- This article is about the animal. For the B-52's song, see Rock Lobster.
Spiny lobsters, also known as langouste or rock lobsters are a family (Palinuridae) of about 45 species of achelate crustaceans, in the Decapoda Reptantia. Spiny lobsters are also called crayfish, sea crayfish or crawfish. Like true lobsters, spiny lobsters are edible and are an economically significant food source; they are the biggest food export of the Bahamas .
The largest spiny lobster on record was over 1 m (3 ft) long and weighed over 11.8 kg (26 lb).
The furry lobsters
) are sometimes separated into a family of their own, the Synaxidae, but are usually considered members of the Palinuridae. The slipper lobsters
(Scyllaridae) are their next closest relatives, and these two or three families make up the Achelata
. Genera of spiny lobsters include Palinurus
and a number of anagrams thereof: Panulirus
was also a helmsman in Virgil
Although they superficially resemble true lobsters in terms of overall shape and having a hard carapace and exoskeleton, the two groups are not closely related. Spiny lobsters can be easily distinguished from true lobsters by their very long, thick, spiny antennae, and by the lack of claws (chelae) on the first four pairs of walking legs, although the females of most species have a small claw on the fifth pair. True lobsters have much smaller antennae and claws on the first three pairs of legs, with the first being particularly enlarged. )
The fossil record
of spiny lobsters has been extended by the discovery in 1995 of a 110 million year-old fossil near El Espiñal
. Workers from the National University of Mexico
have named the fossil Palinurus palaecosi
, and report that it is closest to members of the genus Palinurus
currently living off the coasts of Africa .
Spiny lobsters are found in almost all warm seas, including the Caribbean
and the Mediterranean Sea
, but are particularly common in Australasia
, where they are referred to commonly as crayfish
or sea crayfish (Jasus novaehollandiae
and Jasus edwardsii
), and South Africa
). A new species, Palinurus barbarae
was described in 2006.
Spiny lobsters tend to live in crevices of rocks and coral reefs, only occasionally venturing out at night to seek snails, clams, crabs, sea urchins or carrion to eat. Sometimes, they migrate en masse, in long files of lobsters across the sea floor. Potential predators may be deterred from eating spiny lobsters by a loud screech made by the antennae of the spiny lobsters rubbing against a smooth part of the exoskeleton . Spiny lobsters usually exhibit social habit by being together. However recent studies indicate that healthy lobsters move away from infected ones leaving the diseased lobsters to fend for themselves .
Spiny lobsters produce rasping
sounds to repel predators
. This is done by rubbing the "plectrum" at the base of the spiny lobster's antennae against a "file". The noise is produced by sticking and slipping, in the same way that a violin
string is bowed, and is the only example of this kind of sound production in the animal kingdom . Significantly, the system does not rely on the hardness of the exoskeleton, as many other arthropod
sounds do, meaning that the spiny lobsters can continue to produce the deterrent noises even in the period following a moult
when they are most vulnerable . The stridulating organ is present in all but two genera in the family (Jasus
), and its form can distinguish different species .