Homarus
Encyclopedia
Homarus is a genus
of lobster
s, which include the common and commercially significant species Homarus americanus (the American lobster
) and Homarus gammarus (the European lobster). The Cape lobster
, which was formerly in this genus as H. capensis, was moved in 1995 to the new genus Homarinus.
, which is much more slender, and has grooves along the claws and the abdomen, and Homarinus, the Cape lobster
from South Africa, which is even smaller, and has hairy claws.
, but only two species survive. These two species, the American lobster
and the European lobster
, are very similar and may have speciated
as recently as the Pleistocene
, during climatic fluctuations. The best characters for distinguishing them are the geographic distribution, with the American lobster in the western Atlantic and the European lobster in the eastern Atlantic, and by the presence of one or more teeth on the underside of the rostrum
in H. americanus but not in H. gammarus.
from the eastern Atlantic Ocean
, Mediterranean Sea
and parts of the Black Sea
. It may grow to a length of 60 cm (23.6 in) and a mass of 6 kilograms (13.2 lb), and bears a conspicuous pair of claw
s. In life, the lobsters are blue, only becoming "lobster red" on cooking. Mating
occurs in the summer, producing eggs
which are carried by the females for up to a year before hatching into plankton
ic larvae
. Homarus gammarus is a highly esteemed food, and is widely caught
using lobster pots
, mostly around the British Isles
.
of North America
. It is found as far south as North Carolina
, but is famously associated with the colder waters around the Canadian Maritimes, Newfoundland and Labrador
, Maine
, Massachusetts
, Rhode Island
and New Hampshire
.
They commonly range from 20–60 cm (7.9–23.6 in) in length and 0.5 kilogram in weight, but have been known to reach lengths of well over 1 m (3.3 ft) and weigh as much as 20 kg (44.1 lb) or more, making this the heaviest marine crustacean in the world. An average adult is about 23 cm (9 in) long and weighs 700 gram.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of lobster
Lobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...
s, which include the common and commercially significant species Homarus americanus (the American lobster
American lobster
The American lobster, Homarus americanus, is a species of lobster found on the Atlantic coast of North America, chiefly from Labrador to New Jersey. Within North America, it is also known as the northern lobster or Maine lobster. It can reach a body length of , and a mass of over , making it the...
) and Homarus gammarus (the European lobster). The Cape lobster
Cape lobster
The Cape lobster, Homarinus capensis, is a small lobster that lives off the coast of South Africa, between Cape Town and East London...
, which was formerly in this genus as H. capensis, was moved in 1995 to the new genus Homarinus.
Description
Homarus is one of three extant genera of clawed lobsters to show dimorphism between claws – a specialisation into a crushing claw and a cutting claw. The other similar genera are NephropsNephrops
Nephrops is a genus of lobsters comprising a single extant species, Nephrops norvegicus , and several fossil species. It was erected by William Elford Leach in 1814, to accommodate N...
, which is much more slender, and has grooves along the claws and the abdomen, and Homarinus, the Cape lobster
Cape lobster
The Cape lobster, Homarinus capensis, is a small lobster that lives off the coast of South Africa, between Cape Town and East London...
from South Africa, which is even smaller, and has hairy claws.
Species
Eight extinct species are known from the fossil record, which stretches back to the CretaceousCretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, but only two species survive. These two species, the American lobster
American lobster
The American lobster, Homarus americanus, is a species of lobster found on the Atlantic coast of North America, chiefly from Labrador to New Jersey. Within North America, it is also known as the northern lobster or Maine lobster. It can reach a body length of , and a mass of over , making it the...
and the European lobster
European lobster
Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster from the eastern Atlantic Ocean, Mediterranean Sea and parts of the Black Sea. It is closely related to the American lobster, H. americanus. It may grow to a length of and a mass of , and bears a...
, are very similar and may have speciated
Speciation
Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...
as recently as the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
, during climatic fluctuations. The best characters for distinguishing them are the geographic distribution, with the American lobster in the western Atlantic and the European lobster in the eastern Atlantic, and by the presence of one or more teeth on the underside of the rostrum
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
in H. americanus but not in H. gammarus.
Homarus gammarus
Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobsterLobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...
from the eastern Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
, Mediterranean Sea
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
and parts of the Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
. It may grow to a length of 60 cm (23.6 in) and a mass of 6 kilograms (13.2 lb), and bears a conspicuous pair of claw
Claw
A claw is a curved, pointed appendage, found at the end of a toe or finger in most mammals, birds, and some reptiles. However, the word "claw" is also often used in reference to an invertebrate. Somewhat similar fine hooked structures are found in arthropods such as beetles and spiders, at the end...
s. In life, the lobsters are blue, only becoming "lobster red" on cooking. Mating
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
occurs in the summer, producing eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
which are carried by the females for up to a year before hatching into plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
ic larvae
Crustacean larvae
Crustaceans may pass through a number of larval and immature stages between hatching from their eggs and reaching their adult form. Each of the stages is separated by a moult, in which the hard exoskeleton is shed to allow the animal to grow...
. Homarus gammarus is a highly esteemed food, and is widely caught
Lobster fishing
Lobster fishing, sometimes called lobstering, is the commercial or recreational harvesting of marine lobsters, spiny lobsters or crayfish.-Lobster tools and technology:...
using lobster pots
Lobster trap
Not to be confused with Lobster-tailed potA lobster trap or lobster pot is a portable trap that traps lobsters or crayfish and is used in lobster fishing. A lobster trap can hold several lobsters. Lobster traps are constructed of wire and wood. An opening permits the lobster to enter a tunnel of...
, mostly around the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
.
Homarus americanus
The American lobster, Homarus americanus, is found on the Atlantic coastAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. It is found as far south as North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, but is famously associated with the colder waters around the Canadian Maritimes, Newfoundland and Labrador
Newfoundland and Labrador
Newfoundland and Labrador is the easternmost province of Canada. Situated in the country's Atlantic region, it incorporates the island of Newfoundland and mainland Labrador with a combined area of . As of April 2011, the province's estimated population is 508,400...
, Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...
, Rhode Island
Rhode Island
The state of Rhode Island and Providence Plantations, more commonly referred to as Rhode Island , is a state in the New England region of the United States. It is the smallest U.S. state by area...
and New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
.
They commonly range from 20–60 cm (7.9–23.6 in) in length and 0.5 kilogram in weight, but have been known to reach lengths of well over 1 m (3.3 ft) and weigh as much as 20 kg (44.1 lb) or more, making this the heaviest marine crustacean in the world. An average adult is about 23 cm (9 in) long and weighs 700 gram.
Fossil species
The boundaries between Homarus and the extinct genus Hoploparia are unclear, and some species, such as Hoploparia benedeni have been transferred between the two genera. Eight species have been assigned to Homarus from the fossil record. They are:- Homarus americanusAmerican lobsterThe American lobster, Homarus americanus, is a species of lobster found on the Atlantic coast of North America, chiefly from Labrador to New Jersey. Within North America, it is also known as the northern lobster or Maine lobster. It can reach a body length of , and a mass of over , making it the...
H. Milne-Edwards, 1837 – PleistocenePleistoceneThe Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and .... - Homarus brittonestris Stenzel, 1945 – lower TuronianTuronianThe Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
- Homarus davisi Stenzel, 1945 – lower TuronianTuronianThe Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous epoch, or a stage in the Upper Cretaceous series. It spans the time between 93.5 ± 0.8 Ma and 89.3 ± 1 Ma...
- Homarus hakelensis (Fraas, 1878) – CenomanianCenomanianThe Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
- Homarus lehmanni Haas, 1889 – RupelianRupelianThe Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene epoch/series. It spans the time between and . It is preceded by the Priabonian stage and is followed by the Chattian stage....
- Homarus mickelsoni (Bishop, 1985) – lower CampanianCampanianThe Campanian is, in the ICS' geologic timescale, the fifth of six ages of the Late Cretaceous epoch . The Campanian spans the time from 83.5 ± 0.7 Ma to 70.6 ± 0.6 Ma ...
- Homarus morrisiHomarus morrisiHomarus morrisi is a species of fossil lobster from the Eocene of southern England.-Taxonomy:Specimens of H. morrisi were described as early as 1849, but were assigned to Hoploparia gammaroides rather than Homarus by scientists including Frederick M'Coy and Thomas Bell. In 1987, W. J...
Quayle, 1987 – EoceneEoceneThe Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the... - Homarus neptunianus Polkowsky, 2004 – OligoceneOligoceneThe Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...
- Homarus travisensis Stenzel, 1945 – middle AlbianAlbianThe Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous epoch/series. Its approximate time range is 112.0 ± 1.0 Ma to 99.6 ± 0.9 Ma...