Upstairs & Lobsters

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The scientific name of European lobster is Hommarus gammarus (Linnaeus, 1758). Also has several common names. For example in English is called lobster, in French is hummer, in Spanish is Bogavante and in Catalan is named llamàntol. Its taxonomic information:

Philum: Artropoda

Classe: Crustacea

Subclass: Malacostraca

Order: Decapoda

Suborder: Reptantia

Infraorder: Nephropidea

Superfamily: Astacidea

Family: Nephropidae

Genus: Hommarus

The European lobster Homarus gammarus is a crustacean, an invertebrate with an exoskeleton as a hard chitin shell. Its body is conformed in two parts, the cephalothorax (head with one pair of sensorial antennae and one pair of mouthparts for feeding + thorax with 4 pairs of walking legs and 1 pair of defense pinces) and the abdomen with a terminal swimming appendages. Lobster can grow up to 60 cm long and weigh about 8 kg. The animals have a dark color, bluish with optional little pale spots (after cook turns into red color). As the name of the order suggest, has ten legs, the first pair transformed into a pair of sharp pinces. There are not equal in size and function. The left one, is largest than the right, and serves to grind. The European lobster lives near the coast, until 60 meters deep. The lobsters prefer the rocky caves before the sandy ground, but in this case, they dig burrows, where buried themselves after molting. They have a wide distribution, from Norway to Morocco with an important presence in the Mediterranean and the Black Sea.

Lobsters has an elevate lifespan, reaching 100 years.  Are dioecious animals, with separated sexes. The reproductive organs of the female (ovary) and the male (testis) are H-shaped. Reproduction takes place every year after reaching maturity. A reliable indicator, in males, is the sudden lengthening of second and third walking legs and in females, the increase of the abdomen. The hormones have determinant role in sex differentiation because copulation occurs immediately after the molt. Copulation is head to head and belly to belly with internal sperm (spermatophores) deposition. The female keeps for 1-2 months and then opens the spermatophores with its modified 5th leg at the same time that releases over the recently open sperm mass the eggs from oviduct, fertilizing them. The eggs will be retained in the ventral side of its abdomen, incubating for about 1-11 months. Then, the eggs hatch, releasing larvaes. The fecundity varies from 100 to 2,000 eggs per female.

The foraging and feeding behavior depends on the life stage. When they are larvae, they feed on small worms, crustaceans and other larvae. Even they could process organic matter (with an animal or vegetable origin). But reaching the adulthood is different. Adults are carnivorous and active predators. Sometimes could be cannibals, eating other smaller lobsters. If conditions are not favorable and food is scarce, lobsters could have a scavenger behavior.

DO YOU KNOW…?

… The lobsters dwell inside the caves under the seas with a fish, the conger or Conger conger (Linnaeus, 1758) in a mutual symbiosis. The conger eats octopus, the natural predator of lobsters.

… The lobsters could live more than 100 years. In 2009, PETA rescue a 9 kg and 140 years old lobster from the restaurant “City Crab and Seafood” of New York.

… The fact to have pinces of different size is due to a specific functionality. The lobster could change from right-handed to left-handed if it loses one pince, producing a reallocation of functions while it goes grows back again.

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