Editing Homarus

{{Short description|Genus of lobsters}}
{{Italic title}}
{{Automatic taxobox
| name = ''Homarus''
| fossil_range = {{fossil range|Albian|Recent|[[Albian]]–Recent}}
| image = KreeftbijDenOsse.jpg
| image_caption = ''[[Homarus gammarus]]''
| taxon = Homarus
| authority = [[Friedrich Weber (entomologist)|Weber]], 1795
| type_species = ''[[Homarus gammarus|Astacus marinus]]''
| type_species_authority = [[Johan Christian Fabricius|Fabricius]], 1775
| subdivision_ranks = Extant species
| subdivision = ''H. americanus'' – [[American lobster]]<br/>''[[Homarus gammarus|H. gammarus]]'' – European lobster
}}

'''''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).<ref>{{ITIS |taxon=''Homarus'' Weber, 1795 |id=97313 |accessdate=June 25, 2011}}</ref> The [[Cape lobster]], which was formerly in this genus as ''H. capensis'', was moved in 1995 to the new genus ''Homarinus''.<ref>{{cite journal |author1=Irv Kornfield |author2=Austin B. Williams |author3=Robert S. Steneck |year=1995 |title=Assignment of ''Homarus capensis'' (Herbst, 1792), the Cape lobster of South Africa, to ''Homarius'' new genus (Decapoda: Nephropidae) |journal=[[Fishery Bulletin]] |volume=93 |issue=1 |pages=97–102 |url=http://fishbull.noaa.gov/931/kornfield.pdf }}</ref>

==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 ''[[Nephrops]]'', 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.<ref name="Nephropinae">[ftp://ftp.fao.org/docrep/fao/009/t0411e/t0411e09.pdf Subfamily Nephropinae Dana, 1852]{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}}, pp. 51–86 in [[#refHolthuis|Holthuis (1991)]].</ref>

While analyses of [[morphology (biology)|morphology]] suggest a close relationship between ''Homarinus'' and ''Homarus'', [[molecular phylogenetics|molecular analyses]] using [[mitochondrial DNA]] reveal that they are not [[sister taxa]].<ref name="Tshudy">{{cite book |author1=Dale Tshudy |author2=Rafael Robles |author3=Tin-Yam Chan |author4=Ka Chai Ho |author5=Ka Hou Chu |author6=Shane T. Ahyong |author7=Darryl L. Felder |year=2009 |chapter=Phylogeny of marine clawed lobster families Nephropidae Dana, 1852, and Thaumastochelidae Bate, 1888, based on mitochondrial genes |title=Decapod Crustacean Phylogenetics |editor1=Joel W. Martin |editor2=Keith A. Crandall|editor2-link=Keith A. Crandall |editor3=Darryl L. Felder |publisher=[[CRC Press]] |pages=357–368 |isbn=978-1-4200-9258-5 |doi=10.1201/9781420092592-c18|doi-broken-date=2024-11-12 }}</ref> Both genera lack ornamentation such as [[spine (zoology)|spines]] and [[:wikt:carina|carinae]], but are thought to have reached that state independently, through [[convergent evolution]].<ref name="Tshudy"/> The closest living relative of ''Homarus'' is ''[[Nephrops norvegicus]]'', while the closest relatives of ''Homarinus'' are ''[[Thymops]]'' and ''[[Thymopides]]''.<ref name="Tshudy"/>

==Species==
Eight extinct species are known from the [[fossil record]],<ref name="Grave">{{cite journal|journal=[[Raffles Bulletin of Zoology]] |year=2009 |volume=Suppl. 21 |pages=1–109 |title=A classification of living and fossil genera of decapod crustaceans |author1=Sammy De Grave |author2=N. Dean Pentcheff |author3=Shane T. Ahyong |url=http://rmbr.nus.edu.sg/rbz/biblio/s21/s21rbz1-109.pdf |display-authors=etal |url-status=dead |archiveurl=https://web.archive.org/web/20110606064728/http://rmbr.nus.edu.sg/rbz/biblio/s21/s21rbz1-109.pdf |archivedate=2011-06-06 }}</ref> which stretches back to the [[Cretaceous]],<ref name="Obst">{{cite journal |journal=[[Molecular Ecology (journal)|Molecular Ecology]] |year=2005 |volume=14 |pages=4427–4440 |doi=10.1111/j.1365-294X.2005.02752.x |title=Hidden diversity and host specificity in cycliophorans: a phylogeographic analysis along the North Atlantic and Mediterranean Sea |author1=Matthias Obst |author2=Peter Funch |author3=Gonzalo Giribet |pmid=16313603 |issue=14|s2cid=26920982 }}</ref> but only two species survive. These two species, the [[American lobster]] and the [[European lobster]], are very similar and may have [[speciation|speciated]] as recently as the [[Pleistocene]], during climatic fluctuations.<ref name="Obst"/> 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 (anatomy)|rostrum]] in ''H. americanus'' but not in ''H. gammarus''.<ref>{{cite book |url=http://ip30.eti.uva.nl/bis/lobsters.php?menuentry=tekstsleutel&pagenum=12 |title=''Key to species of the genus'' Homarus |page=57 |access-date=2006-12-02 |archive-url=https://web.archive.org/web/20080608150630/http://ip30.eti.uva.nl/bis/lobsters.php?menuentry=tekstsleutel&pagenum=12 |archive-date=2008-06-08 |url-status=dead }} In [[#refHolthuis|Holthuis (1991)]].</ref>

{| class="wikitable"
|-
! Image !! Scientific name !! Common name!! Description!! Distribution
|-
|[[File:Bugre europeu.jpg|150px]] || ''[[Homarus gammarus]]'' {{small|[[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]}}|| European lobster or common lobster ||  may grow to a length of {{convert|60|cm|abbr=on}} and a mass of {{convert|6|kg}}, and bears a conspicuous pair of [[claw]]s.<ref name="MLW_gammarus"/> In life, the lobsters are most of the time blue, only becoming "lobster red" on cooking.<ref name="Davidson">{{cite book |author=Alan Davidson |year=2004 |title=North Atlantic Seafood: A Comprehensive Guide with Recipes |publisher=[[Ten Speed Press]] |isbn=978-1-58008-450-5 |chapter=Lobster (both European and American) |pages=188–189 |chapter-url=https://books.google.com/books?id=hFhjGhkAqZ0C&pg=PA188}}</ref> ''Homarus gammarus'' is a highly esteemed food, and is widely [[lobster fishing|caught]] using [[lobster trap|lobster pots]],<ref name="MLW_gammarus"/>|| Mostly around the [[British Isles]].<ref>{{cite web |url=http://www.fao.org/fishery/statistics/global-production/en |title=Fishery Statistical Collections. Global Production |work=Fisheries Global Information System |publisher=[[Food and Agriculture Organization]] |accessdate=September 30, 2010}}</ref>
|-
|[[File:Bugre americanu.jpg|150px]] || ''[[Homarus americanus]]'' {{small|H. Milne-Edwards, 1837}} ||  Atlantic lobster, Canadian lobster, true lobster, northern lobster, Canadian Reds, or Maine lobster. ||  commonly ranges from {{convert|20|-|60|cm|in|0|abbr=on}} in length and {{convert|0.5|-|4.1|kg|abbr=on}} in weight, but have been known to reach lengths of {{convert|64|cm|abbr=on}}<ref name="MLW_gammarus58">{{cite book|url=http://nlbif.eti.uva.nl/bis/lobsters.php?menuentry=soorten&id=87 |title=Homarus americanus |page=58 |url-status=dead |archiveurl=https://web.archive.org/web/20110608024508/http://nlbif.eti.uva.nl/bis/lobsters.php?menuentry=soorten&id=87 |archivedate=2011-06-08 }} In [[#refHolthuis|Holthuis (1991)]].</ref> and weigh as much as {{convert|20|kg|abbr=on}} or more, making this the heaviest marine crustacean in the world.<ref name="Guinness">{{cite web|url=http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=51451 |publisher=[[Guinness World Records]] |title=Heaviest marine crustacean |accessdate=August 3, 2006 |archiveurl=https://web.archive.org/web/20060528192250/http://www.guinnessworldrecords.com/content_pages/record.asp?recordid=51451 |archivedate=May 28, 2006}}</ref> An average adult is about {{convert|23|cm|0|abbr=on}} long and weighs {{convert|700|-|900|g|abbr=on}}.<ref name="MLW_gammarus58"/>||Atlantic coast of North America, from Labrador in the north to Cape Hatteras, North Carolina in the south
|-
|}


===Fossil species===
[[File:Hoplopariabearpawensis.jpg|thumb|Fossil of ''Hoploparia bearpawensis''; the relationships between ''Homarus'' and ''Hoploparia'' remain unclear.]]
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.<ref name="Tschudy">{{cite journal |author=Dale Tshudy |year=2003 |title=Clawed lobster (Nephropidae) diversity through time |journal=[[Journal of Crustacean Biology]] |volume=23 |issue=1 |pages=178–186 |doi=10.1651/0278-0372(2003)023[0178:CLNDTT]2.0.CO;2 |jstor=1549871|s2cid=85905108 }}</ref> They are:<ref>{{cite book |author1=Carrie E. Schweitzer |author2=Rodney M. Feldmann |author3=Alessandro Garassino |author4=Hiroaki Karasawa |author5=Günter Schweigert |year=2010 |title=Systematic List of Fossil Decapod Crustacean Species |volume=10 |series=Crustaceana monographs |publisher=[[Brill Publishers|Brill]] |isbn=978-90-04-17891-5}}</ref>{{#tag:ref|Stratigraphic ranges are from Tschudy (2003)<ref name="Tschudy"/> and Polkowsky (2004).<ref>{{cite journal |author=S. Polkowsky |year=2004 |title=Decapode Krebse aus dem oberoligozänem Sternberger Gestein von Kobrow (Mecklenburg) |journal=Tassados |volume=1 |pages=1–126 |publisher=privately published |location=[[Schwerin]]}}</ref>|group=Note}}<ref>{{Cite journal |last1=Garassino |first1=Alessandro |last2=Pasini |first2=Giovanni |last3=Nyborg |first3=Torrey |last4=Haggart |first4=James W. |date=2021-08-31 |title=Report of new lobsters (Crustacea, Decapoda) from the Lower Cretaceous (Albian) of Haida Gwaii Archipelago, Canada |url=http://www.schweizerbart.de/papers/njgpa/detail/301/100014/Report_of_new_lobsters_Crustacea_Decapoda_from_the?af=crossref |journal=Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen |language=en |volume=301 |issue=2 |pages=201–216 |doi=10.1127/njgpa/2021/1009 |issn=0077-7749|url-access=subscription }}</ref>
*''[[Homarus brittonestris]]'' <small>Stenzel, 1945</small> – lower [[Turonian]]
*''[[Homarus davisi]]'' <small>Stenzel, 1945</small> – lower [[Turonian]]
*''[[Homarus fami]]'' <small>Garassino, Pasini, Nyborg, Haggart, 2021</small> – [[Albian]]
*''[[Homarus lehmanni]]'' <small>Haas, 1889</small> – [[Rupelian]]
*''[[Homarus mickelsoni]]'' <small>(Bishop, 1985)</small> – lower [[Campanian]]
*''[[Homarus morrisi]]'' <small>Quayle, 1987</small> – [[Eocene]]
*''[[Homarus neptunianus]]'' <small>Polkowsky, 2004</small> – [[Oligocene]]
*''[[Homarus travisensis]]'' <small>Stenzel, 1945</small> – middle [[Albian]]

==Distribution==
The two extant species of ''Homarus'' are both found in the [[North Atlantic Ocean]]. ''H. americanus'' is found from [[Labrador]] to [[North Carolina]] in the western North Atlantic,<ref name="Cobb">{{cite book |editor=Bruce F. Phillips |year=2006 |title=Lobsters: Biology, Management, Aquaculture and Fisheries |publisher=[[John Wiley & Sons]] |isbn=978-1-4051-2657-1 |chapter=''Homarus'' species |pages=310–339 |author1=J. Stanley Cobb |author2=Kathleen M. Castro |chapter-url=https://books.google.com/books?id=INyDNY-oXLAC&pg=PA310}}</ref><ref name="NOBANIS">{{cite web |author=Gro I. van der Meeren, Josianne Støttrup, Mats Ulmestrand & Jan Atle Knutsen |year=2006 |work=Online Database of the North European and Baltic Network on Invasive Alien Species |title=Invasive Alien Species Fact Sheet: ''Homarus americanus'' |publisher=[[NOBANIS]] |url=http://www.nobanis.org/files/factsheets/homarus_americanus.pdf |accessdate=May 4, 2011}}</ref> while ''H. gammarus'' is found from [[Arctic Norway]] to [[Morocco]], including the [[British Isles]] and the [[Mediterranean Sea]].<ref name="MLW_gammarus">{{cite book |url=http://nlbif.eti.uva.nl/bis/lobsters.php?menuentry=soorten&id=89 |chapter=''Homarus gammarus'' |page=60 |work=FAO Species Catalogue, Volume 13 |title=Marine Lobsters of the World |author=Lipke B. Holthuis |publisher=[[Food and Agriculture Organization]] |year=1991 |isbn=92-5-103027-8 |series=FAO Fisheries Synopsis No. 125 |authorlink=Lipke Holthuis |url-status=dead |archiveurl=https://web.archive.org/web/20100910101108/http://nlbif.eti.uva.nl/bis/lobsters.php?menuentry=soorten |archivedate=2010-09-10 }}</ref><ref name="Cobb"/>

==Life cycle==
[[File:Homarus gammarus zoea.jpg|thumb|left|Zoea larva of ''H.&nbsp;gammarus'']]
[[Mating]] in ''Homarus'' is complex and is accompanied by a number of [[Courtship display|courtship]] behaviours.<ref name="Cobb"/> Males build mating shelters or burrows, and larger males can attract more females, producing a [[polygyny in animals|polygynous]] mating system.<ref name="Cobb"/> A few days before [[ecdysis|moulting]], a female will choose a mate, and will remain in his shelter until the moult. The male will then insert a [[spermatophore]] into the female's seminal vesicle, where it may be stored for several years.<ref name="Cobb"/> The [[egg (biology)|eggs]] of ''Homarus'' species are laid in the autumn, being [[external fertilization|fertilised externally]] as they exit, and are carried by the female on her [[pleopod]]s.<ref name="Cobb"/>

The eggs generally hatch in the spring as a pre-larva, which rapidly develops into the first [[crustacean larvae|larval]] phase.<ref name="Cobb"/> This is followed by three [[zoea]]l phases, the total duration of which can vary from two weeks to two months, depending on the temperature.<ref name="Cobb"/> At the following moult, the young animal becomes a [[post-larva]], with a gross form resembling the adult lobster.<ref name="Cobb"/> Although it can swim, using its pleopods, the post-larva soon settles to the bottom and lives as a [[juvenile (organism)|juvenile]] for 3–5 years.<ref name="Cobb"/>

As adults, ''Homarus'' species moult increasingly infrequently. The size at [[sexual maturity]] varies with temperature; it is around {{convert|70|mm|abbr=on}} for female ''H. americanus'' in southern [[New England]], but {{convert|100|mm|abbr=on}} around the [[Bay of Fundy]].<ref name="Cobb"/> In ''H. gammarus'', the size at sexual maturity is less well defined, but is in the range {{convert|80|-|140|mm|abbr=on}}.<ref name="Cobb"/>

==Notes==
{{Reflist|group=Note}}

==References==
{{Reflist|32em}}

===Bibliography===
*{{cite book |series=FAO Fisheries Synopsis |volume=125 |title=Marine Lobsters of the World |author=Lipke B. Holthuis |publisher=[[Food and Agriculture Organization]] |location=Rome |year=1991 |isbn=978-92-5-103027-1 |authorlink=Lipke Holthuis |ref=refHolthuis}}

==External links==
{{Portal|Crustaceans}}
*{{Commons category-inline|Homarus|''Homarus''}}

{{Nephropidae genera}}

{{Taxonbar|from=Q11827352}}
{{Authority control}}

[[Category:True lobsters]]
[[Category:Crustaceans of the Atlantic Ocean]]
[[Category:Extant Albian first appearances]]