Aquaculture 238 (2004) 221 – 238 www.elsevier.com/locate/aqua-online Aquaculture potential of the common octopus (Octopus vulgaris Cuvier, 1797): a review Paulo Vaz-Pires *, Pedro Seixas, Alexandra Barbosa ICBAS-Institute of Biomedical Sciences Abel Salazar, University of Porto, Largo Prof. Abel Salazar, 2, 4099-003 Oporto, Portugal CIIMAR-Interdisciplinary Centre for Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Oporto, Portugal Received 17 February 2004; received in revised form 4 May 2004; accepted 7 May 2004 Abstract The potential for aquaculture of the cephalopod species Octopus vulgaris is evaluated, taking into consideration biological and physiological characteristics, as well as some economic and marketing aspects, which may be relevant for the future development of octopus farming. O. vulgaris, a widespread, strictly marine species meets many of the requirements to be considered as a candidate for industrial culture: easy adaptation to captivity conditions, high growth rate, acceptance of lowvalue natural foods, high reproductive rate and high market price. The life cycle from eclosion of eggs to settlement or beginning of the benthonic adult phase is not commercially viable, but the published results from laboratory and pilot scales are promising. Comments are also made on general research lines needed to improve the use of octopus as farmed species in the future. D 2004 Elsevier B.V. All rights reserved. Keywords: Octopus vulgaris; Reproduction; Paralarvae; Ongrowing 1. Introduction: the cephalopods Cephalopods are considered as the most active and specialised class of molluscs. They may have a chambered shell (e.g., Nautilus), an internal shell, as in squid (e.g., ´ dicas de Abel Salazar, Universidade do Porto, Largo ˆ ncias Biome * Corresponding author. Instituto de Cie Prof. Abel Salazar. 2, 4099-003 PORTO, Portugal. Tel.: +351-222062200; fax: +351-222062232. E-mail address:
[email protected] (P. Vaz-Pires). 0044-8486/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.aquaculture.2004.05.018 222 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 Loligo) and cuttlefish (e.g., Sepia) or no shell, as in octopods (e.g., Octopus, Eledone). They are almost all fast-swimming carnivores and live pelagically. Cephalopods share certain characteristics with more highly developed vertebrates, such as eyes with lens, pupil and eyelid, a well-developed nervous system and the capability to learn (de Groot, 1995). Only a few of the cephalopod species are commercially fished on a large scale (Kreuzer, 1984). Squid is by far the main cephalopod species, representing 73% of cephalopod world catches. Cuttlefish is the second and octopus the third, with 15% and 8.8%, respectively. Cephalopod total landing reached a peak of 3.6 million tonnes in 2000. As regards Octopus catches, Morocco is the world leader with 35% of the total production, followed by Japan, Thailand, Spain and Mexico (FAO, 2003a). The main cephalopod consuming countries are Japan, Korea, Argentina, Taiwan and China, followed by a group that includes Spain, Portugal, Morocco, Mauritania, Greece and Italy (Baldrati, 1989). Such geographical preference is associated with, but does not exactly match, the proximity of cephalopod fishing areas, due to imports and consumption or processing traditions. During the second half of the last century, Octopus vulgaris and other cephalopods were considered as less conventional resources, and consequently, the capture of these species was recommended as a way of diversifying the fishing effort (Pedrosa-Menabrito and Regenstein, 1988). Cephalopod fisheries are among the few which still show some local potential for expansion. As ground fish landings have declined globally, cephalopod landings have increased (Caddy and Rodhouse, 1998). These authors also postulated that the heavy fishing pressure on finfish stocks could induce a reaction from the ecosystem that could include increases in cephalopod abundance, apart from the increased market demand for these species. Conclusions were, however, based mainly on squid fisheries. In a review published at the end of the 1980s, Boucaud-Camou (1989) indicated four possible directions for the marketing of farmed cephalopods: direct consumption in countries where the value is high (Japan, Spain, Italy, France and Portugal, which are consequently among the first countries where the aquaculture of some species is being attempted); the production of juveniles for natural stock reconstitution; neuro-physiological, for work on giant neurological cells (mainly squid); and finally as ornamental species. These remain the main possibilities, since the culture of these species is only moderately developed. Nowadays, there is a renewed interest in the farming of new species, stimulated by a need to diversify the marine farming industry, which is suffering from relative market saturation for some species like sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata). A high proportion of the first farming trials with new species, for example Senegalese sole (Solea senegalensis) took place in southern Europe, notably Spain and ˜ o et al., 2004); other trials include the black spot Portugal (Dinis et al., 1999; Araga seabream (Pagellus bogaraveo) (Peleteiro et al., 2000). This was also the case of octopus farming. Although the Octopus genus includes approximately 200 species, this review will focus mainly on O. vulgaris Cuvier, 1797 (order Octopoda, suborder Incirrata), which is one of the most important species in terms of landings and commercial value. P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 223 2. Octopus characteristics O. vulgaris is a benthic, neritic species occurring from the coast line to the outer edge of the continental shelf, in depths from 0 to 200 m, where it is found in a variety of habitats, such as rocks, coral reefs and grass. In what concerns the behaviour of octopuses as predators in nature, a complete overview was published by Mather (1993). It was concluded that young O. vulgaris do not normally modify their movement in the presence of others of the same species; they do not appear to attract them, they maintain an individual distance and have specific colours and postures for communication; they do not defend any area, and they do not stay in a location very long. They occupy a home range for several days and then move. They can be described as exploratory and opportunistic, but inactive (Mather and O’Dor, 1991). Most of the bibliographical data on octopus behaviour and biology is based on laboratory observations (Nixon, 1966; Wells et al., 1983; Andreu-Moliner and Cachaza, 1984), but some data have been taken directly from octopus caught in nature (Mangold and Boletzky, 1973). The role of the home in the behaviour of octopus in tanks, including observations on when and how they occupy brick pots and plastic buckets, was described by Boyle (1980). This kind of data is important for future aquaculture engineering dedicated to this species, namely for appropriate tank and home design. O. vulgaris, like many other species of octopus, ejects shells and other prey remains from the den (home); this can be considered an advantage in culture, as the remains do not foul the den (Anderson et al., 1999). General biometry data, including the relationship between live body weight and total and dorsal mantle length were published by Nixon (1970), both for specimens kept in captivity and for animals directly collected from nature. The biometry of several octopus ´quez (1980) working on species is also the subject of articles by Guerra and Manrı Mediterranean octopus caught near Barcelona (Spain), Cunha and Pereira (1995) on O. vulgaris from Azores Islands (Portugal) and Mangold (1998) for Eastern Atlantic Ocean and Mediterranean individuals. 3. Octopus aquaculture 3.1. General characteristics The short life cycle of 12– 18 months, rapid growth of up to 13% body weight per day and food conversion rates of 15 – 43% are considered the most relevant basic characteristics which have influenced O. vulgaris culture (Mangold and Boletzky, 1973; Mangold, 1983; Navarro and Villanueva, 2003). Octopus shows a rapid and easy adaptation to life in captivity (Iglesias et al., 2000a) in aquaria, cylindrical – conical containers, raceways and floating cages. This includes a high resistance to transport and handling stresses, easy and rapid feeding in tanks, and the rapid onset of reproduction behaviour (Villanueva, 1995). Handling of these species, however, can be more complex due to their ability to attach to any surface, for example in weighing operations. Escape from tanks can be avoided by 224 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 the use of a porous surface layer surrounding the tank walls above water level, like foam, which prevents suckers from attaching to the walls. Iglesias et al. (2000a) published a very complete review on experiments performed at the Spanish Institute of Oceanography, based in Vigo (Galicia, Spain). The experiments included reproduction, paralarvae rearing and ongrowing of subadults at different densities and separated by sexes. 3.2. Water requirements The most important water quality parameters are temperature, salinity, pH, O2, À À ammonia (NH3), nitrite (NO2 ) and nitrate (NO3 ). In open systems, only temperature and salinity are likely to fluctuate rapidly, whereas in closed systems, the other parameters are more likely to vary (Boletzky and Hanlon, 1983). Octopus is a strictly marine species, showing very low tolerance to low concentrations of salts. O. vulgaris live in nature at salt concentrations of around 35 g lÀ 1; their minimum salt concentration is around 27 g lÀ 1 (Boletzky and Hanlon, 1983). This means slight fluctuations due to freshwater (e.g., proximity of rivers, strong rain or freshwater from natural subterranean layers) can be fatal for them. Preliminary results about post-prandial ammonia production have been obtained in individual octopus (O. vulgaris) and correlated with the protein intake (Cerezo et al., 2003). It seems that ammonia excretion is very important in this species compared with others, like sea bass and gilthead sea bream. Ammonia production per body weight was found to be much higher in octopuses in some cases. Post-prandial oxygen consumption after a single meal, with crabs and until satiation, was also recently studied by Cerezo and ´a Garcı ´a (2004) in common octopus with body weights between 0.22 and 3.26 kg Garcı and at temperatures of 13.8 and 22.2 jC during a period of 3 days. These authors observed an approximate twofold increase in oxygen consumption, with the maximum value being attained 6– 16 h after the meal ingestion. Ammonia and oxygen are thus important parameters to be taken into account when planning octopus water systems. Ongrowing temperature should be kept ideally between 10 and 20 jC, but growth is higher at higher temperatures in this range. This species shows a preference for live food, but it also accepts dead whole marine organisms. Thus, the water systems should be designed in order to facilitate self-cleaning, due to the high amount of residues produced, like crustacean shells and fish bones. This will help to keep the quality of the water at an acceptable level. 3.3. Reproduction O. vulgaris produces an estimated number of 100 000 – 500 000 eggs per female (Mangold, 1983). Iglesias et al. (1997) obtained a maximum number of 605 000 eggs in their reproduction experiments with octopus. The reproduction stocking comprised a 1:1 ratio of males and females, with water temperature and salinity conditions established in the range of 13 –20 jC and 32– 35 g lÀ 1, respectively. Reproductive behaviour is shown by the copulatory activity of the males, which insert the hectocotylus into the internal mantle cavity of the females. When the latter are ready to P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 225 deposit the spawn, they hide in dens, placing the clusters on the walls and roofs of the tubes or boxes (Iglesias et al., 2000a). Usually, females take care of the eggs alone, and then die when the eggs finally eclode. The spawning season depends on the region. Two spawning peaks per year can be observed throughout its distributional range: In the Mediterranean and the Inland Sea of Japan, the first occurs in April/May, corresponding to the group migrating in shore in spring (most important in the Mediterranean) and the second in October, corresponding to the group migrating in autumn (most important in Japan) (FAO, 2003b). Temperature is described as one of the primary factors mediating embryonic development in cephalopods (Boletzky, 1989). In the Mediterranean, Villanueva (1995) observed a period of 34 days after the onset of spawning until the first hatched paralarvae, when the water temperature was raised to 20 F 1 jC. Iglesias et al. (2000a) under laboratory conditions, observed that in Galicia, Spain the spawning period occurs between February and November and the embryonic development lasts between 80 and 135 days. Recent data pointed an incubation period of 47 days at 17 –19 jC (Iglesias et al., in press). 3.4. Paralarvae and subadult phases The family Octopodidae contains the largest number of known octopus species. In some species, hatchlings are large and immediately benthic like the adults and thus are referred to as juveniles (Villanueva, 1995). However, this is not the case in O. vulgaris. This species has a planktonic posthatching stage termed paralarvae by Young and Harman (1988). At hatching, this species has very small hatchlings (2 mm mantle length) (Boletzky, 1987). The biological characteristics of the early life stages of O. vulgaris were reviewed by Nixon and Mangold (1998). Several experiments on the complete control of octopus paralarvae have appeared in the literature since the nineteen sixties, when the classic article by Japanese researchers (Itami et al., 1963) was published. Working on the northwestern Pacific O. vulgaris, the authors succeeded in the rearing of hatchlings until settlement, with a survival rate of 8% at day 45 and 5% at day 60 at mean water temperature of 24.7 jC. Several years after, Imamura (1990) reported new advances and high survival rates to settlement, on O. vulgaris of the same geographical area. Villanueva (1995) successfully reared Mediterranean O. vulgaris from hatchling to settlement, feeding the planktonic paralarvae with zoeae of two crustacean species, Liocarcinus depurator and Pagurus prideaux. The survival rate observed until day 40 was 32.1% at mean water temperature 21.2 jC. A supply of Carcinus maenas ovaries was given from day 42, when some presettlement reflexes were already noted in paralarvae behaviour. The author described octopuses in the presettlement stage as those individuals that predominantly were planktonic but that intermittently rested on the bottom with arms adhering to the wall or bottom of the tank and (or) that crawled by their arms for short distances along the wall or bottom of the tank. Survival rate at day 60 was 0.8%. Villanueva et al. (2002) studied growth and proteolytic activity of paralarvae fed with Artemia nauplii (supplemented with vitamin complexes) and millicapsules. Starting with a rearing density of 32 paralarvae lÀ 1 and a food ration of 4 nauplii mlÀ 1 dayÀ 1, a survival 226 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 of 38% at day 20 and a doubling time of 14 days were obtained. After this early period, a larger prey or suitable microdiet is required. Carrasco et al. (2003) cited a survival rate of the paralarvae between 89.6% and 93.5% at day 20 in two experiments conducted in 2002, at mean water temperature 21.2 jC. Maia squinado zoeae and Artemia were used as living prey for the planktonic individuals. The settlement of paralarvae was noted on day 52 and at day 60 all individuals were benthic, with a survival rate of 3.4%. Paralarvae is the limiting step in the culture of this species, which means that, currently, aquaculture is commercially confined to the growth of subadults obtained from fisheries. Growth from egg to subadult is only possible at laboratory and pilot scales, according to the available scientific publications. The main factors to be tested in future experiments, to increase survival of paralarvae are prey availability (Villanueva, 1994, 1995) and temperature. Temperature is believed to have a strong influence on settlement which occurs when paralarvae reach a critical size (>7.5 mm of mantle length, irrespective of age) (Forsythe, 1993). In order to clarify the nutritional requirements more precisely, the fatty acid composition of the paralarvae (Navarro and Villanueva, 2000) and ovaries, late eggs and wild subadults (Navarro and Villanueva, 2003) were analysed. These authors found a close relationship between the fatty acid profile of the dietary components and the resulting fatty acid profile of the reared individuals. Poor growth and high mortalities seem to be associated with a nutritional imbalance in the fatty acid profile, namely the docoxahexaenoic acid/eicosapentaenoic acid (DHA/EPA) ratio in artificial feeding. These authors also concluded that co-feeding techniques based on the use of polar lipid and PUFA enriched Artemia, together with palatable pellets, seemed to be a possible way to improve paralarvae and subadult cephalopod culture beyond the experimental scale. It is important to emphasise that a high proportion of the published studies on octopus growth is only available from Mediterranean congresses and seminars in Spain and Italy (Table 1), which makes their use difficult. This fact was noted by cephalopod workers and originated several complete compilations: Santos (1999a), focused on ‘‘grey literature’’ between 1996 and 1999, and Santos (1999b). Lee (1994) stated that dissolved gases and nutrients might contribute significantly to meeting the metabolic and nutritional requirements of cephalopods, especially hatchlings. These dissolved nutrients could be absorbed actively across the epidermis and then either be used immediately for metabolism in the mantle tissue or enter the semi-closed circulatory system for distribution. 3.5. Ongrowing In nature, octopuses attack prey when they perceive movement. Perception is generally monocular and accidental (Boucaud-Camou and Boucher-Rodoni, 1983). Octopuses prefer to be fed slowly; this characteristic must be respected when planning feeding in tanks. While some authors reported O. vulgaris to be more active during the night, being considered dim-light feeders, others found this species more active when darkness approaches (Boucaud-Camou and Boucher-Rodoni, 1983). These authors also point out that this species seems to be opportunistic, prepared to feed at any time. P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 227 Octopus species often switch their food preference from small crustaceans to larger ones during growth (Mangold, 1983). The quantity of food eaten is regulated in all cephalopods that have been studied: they all reject any excess food. It seems to be impossible, by offering food, to overfeed a cephalopod experimentally. Although they prefer live food, they can be adapted to accept dead food like pieces of crabs, fish or molluscs (Boucaud-Camou and Boucher-Rodoni, 1983). An advantage of this species is its easy adaptation to captivity after the benthic stage, which includes high acceptance of natural foods. This is important not only because there is still no satisfactory artificial diet for cephalopods, but also because the potential for the production of a more natural food exists. This could help to distinguish the farmed octopus from other farmed species, which could increase the image of this new product for consumers (for example, leading to the creation of ‘‘biologically produced octopus’’ or the like). However, it should be noted, from the nutritional point of view, that the aquacultural potential of this species will involve a change from natural to commercial dehydrated foods. Lee et al. (1991) performed growth trials with pelleted diets developed for cephalopods and analysed their palatability and acceptance on octopus and cuttlefish. Authors observed that the texture of the dried pellets (10% moisture content) might be a major factor affecting ingestion on Octopus bimaculoides. For raw, live and pureed diets (40% moisture content), texture did not appear to be as important as for dried pellets, although the mean-latency-to-grab was lower in live and raw diets (both composed by shrimp and chicken). Thus, moisture content may be the most important property affecting ingestion. The nutrition of cephalopods was reviewed by Lee (1994). Aspects like the biochemical composition of cephalopods, their feeding behaviour, digestibility and assimilation of nutrients, as well as the importance of proteins on their growth and as a source of energy were focused. This author stated that the feeding behaviour (pursuit and capture) in cephalopods in initiated primarily by visual stimuli, but ingestion is affected by both chemical and textural qualities of the food. Continued ingestion depends on the properties of the food (pre-ingestinal factors) as well as the nutritional quality of the diet (postingestinal factors). An important group of publications with results on O. vulgaris ongrowing in captivity ˜ o et al., 1998) and appeared in Spain (Iglesias et al., 1997, 1999, 2000a), Portugal (Senda Italy (Cagnetta, 1999; Cagnetta and Sublimi, 2000). Several types of food were tested, including crabs (C. maenas, Polybius henslowi) (Iglesias et al., 1997, 2000a), sardines ´a Garcı ´a and Aguado, 2002), of (Sardina pilchardus) and bogues (Boops boops) (Garcı which crabs, especially when live, seem to be the most desirable in terms of growth (Cagnetta and Sublimi, 2000). When crustaceans are given as food in tanks, a high volume of discarded material is produced (external shells); this problem should be minimized by appropriate tank design, automatic separation of rejected materials and regular cleaning procedures. Some other important conclusions taken from recent ongrowing studies are that initial octopus sizes must be similar, initial density should not exceed 10 kg/m3 (Otero et al., 1999), males and females must be cultured separately and artificial structures for hiding must be present in the tanks, in numbers similar to the number of octopus in each tank. There are no important problems of cannibalism or competition for food. Table 1 Summary of the more important results from seminars, technical magazines and internal technical reports on octopus culture Factor, phase General culture procedures Adult behaviour in nature General biology and culture potential Culture potential Biology, biometry General culture procedures Reproduction and hatching Hatching Hatching Paralarvae and ongrowing Paralarvae chemical composition Reproduction, paralarvae and ongrowing (laboratory and cages) Subadult Transportation and ongrowing Ongrowing Major observations or summary System design, water and food needs for laboratory maintenance of several species including O. vulgaris Feeding behaviour, mechanisms and diets of cephalopods Biology, fishing and farming Overall view of O. vulgaris as candidate for aquaculture Biometry parameters used to distinguish two different populations Evaluation of parameters that make O. vulgaris a promising candidate for aquaculture Reproduction behaviour, hatching and paralarvae development 100% mortality from eggs to 40 days (before subadult phase) Effect of Artemia enrichment with lipid and protein sources and density on paralarvae survival 0.5 – 1.0 growth rates and low mortality for subadult; high mortalities for paralarval growth Paralarvae amino acid profile, relationship with nutrients and absorption of amino acids through skin Parameters for the control of the reproduction phase and paralarvae growth; ongrowing from 750 g until 2.5 – 3 kg in 3 – 4 months, mortality 10 – 15% Low-cost closed circuit maintenance in captivity for laboratory studies Effect of temperature in handling and farming; sensitivity to high temperatures Separated sex cultures give best results; males grow faster than females; 3 kg (males) and 2.5 kg (females) are recommended as maximum ongrowing weight in separated sex cultures Crab diet resulted in faster growth than sardine or mullet diets Language Spanish Reference Forsythe, 1987 Kind Seminar proceedings Seminar proceedings Equivalent to MSc thesis Report Seminar proceedings Seminar proceedings Seminar proceedings (abstract of oral presentation) Seminar proceedings (abstract of oral presentation) Seminar proceedings (abstract of oral presentation) Seminar proceedings Seminar proceedings Seminar proceedings 228 English Nixon, 1988 Portuguese Gonc ßalves, 1993 English English English Spanish Spanish Spanish Spanish Spanish English Iglesias et al., 1996 Cunha and Pereira, 1995 Cagnetta et al., 1998 Moxica et al., 1999 Carrasco and ´guez, 1999 Rodrı ´n et al., 1999 Martı Iglesias et al., 1997 Villanueva et al., 2003 Iglesias et al., 1999 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 Spanish Spanish English Andreu-Moliner and Cachaza, 1984 Aguado et al., 1999 ´ nchez et al., 1998 Sa Internal report Seminar proceedings (abstract of oral presentation) Internal report Ongrowing English ˜ o et al., 1998 Senda Seminar proceedings Ongrowing Ongrowing Ongrowing Ongrowing Ongrowing Ongrowing Ongrowing Ongrowing Ongrowing in cages Octopus grow better if sufficient space and freedom for movement is provided From several monodiets tested, crab showed best results Influence of dissolved oxygen in oxygen consumption and ventilatory frequency; 13% saturation (0.8 mg/l) of oxygen is the lower limit Influence of octopus weight and water temperature in oxygen consumption Density of 10 kg/m3 is recommended as maximum High weight gain and low accumulated mortalities in rectangular-shaped tanks; specific growth rate 1.3% Post-prandial oxygen consumption English English Spanish Cagnetta, 1999 Seminar proceedings Cagnetta and Sublimi, 1999 Seminar proceedings ´a Garcı ´a et al., 1999a Seminar proceedings Garcı (abstract of oral presentation) ´a Garcı ´a et al., 1999b Garcı Otero et al., 1999 ´guez and Rodrı Carrasco, 1999 Cerezo and ´a Garcı ´a, 2003 Garcı Cerezo et al., 2003 Rama-Villar et al., 1997 Seminar proceedings (abstract of oral presentation) Seminar proceedings (abstract of oral presentation) Seminar proceedings (abstract of oral presentation) Seminar proceedings Seminar proceedings Seminar proceedings Spanish Spanish Spanish Spanish Spanish Spanish P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 Post-prandial ammonia production Raft-suspended cages can be used, 1 m3 are recommended as maximum; PVC tubes are better shelters than pneumatics or plastic baskets Ongrowing in cages Analysis of a period of 2 years of several ongrowing parameters in 35 cages Subadult and adult pathology Skin ulcers of several Cephalopod species, subsequent pathologies and bacterial agents; minimizing of wall contact is advised Processing Octopus marinating process Preservation, quality evaluation Oscillatory pressurization at 400 MPa at 7 and 40 jC to octopus muscle resulted in reduced microbial load, TMA-N, TVB-N, proteolytic activity, softening and WHC Preservation, quality evaluation Musky octopus (Eledone moschata); sensory, chemical and microbiological analysis during storage Quality evaluation Octopine is considered as better quality indicator than TVB-N, K value and polyamines Reference list Cephalopod internal reports, seminars, congresses and other ‘‘grey’’ literature (1996 – 1999) Reference list Cephalopod scientific references (1996 – 1999) Spanish English Luaces-Canosa and ´ ndez, 1999 Rey-Me Hanlon et al., 1988 Seminar proceedings (abstract of oral presentation) Seminar proceedings English English Baldrati, 1989 Hurtado et al., 1998 Technical magazine Seminar proceedings Italian Spanish English English Civera et al., 1999 Respaldiza et al., 1997 Santos, 1999a Santos, 1999b Technical magazine Technical magazine Seminar working document Seminar working document 229 230 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 The description of the feeding behaviour and techniques regarding live crustaceans (Grisley and Boyle, 1988), bivalve prey (McQuaid, 1994) and the special case of broody females (Wodinsky, 1978) is interesting as general biology and behaviour understanding of this species. Benthic octopuses exhibit negative phototaxis and reclusive behaviour (Villanueva, 1995). Consequently, higher growth rates were obtained when these characteristics were respected by installing artificial shelters in the growth tanks, also known as ‘‘homes’’, ‘‘sheltering homes’’ or ‘‘dens’’ (Mather, 1994). They also prefer dark and opaque dens, with no light inside at all (Anderson et al., 1999). Mather (1994) also stated that octopuses in nature do not just seek suitable homes, but also chose unsuitable ones and modify them, especially by moving stones to reduce the aperture to around 12 cm in diameter. From the industrial point of view, this is the phase of the life cycle showing the highest potential: The species shows no important signs of cannibalism or competition for food, and it is possible to attain a commercial size of 2.5– 3 kg (from 750-g specimens) in 3 or 4 months, with mortality not exceeding 10 –15% (Iglesias et al., 2000a). Industrial ongrowing of small octopus in floating cages was predicted in the late ´ ndez, 1998; Iglesias et al., 2000a) and is now a reality in Galicia (Spain), nineties (Rey-Me where one company is rearing O. vulgaris. Some experiments, performed by the University of Santiago de Compostela group with this company, resulted in growth rates of 0.3– 0.8 kg/month and low mortality (5.7%) using low-value frozen feeds including sardine (S. pilchardus), scad (Trachurus trachurus), blue whiting (Micromesistius poutassou), bogue (B. boops), mackerel (Scomber scombrus) and mussels (Mytilus sp.) (Rama-Villar et al., 1997). Octopus culture is now a strong area of study in Spain; first published results on ongrowing involved cylindrical or square shaped cages, with individual dens (on the walls ´ ndez, 1999). The or in the centre) for 150 individuals (Luaces-Canosa and Rey-Me ongrowing process lasts 4 months, which means three fattening cycles theoretically can be conducted per year. General calculations indicate a company with 25 cages would be able to produce around 11 000 octopuses per year (Iglesias et al., 2000b). Separation of sexes at the ongrowing phase is recommended, as non-fecundated females continue to grow until commercial size; in separate-sex culture, males grow faster than females. Recommended attainable weight in separate-sex cultures is 3 kg for males and 2.5 kg for females, as beyond this point, an increasing rate of mortality reduces ´ nchez et al., 1998). the yield of the ongrowing process (Sa As it is easy to feed octopuses in captivity with low-value natural food like live, fresh or frozen crustaceans and fish, it seems that the development of a pelleted feed was not of main concern or line of research until now. Cephalopods can be adapted to pellet foods, but the costs and labour should be evaluated with care. Specific artificial foods for O. vulgaris are not yet commercially available, but they will probably follow the complete control of the life cycle of this species. On the other hand, as pellet foods can be used for oral administration of antibiotics and food supplements, there will be a need for the production of commercial feeds for these species (Lee et al., 1991). O. vulgaris has a very rapid digestive rate (12 h at 18– 19 jC) compared with other truly benthonic octopuses like Eledone cirrhosa, depending on temperature, sex and P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 231 sexual maturation (Boucaud-Camou and Boucher-Rodoni, 1976; Boucher-Rodoni and Mangold, 1977). Explanations for this rapid digestive rate and for several nutritional characteristics of these species were published by Lee (1994). High growth rates are explained by a very efficient amino-acid metabolism; lipids are not, as in vertebrate carnivores, the predominant long-term energy store. Details on digestion and factors that could interfere with it can be found in Boucher-Rodoni and Mangold (1977). In some growth studies, sex did not appear to have any influence on the growth rate, but ´a Garcı ´a there was some influence on the feeding rate, which was higher in females (Garcı and Aguado, 2002). Some authors observed that males reach higher body weights than females (Mangold, 1983; Iglesias et al., 2000a) because females experience stronger metabolic needs during sexual maturation. However, prior to maturation, females grow as ´a Garcı ´a and Aguado, 2002). rapidly as males (Garcı Protein synthesis and growth were studied by Houlihan et al. (1990), who concluded that rapid growth rates in O. vulgaris are brought about by high rates of protein synthesis and high efficiencies of retention of synthesized protein and, therefore, little protein degradation. ´a Garcı ´a, 2002) were that Major conclusions from another study (Aguado and Garcı growth or food intake were not affected by sex, optimum temperature for growth was 17.5 jC, food intake was higher with crab diet, but food efficiency was better for animals fed on fish, which was reached at 16.5 jC for both diets tested. When temperature was above 23 jC, weight losses and mortality occurred. Taking into account all data obtained, optimum performance of O. vulgaris growth is between 16 and 21 jC; recirculation in closed systems with temperature control is probably a choice to consider. 4. Final overview The complete life cycle of O. vulgaris under culture conditions was attained for the first time in the year 2001 by Iglesias et al. (2002). Using Artemia and spider crab (Maja squinado) zoeas, the survival during the paralarvae rearing was 31.5% per day after hatching. These authors give weights of 0.5 – 0.6 kg at the age of 6 months and 2 months later average weights of 1.6 kg (Iglesias et al., in press). Iglesias et al. (1999, 2000a) presented a review on common octopus culture. The main conclusion was that in order to reduce paralarval mortality rates and thus, to close the culture cycle for this species, it will be necessary to focus future research on finding prey food with a suitable nutritional profile and size. Using Artemia nauplii in the first week of life followed by Artemia metanauplii, the survival rate was 10% until 140 Ag dry weight, but as high as 100% at the end of the experiments (maximum duration of 32 days). Since paralarvae are the main difficulty in the octopus cycle, focus will probably continue on components like fatty and amino acids, as some results until now are promising. O. vulgaris, like almost all species from fisheries, is a carrier in nature of several types of parasite (Pascual et al., 1996), but these are not frequently cited as a problem in the farming of this species. References to other pathologies in captivity are rare (Forsythe et al., 1987, 1990). External pathologies (Hanlon et al., 1988) and fatal penetrating skin 232 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 ulcers were described by Hanlon et al. (1984) for cephalopods reared in captivity for laboratory use. 5. Octopus processing 5.1. General considerations While octopus production systems have been tested extensively, processing and marketing strategies have received little attention. This is also the case with other recently farmed species like tilapia in saline waters (Suresh and Lin, 1992). After death, cephalopods enter a state of high protein degradation by both endogenous and bacterial enzymes. Such rapid protein degradation results in the release of high levels of nitrogen from the muscle, promoting bacterial growth and leading to rapid decomposition. Consequently, the shelf life of an octopus is extremely limited, typically 6– 7 days after catch even at a low storage temperature of 2.5 jC (Hurtado et al., 1999) or 8 days at 0 jC (Barbosa and Vaz-Pires, 2003). Farmers and processors must consider this difference from other species. One biological peculiarity of cephalopod meat is the high solubility of its fibrilar proteins, causing loss in nutritive value by the leaching out of a considerable amount of protein when in contact with water. Washing, bleaching, brining, thawing in water, chilling, etc., need careful attention in the processing plants if nutritive quality and flavour are to be retained. Cephalopod muscle, in general, gains in weight when in contact with cold water but loses nutrients quickly, much more readily than finfish muscle. Spanish researchers performed experiments on the extension of octopus shelf life in ice and texture improvement using exposure to high pressure as pre-treatment (Hurtado et al., 1998) and combinations of heat and high pressure (Hurtado et al., 2001a,b), but although some quality-related chemical and microbiological parameters were positively affected by this method, no softening effects on the muscle texture were observed. The presence of chromatophores in the skin (pigment organs) also creates a series of processing problems, mainly in handling, freezing, cold storage, thawing and drying (Kreuzer, 1984). After death, the muscles attached to the chromatophores are no longer controlled, the chromatophores remain expanded and the muscles relax slowly, causing skin colour changes from dark to light within a few hours of death. This process seems to be concluded with the onset of rigor mortis. Within the official sensory schemes of the European Union (Council Regulation, 1996), the table for cephalopods only applies to cuttlefish (Sepia officinalis and Rossia macrosoma). However, recent efforts have tested sensory tables (Barbosa and Vaz-Pires, 2003), microbial counts and physical instruments (Vaz-Pires and Barbosa, 2003), chemical evaluations like agmatine (Yamanaka et al., 1987; Ohashi et al., 1991) and octopine (Respaldiza et al., 1997), and also microbial counts of psychrophilic bacteria like Photobacterium phosphoreum and Pseudoalteromonas (Paarup et al., 2002). All these are methods recently recommended for quality evaluation. Some work has also been published in Italy on the chemical and microbiological characterisation of cephalopods during storage (Civera et al., 1999). P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 233 5.2. Processing yield and edible parts Due to lack of bones, the average edible portion of the cephalopods is 80 –85% of the total body, very high when compared with crustaceans (40 – 45%), teleosts (40 – 75%) and cartilaginous fish (25%) (Kreuzer, 1984). This emphasises the potential of the species of this group, as the rejected tissues are very low in percentage. 6. Octopus marketing It is not too risky to predict that octopus will be included in the list of farmed species in a relatively short time. The authors believe that the next 5 – 10 years will represent a very good opportunity to create an appropriate market position for this species, as farmed octopus will co-exist with octopus caught in nature for a long time. Two different approaches are possible: to introduce farmed octopus in the same competition level as the octopus caught in nature (as was the case for most other farmed species), or to create a different product, and consequently, a different market for this new product. The authors are convinced this second option is much more likely to be successful, as a good set of advantages can be used to educate consumers and increase their respect for farmed octopus. These include the already cited dietary, yield, convenience and environmental advantages, but also the natural food farmers now use to grow octopus in captivity, far different from the artificial foods used to grow many other animals for human consumption. The creation of special guarantees and labels to emphasise this characteristic would be of great interest for all involved in octopus aquaculture. Farmed octopus marketing will also depend on the development of new products and processing methods, and recovering of traditional products that were abandoned or have only local importance. These include octopus canning, common in countries like Portugal and Spain and marinating, as described by Baldrati (1989). 7. Future Scientific results obtained with octopus are not as common as for other cephalopods such as squid and cuttlefish. A great part of the bibliography is presented in a form of reports produced by the research organizations, mainly for internal use, or as posters or short communications at scientific meetings, which are always more difficult to find and use; part of the information is not available in English: Spanish, Italian, Japanese and Portuguese are quite common languages in the cephalopod field. It is advisable for authors to increase their range of target readers by publishing in English, in accepted international scientific journals. From the available bibliography in English and in Spanish, it is reasonable to suppose that the life cycle of O. vulgaris is now understood, but paralarvae rearing is only possible under laboratory conditions and mortality is still too high. Main questions for future research are paralarvae nutrition and the correct combination of physical parameters like temperature, salinity and other water quality factors. 234 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 Ongrowing of subadult wild individuals is the only industrialized phase of the life cycle, both in tanks and floating cages, with promising technical and financial results. Production in NW Spain was estimated at around 32 tonnes yearÀ 1 in 1998 and 1999 (FAO, 2001, 2002). Easy adaptation to captivity and feeding based on low-value foods, as well as a rapid growth and high commercial value, are the main reasons for being optimistic about the future aquaculture of this species. As a conclusion, it can be said that the future research required to move forward in the topic of O. vulgaris aquaculture will be focused on the need for stardardisation of paralarvae rearing methods, especially on live prey versus inert diets. Experiments on the survival during the weaning process and studies directed to the development of dry diets for subadult growing will also be of major importance. Acknowledgements The authors gratefully acknowledge the support from the EU program ‘‘Iniciativa ´ ria-Pequenas e Me ´ dias Empresas’’ and Age ˆ ncia de Inovac ˜ o (Eng. Joa ˜ o Santos Comunita ßa Silva), Lisbon, Portugal, who financed the author Alexandra Barbosa (project ‘‘The Use of the Crab P. henslowi as Food for Aquaculture’’). The authors also thank the invaluable advices and detailed revision work kindly offered by Professor Graham A.E. Gall, University of California, Davis, USA. References ´a Garcı ´a, B., 2002. Growth and food intake models in Octopus vulgaris Cuvier (1797): Aguado, F., Garcı influence of body weight, temperature, sex and diet. Aquac. Int. 10 (5), 361 – 377. ´ lez, R.F.M., Nicolas, E.M.A., Llorente, H.M.D., Munuera, F.F., Garcı ´a Garcı ´a, B., 1999. Aguado, F., Gonza ´ n y engorde de Octopus vulgaris Efecto de la temperatura sobre la supervivencia en el transporte, estabulacio ´ neo Occidental. Libro de resumenes, 7j Congreso Nacional de Acuicultura. Las Cuvier (1797) en el Mediterra Palmas de Gran Canaria, 19 – 21 Mayo. Anderson, R.C., Hughes, P.D., Mather, J.A., Steele, C.W., 1999. Determination of the diet of Octopus rubescens Berry, 1953 (Cephalopoda: Octopodidae), through examination of its beer bottle dens in puget sound. Malacologia 41 (2), 455 – 460. Andreu-Moliner, E.S., Cachaza, A.N., 1984. Tecnica para el mantenimiento de Octopus vulgaris en acuarios ´ n cerrada de agua. Inf. Te ´ c. Inst. Esp. Oceanogr. 28 (11 pp.). marinos con circulacio ˜ o, C., Conceic ˜ o, L., Martins, D., Rønnestad, I., Gomes, E., Dinis, M.T., 2004. A balanced dietary amino Araga ßa acid profile improves amino acid retention in post-larval Senegalese sole (Solea senegalensis). Aquaculture 233, 293 – 304. Baldrati, G., 1989. Handling, marketing and processing of cephalopods in Italy. Ind. Conserve 64, 353 – 355. Barbosa, A., Vaz-Pires, P., 2003. Quality index method (QIM): development of a sensorial scheme for common octopus (Octopus vulgaris). Food Control 15 (3), 161 – 168. Boletzky, S.v., 1987. Embryonic phase. In: Boyle, P.R. (Ed.), Cephalopod Life Cycles. Comparative Reviews, vol. II. Academic Press, London, pp. 23 – 25. Boletzky, S.v., 1989. Recent studies on spawning, embryonic development and hatching in the Cephalopoda. Adv. Mar. Biol. 25, 85 – 115. Boletzky, S.v., Hanlon, R.T., 1983. A review of the laboratory maintenance, rearing and culture of cephalopod molluscs. Mem. Natl. Mus. Vic. 44, 147 – 187. P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 235 Boucaud-Camou, E., 1989. L’aquaculture des cephalopodes: evaluation et perspectives. Haliotis 19, 201 – 214. Boucaud-Camou, E., Boucher-Rodoni, R., 1976. Digestive absorption in Octopus vulgaris (Cephalopoda: Mollusca). J. Zool. (Lond.) 179, 261 – 271. Boucaud-Camou, E., Boucher-Rodoni, R., 1983. Feeding and digestion in cephalopods. In: Wilbur, A.S.M. (Ed.), The Mollusca. Physiology, Part 2, vol. 5. Academic Press, London. 189 pp. Boucher-Rodoni, R., Mangold, K., 1977. Experimental study of digestion in Octopus vulgaris (Cephalopoda: Octopoda). J. Zool. (Lond.) 183, 505 – 515. Boyle, P.R., 1980. Home occupancy by male Octopus vulgaris in a large seawater tank. Anim. Behav. 28, 1123 – 1126. Caddy, J.F., Rodhouse, P.G., 1998. Cephalopod and groundfish landings: evidence for ecological change in global fisheries? Rev. Fish Biol. Fish. 8, 431 – 444. Cagnetta, P., 1999. The effect of 3 different rearing strategies on the productive responses of the common octopus (Octopus vulgaris C). Seminar on the Mediterranean Marine Aquaculture Finfish Species Diversification. Zaragoza, Spain, 24 – 27 May. Cagnetta, P., Sublimi, A., 1999. Productive performance of the common octopus (Octopus vulgaris C.) when fed on a monodiet. Seminar on the Mediterranean Marine Aquaculture Finfish Species Diversification. Zaragoza, Spain, 24 – 27 May. Cagnetta, P., Sublimi, A., 2000. Productive performance of the common octopus (Octopus vulgaris C.) when fed on a monodiet. Recent Advances in Mediterranean Aquaculture Finfish Species Diversification. Cahiers ´ diterrane ´ ennes, vol. 47, pp. 331 – 336. Options Me Cagnetta, P., Zezza, L., Perniola, R., 1998. Preliminary trials on octopus (Octopus vulgaris C.) rearing under controlled conditions. Atti del 33j International Symposium on new species for Mediterranean aquaculture. Alghero, Italy, 23 – 24 Aprile. ´guez, C., 1999. Cultivo larvario del pulpo (Octopus vulgaris, Cuvier). Evolucio ´ n de la Carrasco, J.F., Rodrı supervivencia. Libro de resumenes, 7j Congreso Nacional de Acuicultura. Las Palmas de Gran Canaria, 19 – 21 Mayo 1999. ´guez, C., Rodrı ´guez, M., 2003. Cultivo intensivo de paralarvas de pulpo (Octopus vulgaris, Carrasco, J.F., Rodrı ´ n zoeas vivas de crusta ´ ceos. IX Congreso Nacional de Cuvier 1797) utilizando como base de la alimentacio ´ diz, 12 – 16 Mayo 2003. Acuicultura, Ca ´a Garcı ´a, B., 2003. Descripcio ´ n del patro ´ n de consumo de oxı ´geno postprandial en el pulpo de Cerezo, J., Garcı ´ diz, 12 – 16 Mayo 2003. roca (Octopus vulgaris Cuvier, 1797). IX Congreso Nacional de Acuicultura, Ca ´a Garcı ´a, B., 2004. Influence of body weight and temperature on post-prandial oxygen conCerezo, J., Garcı sumption of common octopus (Octopus vulgaris). Aquaculture 233, 599 – 613. ´ mez, E., Garcı ´a Garcı ´a, B., 2003. Resultados preliminares sobre la produccio ´ n de amoniaco en el Cerezo, J., Go pulpo de roca (Octopus vulgaris Cuvier, 1797) obtenidos mediante un electrodo de ion selectivo. IX Congreso ´ diz, 12 – 16 Mayo 2003. Nacional de Acuicultura, Ca Civera, T., Grassi, M.A., Pattono, D., 1999. Caractteristiche chimiche e microbiologiche di molluschi cefalopodi nel corso della conservazione. Ind. Aliment. 38, 933 – 937. Council Regulation (EC), 1996. No 2406/96 of 26 November 1996 laying down common marketing standards for certain fishery products. Off. J. L. 334, 1 – 15 (23/12/1996). ˜ o Miguel (Azores)—a biometrical Cunha, M.M., Pereira, J.M.F., 1995. Octopus vulgaris Cuvier, 1797 from Sa approach. Proceedings of the Second International Workshop of Malacology and Marine Ecology. Ac ¸ oreana (Supplement 1995). Sociedade de Estudos Ac ¸ oreanos ‘‘Afonso Chaves’’, Azores, Portugal, pp. 297 – 311. de Groot, S.J., 1995. Edible species. In: Ruiter, A. (Ed.), Fish and Fishery Products: Composition, Nutritive Properties and Stability. CAB International, UK, pp. 31 – 76. Dinis, M.T., Ribeiro, L., Soares, F., Sarasquete, C., 1999. Cultivation potential of sole Solea senegalensis in Portugal and Spain. Aquaculture 176, 27 – 38. FAO, 2001. Fish and Fisheries Products. Food Outlook 1, February, vol. 11. FAO/GIEWS, Rome, Italy. FAO, 2002. The State of the World Fisheries and Aquaculture 2002. FAO, Rome. FAO, 2003a. Cephalopods commodity update. http://www.globefish.org/publications/commodityupdate/200311/ 200311.htm. FAO, 2003b. Species identification sheets. http://www.fao.org/figis/servlet/FiRefServlet?ds=species&fid=3571. 236 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 Forsythe, J.W., 1987. Principales consideraciones en el cultivo de pulpos en laboratorio. In: Solis-Ramirez, M.J. ´ n, Yacata ´ n, Me ´ xico, 10 (Ed.), Memoria del Simposio sobre Investigaciones de Pulpos y Calamares, Yacalpete al 11 de Nov. Instituto Nacional de la Pesca, Yucalpeten, Yucatan, Mexico, pp. 25 – 46. Forsythe, J.W., 1993. A working hypothesis of how seasonal temperature change may impact the field growth of young cephalopods. In: Okutani, T., O’Dor, R.K., Kubodera, T. (Eds.), Recent Advances in Fisheries Biology. Tokay Univ. Press, Tokyo, pp. 133 – 143. Forsythe, J.W., Hanlon, R.T., Lee, P.G., 1987. A synopsis of cephalopod pathology in captivity. Proceedings of the 18th Annual IAAAM Conference 1987 (Monterey, California) 1 (4), 130 – 135. Forsythe, J.W., Hanlon, R.T., Lee, P.G., 1990. A formulary for treating cephalopod mollusc diseases. In: Perkins F., Cheng, T. (Eds.), Pathology in Marine Science. Academic Press, San Diego, pp. 51 – 63. ´a Garcı ´a, B.G., Aguado, F., 2002. Influence of diet on ongrowing and nutrient utilization in the common Garcı octopus (Octopus vulgaris). Aquaculture 211, 171 – 182. ´a Garcı ´a, B., Aguado, F., Llorente, H.M.D., Gonza ´ lez, R.F.M., Nicola ´ s, E.M.A., 1999a. Efecto de la Garcı ´ n de oxı ´geno disuelto sobre el consumo de oxı ´geno y la frecuencia ventilatoria, y nivel letal concentracio ´ n (Octopus vulgaris Cuvier, 1797). Libro de resumenes, 7j Congreso Nacional de Acuien el pulpo comu cultura. Las Palmas de Gran Canaria, 19 – 21 Mayo. ´a Garcı ´a, B., Aguado, F., Nicola ´ s, E.M.A., Llorente, H.M.D., Gonza ´ lez, R.F.M., 1999b. Influencia del Garcı ´geno de rutina en el pulpo comu ´ n (Octopus vulgaris peso y la temperatura sobre el consumo de oxı Cuvier, 1797). Libro de resumenes, 7j Congreso Nacional de Acuicultura. Las Palmas de Gran Canaria, 19 – 21 Mayo. ˜ o. Gonc ß alves, J.M.A., 1993. Octopus vulgaris Cuvier 1797 (polvo-comum): sinopse da biologia e explorac ßa ´ gica e Capacidade Cientı ´fica. University of Ac ˜ o Pedago Provas de Aptida ßores, Horta, Portugal. Grisley, M.S., Boyle, P.R., 1988. Recognition of food in Octopus digestive tract. J. Exp. Mar. Biol. Ecol. 118, 7 – 32. ´quez, M., 1980. Para ´ metros biome ´ tricos de Octopus vulgaris. Investig. Pesq. 44 (1), 177 – 198. Guerra, A., Manrı Hanlon, R.T., Forsythe, J.W., Cooper, K.M., Folse, D.S., Kelly, M.T., 1984. Fatal penetrating skin ulcers in laboratory-reared octopuses. J. Invertebr. Pathol. 44, 67 – 83. Hanlon, R., Forsythe, J., Lee, P., 1988. External pathologies of cephalopods in captivity. Proceedings 3rd International Colloq. Pathology in Marine Aquaculture. Gloucester Point, Virginia, pp. 2 – 8. Houlihan, D.F., McMillan, D.N., Agnisola, C., Genoino, I.T., Foti, L., 1990. Protein synthesis and growth in Octopus vulgaris. Mar. Biol. 106, 251 – 259. ´as, A.J., 1998. Chilled storage of pressurized octopus (Octopus vulgaris). Hurtado, J.L., Montero, P.E., Borderı 28th Western European Fish Technologists Association Conference, October 4 – 7, Tromso ¨ , Norway. ´as, J., Montero, P., An, H., 1999. Characterization of proteolytic activity in octopus Hurtado, J.L., Borderı (Octopus vulgaris) arm muscle. J. Food Biochem. 23, 469 – 483. ´as, J., 2001a. Behavior of octopus muscle (Octopus vulgaris) under a process Hurtado, J.L., Montero, P., Borderı of pressure – time – temperature combinations. Food Sci. Technol. Int. 7, 259 – 267. ´as, J., Solas, M.T., 2001b. High-pressure/temperature treatment effect on the Hurtado, J.L., Montero, P., Borderı characteristic of octopus (Octopus vulgaris) arm muscle. Eur. Food Res. Technol. 213, 22 – 29 (doi: 10.1007/ s002170100321). ´ nchez, F.J., Otero, J.J., 1996. The octopus (Octopus vulgaris Cuvier): a candidate for aquaculture? Iglesias, J., Sa International Council for the Exploration of the Sea (ICES), C.M. 1996/F, vol. 10. ICES, Copenhagen, Denmark (5 pp). ´ nchez, F.J., Otero, J.J., 1997. Primeras experiencias sobre el cultivo integral del pulpo (Octopus Iglesias, J., Sa ´a. Actas del VI Congreso Nacional de Acuicultura. ˜ ol de Oceanografı vulgaris Cuvier) en el Instituto Espan Cartagena, Spain, 9, 10 and 11 July. ´ nchez, F.J., Otero, J.J., Moxica, C., 1999. Culture of octopus (Octopus vulgaris, Cuvier): present Iglesias, J., Sa knowledge, problems and perspectives. Seminar on the Mediterranean Marine Aquaculture Finfish Species Diversification. Zaragoza, Spain, 24 – 27 May. ´ nchez, F.J., Otero, J.J., Moxica, C., 2000a. Culture of octopus (Octopus vulgaris, Cuvier): present Iglesias, J., Sa knowledge, problems and perspectives. Recent advances in Mediterranean Aquaculture Finfish Species ´ diterrane ´ ennes, vol. 47, pp. 313 – 322. Diversification. Cahiers Options Me ´ nchez, F.J., Otero, J.J., Moxica, C., 2000b. Ongrowing, reproduction and larvae rearing of octopus Iglesias, J., Sa P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 237 (Octopus vulgaris Cuvier), a new candidate for aquaculture in Galicia (NW Spain). Workshop on New Species for Aquaculture, Faro, Portugal, November. ´ nches, F.J., 2002. Paralarvae culture of octopus (Octopus Iglesias, J., Otero, J.J., Moxica, C., Fuentes, L., Sa vulgaris) using artemia and zoeas, and first data on juvenile growth up to eight months of age. Seafarming Today and Tomorrow-Extended Abstracts and Short Communications. Presented at the Aquaculture Europe 2002, Trieste, Italy, October 16 – 19. EAS Special Publication, vol. 32. European Aquaculture Society, EAS, Oostende, Belgium, pp. 268 – 269. ´ nches, F.J., in press. The complete life cycle of octopus Iglesias, J., Otero, J.J., Moxica, C., Fuentes, L., Sa (Octopus vulgaris Cuvier) under culture conditions: paralarvae rearing using Artemia and zoeae, and first data on juvenile growth up to eight months of age. Aquac. Int. Imamura, S., 1990. Larval rearing of octopus (Octopus vulgaris Cuvier). The progress of technological development and some problems remained. Collect. Breed. 52, 339 – 343 (Japanese text, English abstract). Itami, K., Izawa, Y., Maeda, S., Nakai, K., 1963. Notes on the laboratory culture of the octopus larvae. Bull. Jpn. Soc. Sci. Fish., vol. 29, pp. 514 – 520. Japanese text, English abstract. Kreuzer, R., 1984. Cephalopods: handling, processing and products. FAO Fish. Tech. Pap. 254 (108 pp.). Lee, P.G., 1994. Nutrition of cephalopods: fuelling the system. Mar. Freshw. Behav. Physiol. 25, 35 – 51. Lee, P.G., Forsythe, J.W., DiMarco, F.P., DeRusha, R.H., Hanlon, R.T., 1991. Initial palatability and growth trials on pelleted diets for cephalopods. Bull. Mar. Sci. 49 (1 – 2), 362 – 372. ´ ndez, M., 1999. El engorde industrial de pulpo (Octopus vulgaris) en jaulas: ana ´ lisis Luaces-Canosa, M., Rey-Me ´a Camarin ˜ os de cultivo en la Rı ˜as (Galicia). Libro de resumenes, 7j Congreso Nacional de de dos an Acuicultura. Las Palmas de Gran Canaria, 19 – 21 May. Mangold, K., 1983. Food, feeding and growth in cephalopods. Mem. Natl. Mus. Vic. 44, 81 – 93. Mangold, K., 1998. The Octopodinae from the Eastern Atlantic Ocean and the Mediterranean Sea. In: Voss, N.A., Veccione, M., Toll, R.B., Sweeney, M.J. (Eds.), Systematics and Biogeography of Cephalopods. Smithsonian Contributions to Zoology, vol. II. 586 pp. Mangold, K., Boletzky, S.v., 1973. New data on reproductive biology and growth of Octopus vulgaris. Mar. Biol. 19, 7 – 12. ´n, A.Y., Izquierdo, M., Ferna ´ ndez-Palacios, H., Herna ´ ndez-Cruz, C.M., Castro, J., Herna ´ ndez-Garcı ´a, V., Martı ´ n del enriquecimiento de Artemia y la densidade de estabulacio ´ n en el cultivo larvario de Octopus 1999. Variacio vulgaris. Libro de resumenes, 7j Congreso Nacional de Acuicultura. Las Palmas de Gran Canaria, 19 – 21 May. Mather, J.A., 1993. Octopuses as predators: implications for management. In: Okutani, T., O’Dor, R.K., Kubodera, T. (Eds.), Recent Advances in Fisheries Biology. Tokai Univ. Press, Tokyo, pp. 275 – 282. Mather, J.A., 1994. ‘Home’ choice and modification by juvenile Octopus vulgaris, (Mollusca: Cephalopoda): specialized intelligence and tool use? J. Zool. (Lond.) 233, 359 – 368. Mather, J.A., O’Dor, R.K., 1991. Foraging strategies and predation risk shape the natural history of juvenile Octopus vulgaris. Bull. Mar. Sci. 49 (1/2), 256 – 269. McQuaid, C.D., 1994. Feeding behaviour and selection of bivalve prey by Octopus vulgaris Cuvier. J. Exp. Mar. Biol. Ecol. 177, 187 – 202. ´ nchez, F.J., 1999. Comportamiento reproductor, puestas e desarrollo Moxica, C., Otero, J.J., Iglesias, J., Sa embrionario del pulpo (Octopus vulgaris, Cuvier) en cautividad. Libro de resumenes, 7j Congreso Nacional de Acuicultura. Las Palmas de Gran Canaria, 19 – 21 May. Navarro, J.C., Villanueva, R., 2000. Lipid and fatty acid composition of early stages of cephalopods: an approach to their lipid requirements. Aquaculture 183, 161 – 177. Navarro, J.C., Villanueva, R., 2003. The fatty acid composition of Octopus vulgaris paralarvae reared with live and inert food: deviation from their natural fatty acid profile. Aquaculture 219, 613 – 631. Nixon, M., 1966. Changes in body weight and intake of food by Octopus vulgaris. J. Zool. (Lond.) 150, 1 – 9. Nixon, M., 1970. Some parameters of growth in Octopus vulgaris. J. Zool. (Lond.) 163, 277 – 284. Nixon, M., 1988. The feeding mechanisms and diets of Cephalopods—living and fossil. In: Wiedmann, J., Kulmann, J. (Eds.), Cephalopods. Present and Past (Second International Cephalopod Symposim. E. Schweizerbartsche Verlagsbuchhandlung (Nagelle u. Obermiller). Schweizerbart’sche Verlagsbuchhandlung, Stuttgart, Germany, pp. 641 – 652. Nixon, M., Mangold, K., 1998. The early life of Sepia officinalis, and the contrast with that of Octopus vulgaris (Cephalopoda). J. Zool. (Lond.) 245, 407 – 421. 238 P. Vaz-Pires et al. / Aquaculture 238 (2004) 221–238 Ohashi, E., Okamoto, M., Ozawa, A., Fujita, T., 1991. Characterization of common squid using several freshness indicators. J. Food Sci. 56 (161 – 163), 174. ´ nchez, F.J., Iglesias, J., 1999. Engorde de pulpo (Octopus vulgaris Cuvier) a diferentes Otero, J.J., Moxica, C., Sa ´ n. Libro de resumenes, 7j Congreso Nacional de Acuicultura. Las Palmas de Gran densidades de estabulacio Canaria, 19 – 21 May. Paarup, T., Sanchez, J.A., Moral, A., Christensen, H., Bisgaard, M., Gram, L., 2002. Sensory, chemical and bacteriological changes during storage of iced squid (Todaropsis eblanae). J. Appl. Microbiol. 92, 941 – 950. ´ vez, J.M., Rodrı ´guez, H., Soto, M., Abollo, E., Arias, C., 1996. Parasites in commerPascual, S., Gestal, C., Este cially-exploited cephalopods (Mollusca Cephalopoda) in Spain: an update perspective. Aquaculture 142, 1 – 10. Pedrosa-Menabrito, A., Regenstein, J.M., 1988. Shelf-life extension of fresh fish—a review: part I. Spoilage of fish. J. Food Qual. 11, 117 – 127. ´ lvarez-Bla ´ squez, B., 2000. Culture of Pagellus bogaraveo: present knowledge, Peleteiro, J.B., Olmedo, M., A problems and perspectives. Recent advances in Mediterranean aquaculture finfish species diversification. ´ diterrane ´ ennes, vol. 47, pp. 141 – 152. Cahiers Options Me ´ ndez, M., 1997. Engorde de pulpo (Octopus vulgaris) Rama-Villar, A., Faya-Angueira, V., Moxica, C., Rey-Me ˜ a, 9 – 11 July. en batea. Actas del VI Congreso Nacional de Acuicultura, Cartagena, Espan ´ n del nivel de octopina en cefalo ´ podos comesRespaldiza, E.E., Delgado, M.C., Moral, A., 1997. Determinacio tibles y su uso potencial como ´ ındice de frescura. Aliment. Equipos Tecnol., 85 – 88 October. ´ ndez, M., 1998. Cultivo de polbo en Galicia: dos resultados experimentais o ´ cultivo industrial. In: Rey-Me ´ ndez Casal, J., Rey-Me ´ ndez, M., Cervin ˜ o, A. (Eds.), Foro dos Recursos Marin ˜ os e da Acuicultura Ferna ´as Galegas. O Grove, Spain, pp. 67 – 81. das Rı ´guez, C., Carrasco, J.F., 1999. Engorde del pulpo (Octopus vulgaris, Cuvier). Resultados de crecimiento, Rodrı ´ n. Libro de resu ´ menes, 7j Congreso Nacional de Acuicultura. Las Palmas de supervivencia y reproduccio Gran Canaria, 19 – 21 May. ´ nchez, F.J., Iglesias, J., Moxica, C., Otero, J.J., 1998. Growth of octopus (Octopus vulgaris) males and females Sa under culture conditions. International Council for the Exploration of the Sea (ICES), CM 1998/M: 47. ICES, Copenhagen, Denmark (3 pp). Santos, M.B., 1999a. Cephalopod grey literature (1996 – 1999). Working document. ICES Working Group of Cephalopod Fisheries and Life History, Heraklion, 25 – 27 March. Santos, M.B., 1999b. Cephalopod reference list (1996 – 1999). Working document. ICES Working Group of Cephalopod Fisheries and Life History, Heraklion, 25 – 27 March. ˜ o, J.C., Carvalho, V., Borges, T.C., 1998. Rearing octopus (Octopus vulgaris, Cuvier) with three different Senda diets. Livro de resumos, VI Congresso Nacional de Aquacultura. Viana do Castelo, Portugal, 15 – 16 October. Suresh, A.V., Lin, C.K., 1992. Tilapia culture in saline waters: a review. Aquaculture 106, 201 – 226. Vaz-Pires, P., Barbosa, A., 2003. Sensory, microbiological, physical and nutritional properties of iced common octopus (Octopus vulgaris). Lebensm.-Wiss. Technol. 37 (1), 105 – 114. Villanueva, R., 1994. Decapod crab zoeae as food for rearing cephalopod paralarvae. Aquaculture 128, 143 – 152. Villanueva, R., 1995. Experimental rearing and growth of planktonic Octopus vulgaris from hatching to settlement. Can. J. Fish. Aquat. Sci. 52, 2639 – 2650. Villanueva, R., Koueta, N., Riba, J., Boucaud-Camou, E., 2002. Growth and proteolytic activity of Octopus vulgaris paralarvae with different food rations during first feeding, using Artemia nauplii and compound diets. Aquaculture 205, 269 – 286. ´z Capillas, C., Gonza ´ lez, A.V., Baeta, M., 2003. Composicio ´ n de aminoa ´ cidos en Villanueva, R., Riba, J., Ruı ´ diz, Espan ˜ a, 12 – 16 Octopus vulgaris durante su desarrollo inicial. IX Congreso Nacional de Acuicultura, Ca Mayo 2003. ´ Dor, R.K., Mangold, K., Wells, J., 1983. Diurnal changes in activity and metabolic rate in Octopus Wells, M.J., O vulgaris. Mar. Behav. Physiol. 9, 275 – 287. Wodinsky, J., 1978. Feeding behaviour of broody female Octopus vulgaris. Anim. Behav. 26, 803 – 813. Yamanaka, H., Shiomi, K., Kikuchi, T., 1987. Agmatine as a potential index of freshness of common squid (Todarodes pacificus). J. Food Sci. 52, 936 – 938. Young, R.E., Harman, R.F., 1988. ‘‘Larva’’, ‘‘paralarva’’ and ‘‘subadult’’ in cephalopod terminology. Malacologia 29 (1), 201 – 207.