thousand centuries early.
