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'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 ^[1].
The largest spiny lobster on record was over 1 m (3 ft) long and weighed over 11.8 kg (26 lb)^[2].

Contents

Relatives

Fossil record

Ecology

Sound

Gallery

Living animals

Cooked

References

Relatives

The furry lobsters (''e.g.'' ''Palinurellus'') 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'', ''Linuparus'', ''etc.'' (Palinurus was also a helmsman in Virgil's Æneid.)
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.^[3] True lobsters have much smaller antennae and claws on the first three pairs of legs, with the first being particularly enlarged.

Fossil record

The fossil record of spiny lobsters has been extended by the discovery in 1995 of a 110 million year-old fossil near El Espinal in Chiapas, Mexico. 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 ^[4].

Ecology

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 (''Jasus lalandii''). 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 ^[5]. 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 ^[6].

Sound

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 ^[7]. Significantly, the system does not rely on the hardness of the exoskeleton, as many other arthropod noises 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 ''Projasus'' ^[8]), and its form can distinguish different species ^[9].

Gallery

Living animals

Cooked

References

1. The ‘spiny’ focus of fisheries
2. California spiny lobster ''Panulirus interruptus''
3. Marine Lobsters of the World > Glossary
4. Photo in the News: Oldest Lobster Fossil Found in Mexico
5. Decoding Spiny Lobsters' Violin-Like Screech
6. Lobsters have innate way to stay healthy, ODU researchers say in Nature article
7. Spiny lobsters stick and slip to make sound, Sheila N. Patek, , , Nature, 2001
8. FAO species catalogue Vol. 13: Marine Lobsters of the World, Lipke Holthuis, , , Food and Agriculture Organization, 1991, ISBN 92-5-103027-8
9. The Lobster's Violin Adam Summers