Octopus Vulgaris Cuvier Research Articles

Movement estimation of Octopus vulgaris Cuvier, 1797 from mark recapture experiment

The movements of Octopus vulgaris were investigated by a mark–recapture study (1604 specimens tagged), carried out during a commercial octopus traps fishery, at a depth of 20–50m, over a rocky substrate area of the Sardinian Sea (central western Mediterranean Sea). Overall 87 specimens (56 males and 31 females) were recaptured after 4 and 63days from the tagging. The difference between the depth at release and recapture varied up to 5.0m but in 100% of males and in 80% of females the variation was less than 3.0m. Theoretical straight distances travelled by recaptures ranged from 9 to 5800m in males and from 9 to 1700m in females, regardless of the days of freedom.There was no correlation between distances and sex or body size and no marked orientation was found except for medium males that move preferentially in the south western direction. The movements of O. vulgaris, generally linked to the availability of food, partners and/or shelters, in this study were limited within 1km in most of the recaptures (84–86%). This high site fidelity, within the rocky area investigated, could represent useful information for management plans of this species like the creation of small no-take areas.

A new set of pure microsatellite loci in the common octopus Octopus vulgaris Cuvier, 1797 for multiplex PCR assay and their cross-amplification in O. maya Voss & Solís Ramírez, 1966

Assessing the genetic structure of cosmopolitan species is essential for conservation purposes, and it assumes particular importance in the case of commercially exploited species and model organisms. Among cephalopods, the common octopus Octopus vulgaris Cuvier, 1797 is a good example of cosmopolitan harvested species whose population structure and connectivity is still unknown in many areas of its distribution. Ten new pure microsatellite loci were isolated in Mediterranean specimens of this species and assembled in multiplex for a quickest and cheapest amplification. The number of alleles ranged from 2 to 16, and the expected heterozygosity from 0.097 to 0.900. These loci have been tested in specimens from the Mediterranean Sea, the Atlantic and Pacific Ocean, and in the congeneric species O. maya. These markers will be added to the existing ones and used for the determination of genetic structure, connectivity among distant populations and stock management.

An integration of historical records and genetic data to the assessment of global distribution and population structure in Octopus vulgaris

The common octopus (Octopus vulgaris Cuvier, 1797) is one of the most widely distributed species belonging to the genus Octopus as well as an important commercially harvested species and a model organism for behavioral biology of invertebrates. It has been described for the first time in the Mediterranean Sea but it is considered a cosmopolitan species inhabiting the temperate and tropical sea of the northern and southern hemispheres. In the last few years, several species previously considered as O. vulgaris have been recognized as new species, limiting the distributional range of “vulgaris” and reinforcing the thesis of a species complex. Where it is an important fishery resource, numerous studies have been conducted in order to define its genetic structure with the purpose of managing different stocks. However, many locations are still poorly investigated from this point of view and others are under taxonomic revision to exclude or confirm its occurrence. Here we provide a summary of the current status of knowledge on distribution and genetic structure in this species in the different oceanic regions.

Comparison of the Exopeptidase Activity of Fractions from Crude Extracts of Octopus Octopus vulgaris Cuvier Hepatopancreas Using Different Fractionation Methods

This study was performed to identify the optimum fractionation method and conditions to obtain exopeptidase-active fractions from octopus hepatopancreas (HP) crude extracts (CEs) using four techniques: solid ammonium sulfate fractionation, polyethylene glycol (PEG) fractionation, anion exchange chromatography, and gel filtration chromatography. The fractions with the highest total activity toward L-leucine-p-nitroanilide (Leu-pNA) were fraction IV from the ammonium sulfate and PEG fractionation, and fraction II in ion exchange and gel filtration chromatography. The total exoprotease activity of these fractions was highest in fraction IV (4,050.20 U) of ammonium sulfate fractionation, followed by fraction II (3,600.28 U) from gel filtration chromatography, fraction IV (2,861.30 U) from PEG fractionation, and fraction II (2,576.28 U) from ion exchange chromatography. These results suggest that ammonium sulfate fractionation using 60-80% ammonium sulfate was the most efficient method for separating the exoprotease active fractions from CEs of octopus HP.

Preliminary study on adaptation of common octopus (Octopus vulgaris Cuvier) by individually stocking technique

Bu ön çalışmada, bireysel stoklama tekniği kullanılarak ahtapot (Octopus vulgaris)’ların adaptasyonu amaçlanmıştır. Bunun için doğadan yakalanan 10 ahtapot bireyi, tek tek 10 lt lik şeffaf, delikli plastik kaplara konulmuştur. Ahtapotların %80 yaşama oranı ile adaptasyon süreleri 5 gün sürmüştür

Preliminary study on adaptation of common octopus (Octopus vulgaris Cuvier) by individually stocking technique.

Bu on calismada, bireysel stoklama teknigi kullanilarak ahtapot (Octopus vulgaris)’larin adaptasyonu amaclanmistir. Bunun icin dogadan yakalanan 10 ahtapot bireyi, tek tek 10 lt lik seffaf, delikli plastik kaplara konulmustur. Ahtapotlarin %80 yasama orani ile adaptasyon sureleri 5 gun surmustur

A simple format feed to test the acceptability of ingredients for common octopus (Octopus vulgarisCuvier, 1797)

A simple format feed to test the acceptability of ingredients for common octopus (<i>Octopus vulgaris</i>Cuvier, 1797)

Variations in Weight and Proximate Composition of Newly Hatched Octopus vulgaris (Cuvier 1797) Paralarvae

Survival and growth of juvenile octopi vary considerably. The objective of this research was to determine variations in weight, total lipids (TL), and total protein (TP) of newly hatched Octopus vulgaris paralarvae (0 days old) over the course of the spawning period. Newly hatched paralarvae dry weight from three females decreased throughout the spawning period. Similarly, newly hatched paralarvae TL percent decreased consistently (p < 0.05) in two of them and remained similar (p > 0.05) for the third female. Contrary, TP% did not vary regardless of the female or the time of hatching throughout paralarvae spawning. In conclusion, we believe that paralarvae used in O. vulgaris culture should be collected during the first 10 days of spawning, as they are larger and have higher lipid content; this increases the chances of a successful paralarvae culture, which is the major bottleneck in the culture of this species.

Development of sexual organs and fecundity in Octopus vulgaris Cuvier, 1797 from the Sardinian waters (Mediterranean Sea)

In this paper we report information about the sexual maturity process of 245 Octopus vulgaris specimens (75 females and 170 males) from the Mediterranean Sea. For both sexes, six stages of sexual maturity (immature, developing, maturing, mature, spawning, and spent) are identified on the basis of macroscopic and microscopic observations of the reproductive system and linked with some reproductive indices. A good correspondence between gonad appearance and its histological structure is observed, highlighting, in females, how oviducal gland morphology plays a crucial role in the macroscopic evaluation of maturity. The Gonadosomatic and Hayashi indices, in the two genders, and the Oviducal Gland index in females alone do not allow distinguishing all the stages in an irrefutable way. Data on the potential fecundity, oocyte and spermatophore size are reported and compared with literature. In addition, spermatophore components are also computed. The results reported in this paper lead to easy identification of the different phases of sexual maturation of O. vulgaris and could constitute an important tool for defining assessment models in view of sound management of this species.

Genetic structure of Octopus vulgaris (Cephalopoda, Octopodidae) in the central Mediterranean Sea inferred from the mitochondrial COIII gene

The polymorphism of the mitochondrial gene cytochrome oxidase III was studied in the Mediterranean octopus, Octopus vulgaris Cuvier, 1797. A total of 202 specimens from seven sampling sites were analysed with the aim of elucidating patterns of genetic structure in the central Mediterranean Sea and to give an insight into the phylogeny of the Octopus genus. Phylogenetic analyses showed that individuals from the central Mediterranean belong to the O. vulgaris species whose limits should nevertheless be clarified. Concerning genetic structure, two high-frequency haplotypes were present in all locations. The overall genetic divergence (ΦST=0.05, P<0.05) indicated a significant genetic structuring in the study area and an AMOVA highlighted a significant break between western and eastern Mediterranean basins (ΦCT=0.094, P<0.05). Possible explanations for the observed patterns of genetic structuring are discussed with reference to their relevance for fisheries management.

Stock Assessment of the Common Octopus (&lt;i&gt;Octopus vulgaris&lt;/i&gt;) in Monastir; the Mid-eastern Coast of Tunisia

The common octopus, ( Octopus vulgaris Cuvier, 1797) is widely distributed through the world. It represents an important resource with high economic value. It is exploited by trawl and by other gears such as trammel net, pots and it is also captured by diving. Although the multitude of assessment techniques, few fisheries cephalopods were well managed. In Tunisia, common octopus ( Octopus vulgaris ) is captured particularly in southern coast and the Sahel defined by three regions (Mahdia, Sousse and Monastir). Our study constitutes the first assessment stock in Monastir situated in the mid of the eastern coasts of Tunisia. Using surplus production models, an under fishing state of Octopus in the East of Tunisia is shown. This study confirms also the necessity of the incorporation of environmental parameters for a better explanation of the variability of common octopus abundance and the importance of these results in the assessment and management of this species.

Development and characterization of 17 polymorphic microsatellite loci in Octopus vulgaris Cuvier, 1797

17 polymorphic microsatellite loci were screened and characterized in Octopus vulgaris using a microsatellite enriched genomic library. The number of alleles per polymorphic microsatellite locus ranged from 3 to 17, and the observed and expected heterozygosities varied from 0.154 to 1.000 and from 0.214 to 0.925, respectively. These microsatellite loci will be useful for further studies on the population structure and genetic variation of this species.

Fatty acid composition of polar and neutral lipid fractions of Octopus vulgaris Cuvier, 1797 paralarvae reared with enriched on-grown Artemia

Rearing of common octopus Octopus vulgaris is limited by the lack of success during the paralarval stage, with generalized mortalities occurring before the settlement of the juveniles. The use of on-grown Artemia cultured with the microalga Isochrysis galbana and further enriched with Nannochloropsis sp. has led to a certain degree of success. The present work aims at studying the effects of this rearing protocol (Nanno) on the fatty acid composition of paralarvae, by comparison with a diet based on on-grown Artemia further enriched with a high polyunsaturated fatty acid oil emulsion (M70). After 28 days, survival was estimated at 3% for M70 and 22.5% for Nanno, whereas the average dry weight was not significantly different (Nanno: 1.76± 0.28 mg; M70: 1.88±0.22 mg). Although apparently no clear association between the fatty acid composition of the enriched preys and that of the total lipids of paralarvae could be established, further fractionation and fatty acid analysis of the total lipids into polar and neutral classes, followed by principal components analysis, revealed that irrespective of the diet, both lipid fractions showed distinct fatty acid patterns. Besides, the fatty acid composition of the polar lipids was more conservative, whereas that of the neutral lipids was more influenced by the diet, showing more variation among dietary treatments.

A new artificial reef design for octopus (Octopus vulgaris cuvier, 1797) in the Aegean sea and preliminary results

This study was carried out in the Gulf of 0zmir in the Aegean Sea between June 2006 and November 2008. The purpose was the creation of a new concept of the artificial reef for Octopus vulgaris, with a view to establishing new artificial reef sites to be used in the fisheries management of this species (MPA, NTZ or fishing areas). First, the main characteristics of natural octopus nests were recorded (entrance width, length, etc.) by divers. These characteristics were used in the construction of new octahedral artificial reef blocks. The blocks were made of reinforced concrete, in a shape like that of an inverted pyramid, with an upper surface of 100x100x25 cm³ and a lower one of 60x60 cm². Four cylindrical holes each with two ellipsoidal openings were placed in one face and in the lateral edge of the octo-block, to serve as the entrances to the artificial nest. Each nest has a volume of 5000 cm³. Eighty octo-blocks were deployed as artificial reefs at 10 m from each other at 15 different depths at two sites by divers with the help of the winch of the R/V EGESUF. These artificial octo-reefs were censused by direct observation. Twenty-eight octopuses were sampled at the end of 25 dives. Minimum mantle length of the octopuses was 75 mm and the maximum 249 mm, with an average of 152.71 mm. The average total length was calculated to be 918.57 mm. The weight of the specimens was between 244 g and 7140 g with an average of 2335.43 g. The results showed that both sites were inhabited by octopuses coming from the artificial reefs, which used them as nests. These nests seem to have constituted special places for fisheries management and will permit the assessment of reserve areas or marine protection areas (MPA), thus opening up a new perspective for Turkish fisheries.

Age estimation obtained from analysis of octopus ( Octopus vulgaris Cuvier, 1797) beaks: Improvements and comparisons

Two methods are currently available for age estimation in octopus beaks. They have been applied to the same specimen from a sample of 30 individuals of Octopus vulgaris caught in central-eastern Atlantic waters. These techniques aim at revealing growth increments in the rostrum sagittal sections (RSS) and lateral wall surfaces (LWS) of octopus upper and lower beaks. Both methods were improved to reduce the time of sample preparation and to enhance the appearance of the increments. For each individual, two independent readings were done for upper and lower beak sections, as well as for the lateral wall surfaces. Vertical reflected light (epifluorescence) and image analysis system were shown to be useful in the observation and analysis of the sequence of increments. Precision of the ageing, increment counts obtained by both techniques, and increment widths were discussed. Using upper beak RSS led to more precise age estimates, whereas preparing LWS was quicker and simpler, and revealed a higher number of increments. Therefore, our study recommends counting growth increments in LWS of beaks to age adult common octopus.

Morphological and genetic evidence that Octopus vulgaris Cuvier, 1797 inhabits Amsterdam and Saint Paul Islands (southern Indian Ocean)

AbstractGuerra, Á., Roura, Á., González, Á. F., Pascual, S., Cherel, Y., and Pérez-Losada, M. 2010. Morphological and genetic evidence that Octopus vulgaris Cuvier, 1797 inhabits Amsterdam and Saint Paul Islands (southern Indian Ocean). – ICES Journal of Marine Science, 67: 1401–1407. The coastal octopus at Saint Paul and Amsterdam Islands is Octopus vulgaris Cuvier 1797. Meristic and morphological characters, along with phylogenetic analysis of COI and COIII DNA sequences, were used to identify 11 animals collected in 2000 or 2001. The range of the species is therefore expanded to include the oceanic islands of the central southern Indian Ocean. The trees also depicted the genus Octopus as polyphyletic and O. vulgaris sense Cuvier or sensu stricto as monophyletic.

Influence of natural diet on growth and biochemical composition of Octopus vulgaris Cuvier, 1797

The influence of diet on growth and biochemical composition of cultured Octopus vulgaris was investigated. Octopuses were reared in a open recirculation seawater system and during the experiment were kept apart in cages. Experiment lasted 30 days. Three experimental dietary groups were established: group I (mixed diet: Carcinus mediterraneus, Boops boops and Mytilus galloprovincialis), group II (monodiet on B. boops) and group III (monodiet on M. galloprovincialis). The best results were obtained with the monodiet based on bogue that gave a weight gain of 390.65 ± 37.54, an absolute growth rate of 13.02 g day−1 and feed efficiency of 44.79 ± 0.96%. Regarding to biochemical composition, the mussel-fed and bogue-fed groups showed the highest protein content. Animals fed on bogue also showed the highest carbohydrate content, while the lowest value was observed in the mussels-fed group. The lipid content was found to be very low in all dietary groups. Saturated fatty acids were the most abundant fatty acid class, ranging from 58.22% in wild octopuses to 46.83% in bogues-fed octopuses. Polyunsaturated fatty acids (PUFAs) were the second most abundant fatty acids class in all dietary treatments (25.65–37.00% as a per cent of total FAs) except in octopuses fed with mussels. MUFAs ranged from 11.44 to 26.93% of total FAs. Although it is empirically known that a varied diet better covers the nutritional requirements than a monodiet, the results of this study reveal that a monodiet of B. boops may be used.

Bottom-up control of common octopus Octopus vulgaris in the Galician upwelling system, northeast Atlantic Ocean

This paper investigates the possible underlying causes of the wide interannual fluctua- tions in catch of the common octopus Octopus vulgaris Cuvier, 1797 in one of the main small-scale fisheries off the coast of Galicia (northwest Spain). Galicia is at the northern boundary of the Iberian-Canary current upwelling system in the northeast Atlantic Ocean, where local winds induce seasonal upwelling, largely driving the annual cycles of primary and secondary production. We hypothesize that such dynamics are also fundamental for the survival of the planktonic stages of octopus and set the year class strength. We address this hypothesis by investigating the influence of upwelling on time-series of octopus fishery data. Wind stress structure during the spring-summer (prior to the hatching peak) and autumn-winter (during the planktonic stage) was found to affect the early life phase of this species, and explains up to 85% of the total variance of the year-to-year variability of the adult catch. Despite this bottom-up modulation via environmental conditions, our results also provide evidence for a between-cohort density-dependent interaction, probably caused by cannibalism and competition for habitat.

A new approach to octopuses' body pattern analysis: A framework for taxonomy and behavioral studies*

We systematically analyzed octopus body patterns, based on locations of chromatophore nerve projection, using a proposed new species in the Octopus vulgaris Cuvier, 1797 complex, Octopus insularis Leite and Haimovici, 2008. Although some taxonomic studies have used body patterns as characters to describe octopus species, a systematic analysis would provide detailed descriptions to assist reliable comparisons among species. This approach also links body patterns, behaviors, and underlying physiology of the chromatophore system. Body patterns were characterized by percent occurrence, areas of skin, and number of components in each. To verify the distribution of chromatic components, skin patterns, and colors among areas of the body, we ran a cluster analysis on occurrence of the components. We identified a total of 16 chromatic, 5 texture, 9 skin units, 6 colors, and 9 chronic body patterns. The cluster analysis showed twelve distinct skin areas of the components' distribution (expressive fields). Smaller f...

Isolation and characterization of Glyceraldehyde-3-phosphate dehydrogenase from the common octopus (Octopus vulgaris Cuvier, 1797)

The NAD+ dependent cytosolic Glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) from arms of Octopus vulgaris, Cuvier, 1787, (Octopoda, Cephalopoda) was purified to homogeneity and its kinetic properties investigated. The purification method consisted of ammonium sulfate fractionation followed by Blue Sepharose CL-6B chromatography resulting in a 26-fold increase in specific activity and a final yield of approximately 16%. The apparent molecular weight of the purified native enzyme was 153 kDa. The protein is an homotetramer, composed of identical subunits with an apparent molecular weight of approximately 36 kDa. The Michaelis constants Km for both NAD+ and d-G3P were 66 μM and 320 μM, respectively. The maximal velocity Vmax of the purified enzyme was estimated to be 21.8 U/mg. Only one GAPDH isoform (pI 6.6) was obtained by isoelectrofocusing in polyacrylamide slab gels holding ampholyte generated pH gradients. Under the conditions of assay, the optimum activity occurs at pH 7.0 and at temperature of 35°C. Polyclonal antibodies raised in rabbits against the purified GAPDH immunostained a single 36 kDa GAPDH band on crude extract protein preparations blotted onto nitrocellulose.