Octopus aquaculture describes the captive-raising of octopuses and commercial sale of their meat. A complex and labor-intensive form of farming, octopus aquaculture is being driven by strong market demand in the Mediterranean and in South American and Asian countries.Iglesias, J., Otero, J.J., Moxica, C., Fuentes, L., Sánchez, F.J. (2004
"The completed life cycle of the octopus (''Octopus vulgaris'', Cuvier) under culture conditions: paralarval rearing using ''Artemia'' and ''zoeae'', and first data on juvenile growth up to 8 months of age"
'' Aquac. Int.'' 12: 481–487. Annual global demand for octopus more than doubled from 1980 to 2019, from roughly 180,000 to about 370,000 tons. The supply of octopus has been constrained by

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in th ...

in many key

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...

FAO (2010)
The State of the World Fisheries and Aquaculture 2010
'. FAO, Rome. Page 41. and proponents of farming suggest human-induced culturing could help restock natural populations. Opponents of the nascent industry argue that

cephalopod intelligence Cephalopod intelligence is a measure of the cognitive ability of the cephalopod Class (biology), class of molluscs. Intelligence is generally defined as the process of acquiring, storing, retrieving, combining, comparing, and recontextualizing ...

and emotional capacity, as well as the solitary and carnivorous character of octopuses, make them particularly ill-suited to intensive, captive breeding. Commercial sale may stimulate market demand, hastening rather than offsetting the decline in wild stocks. An announcement that a Spanish firm would begin octopus aquaculture as early as 2022 prompted ethical and scientific controversy. Octopuses live short lives, grow quickly and mature early and they typically reach 2 to 3 kg, high weights for an invertebrate. Octopuses are 75 to 90% muscle at their total live weight, basically a pure protein food with very little fat. In nature there is little overlap between successive generations,Boyle, P.R., Rodhouse, P.G. (2005
''Cephalopods: ecology and fisheries''
Wiley-Blackwell. . which makes them sensitive to changing environmental conditions. It is currently difficult to culture the early life stages of octopus and maintain high survival rates for their

paralarvae Paralarvae (singular: ''paralarva'') are young cephalopods in the planktonic stages between hatchling and subadult. This stage differs from the larval stage of animals that undergo true metamorphosis. Paralarvae have been observed only in mem ...

, mainly because of high mortality rates by poor zoo-technical conditions or equipment, and also because of

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organ ...

cannibalism. A requirement for live and high-quality food is another constraint: crab zoea or

rotifer The rotifers (, from the Latin , "wheel", and , "bearing"), commonly called wheel animals or wheel animalcules, make up a phylum (Rotifera ) of microscopic and near-microscopic pseudocoelomate animals. They were first described by Rev. John H ...

are necessary, since

Artemia ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia La ...

microalgae Microalgae or microphytes are microscopic algae invisible to the naked eye. They are phytoplankton typically found in freshwater and marine systems, living in both the water column and sediment. They are unicellular species which exist indiv ...

, or pellets is insufficient. These difficulties have limited the development of fully closed life cycle octopus hatchery systems. In 2021, Nueva Pescanova Group located in Spain, announced that they had achieved many generations of ''Octopus vulgaris'' by culture; the conditions octopuses are to be kept in, type of food, and killing techniques were not disclosed.

Species

The

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

potential of several octopuses species has been investigated in recent years, including ''

Octopus maya ''Octopus maya'', known colloquially as the Mexican four-eyed octopus, is a shallow water octopus that can be found in the tropical Western Atlantic Ocean. It is common to sea grass prairies and coral formations. The species was initially discove ...

'' (red octopus), ''

Octopus bimaculoides The California two-spot octopus (''Octopus bimaculoides''), often simply called a "bimac", is an octopus species native to many parts of the Pacific Ocean including the coast of California. One can identify the species by the circular blue eyesp ...

'' (California two-spot octopus), '' Octopus ocellatus'' (now re-named ''

Amphioctopus fangsiao ''Amphioctopus fangsiao'', called webfoot octopus, is a species of octopus, a cephalopod belonging to the genus ''Amphioctopus''. It is found in the Pacific Ocean, including off the coasts of New Zealand as well as in the Yellow Sea and surround ...

'')'',

Octopus mimus ''Octopus mimus'' (Gould octopus) is commonly found between northern Peru and northern Chile.Tresierra, A., P. Ramirez, S. Alfaro, S. Campos & L. De Lucio. 2009. Catalogo de Invertebrados Marinos de La Región La Libertad. Inst. Mar del Peru. 11 ...

'' (changos octopus), ''

Enteroctopus megalocyathus ''Enteroctopus megalocyathus'', also known as Patagonian red octopus (EN), Pulpo del sur (Chile) and Pulpo colorado (Argentina); is a medium-sized octopus, and the type species for the genus '' Enteroctopus''. Size and description ''E. megalocy ...

'' (Patagonian red octopus) and ''Robsonella fontaniana''. The

common octopus The common octopus (''Octopus vulgaris'') is a mollusc belonging to the class Cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. The ...

, ''Octopus vulgaris'', appears to be the most serious candidate for aquaculture in terms of its biological and market potential. It has a worldwide distribution in tropical, subtropical and temperate waters. It is a

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

species occurring from the coastal line to the outer edge of the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

, at depths to 200 m and in very diverse

marine habitat Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term ''marine'' comes from the Latin ''mare'', meaning sea or ocean). A habitat is an ecological or environmental a ...

s. The common octopus is easily adapted to captive conditions and has a rapid growth rate of 5% body weight per day.Iglesias J., Sánchez F.J. and Otero J.J. (1997) "Primeras experiencias sobre el cultivo integral del pulpo (''Octopus vulgaris'', Cuvier) en el Instituto Español de Oceanografía". In: Costa J., Abellán E., García García B., Ortega A. and Zamora S. (Eds.), ''VI Congreso Nacional de Acuicultura'', Cartagena, Spain, pp. 221–226. It also has a high feed conversion rate with 30–60% of ingested food being incorporated in its own weight,Mangold, K.M. (1983) "Octopus vulgaris". In: Boyle, P.R. (Ed.), ''Cephalopod Life Cycles'', vol. 1. Academic Press, London, pp. 335–364.Aguado, F., García García, B. (2002
"Growth and food intake models in ''Octopus vulgaris'' Cuvier/1797: influence of body weight, temperature, sex and diet"
'' Aquac. Int.'' 10: 361–377. and a high

fecundity Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...

of 100,000–500,000 eggs per female.

Temperature

There is an optimum temperature at which a cold-blooded species does best in terms of growth, survival and food intake. The common octopus is sensitive to temperature, with an optimum range for commercial growth of 16–21°C. Above its optimal thermal range, growth and food intake decrease, and above 23 °C loss in weight and increased mortality has been recorded. A narrow thermal band can mean seasonality in growth due to seasonal variations in water temperatures. The incorporation of temperature control mechanisms, such as in the use of closed or onshore farming systems, can reduce seasonal variances in production.

Nutrition

Crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, such as

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s and

lobster Lobsters are a family (biology), family (Nephropidae, Synonym (taxonomy), synonym Homaridae) of marine crustaceans. They have long bodies with muscular tails and live in crevices or burrows on the sea floor. Three of their five pairs of legs ...

are an important dietary constituent of both natural and captive populations of octopus.García García, B., Cerezo Valverde, J. (2006
"Optimal proportions of crabs and fish in diet for common octopus (Octopus vulgaris) ongrowing"
''

Aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...

,'' 253: 502–511. Fish are not as important. Fish-based diets have been shown to provide both lower growth rates and food conversion to growth ratios in captive octopus. This may be because of high

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

levels in fish flesh.

Cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s, such as octopus and

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

s, show low lipid digestibility as a result of low lipid requirements. Consequently, a large component of the fish feed will not be taken up.Lee P.G. (1994
"Nutrition of cephalopods: Fueling the system"
In: Pörtner H.O., O’Dor R.K. and Mac- millan D.L. (eds)
''Physiology of Cephalopod Molluscs: Lifestyle and Performance Adaptations''
Gordon & Brench Publishers, Switzerland, pp. 35–51. Crustacean diets are favored possibly as a result of their high protein relative to lipid levels. Whether octopus farming is profitable depends in large part on how much it costs to maintain a steady supply of crustaceans. Economic profitability can be maximized without significantly compromising biological productivity by incorporating a mix of fish and crustacean-based feed strategies. García García and Cerezo Velverde (2006) found a feeding regime of one day of crab followed by three days of fish can reduce the cost of producing one kg of octopus by a predicted value of €2.96.

Juveniles

Commercial aquaculture so far has been confined to starting with young juveniles caught in the wild, weighing about 750 g. In Spain, these juveniles are purchased from local fishermen and transferred to offshore floating

sea cage The aquaculture of salmonids is the farming and harvesting of salmonids under controlled conditions for both commercial and recreational purposes. Salmonids (particularly salmon and rainbow trout), along with carp, and tilapia are the three mos ...

s. There they are fattened with

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

(fish, molluscs and crabs) for several months until a commercial size, about 3 kilograms, is reached. However, acquiring juveniles in this way, from the wild, further increases the fishing pressure on octopus stocks that are already managed badly, possibly producing cascades in marine ecosystems. A cost analysis of this practice found that over 40% of total costs went into acquiring the juveniles. The profitability of this approach is low, depending as it does on fishing and the supply of sub-adults, a costly and highly variable process.García García, J., Rodriguez Gonzalez, L.M., García García, B. (2004
"Cost analysis of octopus ongrowing installation in Galicia"
''Span. Jour. Agr. Res.'' 2(4): 521-537.

Paralarva

The bottleneck currently hindering the commercial development of octopus aquaculture is the difficulty of rearing octopus during their early paralarva stage.Carrasco, J.F., Arronte, J.C., Rodríguez, C. (2006
"Paralarval rearing of the common octopus, ''Octopus vulgaris'' (Cuvier)"
''Aquac. Res.'' 37: 1601–1605.

Paralarva Paralarvae (singular: ''paralarva'') are young cephalopods in the planktonic stages between hatchling and subadult. This stage differs from the larval stage of animals that undergo true metamorphosis. Paralarvae have been observed only in membe ...

is the name given to the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...

of cephalopods. Paralarvae are small, less than 3 millimetres at hatching, with a long

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

ic life stage. Current rearing techniques are inadequate, resulting in very high mortality rates.Moxica, C; F. Linares, J. J. Otero, J. Iglesias and F. J. Sánchez(2002
"Cultivo intensivo de paralarvas de pulpo, ''Octopus vulgaris'' Cuvier, 1797, en tanques de 9 m3"
''Bol. Inst. Esp. Oceanogr.'', 18 (1-4): 31-36. Results vary when octopus paralarvae are fed different combinations of prey. The best results have been with a mix of

brine shrimp ''Artemia'' is a genus of aquatic crustaceans also known as brine shrimp. It is the only genus in the family Artemiidae. The first historical record of the existence of ''Artemia'' dates back to the first half of the 10th century AD from Urmia La ...

and other living prey, such as crab zoeae. However the survival and settlement rates of the paralarvae is typically low in such studies, highlighting the difficulties in raising octopus paralarvae. Maintaining high survival rates for paralarvae appears to be the main factor limiting the development of a fully closed life cycle octopus hatchery system.Iglesiasa J.; F.J. Sáncheza, J.G.F. Bersanob, J.F. Carrascoc, J. Dhontd, L. Fuentesa, F. Linarese, J.L. Muñozf, S. Okumurag, J. Rooh, T. van der Meereni, E.A.G. Vidalj and R. Villanuevak (2007
"Rearing of Octopus vulgaris paralarvae: Present status, bottlenecks and trends"
''Aquaculture,'' 266 (1-4): 1–15. To achieve both profitable and environmentally sustainable results, much research has been focused on paralarval rearing.Vaz-Pires, P., Seixas, P., Barbosa, A. (2004
"Aquaculture potential of the common octopus (''Octopus vulgaris'' Cuvier, 1797): a review"
''

'', 238(1–4): 221–238. In 2005, scientists from the principal research groups in the field concluded the key factor affecting paralarval mortality is nutrition, making nutritional research the highest priority. There is "no reason not to believe that the aquacultural rearing of octopus will be of great economic potential" as soon as the rearing technology and nutritional issues have been addressed. Research in these areas is promising.

Ethical complications

Many people believe that it is unethical to be farming octopuses, with the main reasons being that octopuses and other

cephalopods A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, an ...

are shown to be intelligent animals and that they are solitary.

References

External links

* Jiménez, Lourdes; Virgilio Arenas, Daniel Méndez, Gerardo Preciado, Ana Gabriela Díaz and Mitzy Blanco (2009
Sustainable Octopus Fishery Program in Veracruz Reef System National Park, Mexico
''World Aquaculture Society, '', World Aquaculture 2009
Conference presentation
* Seixas, Pedro F. and Manuel Rey-Méndez (2006
Potential use of octopus species for aquaculture: Present state of the situation, perspectives and limitations
''World Aquaculture Society'', AQUA 2006, Firenze, Italy
Conference presentation
{{Edible molluscs Aquaculture Octopuses Commercial molluscs