Cirolanidae Family of Isopods
One Cirolanid Isopod of the Cirolanidae Family can be found in this website:
Harford’s Isopod, Cirolana harfordi. A representative of the Cirolanidae Family of Isopods.
Phylogeny: Cirolanid Isopods of the Cirolanidae Family are in the phylum Arthropoda, meaning that they have jointed legs. They are in the subphylum Crustacea, the same as crabs and lobsters, and in the class Malacostra. Like terrestrial pill bugs, sow bugs, and wood lice, they are in the order Isopoda. The Cirolanidae Family is one of nine families in the superfamily Cymothooidea and that superfamily is one of two superfamilies in the suborder Cymothoida. The Cirolanidae Family is large and consists of forty-seven genera and between four hundred twenty and five hundred species. Species in the Cirolanidae Family are also commonly known as Cirolanids. The name Cirolanidae comes from the genus Cirolana. Cirolana is an anagram for an unknown woman named Caroline or Carolina. This anagram was coined by the British naturalist William Leach.
Morphology: Cirolanid Isopods have a rigid, segmented, exoskeleton, two pairs of antennae, seven limbs, and five respiratory appendages. Isopods in this family have sleek symmetrical, bodies that are sometimes described as semi-cylindrical. They are two to six and a half times longer than wide. Their heads are not capable of lateral movement. The dorsal surface may be smooth, wrinkled, or nodulous. The antennae are usually unequal in length, and they are multiarticulate. The eyes are lateral and small to moderate in size. The eyes are absent in some deep water and subterranean species. There are six abdominal segments. The first three pairs of legs are prehensile. The last four pairs are ambulatory. The pleopods are well developed for swimming and respiration. The uropods form the tail fan with the pleotelson. The mouth parts are generally robust in these efficient predator/scavengers. Some species use these mouth parts to deliver painful bites to swimmers. Cave-dwelling Cirolanids exhibit more morphological diversity than other species. Some Cirolanid species exhibit sexual dimorphism. Cirolanids vary greatly in size ranging from 2.8 mm (0.11 inches) to 50 cm (19.7 inches) in length.
Habitat and Distribution: Cirolanids live in freshwater, underground water, and marine environments. Marine Cirolanids are found in a variety of habitats including: buried in sand, under rocks, in algae clusters, on kelp holdfasts, in mussel beds, on sponges, and in the burrows of other animals. Most live in the intertidal zone or in shallow waters, but some reach deep waters, exceeding 3,000 m (9,840 feet). Cirolanid Isopods are found worldwide in tropical to polar seas. Twenty species from the Cirolanidae Family are found in the marine waters of Mexico.
Reproduction: Cirolanids are gonochoric (male or female for life). Reproduction is sexual, generally with external fertilization. The males deposit sperm into the female’s brood pouch (marsupium). The female carries the fertilized eggs until they hatch. Some species have internal fertilization and the eggs hatch inside the mother (ovoviviparous).
Ecosystem Interactions: Cirolanids prey on polychaete worms, small crustaceans, sick or injured fish, and fish trapped in nets. They scavenge dead animals. It has been noted that they can strip a fish to bones in a matter of hours. Most species are strong swimmers and can enter the water column to find prey. Cirolanids are preyed upon by shore birds, crustaceans, fish, and mollusks. Most are thought to be nocturnal.