Editing Squid (section)

==Ecology==
Squid mostly have an annual life cycle, growing fast and dying soon after spawning. The diet changes as they grow but mostly consists of large [[zooplankton]] and small [[nekton]]. In Antarctica for example, [[krill]] is the main constituent of the diet, with other food items being [[Amphipoda|amphipods]], other small [[crustacean]]s, and large [[Chaetognatha|arrow worms]]. Fish are also eaten, and some squid are [[Cannibalism|cannibalistic]].<ref>{{cite book |author1=Nemoto. T. |author2=Okiyama M. |author3=Takahashi, M. |year=1985 |chapter=Aspects of the Roles of Squid in Food Chains of Marine Antarctic Ecosystems |title=Antarctic Nutrient Cycles and Food Webs |pages=415–420 |doi=10.1007/978-3-642-82275-9_58 |isbn=978-3-642-82277-3 }}</ref>

Different species of squid vary wildly in size, and even giant squid young are rice-grain-sized at hatching.<ref>{{cite book|author=Staaf, Danna |title=Squid Empire: The Rise and Fall of the Cephalopods|url=https://books.google.com/books?id=udIwDwAAQBAJ |year=2017 |publisher=University Press of New England |isbn=978-1-5126-0128-2 |page=172}}</ref> Throughout their life cycle, they can serve as a food source for many sizes of predator.<ref name="Staaf">{{cite book|author=Staaf, Danna |title=Squid Empire: The Rise and Fall of the Cephalopods|url=https://books.google.com/books?id=udIwDwAAQBAJ |year=2017 |publisher=University Press of New England |isbn=978-1-5126-0128-2 |page=2}}</ref> Juvenile squid provide part of the diet for [[Polychaete|worms]] and small fish. Larger squid are food for larger predators, including sharks, sea birds, seals and whales.

When researchers studied the contents of the stomachs of [[elephant seal]]s in South Georgia, they found 96% squid by weight.<ref name=Staaf/> In a single day, a sperm whale can eat 700 to 800 squid,<ref name="Staaf"/> and a [[Risso's dolphin]] entangled in a net in the Mediterranean was found to have eaten [[Ancistroteuthis|angel clubhook squid]], [[Histioteuthis bonnellii|umbrella squid]], [[Histioteuthis reversa|reverse jewel squid]] and [[European flying squid]], all identifiable from their indigestible beaks.<ref name=Blanco>{{cite journal |author1=Würtz, M. |author2=Poggi, R. |author3=Clarke, Malcolm R. |year=1992 |title=Cephalopods from the stomachs of a Risso's dolphin (''Grampus griseus'') from the Mediterranean |journal=Journal of the Marine Biological Association of the United Kingdom  |volume=72 |issue=4 |pages=861–867 |doi=10.1017/S0025315400060094 |bibcode=1992JMBUK..72..861W |s2cid=83587961 }}</ref> 

''[[Ornithoteuthis volatilis]]'', a common squid from the tropical Indo-Pacific, is predated by [[yellowfin tuna]], [[Alepisaurus ferox|longnose lancetfish]], [[Mahi-mahi|common dolphinfish]] and [[swordfish]], the [[tiger shark]], the [[scalloped hammerhead|scalloped hammerhead shark]] and the [[Smooth hammerhead|smooth hammerhead shark]]. Sperm whales also hunt this species extensively as does the [[brown fur seal]].<ref>{{cite book | editor1 = Jereb, P. | editor2 = Roper, C.F.E. | year = 2010 | title = Cephalopods of the World an Annotated and Illustrated Catalogue of Cephalopod Species Known to Date Volume 2 Myopsid and Oegopsid Squids | publisher = [[Food and Agriculture Organization]] Rome | isbn =  978-92-5-106720-8 | pages = 309–310 | url = http://www.fao.org/docrep/014/i1920e/i1920e.pdf}}</ref> In the [[Southern Ocean]], [[penguin]]s and [[wandering albatross]]es are major predators of ''[[Gonatus antarcticus]]''.<ref>{{cite journal | last1 = Guerreiro | first1 = Miguel | last2 = Phillips | first2 = Richard A. | last3 = Cherel | first3 = Yves | last4 = Ceia | first4 = Filipe R. | last5 = Alvito | first5 = Pedro | last6 = Rosa | first6 = Rui | last7 = Xavier | first7 = José C. | year = 2015 | title = Habitat and trophic ecology of Southern Ocean cephalopods from stable isotope analyses | journal = Marine Ecology Progress Series | volume =  530| pages =  119–134| doi = 10.3354/meps11266 | bibcode = 2015MEPS..530..119G | doi-access = free }}</ref>