Editing Lobster (section)

=== Body ===
{{See also|Decapod anatomy}}
Lobsters are [[invertebrate]]s with a hard protective [[exoskeleton]].<ref name="Quarmby">{{cite journal |author1=R. Quarmby |author2=D.A. Nordens |author3=P.F. Zagalsky |author4=H.J. Ceccaldi |author5=D. Daumas |title=Studies on the quaternary structure of the lobster exoskeleton carotenoprotein, crustacyanin|journal=Comparative Biochemistry and Physiology Part B: Comparative Biochemistry|date=1977|volume=56|issue=1|pages=55–61|doi=10.1016/0305-0491(77)90222-X |pmid=830471 }}</ref> Like most [[arthropod]]s, lobsters must [[ecdysis|shed]] to grow, which leaves them vulnerable. During the shedding process, several species change color. Lobsters have eight walking legs; the front three pairs bear claws, the first of which are larger than the others. The front pincers are also biologically considered legs, so they belong in the order Decapods ("ten-footed").<ref>{{cite book |editor1=Mark W. Denny |editor2=Steven Dean Gaines |year=2007 |title=Encyclopedia of tidepools and rocky shores |publisher=[[University of California Press]] |isbn=978-0-520-25118-2 |first=Carlos |last=Robles |chapter=Lobsters |pages=333–335 |chapter-url=https://books.google.com/books?id=uufQnE7MzMkC&pg=PA333 |access-date=July 27, 2013}}</ref> Although lobsters are largely [[bilateral symmetry|bilaterally symmetrical]] like most other arthropods, some [[Genus|genera]] possess unequal, specialized claws.{{cn|date=May 2025}}

Lobster anatomy includes two main body parts: the [[cephalothorax]] and the [[Abdomen#Arthropoda|abdomen]]. The cephalothorax fuses the head and the [[Thorax (arthropod anatomy)|thorax]], both of which are covered by a [[chitin]]ous [[carapace]]. The lobster's head bears [[Antenna (biology)|antennae]], antennules, [[Mandible (arthropod)|mandibles]], the first and second [[Maxilla (arthropod)|maxillae]]. The head also bears the (usually stalked) [[compound eye]]s. Because lobsters live in murky environments at the bottom of the ocean, they mostly use their antennae as sensors. The lobster eye has a reflective structure above a convex retina. In contrast, most complex eyes use refractive ray concentrators (lenses) and a concave retina.<ref>{{cite journal|vauthors=Land MF |year=1976|title=Superposition images are formed by reflection in the eyes of some oceanic decapod Crustacea|journal=[[Nature (journal)|Nature]]|volume=263|issue=5580|pages=764–765|bibcode=1976Natur.263..764L|doi=10.1038/263764a0|pmid=995187 |s2cid=4215770| issn=0028-0836}}</ref> The lobster's thorax is composed of [[Decapod anatomy|maxillipeds]], appendages that function primarily as mouthparts, and [[Decapod anatomy|pereiopods]], appendages that serve for walking and for gathering food. The abdomen includes [[pleopods]] (also known as ''swimmerets''), used for swimming, as well as the tail fan, composed of [[uropod]]s and the [[telson]].

Lobsters, like snails and spiders, have blue blood due to the presence of [[hemocyanin]], which contains [[copper]].<ref>{{cite web |url=http://resources.schoolscience.co.uk/cda/11-14/biology/copch31pg1.html |title=Copper for life – Vital copper |publisher=[[Association for Science Education]] |access-date=November 20, 2008 |archive-date=August 12, 2011 |archive-url=https://web.archive.org/web/20110812175031/http://resources.schoolscience.co.uk/cda/11-14/biology/copch31pg1.html |url-status=dead }}</ref> In contrast, vertebrates, and many other animals have red blood from [[iron]]-rich [[hemoglobin]]. Lobsters possess a green [[hepatopancreas]], called the [[tomalley]] by chefs, which functions as the animal's [[liver]] and [[pancreas]].<ref>{{cite journal |doi=10.1039/b314101b |title=Arsenic speciation in marine certified reference materials |year=2004 |author1=Shona Mcsheehy |author2=Zoltán Mester |name-list-style=amp |journal=[[Journal of Analytical Atomic Spectrometry]] |volume=19 |pages=373–380 |issue=3}}</ref>

Lobsters of the family Nephropidae are similar in overall form to several other related groups. They differ from freshwater [[crayfish]] in lacking the joint between the last two segments of the thorax,<ref name="Tshudy">{{cite journal |first=Dale |last=Tshudy |name-list-style=amp |author2=Loren E. Babcock |author2-link=Loren E. Babcock |year=1997 |title=Morphology-based phylogenetic analysis of the clawed lobsters (family Nephropidae and the new family Chilenophoberidae) |journal=[[Journal of Crustacean Biology]] |volume=17 |issue=2 |pages=253–263 |jstor=1549275 |bibcode=1997JCBio..17..253T }}</ref> and they differ from the reef lobsters of the family [[Enoplometopidae]] in having full claws on the first three pairs of legs, rather than just one.<ref name="Tshudy" /> The distinctions from fossil families such as the [[Chilenophoberidae]] are based on the pattern of grooves on the carapace.<ref name="Tshudy" />

Analysis of the neural gene complement revealed extraordinary development of the chemosensory machinery, including a profound diversification of ligand-gated ion channels and secretory molecules.<ref>{{cite journal |last1=Polinski |first1=Jennifer |title=The American lobster genome reveals insights on longevity, neural, and immune adaptations |journal=Science Advances |date=23 June 2021 |volume=7 |issue=26 |pages=eabe8290 |doi=10.1126/sciadv.abe8290 |pmid=34162536 |pmc=8221624 |bibcode=2021SciA....7.8290P }}</ref>