Sand isopod

Chiridotea caeca

FAMILY

Idoteidae

TAXONOMY

Chiridotea caeca Say, 1818, northwest Atlantic Ocean.

OTHER COMMON NAMES

None known.

PHYSICAL CHARACTERISTICS

Adults are dorsoventrally flattened with a thorax that is almost round when viewed from above and have long, robust legs equipped with conspicuous, plumose setae. A long, pointed abdomen follows. Individuals reach approximately 0.6 in (15 mm) in length and 0.3 in (7 mm) in width.

DISTRIBUTION

Western Atlantic Ocean, from Nova Scotia to Florida.

HABITAT

This benthic, marine species populates the coarse, sandy bottom of the intertidal, sometimes subtidal, zone along the ocean shoreline.

BEHAVIOR

A burrowing species of the suborder Valvifera, the sand isopod uses its hindmost pereopods to dig tunnels in the sand. If they are removed from their tunnels, perhaps by wave action, sand isopods swim—often upside down—to the substrate, where they again seek underground protection. Mating occurs while the pair is buried in the substrate.

FEEDING ECOLOGY AND DIET

Apparently carnivorous. Little is known about the diet and feeding ecology of this burrowing species. Predators include a variety of fishes, including flounders and puffers, and shore birds.

REPRODUCTIVE BIOLOGY

Eggs, which are oval shaped, number two to three dozen, occasionally reaching six dozen. Juvenile instars approximately 0.1 in (2.5 mm) long and 0.05 in (1.25 mm) wide appear in the spring. Juveniles go through approximately six instars and mature at a length of approximately 0.4 in (10 mm). Females become ovigerous in December. Mating can take several days. Females undergo the last maturation molt while in amplexus with males. Sand isopods produce one brood per year.

CONSERVATION STATUS

Not listed by the IUCN.

SIGNIFICANCE TO HUMANS

None known.