California two-spot octopus
| California two-spot octopus | |
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| At Heal the Bay Aquarium | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | Octopoda |
| Family: | Octopodidae |
| Genus: | Octopus |
| Species: | O. bimaculoides
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| Binomial name | |
| Octopus bimaculoides Pickford & McConnaughey, 1949[2]
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TheCalifornia two-spot octopus(Octopus bimaculoides), often simply called a "bimac", is anoctopusspecies native to many parts of the Pacific Ocean including the coast ofCalifornia.One can identify the species by the circular blue eyespots on each side of its head. Bimacs usually live to be about two years old. They are closely related to Verrill's two-spot octopus (Octopus bimaculatus). In 2015, thegenomewas sequenced.[3]
Description
[edit]Octopus bimaculoidesreaches amantlesize of 17.5 cm (6.9 in) with arms to 58 cm (23 in). Not usually heavily textured, it has several common colors, such as grey with yellow splotches, and uses highly developedcrypsis,which is camouflage or color-changing to match the environment.
Octopuses achieve color change in part bychromatophores,iridophores,andleucophores.All are structures of the skin in increasing depth. Chromatophores are elastic pigment sacs with muscle fibers attached by which they can expand and contract. The leucophores are important because they allow for the reflection of white light, and allow the skin to reflect wavelengths of light which are prevalent in their habitat, and produce disruptive patterns. The other aspect tocephalopodcamouflage is the brain, which contains nerves coated in chromatophore fibers, controlling coloration patterning.
This octopus is named for the false eye spot (ocellus) under each real eye. These ocelli are an iridescent blue, chain-link circle, set in a circle of black.
On its arms, the octopus possesses many "suckers" that it uses to taste. They have three hearts, two gills, blue blood, and a donut-shaped brain.[4]
Distribution and habitat
[edit]O. bimaculoidesare found in coastal waters, in the easternPacificalong mid- and southern-California and the western side of theBaja California Peninsulain Mexico. They live at depths from theintertidal,down to at least 20 m (66 ft),[1][5]
This species of octopus is found insubtidalto a depth of 20 m (66 ft). It prefersrocky reefsor debris for hiding. It tolerates a wide temperature range 15–26 °C (59–79 °F)[citation needed].It prefers 18–22 °C (64–72 °F).
Ecology and behavior
[edit]Lifespan
[edit]These octopuses live around one to one and a half years in their natural habitat, but can live for up to two years in captivity. The end is signaled by egg-laying in the female andsenescencein both males and females.[6]
Diet
[edit]Since these octopuses do not live for long, they mature rapidly and can hunt for food to feed themselves right after hatching.[7]Hatchlings feed onamphipodsormysidshrimp.[8][9]As they grow, the list of what they eat grows with them. California two-spot octopuses eat anything they can find, like fish and crustaceans. They are nocturnal, and hunt at night. Their camouflage abilities give them an advantage while hunting.[6]
Reproduction
[edit]Towards the end of their lifespan, they are ready to reproduce. These octopuses aresemelparous:they mate and reproduce only once in their lives.[7]They can mate at any point of the year. It is most common during the summer when the water is warmer. Using itsspermatophores,the male fertilizes the female. The male dies soon after the reproductive act.[6]
After mating, the female creates a den, where she will lay 20 to 100 eggs.[citation needed]After laying her eggs, she must keep them alive and well. She blows cool water through her siphon so that the eggs receive oxygen. This will go on until the eggs hatch, which ranges from 150 to 210 days[dubious–discuss][citation needed].During this process, the female does not eat, and her condition deteriorates, usually culminating in death.
Genetics
[edit]In recent years new technology, such as genome sequencing, has provided new information on the large amounts of clusteredprotocadherins(PCDH) inOctopus bimaculoides.The octopus was found to have 168 PCDH genes, about 120 clustered and 50 non-clustered PCDH. Unlike what has been documented about mammalian clustered PCDH, octopus PCDH are clustered around the genome in an organized manner, creating a head-to-tail arrangement.[10]
Studies
[edit]Researchers collected and tagged the octopus species, Octopus bimaculatus, to conduct an acoustic telemetry research on them. They measured the position of the octopuses in the environment over the course of two weeks. They recorded the daily movement of each octopus. The study showed that the Octopus bimaculatus always moves from one den to another every few days. To avoid predation, their daytime movement patterns and the distances they travel vary a lot.[11]
Researchers used Stable Isotope Analysis (SIA) to determine if there is a difference between the Octopus bimaculatus that live in Marine Protected Area (MPA) sites, versus non-protected sites. With the SIA, the isotopic composition of the octopus's prey can be found in their tissues. By analyzing the isotope ratios of carbon to nitrogen in both the octopuses and any nearby prey, from both MPA and non MPA, researchers discovered that the octopuses living in the MPA have a more diverse diet. Due to this result, it can be concluded that because of the MPA, the octopuses play a different role than the ones in the non-MPA.[11]
See also
[edit]References
[edit]- ^abAllcock, L.; Taite, M.; Headlam, J. (2018)."Octopus bimaculoides".IUCN Red List of Threatened Species.2018:e.T163004A963213.doi:10.2305/IUCN.UK.2018-2.RLTS.T163004A963213.en.Retrieved18 February2022.
- ^Pickford, G.E.; McConnaughey, B.H. (1949). "TheOctopus bimaculatusproblem: a study in sibling species ".Bulletin of the Bingham Oceanographic Collection.12:1–66.
- ^Albertin CB, Simakov O, Mitros T, Wang ZY, Pungor JR, Edsinger-gonzales E, Brenner S, Ragsdale CW, Rokhsar DS (2015)."The octopus genome and the evolution of cephalopod neural and morphological novelties".Nature.524(7564): 220–224.Bibcode:2015Natur.524..220A.doi:10.1038/nature14668.PMC4795812.PMID26268193.
- ^"MBL March Madness: California Two-Spot Octopus".Marine Biological Laboratory.Retrieved2023-10-18.
- ^Jereb, Patrizia; Roper, Clyde F. E.; Norman, Mark D.; Finn, Julian K.Cephalopods of the world. An annotated and illustrated catalogue of cephalopod species known to date. Volume 3. Octopods and Vampire Squids.p. 49.
- ^abcFirdous, Fatima (2023-02-19)."California Two-Spot Octopus: Habitat, Description & Facts".Ocean Fauna.Retrieved2023-10-25.
- ^ab"California Two-Spot Octopus - American Oceans".2021-02-02.Retrieved2023-10-25.
- ^"California Two-spot Octopus - Octopus bimaculoides".Encyclopedia of Life.Retrieved2 October2016.
- ^King, Nancy."Octopus bimaculoides Care Sheet".Retrieved2 October2016.
- ^Styfhals, Ruth; Seuntjens, Eve; Simakov, Oleg; Sanges, Remo; Fiorito, Graziano (January 14, 2019)."In silicoIdentification and Expression of Protocadherin Gene Family inOctopus vulgaris".Frontiers in Physiology.9:1905.doi:10.3389/fphys.2018.01905.PMC6339937.PMID30692932.
- ^abHofmeister, Jennifer Krista Kaulalani (2015).Movement, Abundance Patterns, and Foraging Ecology of the California Two Spot Octopus,Octopus bimaculatus(Ph.D. thesis). University of California, Berkeley.ProQuest1779253210.