| Scyllarides latus | |
|---|---|
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Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Malacostraca |
| Order: | Decapoda |
| Suborder: | Pleocyemata |
| Family: | Scyllaridae |
| Genus: | Scyllarides |
| Species: | S. latus |
| Binomial name | |
| Scyllarides latus | |
| Synonyms | |
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Scyllarides latus, theMediterranean slipper lobster, is aspecies ofslipper lobster found in theMediterranean Sea and in the easternAtlantic Ocean. It is edible and highly regarded as food, but is now rare over much of its range due tooverfishing. Adults may grow to 1 foot (30 cm) long, arecamouflaged, and have noclaws. They arenocturnal, emerging from caves and other shelters during the night to feed onmolluscs. As well as being eaten by humans,S. latus is also preyed upon by a variety of bony fish. Its closest relative isS. herklotsii, which occurs off the Atlantic coast of West Africa; other species ofScyllarides occur in the western Atlantic Ocean and theIndo-Pacific. The larvae and young animals are largely unknown.
Scyllarus latus is found along most of the coast of theMediterranean Sea (one exception being the northernAdriatic Sea[3]), and in parts of the easternAtlantic Ocean from nearLisbon inPortugal south toSenegal, including the islands ofMadeira, theAzores, theSelvagens Islands and theCape Verde Islands.[2] In Senegal, it occurs together with a related speciesScyllarides herklotsii, which it closely resembles.[3]
S. latus can grow to a total body length about 45 centimetres (18 in), although rarely more than 30 cm (12 in). This is equivalent to acarapace length of up to 12 cm (4.7 in).[2] An individual may weigh as much as 1.5 kilograms (3.3 lb).[3] As in all slipper lobsters, the second pair ofantennae are enlarged and flattened into "shovels" or "flippers".[4] Despite the name "lobster", slipper lobsters such asScyllarides latus have noclaws, and nor do they have the protective spines ofspiny lobsters. Instead, theexoskeleton, and particularly thecarapace, are thicker than inclawed lobsters and spiny lobsters, acting as resilientarmour.[3] Adults arecryptically coloured, and the carapace is covered in conspicuous, hightubercles.[2]
S. latus lives on rocky orsandysubstrates at depths of 4–100 metres (13–328 ft).[2] They shelter during the day in natural dens, on the ceilings ofcaves, or inreefs, preferring situations with more than one entrance or exit.[3]
The diet ofS. latus consists generally ofmolluscs. The preferred prey is, according to different sources, eitherlimpets[2] orbivalves.[3] The prey, whichS. latus can detect even under 3.5 cm (1.4 in) ofsediment, is opened by careful use of the strong pointedpereiopods. They will also eatoysters andsquid, but notsea urchins ormuricidsnails. They eat more in warmer seasons, getting through 3.2 oysters per day in July, but only 0.2 oysters per day in January.[3]
The most significantpredator ofS. latus is thegrey triggerfish,Balistes capriscus, although a number of other fish species have also been reported to prey onS. latus, including dusky groupers (Epinephelus guaza), combers (Serranus spp.),Mediterranean rainbow wrasse (Coris julis),red groupers (Epinephelus morio) andgag groupers (Mycteroperca microlepis).[3] AnOctopus vulgaris has been observed to eatS. latus in an artificial setting, but it is unclear whetherS. latus is preyed on byoctopuses in nature.[3]
MaleScyllarus latus carryspermatophores at the base of the last two pairs ofpereiopods in April.[3]Fertilisation has not been observed in this species, but mostreptant decapods mate with the ventral surfaces together.[5] Between July and August, females carry around 100,000eggs on their enlarged, featherypleopods. The eggs develop from being a bright orange colour to a dark brown before being shed into the water after around 16 days of development. There is normally only onegeneration per year.[3]
Thelarvae are much less well known than the adults. An initial 1.3 millimetres (0.05 in) long naupliosoma stage, which swims using itsantennae,moults into the first of elevenphyllosoma stages, which swim using theirthoracic legs.[6] The last phyllosoma stage may reach a size of 48 mm (1.9 in) and can be up to 11 months old; most of the intermediate phyllosoma stages have not been observed.[3] A singlenisto (juvenile has been recorded, having been caught offReggio Calabria in 1900, but only recognised as being a juvenileS. latus in 2009.[7] Young adults are also rare; a museum specimen with a carapace length of 34 mm (1.3 in) is the smallest adult yet observed. Adultsmoult annually, and probablymigrate to cooler waters with a temperature of 13–18 °C (55–64 °F) to do so. The old exoskeleton softens over a period of 10–22 days before being shed, and the new, pale exoskeleton takes around three weeks to harden completely. Smaller individuals typically gain weight over the course of a moult, but this difference is less pronounced in larger animals.[3]
Scyllarides latus is mostly nocturnal in the wild, since most of itspredators are diurnal. While sheltering,S. latus tends to begregarious, with several individuals sharing the same shelter. When confronted with a predator,S. latus has no claws or spines to repel the predator, and instead either clings to the substrate, or swims away with powerful flexion of theabdomen, or "tail-flips". Larger lobsters can exert a stronger grip than smaller ones, with a force of up to 150newtons (equivalent to a weight of 15 kilograms or 33 pounds) required to dislodge the largest individuals.[3]
Predator avoidance may also explain the frequent behaviour whereS. latus will carry food items back to a shelter before consuming them. When twoS. latus individuals compete for a food item, they may use the enlarged second antennae to flip their opponent over, by wedging the antennae underneath the opponent's body and quickly raising them. An alternative strategy is to grip an opponent and begin the tail-flipping movement, or to engage in atug of war.[3]
Scyllarides latus was originally classified in the genusScyllarus, along with the four other slipper lobsters known at the time (Scyllarus arctus,Scyllarides aequinoctialis,Thenus orientalis andArctides guineensis). Separate genera were first introduced byWilliam Elford Leach in 1815, namelyThenus andIbacus. In 1849,Wilhem de Haan divided the genusScyllarus into two genera,Scyllarus andArctus, but made the error of including thetype species ofScyllarus in the genusArctus. This was first recognised by theichthyologistTheodore Gill in 1898, whosynonymisedArctus withScyllarus, and erected a new genusScyllarides to hold the species that De Haan had placed inScyllarus.[8]Scyllarides is placed in the subfamilyArctidinae, which is differentiated from other subfamilies by the presence of multiarticulatedexopods on all threemaxillipeds, and a three-segmentedpalp on themandible. The only other genus in the subfamily,Arctides, is distinguished by having a more highly sculptured carapace, with an extra spine behind each eye, and a transverse groove on the first segment of the abdomen.[9]
The only other species ofScyllarides to occur in the Eastern Atlantic isScyllarides herklotsii, which differs fromS. latus mostly in the ornamentation on the carapace; while inS. latus the tubercles (lumps projecting from the surface) are high and pronounced, they are lower and more rounded inS. herklotsii.[10]
Thetype locality given byPierre André Latreille in his original description of the species was simply "Mediterranée" (Mediterranean Sea), without designating atype specimen.Lipke Holthuis later chose alectotype for the species, which was the animal illustrated by Cornelius Sittardus, and published inConrad Gesner'sHistoriae animalium in 1558 (book 4, p. 1097).[2] This illustration, originally awatercolour but reproduced by Gesner in awoodcut, had been mentioned by Latreille in his description as being particularly fine, and is all that remains of the type specimen.[11] Given that Sittardus was working inRome at the time, it is likely that the type specimen was a fresh specimen from theTyrrhenian Sea near Rome.[11]
S. latus is edible, but it is a relatively rare species, and is therefore of little interest tofisheries. However, it is caught in small numbers throughout its distribution, mostly intrammel nets, bytrawling and inlobster pots. An annual catch of 2,000–3,000 kg (4,400–6,600 lb) has been reported forIsrael. Catching by hand has become increasingly frequent, since the advent ofSCUBA diving made the animal's habitat more accessible to humans. This may have affected population sizes ofS. latus in some areas.[2]
Media related toScyllarides latus at Wikimedia Commons
