Search

A recent revival in using cephalopods as experimental animals has rekindled interest in their biology and life cycles, information with direct applications also in the rapidly growing ornamental aquarium species trade and in commercial aquaculture production for human consumption. Cephalopods have high rates of growth and food conversion, which for aquaculture translates into short culture cycles, high ratios of production to biomass and high cost-effectiveness. However, at present, only small-scale culture is possible and only for a few species: the cuttlefish Sepia officinalis, the loliginid squid Sepioteuthis lessoniana and the octopuses Octopus maya and O. vulgaris. These four species are the focus of this chapter, the aims of which are as follows: (1) to provide an overview of the culture requirements of cephalopods, (2) to highlight the physical and nutritional requirements at each phase of the life cycle regarded as essential for successful full-scale culture and (3) to identify current limitations and the topics on which further research is required. Knowledge of cephalopod culture methods is advanced, but commercialization is still constrained by the highly selective feeding habits of cephalopods and their requirement for large quantities of high-quality (preferably live) feed, particularly in the early stages of development. Future research should focus on problems related to the consistent production of viable numbers of juveniles, the resolution of which requires a better understanding of nutrition at all phases of the life cycle and better broodstock management, particularly regarding developments in genetic selection, control of reproduction and quality of eggs and offspring., (© 2014 Elsevier Ltd All rights reserved.)

A novel general model has been developed to fit biomass growth data of coleoid cephalopods as a function of time and temperature from hatching to maximum size in a single curve. This model has been obtained formally from a formulation of product‐integral, solves the discontinuity problem present in two‐phase growth models and describes both asymptotic and non‐asymptotic growth. Within the usual temperature range in which the organism develops, our model describes a non‐asymptotic growth achieving a good fit with the experimental data (R2>0.98)$({{R^2} > 0.98})$. In particular, the model provides precise calculation of the time k at which the growth curve inflection occurs, time μ1 at which sexual maturity begins and time μ2 at which the maximum size is reached. When the model was parameterized as a function of temperature, it corroborated different results on Octopus maya fitness, in particular, 25.7°C was obtained as the temperature that generates the highest average growth rate and 21.7°C as the temperature with the highest biomass accumulation over time. This result confirms that the temperature range of 22–26°C is suitable for the growth of O. maya and shows that the developed model can be a useful tool for aquaculture. [ABSTRACT FROM AUTHOR]

The Novel Object Recognition task (NOR) is widely used to study vertebrates' memory. It has been proposed as an adequate model for studying memory in different taxonomic groups, allowing similar and comparable results. Although in cephalopods, several research reports could indicate that they recognize objects in their environment, it has not been tested as an experimental paradigm that allows studying different memory phases. This study shows that two-month-old and older Octopus maya subjects can differentiate between a new object and a known one, but one-month-old subjects cannot. Furthermore, we observed that octopuses use vision and tactile exploration of new objects to achieve object recognition, while familiar objects only need to be explored visually. To our knowledge, this is the first time showing an invertebrate performing the NOR task similarly to how it is performed in vertebrates. These results establish a guide to studying object recognition memory in octopuses and the ontological development of that memory. [ABSTRACT FROM AUTHOR]

High temperatures alter the physiological condition of Octopus maya embryos, juveniles, and adults, and the time of exposure could have a key role in their thermal tolerance. The present study evaluates the effects of temperature and exposure time on octopus juveniles obtained from a thermally stressed female and a control female when exposed to optimal (25 °C) and high temperatures (30 °C) for 20 and 30 days, respectively. The results showed a transgenerational temperature effect that was expressed with low survival, depressed routine resting and high metabolic rates. Moreover, a collapse of antioxidant defense enzymes and high levels of oxidative damage products were detected in juveniles from thermally stressed females. Stress was lethal for animals acclimated at 30 °C, while the performance of juveniles acclimated at optimal temperature (25 °C) was conditioned by high oxidative stress levels and a reduction of the high metabolic rate (HMR) even after 30 days of experiment. In contrast, juveniles from the non-thermally stressed female had an optimal performance when acclimated at 25 °C but at 30 °C, they had a comparatively higher HMR during the first 8 days. These results suggest energy surplus in those animals to escape from warming scenarios before experiencing oxidative damage accumulation. Further studies should confirm if epigenetic alterations could be involved. [ABSTRACT FROM AUTHOR]

Mitochondrial respirometry is key to understand how environmental factors model energetic cellular process. In the case of ectotherms, thermal tolerance has been hypothesized to be intimately linked with mitochondria capability to produce enough adenosine triphosphate (ATP) to respond to the energetic demands of animals in high temperatures. In a recent study made in Octopus maya was proposed the hypothesis postulating that high temperatures could restrain female reproduction due to the limited capacity of the animals' heart to sustain oxygen flow to the body, affecting in this manner energy production in the rest of the organs, including the ovarium Meza-Buendia AK et al. (2021). Unfortunately, until now, no reports have shown temperature effects and other environmental variables on cephalopod mitochondria activity because of the lack of a method to evaluate mitochondrial respiratory parameters in those species' groups. In this sense and for the first time, this study developed a method to obtain mitochondrial respirometry data of adult Octopus maya's heart. This protocol illustrates a step-by-step procedure to get high yield and functional mitochondria of cephalopod heart and procedure for determining the corresponding respiratory parameters. The procedure described in this paper takes approximately 3 to 4 hours from isolation of intact mitochondria to measurement of mitochondrial oxygen consumption. [ABSTRACT FROM AUTHOR]

Since thermal stress enhances the energy demands, it is possible to hypothesize that the harmful effects of high temperatures observed in Octopus maya are the result of the limited capacity of adults to channel more energy that reproductive activity demands. The present study was designed to know how temperature modulates the energy physiology of O. maya adults. It was evaluated through the relationship between temperature, respiratory metabolism (measured as thermal metabolic scope: TMS), antioxidant defence mechanisms (ANTIOX) and oxidative damage indicators (ODI). Groups of males and females of O. maya were individually distributed at 24℃, 26℃ and 30℃. TMS resulted lower in animals acclimated to 30℃. Also, higher values of ANTIOX and ODI were registered in the branchial hearts in octopus acclimated to 30℃. Results demonstrate that 30℃ is a temperature that limits the energy production in O. maya, probably because of the incapacity of animals to transport oxygen to mitochondria. Although the animals are adapted to satisfy their basic energy requirements at 30℃, we hypothesize that it is not enough to cover all the energy demands needed for reproduction. At 30℃, joint with a reduction on physiologically available energy a high level of oxidative stress was observed, both explaining the previously reported reduction in the production of eggs, in the production of viable sperm and therefore in the quality of the progeny. [ABSTRACT FROM AUTHOR]

This paper contributes to the knowledge of the reproductive biology of Octopus hubbsorum Berry 1953. Its reproductive season in Bahía Magdalena, Baja California Sur ranges from May to October. The increase of gonadosomatic index in females coupled with the decline in Guerra’s index and the increase in oocyte diameter in May and September were indicative of spawning. The total sex ratio was 1:1; males were larger than females. Females reach sexual maturity at 119.7 mm of dorsal mantle length and 628.6 g of total weight. This paper also addressed different aspects on reproductive studies, allowing the identification of the type of gonadal development as a group-synchronous type and the transition from physiological to functional maturity, in both qualitative and quantitative terms (proportion of oocyte stages). Detailed descriptions of the oogenesis/folliculogenesis stages of O. hubbsorum are presented with detailed photographs (in Supplemental online material). [ABSTRACT FROM AUTHOR]

Digestive physiology is one of the bottlenecks of octopus aquaculture. Although, there are successful experimentally formulated feeds, knowledge of the digestive physiology of cephalopods is fragmented, and focused mainly on Octopus vulgaris. Considering that the digestive physiology could vary in tropical and sub-tropical species through temperature modulations of the digestive dynamics and nutritional requirements of different organisms, the present review was focused on the digestive physiology timing of Octopus maya and Octopus mimus, two promising aquaculture species living in tropical (22-30°C) and sub-tropical (15-24°C) ecosystems, respectively. We provide a detailed description of how soluble and complex nutrients are digested, absorbed, and assimilated in these species, describing the digestive process and providing insight into how the environment can modulate the digestion and final use of nutrients for these and presumably other octopus species. To date, research on these octopus species has demonstrated that soluble protein and other nutrients flow through the digestive tract to the digestive gland in a similar manner in both species. However, differences in the use of nutrients were noted: in O. mimus, lipids were mobilized faster than protein, while in O. maya, the inverse process was observed, suggesting that lipid mobilization in species that live in relatively colder environments occurs differently to those in tropical ecosystems. Those differences are related to the particular adaptations of animals to their habitat, and indicate that this knowledge is important when formulating feed for octopus species. [ABSTRACT FROM AUTHOR]

Previous studies on cephalopod feeding have suggested that predetermined preference for certain prey types can be modified by exposing newly hatched individuals to visual or chemical stimuli (imprinting), or by familiarizing them to feed on prey different from those preferred (associative learning). The aim of our study was to determine whether preference to attack crabs in Octopus maya could be modified by early experience with or without food reinforcement using palaemonid shrimp, a prey octopuses consume readily, but will reject if crabs are available. We conducted experiments on the attack response of juvenile octopuses that had been either exposed to (visual and chemical stimuli for at least 48 h before and after hatching) or had fed only on palaemonids (16 days after hatching). Octopuses were then presented with crabs and palaemonids simultaneously and attacks on either prey were recorded. Control treatments, where octopuses had to choose between two similar alternatives (no choice) were included in order to discriminate between active and passive selection. Results were analysed by means of asymmetrical X² contingency tables. Both, octopuses that had only been exposed to stimuli from palaemonids and those that fed on shrimp, selectively attacked crabs when first presented with both alternative prey ( X² = 6.09 and X² = 5.01, respectively; both p < 0.05). These results indicate that preference for crabs in early juvenile O. maya could not be modified through experience with other prey. Because octopuses had never been in contact with crabs prior to trials, such preference was not obtained through their short life experience but could be pre-determined. [ABSTRACT FROM AUTHOR]

The effects of feeding two alternative live prey Hyalella azteca (freshwater gammarids) and Hyale media (marine gammarids) to Octopus maya hatchlings were compared with feeding adult Artemia sp., traditionally used during the first weeks of the life cycle. Hatchlings were fed ad libitum these three live preys during the first 15 days, and a paste elaborated with fresh squid and shrimp during the next 15 days when hatchling can be fed prepared diets. Weight (g) and specific growth rates (% day−1) were determined every 15 days. Octopus maya hatchlings fed with marine gammarids grew larger (6.9 ± 0.2% day−1) compared with hatchlings fed Artemia sp. or freshwater gammarids (4.8 ± 0.2% and 5.0 ± 0.3% day−1 respectively). Survival was also higher (92.2 ± 6.8%) for hatchlings fed marine gammarids, than for those fed Artemia sp. (74.5 ± 23.8%) or freshwater gammarids (41.2 ± 21.2%). The content of acylglycerides, cholesterol and proteins in O. maya fed marine gammarids suggested a better nutrient assimilation by the hatchlings. Also, polyunsaturated fatty acids levels ( EPA and DHA) were more abundant in marine gammarids, possibly contributing to the higher growth rates observed. This is the first study revealing a successful use of marine gammarids as alternative prey for octopus hatchlings culture. [ABSTRACT FROM AUTHOR]

Octopus maya has high growth rates, direct embryonic development and high hatchling survival, making it a good candidate for aquaculture diversification. The present study was designed to evaluate growth rate, survival and food conversion of O. maya juveniles cultured in outdoor tanks. Octopuses were captured from the wild during the fishing season, and fed discarded fish heads and whole crabs. Three trials were conducted between 23 and 32 days, in September (trial 1), October (trial 2) and November (trial 3) where a decrease in sea water temperature was registered (29-24 °C, from September to November respectively). Octopuses were held in three outdoor tanks of 5 m2 of bottom area and 0.5 m deep, aerated sea water and water flow allowing 10% of water exchange per day. Initial density was between 2.9 and 3.8 kg m−3 with different initial mean weight of 542.3 ± 18.8, 493 ± 11.9 and 321 ± 7.8 g, for trials 1, 2 and 3 respectively. Specific growth rate varied between 1.8 and 2.7% BW day−1 with no apparent relation with the culture temperature. These results put in evidence that tanks used are adequate for the ongrowing of O. maya juveniles, with commercial size being attained in a few weeks. [ABSTRACT FROM AUTHOR]

Briceño, F., Mascaró, M., and Rosas, C. 2010. GLMM-based modelling of growth in juvenile Octopus maya siblings: does growth depend on initial size? – ICES Journal of Marine Science, 67: 1509–1516.In most studies on cephalopod growth, variability in initial size is masked by the assumption of a similar growth “starting point” for all hatchlings and by calculating the growth rate (GR) through modelling the average size of individuals through time. Statistical interpretations based on such models are limited because regression assumptions (e.g. homoscedasticity and independence between subjects) are frequently violated. To avoid these limitations, generalized linear mixed modelling was used to model the early growth of two sets of siblings of the holobenthic octopus Octopus maya under controlled conditions. The aim was to (i) determine the effect of initial weight (IW) on the GR of individuals grouped in three size categories (small, medium, and large), (ii) obtain statistically reliable estimates of parameters in an exponential growth model for juveniles up to 105 d old, and (iii) evaluate the influence of hatching date on weight at hatching. Using restricted maximum likelihood, linear models were fitted between (i) IW and final weight (FW) for octopuses in each size category, and (ii) the natural logarithm of IW as a function of time. The models were validated by visually inspecting the residuals. Individual FW depended on IW, but GR did not differ between juveniles of different sizes. The exponential growth model for individuals of all size categories was, with ɛi ∼ N(0,σ2 [agei]2δ). Hatching date had no effect on hatching size (F = 1.93; p = 0.11). The GR value is similar to those reported for other holobenthic species, and one of the first estimates of the magnitude (δ = 0.20) and structure of the increase in variance of individual weight through time is provided. [ABSTRACT FROM PUBLISHER]

Globally, octopus larviculture is one of the challenges faced in the attempt to diversify aquaculture and achieve cephalopod farming. Currently, only juveniles of Octopus vulgaris, Octopus joubini, and Enteroctopus dofleini have been obtained at an experimental level. This is the first study to look at the characteristics of planktonic and benthic Robsonella fontaniana juveniles in an effort to analyze the morphometric changes occurring during their planktonic and benthic phases and to explore the feasibility of obtaining settlement under controlled conditions. The morphometric measurements varied exponentially over time and did not show different tendencies before and after settlement. Mantle growth in relation to total length fit a logarithmic regression, whereas arm length and eye diameter increased linearly with respect to total length throughout the entire paralarval and juvenile periods. This suggests that the size of the mantle decreases with age in proportion to the total octopus length, whereas the organs more directly involved in catching prey tend to increase in direct proportion to the total length. The present study shows that R. fontaniana can be reared from hatching through the final paralarval stage on a diet of Lithodes santolla (king crab) zoeae; after settlement, the juveniles can be reared on a diet of crab such as Petrolisthes. [ABSTRACT FROM AUTHOR]

Abstract: At present, the production of merobenthic octopuses with a post-eclosion planktonic phase is a great challenge for global aquaculture. So far, juveniles from only four species have been reported to have been obtained under controlled rearing conditions: Octopus vulgaris, Octopus joubini, Enteroctopus dofleini and Robsonella fontaniana, the only Chilean species. R. fontaniana (Orbigny, 1834) is a small-sized octopus traded in international markets as “baby octopus”. It is distributed over nearly the entire southern coast of South America, both in the Pacific and Atlantic coasts. This study shows new results regarding the biochemical characteristics in embryonic and paralarval stages, as well as the characteristics of food consumption during the paralarval stage that allow us to discuss a baseline on which to define a strategy for the larviculture of this species. [Copyright &y& Elsevier]

Abstract: Octopus maya is an endemic cephalopod from the Yucatán Peninsula in Mexico, with interest to develop their commercial culture. Like all cephalopods, protein is an important nutrient both for growing and energetic metabolism. This condition results in a high demand for protein and specifically for certain amino acids (AAs). In this study it is examined the effects of inanition and re-feeding on growth and AA content in soft tissue to detect the amino acid (AA) mobilization to identify the principal metabolic reserves in juvenile O. maya. After 25days re-feeding of all starved groups, the octopuses were unable to reach the similar weight as the control group. However, SGR of some groups were greater than that of the controls, although the differences were not significant due to variability in the data. Therefore, it is assumed that the juveniles of O. maya would need a longer period of time to reach the control group. It is therefore demonstrated that juveniles of O. maya have a wide plasticity to tolerate, at least 10days of food deprivation without any apparently physiological damage. Moreover, during inanition the juveniles of O. maya used preferentially Thr, Phe, Ile, Ala, Glu and Ser, suggesting a strong mobilization of both essential and non essential AA to maintain the homeostasis. Prove of that is that survival of the animals during fasting and re-feeding period was not affected by treatments. [Copyright &y& Elsevier]