Spiny lobster
Spiny lobsters, also known as langustas, langoustes, or rock lobsters are marine decapod crustaceans belonging to the family Palinuridae. Spiny lobsters are also, especially in Australia, New Zealand, Ireland, South Africa, and the Bahamas, called crayfish, sea crayfish, or crawfish, terms which elsewhere are reserved for freshwater crayfish.
Classification
Like true lobsters, spiny lobsters belong to the clade Reptantia. The furry lobsters were previously separated into a family of their own, the Synaxidae, but they are usually considered members of the Palinuridae. The slipper lobsters 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. The name derives from the small Italian port of Palinuro, which was known for harvesting the European spiny lobster in ancient Roman times. The town itself was named for the legendary figure of Palinurus, who was a helmsman in Virgil's Æneid.In total, 12 extant genera are recognised, containing around 60 living species:
- Jasus Parker, 1883
- Justitia Holthuis, 1946
- Linuparus White, 1847
- Nupalirus Kubo, 1955
- Palibythus Davie, 1990
- Palinurellus De Man, 1881
- Palinurus Weber, 1795
- Palinustus A. Milne-Edwards, 1880
- Panulirus White, 1847
- Projasus George and Grindley, 1964
- Puerulus Ortmann, 1897
- Sagmariasus Holthuis, 1991
Description
Spiny lobsters typically have a slightly compressed carapace, lacking any lateral ridges. Their antennae lack a scaphocerite, the flattened exopod of the antenna. This is fused to the epistome. The flagellum, at the top of the antenna, is stout, tapering, and very long. The ambulatory legs end in claws.
Size
The size of the adults varies from a few centimetres to. In general, it is said that rarely some individuals can reach .Nevertheless, some reports – the authenticity of which can be questioned – are of much larger lobsters. One such source is Bernard Gorsky's travel book La dernière île. In this, the author lists the following statements:
- According to a 1956 article from the New Caledonian daily newspaper La France Australe : "Since yesterday, a so-called porcelain spiny lobster, stuffed, can be seen in the window of Balande. Its length is, and it weighed
- Inhabitants of a small island in the Coral Sea caught a 2 m 10 cm, porcelain spiny lobster, according to an Australian publication.
- Gorsky himself caught lobsters with local tribesmen on the Loyalty Islands group's Mouli island and mentioned them in the article in La France Australe. However, according to the locals, even bigger crabs can live there. According to the residents, a man from the Leikigne tribe reported the following: he once went fishing with a friend and the friend drowned. He did not come to the surface, he followed him into the depths. Two legs protruded from a hollow, and in the hollow sat a huge crayfish, and it was eating the fisherman. The crawfish was said to be as thick as the trunk of a full-grown palm tree. Since one of Gorsky's narrators was 20 years old at the time of the story, and the incident occurred when he was 12, the story must have been around 1957 if true.
- A study was conducted regarding the effect of growth and survival when you change the frequency of feeding the Spiny Lobster and it was determined that if there is increased feed frequency from one to sixteen feeds daily then that is where growth and feed attraction are at the peak of their performance. If the lobsters are fed too much though, more than 16 feeds a day causes decreased feed intake and reduction in overall growth. It was also determined that the rapid leaching of feed suggests that there is a beneficial effect of feeding multiple frequencies on growth and intake.
Fossil record
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, and in South Africa.Spiny lobsters tend to live in crevices of rocks and coral reefs, only occasionally venturing out at night to seek snails, clams, sea-hares, crabs, or sea urchins to eat. They sometimes migrate in very large groups in long files of lobsters across the sea floor. These lines may be more than 50 lobsters long. Spiny lobsters navigate using the smell and taste of natural substances in the water that change in different parts of the ocean. It was recently discovered that spiny lobsters can also navigate by detecting the Earth's magnetic field. They keep together by contact, using their long antennae. 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 the social habit of being together. However recent studies indicate that healthy lobsters move away from infected ones, leaving the diseased lobsters to fend for themselves.
Like true lobsters, spiny lobsters are edible and are an economically significant food source; they are the biggest food export of the Bahamas, for instance.