Animal Diversity Web

Ge­o­graphic Range

Caribbean reef oc­to­puses, Oc­to­pus bri­areus, are pre­dom­i­nately found in the Neotrop­i­cal re­gion of the world in warm wa­ters. The range of this species stretches from south­ern Florida in North Amer­ica, through the south­east coast of the Gulf of Mex­ico, the Ba­hamas, and the Caribbean, and con­tin­ues south to the north­ern coast of South Amer­ica. Caribbean reef oc­to­puses have also been known to range into the West In­dies and off the coast of Curaçao. ("Cephalopods of the world: An an­no­tated and il­lus­trated cat­a­logue of cephalo­pod species known to date", 2014)

• Biogeographic Regions
• neotropical
  • native
• atlantic ocean
  • native

Habi­tat

Caribbean reef oc­to­puses are pri­mar­ily found in trop­i­cal re­gions, off the coast, in shal­low wa­ters rang­ing from 3-20 me­ters. These oc­to­puses pre­dom­i­nantly in­habit areas with water tem­per­a­tures around 20-30°C. Caribbean reef oc­to­puses are nor­mally found in or around coral reefs, which they use for pro­tec­tion and dens. The dens cho­sen by these oc­topods are usu­ally dark and ex­clude other or­gan­isms. ("Cephalopods of the world: An an­no­tated and il­lus­trated cat­a­logue of cephalo­pod species known to date", 2014; Borer and Lane, 1971; Brunt and Davies, 1994; Jor­dan, 2010)

• Habitat Regions
• tropical
• saltwater or marine

• Aquatic Biomes
• reef
• coastal

• Range depth

  3 to 20 m

  9.84 to 65.62 ft

Phys­i­cal De­scrip­tion

Caribbean reef oc­to­puses are typ­i­cally bright green and blue with red-brown specks across their bod­ies. Chro­matophores, which are spe­cial­ized cells in the skin, allow these oc­to­puses to change col­ors in order to blend in with their back­ground and dis­guise them­selves from preda­tors and prey. These oc­to­puses have siz­able, promi­nent dark red-brown eyes. Their man­tles, the body ex­clud­ing their arms, are an av­er­age of 54 mm long and have been known to grow up to 120 mm. This or­gan­ism, on av­er­age, weighs 1 kg.

At hatch­ing, the young are 15mm, with arms of 7-9mm and a man­tle av­er­ag­ing 5.5 mm. These oc­to­puses emerge with the ap­pear­ance of small adults.

Caribbean reef oc­to­puses have seven rows of teeth. The longest of these oc­to­puses' eight arms, the sec­ond and third, grow, on av­er­age, five times the length of the man­tle. Each arm con­sists of two rows of suck­ers, which are con­nected by loose webs that as­sist in hunt­ing. In males, the right third arm has a hec­to­coty­lus that de­posits sper­matophores, sacks con­tain­ing the sperm for mat­ing. ("Cephalopods of the world: An an­no­tated and il­lus­trated cat­a­logue of cephalo­pod species known to date", 2014; Ka­plan, 1982)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes shaped differently

• Average mass

  1 kg

  2.20 lb

• Range length

  120 (high) mm

  4.72 (high) in

• Average length

  54 mm

  2.13 in

De­vel­op­ment

Caribbean reef oc­to­puses hatch roughly 80 days after the eggs are laid. At hatch­ing, they are 15mm, with arms of 7-9mm and a man­tle av­er­ag­ing 5.5 mm. They exit the egg about 15 sec­onds after they first crack it. These oc­to­puses emerge with the ap­pear­ance of small adults. Caribbean reef oc­to­puses grow at a rapid rate, in­creas­ing their weight by 5 per­cent a day. Once oc­to­puses have sex­u­ally ma­tured at five months, they will con­tinue to grow, and ex­hibit in­de­ter­mi­nate growth. By the time they die they will weigh one-third of the amount of food they have eaten over the course of their life. (Sax­ena, 2005; Scheel, et al., 2017)

• Development - Life Cycle
• indeterminate growth

Re­pro­duc­tion

Oc­to­puses are monog­a­mous, mean­ing one fe­male and male mate. Caribbean reef oc­to­puses do not have a known mat­ing rit­ual. Be­cause oc­to­puses are soli­tary, mates are op­por­tunis­ti­cally cho­sen. Sex­ual re­pro­duc­tion can occur in two dif­fer­ent ways for Caribbean reef oc­to­puses. Males can ei­ther mount the fe­male, reach its hec­to­coty­lus, the sperm con­tain­ing ten­ta­cle, into her oviduct, re­leas­ing its sperm to cover the eggs, or take off its hec­to­coty­lus and give it to the fe­male so that she can store his arm in her man­tle and use it when the eggs are ready to be in­ter­nally fer­til­ized. The males die sev­eral months after fer­til­iz­ing the eggs, while the fe­males die shortly after lay­ing the eggs. (Scheel, et al., 2017)

• Mating System
• monogamous

Oc­to­puses are semel­parous, mean­ing that they only breed once in their life­time be­fore death, and oviparous, which means they are egg lay­ers. Al­though oc­to­puses breed year-round, spawn­ing peaks around Feb­ru­ary-March. Oc­to­puses reach sex­ual ma­tu­rity at five months, but may not re­pro­duce for sev­eral years. Fe­male oc­to­puses can lay up to 200,000 eggs, each of which take ap­prox­i­mately 65 days to hatch. When oc­to­puses hatch, they weigh 0.095g and are 15mm in length on av­er­age. Be­cause both the par­ents are usu­ally de­ceased by the time the eggs hatch, oc­to­puses emerge from their eggs fully in­de­pen­dent. (Aron­son, 1986; Han­lon, 1977; Sax­ena, 2005; Scheel, et al., 2017)

• Key Reproductive Features
• semelparous
• sexual
• fertilization
  • internal
• oviparous
• sperm-storing

• Breeding interval

  Octopuses breed once in their lifetime.

• Breeding season

  Although octopuses breed year-round, spawning peaks around February-March. Most breed between six months to a few years after they reach maturity.

• Range number of offspring

  200,000 (high)

• Average gestation period

  65 days

• Average time to independence

  0 minutes

• Average age at sexual or reproductive maturity (female)

  5 months

• Average age at sexual or reproductive maturity (male)

  5 months

Male Caribbean reef oc­to­puses do not have any parental in­volve­ment other than pro­vid­ing sperm to fer­til­ize the eggs. The male oc­to­puses are dead by the time the eggs have hatched. The fe­males pro­tect the eggs pre-fer­til­iza­tion by keep­ing them in­side of their body cav­i­ties. Once the fe­males lay the eggs in crevices, they do not leave them alone, not even to feed. The fe­male oc­to­puses pro­tect the eggs from preda­tors and keep them clean by push­ing water past them. The fe­males usu­ally die be­fore the eggs hatch. (Sax­ena, 2005; Scheel, et al., 2017)

• Parental Investment
• female parental care
• pre-fertilization
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • female

Lifes­pan/Longevity

Caribbean reef oc­to­puses live 10-12 months, on av­er­age, in the wild. The spo­radic feed­ing habits of these oc­to­puses will de­crease their lifes­pan in the wild. When kept in cap­tiv­ity, these oc­to­puses live 10-17 months on av­er­age. In cap­tiv­ity, their lifes­pan can be de­creased by can­ni­bal­ism, dis­ease, lab­o­ra­tory ac­ci­dents, and es­capes. Male Caribbean reef oc­to­puses die a few months after they give their hec­to­coty­lus to the fe­males for re­pro­duc­tion. The fe­males usu­ally die shortly after lay­ing the eggs and en­sur­ing the eggs are well hid­den to max­i­mize chance of sur­vival. (Han­lon and Forsythe, 1985; Sax­ena, 2005)

• Average lifespan
  Status: wild

  10-12 months

• Average lifespan
  Status: captivity

  10-17 months

Be­hav­ior

Caribbean reef oc­to­puses are soli­tary. They live alone in dens along coral reefs, only in­ter­act­ing with oth­ers for mat­ing pur­poses. These oc­to­puses are ter­ri­to­r­ial and de­fend their den, along with the sur­round­ing area, from other oc­to­puses and preda­tors. They can kill other oc­to­puses within their ter­ri­tory and then eat them.

Caribbean reef oc­to­puses are noc­tur­nal, and the night pro­tects them from preda­tors and makes it eas­ier to sneak up on prey.

Oc­to­puses are monog­a­mous, mean­ing one fe­male and male mate. Caribbean reef oc­to­puses do not have a known mat­ing rit­ual. The male ei­ther mounts the fe­male, or take off its hec­to­coty­lus and give it to the fe­male so that she can store it and use the sperm when the eggs are ready to be in­ter­nally fer­til­ized.

Caribbean reef oc­to­puses have many ways to com­mu­ni­cate with other oc­to­puses. These or­gan­isms have a sender-re­ceiver match (a species-spe­cific vo­cal­iza­tion) that al­lows them to com­mu­ni­cate with each other. Oc­to­puses use a com­plex skin dis­play, using the chro­matophores, to form pat­terns that other oc­to­puses are able to com­pre­hend. These oc­to­puses also use their lay­ers of iri­do­cytes deep in the der­mis of their skin, which pro­duce re­flec­tions off the skin, sig­nal­ing to other oc­to­puses. (Aron­son, 1991; Han­lon and Mes­sen­ger, 1996; Igle­sias, et al., 2014; Sny­der­man and Wise­man, 1996)

• Key Behaviors
• nocturnal
• motile
• sedentary
• solitary
• territorial

Home Range

Caribbean reef oc­to­puses are seden­tary. They mainly stay around the same reef, and even the same den, for the ma­jor­ity of their lives. These oc­to­puses are known to only change dens a few times over their life­times. They al­most al­ways re­turn to their dens after hunt­ing. Caribbean reef oc­to­puses change their dens when they are dis­turbed by an in­truder. Home range and ter­ri­tory sizes have not been re­ported in lit­er­a­ture. (Aron­son, 1991; Igle­sias, et al., 2014; Sny­der­man and Wise­man, 1996)

Com­mu­ni­ca­tion and Per­cep­tion

In gen­eral, all oc­to­puses have high-acu­ity-lens eyes on the sides of their heads. This place­ment forces them to use monoc­u­lar vi­sion, which means they only use one eye at a time. They are also color blind, but are able to dis­tin­guish be­tween dif­fer­ent hues and bright­nesses. Oc­to­puses re­spond to sound and use it as a way to find prey. Oc­to­puses have var­i­ous ways of com­mu­ni­cat­ing among them­selves. These or­gan­isms have a sender-re­ceiver match (a species-spe­cific vo­cal­iza­tion) that al­lows them to com­mu­ni­cate with each other. Oc­to­puses use a com­plex skin dis­play, using the chro­matophores, to form pat­terns that other oc­to­puses are able to com­pre­hend. An­other form of com­mu­ni­ca­tion for these species are using their lay­ers of iri­do­cytes in the der­mis of their skin, which pro­duce re­flec­tions off the skin, sig­nal­ing to other oc­to­puses. Oc­to­puses can also change the ap­pear­ance of their skin and their pos­ture, shap­ing their bod­ies into dif­fer­ent pat­terns. These or­gan­isms use their ad­vanced eye­sight and ten­ta­cles, loaded with nerve end­ings, to per­ceive their en­vi­ron­ment. (Bouwma and Her­rnkind, 2010; Byrne, et al., 2002; Shashar and Cronin, 1996)

• Communication Channels
• visual
• tactile

• Perception Channels
• visual
• acoustic

Food Habits

Caribbean reef oc­to­puses are car­ni­vores. Their pri­mary prey are Caribbean spiny lob­sters (Pan­ulirus argus). These oc­to­puses have also been known to eat other aquatic crus­taceans (i.e., crabs and shrimp), small fish, and small mol­lusks. They are also known to eat other Caribbean reef oc­to­puses, mak­ing the smaller ones vul­ner­a­ble. Caribbean reef oc­to­puses use their seven rows of teeth, suck­ers on their arms, and the web-like struc­tures that con­nect the tops of their arms to­gether to cap­ture and eat prey. These oc­to­puses are known to hur­dle them­selves over reefs, sur­pris­ing their prey, and cap­tur­ing them in their web. Then, the oc­to­puses reach un­der­neath, grab­bing their prey, and guide it to­wards their mouths. They also snatch their prey with an arm and roll it up un­der­neath of them, after which they eat the prey. Less fre­quently, Caribbean reef oc­to­puses have been known to lurk be­hind their prey and grab it with their front arms. Oc­to­puses' food in­take de­pends on the amount of food avail­able, the water tem­per­a­ture (higher tem­per­a­tures favor more food eaten), and whether or not the fe­male is preg­nant (two weeks be­fore lay­ing the eggs, the fe­male re­duces her food in­take by 50 per­cent). ("Sci­en­tists in the Sea", 1972; Borer and Lane, 1971; Borer, 1971; Brunt and Davies, 1994; Han­lon and Mes­sen­ger, 1996)

• Primary Diet
• carnivore
  • piscivore
  • eats non-insect arthropods
  • molluscivore

• Animal Foods
• fish
• mollusks
• aquatic crustaceans

Pre­da­tion

The known preda­tors of oc­to­puses are sharks, large fish, birds, eels, hu­mans (Homo sapi­ens), other oc­to­puses (feed­ing on smaller in­di­vid­u­als), and some dol­phins and whales. Oc­to­puses have nu­mer­ous anti-preda­tor adap­ta­tions. They have an in­stinct to flee when they feel threat­ened, and they are able to squeeze into smaller spaces, giv­ing them an ad­van­tage over their big­ger preda­tors. Oc­to­puses re­lease ink from a gland which cre­ates a black cloud and al­lows them to es­cape under the dark­ness. Oc­to­puses also are able to change the color of their skin, which is a cryp­tic adap­ta­tion, cam­ou­flag­ing them into their back­ground and hid­ing them from preda­tors. Lastly, oc­to­puses are known to mimic larger an­i­mals by con­fig­ur­ing their bod­ies into dif­fer­ent shapes to scare off preda­tors. (Aron­son, 1991; Sax­ena, 2005; Aron­son, 1991; Sax­ena, 2005)

• Anti-predator Adaptations
• mimic
• cryptic

• Known Predators

  • sharks (Chondrichthyes)
  • large fish
  • birds (Aves)
  • eels (Anguillidae)
  • humans (Homo sapiens)
  • other octopuses (Octopoda)
  • dolphins and whales (Delphinidae)

Ecosys­tem Roles

Caribbean reef oc­to­puses are the hosts for Ag­gre­gata oc­topi­ana, which are par­a­sitic alve­o­lates mainly as­so­ci­ated with in­flam­ma­tion, ul­cer­a­tion, and the de­struc­tion of the host's or­gans, and Di­ge­netic trema­todes. These oc­to­puses are af­fected by ec­topar­a­sitic pro­to­zoans, Ichthy­obodo neca­tor, and meta­zoan par­a­sites in the phy­lum Di­cyemida. Caribbean reef oc­to­puses pri­mar­ily prey on Caribbean spiny lob­sters, Pan­ulirus argus, but are also known to eat aquatic crus­taceans, such as crabs and shrimp, small fish, and small mol­lusks, and other Caribbean reef oc­to­puses. These oc­to­puses are prey for sharks, large fish, birds, eels, hu­mans, Homo sapi­ens, other oc­to­puses, and some dol­phins and whales. (Castel­lanos-Martínez and Gestal, 2013; Gestal, et al., 1999; Glynn and Enochs, 2011; Han­lon and Forsythe, 1985; Han­lon, et al., 1984; Over­street and Hochberg, 1975)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Caribbean reef oc­to­puses are mainly cap­tured by ar­ti­sanal fish­er­men who end up sell­ing them for pet trade, and, rarely, sold to fish mar­kets for peo­ple to con­sume. These oc­to­puses are used in bio­med­ical re­search, par­tic­u­larly when re­lat­ing the ner­vous sys­tem to be­hav­ior, be­cause of their sim­i­lar be­hav­ior to ver­te­brates. Oc­to­puses have been used to study blood-brain bar­ri­ers, blood pig­ments, im­mune mech­a­nisms, neu­ro­trans­mit­ters, en­vi­ron­men­tal tox­i­col­ogy, and hor­monal con­trol of re­pro­duc­tion and aging. (Han­lon and Forsythe, 1985; Han­lon, 1977)

• Positive Impacts
• pet trade
• food
• research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known neg­a­tive eco­nomic im­pacts of Caribbean reef oc­to­puses on hu­mans.

Con­ser­va­tion Sta­tus

Caribbean reef oc­to­puses have not been eval­u­ated by the IUCN Red List. These oc­to­puses have no spe­cial sta­tus on the U.S. Fed­eral List, the State of Michi­gan List, nor the in­ter­na­tional list (CITES). Granted there are no major threats to Caribbean reef oc­to­puses, but minor threats in­clude their har­vest­ing by hu­mans for re­search, food, and pet trade. Ad­di­tional threats in­clude bac­te­r­ial in­fec­tions, Vib­rio para­haemolyti­cus, Vib­rio damsela, and Pseudomonas stutzeri; all cause ul­cers that are com­mon when these oc­to­puses are kept close in cap­tiv­ity. (Han­lon and Forsythe, 1985; Han­lon, 1977)

• IUCN Red List

  Not Evaluated

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Lind­sey Lee (au­thor), Rad­ford Uni­ver­sity, Alex At­wood (ed­i­tor), Rad­ford Uni­ver­sity, Karen Pow­ers (ed­i­tor), Rad­ford Uni­ver­sity, Joshua Turner (ed­i­tor), Rad­ford Uni­ver­sity, Tanya Dewey (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

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