Octopus Vulgaris Research Articles

Hepatoprotective and antioxidant effects of Octopus vulgaris extract against Depakine®-induced hepatotoxicity in adult rats

Background and objective Antiepileptic drug Depakine® is often used, although it can cause birth defects in both human and animals. This study’s goal was to assess the Octopus vulgaris extract’s (OE) ability to protect against the hepatotoxicity caused by Depakine in an effort to advance its clinical application. Patients and methods Four groups of adult male Wistar rats (150–180 g b.w.) have been designed at random (10 rats each) as: 1) healthy control group; 2) healthy rats treated orally with OE (50 mg/kg/day); 3) rats administrated orally with Depakine® (500 mg/kg/day); 4) rats treated with OE in combination with Depakine. Results and conclusion After 6 weeks of treatment, the results demonstrated that OE was effective in lowering Depakine®-induced hepatotoxicity. This was shown by a significant rise in liver glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) values as well as albumin and total protein levels. Additionally, there was a considerable drop in the serum levels of tumor necrosis alpha (TNF-α), interlukin-1beta (IL-1β), interlukin-4 (IL-4), interlukin-6 (IL-6), and interlukin-10 (IL-10), which exacerbated the structural recovery of the liver’s histological image. Conclusion: OE was highly effective in reducing the oxidative stress caused by Depakine® and protecting the liver from its toxic effects. OE is a viable supplement candidate for liver protection against the negative effects of that antiepileptic medication.

Happy families? Insight into the coexistence between the curled octopus (Eledone cirrhosa) and common octopus (Octopus vulgaris) in waters around the UK

AbstractThis case study investigated the co‐occurrence of the curled octopus (Eledone cirrhosa) and common octopus (Octopus vulgaris), in waters around the United Kingdom. The findings suggest that coexistence may be maintained because of the lack of competition for E. cirrhosa against the seemingly declining O. vulgaris populations, and that habitat and temporal partitioning are the likely mechanisms. It is contemplated whether species misidentification may an important factor in masking the accuracy of population dynamics of co‐occurring octopus species, and, as such, potential uncertainty in octopus coexistence and any future fishery management decisions. It is confidently suggested that, currently, only two octopus species are resident to UK waters. Now, further studies should include diet partitioning to determine whether diet partitioning is a mechanism for E. cirrhosa and O. vulgaris coexistence, and monitoring may make us understand their population dynamics.

Living in a dynamic environment: The effects of multi-ways temperature variation on embryo and newborn juveniles of a shallow-water octopus (Amphioctopus fangsiao)

Shallow waters are characterized by fluctuating environmental conditions, modulating marine life cycles and biological phenomena. Multiple variations in water temperature could affect eggs and embryos during spawning events of many marine invertebrate species, yet most of the findings on embryonic development in invertebrates come from experiments based on the constant temperature. In this study, to examine the effects of temperature variation on octopus embryos, Amphioctopus fangsiao, a common shallow-water octopus along the coast of China, was exposed to the constant temperature (18 °C, in situ temperature of the seawater in Lianyungang), ramping temperatures (from 18 to 24 °C), diel oscillating temperatures (18 °C and 20 °C for 12 h each day), and acute increasing temperatures (the temperature increased sharply from 18 °C to 24 °C at embryonic development stage XIX) for 47 days (from embryogenesis to settlement). The results demonstrated that the temperature variations accelerated the development time of A. fangsiao embryos. Temperature fluctuations could cause embryonic oxidative damage and disorder of glycolipid metabolism, thereby affecting the growth performance of embryos and the survival rate of hatchings. Through transcriptome sequencing, the mechanistic adaption of the embryo to environmental temperature variations was revealed. The pathways involved in the TCA cycle, DNA replication and repair, protein synthesis, cell signaling, and nervous system damage repair were significantly enriched, indicating that the embryo could improve heat tolerance to thermal stress by regulating gene expression. Moreover, acute warming temperatures posed the most detrimental effects on A. fangsiao embryos, which could cause embryos to hatch prematurely from the vegetal pole, further reducing the survival of hatchings. Meanwhile, the diel oscillating temperature was observed to affect the normal morphology of the embryo, resulting in embryo deformities. Thus, the constant temperature is critical for balanced growth and defense status in octopuses by maintaining metabolism homeostasis. For the first time, this study evaluates the effects of multiple temperature fluctuations on embryos of A. fangsiao, providing new insights into the physiological changes and molecular responses of cephalopod embryos following dynamic temperature stress.

The best defense is a good offense: Anti-predator behavior of the common octopus (Octopus vulgaris) against conger eel attacks.

We present the description of defensive behavior in wild Octopus vulgaris against conger eel (Conger conger) attacks based on three video sequences recorded by recreational SCUBA divers in the eastern Atlantic off the coast of Galicia (NW Spain) and in the Cantabrian Sea (NW Spain). These records document common traits in defensive behavior: (1) the octopuses enveloped the conger eel's head to obscure its view; (2) they covered the eel's gills in an attempt to suffocate it; (3) they released ink; (4) the octopuses lost some appendages because of the fight. In the third video, the octopus did not exhibit the defensive behavior described in the first two videos due to an inability to utilize its arms in defense, and the conger eel's success in capturing octopuses is discussed. Additionally, both the cost that the octopus could face by losing some arms during the fight and whether the experience it acquires can be an advantage for future encounters are analyzed. The defensive behavior exhibited by octopuses in this study highlights their ability to survive in a hostile environment and serves as an example of the extensive repertoire of anti-predator strategies employed by these cephalopods.

Disappeared Steps in Melanin Formation in Octopus vulgaris as a Model of Higher Organisms from the Red Sea, Egypt

Disappeared Steps in Melanin Formation in Octopus vulgaris as a Model of Higher Organisms from the Red Sea, Egypt

Sex-specific bacterial microbiome variation in octopus vulgaris skin.

Growing knowledge of the host-microbiota of vertebrates has shown the prevalence of sex-specific differences in the microbiome. However, there are virtually no studies assessing sex-associated variation in the microbiome of cephalopods. Here we assess sex-specific variation in the common octopus (Octopus vulgaris) skin microbiome using amplicon sequencing targeting the V4 hypervariable region of prokaryote 16S rRNA genes. Skin and mantle-associated mucus was collected from wild adult individuals of common Octopus (Octopus vulgaris) (9 males and 7 females of similar size). There were no significant differences in the alpha diversity of microbial communities associated with skin or mantle mucosa between sexes. However, our results clearly indicate that adult octopus males and females have a distinct microbial community composition in both skin and mantle associated mucus communities, with female microbiome being dominated by Firmicutes (48.1%), while that of males contained a majority of Proteobacteria (60.5%), with Firmicutes representing only 3.30%, not finding significant differentiation in the microbial communities between the tissues explored. The dominance of different taxa in the skin of O. vulgaris females and males (e.g., Mycoplasmatales and Lactococcus in females and Rhizobiales and Rhodobacteriales in males) suggests a sex-specific symbiosis in which those microbes benefit from easy access to distinct substrates present in female and male skin, respectively. Given the lack of differences in size between specimens of both sexes in this study, we hypothesize differences in hormone profile, as well as behavioral or ecological differences between sexes in the wild, as the main drivers of microbiome differentiation between sexes. Most knowledge of cephalopod microbiota is limited to the digestive tract and the reproductive system. However, cephalopod skin is an organ with a plethora of functions. This is a first attempt to characterize cephalopod skin microbiota and determine sex influence on it.

Trophic role and predatory interactions between the blue crab, Callinectes sapidus, and native species in open waters of the Ebro Delta

The Ebro Delta has become a major blue crab (Callinectes sapidus) fishery area in the NW Mediterranean, but there is limited information on factors controlling the abundance of populations in open waters, a crucial habitat for ovigerous females. Here, we use a stable isotope approach (δ15N and δ13C), to assess blue crab trophic position, the potential consumption of food items using mixing models, and the isotopic niche overlap with local commercial species. For Octopus vulgaris, a potential blue crab key predator, a trophic enrichment experiment was also conducted to further assess predation control in wild populations. The blue crab showed 1.6 times higher trophic position than in other habitats of the Ebro Delta, and similar to that found in the harbor crab, Liocarcinus depurator, and several predatory fish. Additionally, the isotopic niche of blue crabs showed overlaps from 46.2 to 14.9% with native predators, and mixing models also suggest even dietary contributions throughout the food web. For O. vulgaris, field results showed a trophic position of 3.93, lower than that of blue crab, and lower δ15N signatures were also obtained in a captivity experiment drawing negative fractionation (−1.1‰). We conclude that high dietary contribution of animal prey might provide a high protein diet that could be crucial for allowing the maintenance of a large local population, but the overall functional trophic similarity could also disfavor local native species. The similarity between experimental fractionation and field differences between predator and prey (−1.6‰) suggests that predation of blue crab is possible, but further research is needed to clarify the metabolic routes involved in octopus δ15N fractionation.

Comparative Spectral Analysis of Octopus vulgaris Cuvier, 1797, Jellyfish and Seawater from Aegean Sea, Evia, Greece

Research was conducted using the Fourier Transform Infrared (FTIR) spectral spectroscopy method on octopus, jellyfish, and seawater from the Aegean Sea, Chalkida, Evia Island, Greece. Our analyses of two peaks at 896 and 933 cm-1 indicate their presence in the octopus. These peaks are expressed in Martian minerals and meteorites. The results suggest that the octopus is adaptable to conditions on another planet. Our data provide a basis for speculating that it is an organism from Mars or another planet with similar characteristics. However, the spectral characteristics of the jellyfish and seawater do not correspond to the spectral characteristics of Martian minerals and meteorites. Studies have been conducted also on the microbial flora on the skin of octopus of the species Octopus vulgaris Cuvier, 1797, captured in the Aegean Sea near Chalkida, Greece, on the island of Euboea (Evia). The aim was to assess their role as carriers of pathogenic microorganisms. Bacteria from the families Micrococcaceae and Enterobacteriaceae have been isolated, as well as Aeromonas hydrophilia ssp. hydrophilia, Enterococcus caseiflavus, and Candida lusitaniae. Staphylococci prevail, with the highest quantity being Staphylococcus simulans (107.67 + 10.21 CFU cm-2 on the head and 67.33 + 6.02 CFUcm-2 on the tentacles), followed by Staphylococcus piscifermentans (14.33+1.69 CFU cm-2 on the head and 37.33+1.25 CFU cm-2 on the tentacles) and Staphylococcus hyicus (3.67+1.25 CFU cm-2 on the head and 14.67 + 3.39 CFU cm-2 on the tentacles). Among the Gram-negative bacteria, Aeromonas hydrophilia ssp. hydrophilia piscifermentans predominated, found only on the head of octopuses at 9.67+2.05 CFU cm-2, followed by Klebsiella pneumoniae ssp. ozaenae, also isolated solely from the head (4.00+1.63 CFU cm-2). Escherichia coli was the least prevalent, but it was detected both on the head (2.67+0.47 CFU cm-2) and the tentacles of the studied animals (1.67+0.47 CFU cm-2). Enterococci and fungi were isolated in small quantities from the octopuses' heads and tentacles. The isolated bacteria demonstrated in vitro resistance to most of the tested antibiotics. They were only sensitive to broad-spectrum agents such as amphenicols, tetracyclines, aminoglycoside-aminocyclitols (excluding kanamycin), and quinolones. Staphylococci also showed sensitivity to some penicillins (ampicillin, amoxicillin). However, lincosamides (clindamycin) were ineffective in vitro against the studied bacteria. Potentiated sulfonamides exhibited high activity against the Gram-negative bacteria but not against Gram-positive ones.Aeromonas hydrophila is known to be pathogenic to marine inhabitants, including octopuses. S. simulans, E. coli, and K. pneumoniae are conditionally pathogenic to animals and humans. Their presence on the surface of the studied octopuses, especially E. coli, could indicate seawater fecal contamination and possibly other pathogenic species. The current results also reveal the distribution of multidrug-resistant bacterial strains, even among bacteria that are representatives of the normal microflora of octopuses.

The complete mitochondrial genome of Octopus vulgaris

BackgroundThe Octopus vulgaris species complex consists of numerous morphologically similar but genetically distinct species. The current publicly available mitogenome of this species has been generated from a specimen collected from Tsukiji Fish Market, Tokyo, Japan. Octopus from the northwestern Pacific Ocean are now considered to be a separate species, Octopus sinensis. For this reason, we hypothesised that the current record of O. vulgaris was sequenced from a specimen of O. sinensis. Here, we sequenced the first complete mitogenome of a specimen of Octopus vulgaris sensu stricto that was collected from the species’ confirmed distribution areas in northeastern Atlantic.Methods and resultsThe complete mitogenome was assembled de novo and annotated using 250 bp paired-end sequences. A single circular contig 15,655 bp in length with a mean read coverage of 1089 reads was reconstructed. The annotation pipeline identified 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNA) and two ribosomal RNAs. A maximum likelihood phylogenetic tree recovered the assembled mitogenome as the sister taxon of a monophyletic group comprising O. sinensis and the previously published mitogenome of “O. vulgaris” from Japan. This confirms that the latter was a Japanese specimen of O. sinensis.ConclusionThe mitogenome sequenced here is the first to be published for Octopus vulgaris sensu stricto. It represents an important first step in genetics-informed research on the evolution, conservation, and management of this commercially important species.

Citizen science approach for genetic species identification in a local French seafood speciality

In coastal regions of France, seafood is a key element of traditional cuisine and is valued by consumers as quality food. However, in the last decades, the mislabelling of food products has undermined consumers' confidence in their food choices. In this study, we used genetic identification of the seafood species used to prepare a traditional dish of the city of Sète, to initiate a discussion on food labelling and sustainability. The dish, named “Tielle sétoise", is a pie traditionally filled with octopus cooked in a spicy tomato sauce. The recent substitution of octopus by jumbo flying squid (Dosidicus gigas) has triggered debates among locals about how the use of non-native cephalopod species impacts the flavour of tielles. To test this hypothesis, we coordinated a tasting event involving 35 testers from the local population and used CO1-gene metabarcoding to identify the species composition in 25 different tielles. Besides locally available octopuses’ species, including common commercial species Eledone cirrhosa, E. moschata and Octopus vulgaris, we found jumbo flying squid in 17 out of 25 tielles, of which eight (35%) were mislabelled as octopus-based products. Contrary to local belief, anonymous blind-tasting evaluations showed no significant correlation between the flavour or price of a tielle and the cephalopod composition of its filling. Our results support the impact of texture, acidity, and spices on flavour, suggesting that flavour depends more on how tielles are prepared than on the cephalopod species used. The participants in our study expressed their willingness to make informed choices about purchasing tielles based on the carbon footprint and its impact on cephalopod stocks. Our results call for further research to enable citizens to make informed food choices. Our study also highlights the need for improved labelling of traded cephalopods to improve communication between the food industry and society, as well as the possibility of evaluating this with citizen science.

Octopus vulgaris Exhibits Interindividual Differences in Behavioural and Problem-Solving Performance.

By presenting individual Octopus vulgaris with an extractive foraging problem with a puzzle box, we examined the possible correlation between behavioural performances (e.g., ease of adaptation to captive conditions, prevalence of neophobic and neophilic behaviours, and propensity to learn individually or by observing conspecifics), biotic (body and brain size, age, sex) and abiotic (seasonality and place of origin) factors. We found more neophilic animals showing shorter latencies to approach the puzzle box and higher probability of solving the task; also, shorter times to solve the task were correlated with better performance on the individual learning task. However, the most neophilic octopuses that approached the puzzle box more quickly did not reach the solution earlier than other individuals, suggesting that strong neophilic tendency may lead to suboptimal performance at some stages of the problem-solving process. In addition, seasonal and environmental characteristics of location of origin appear to influence the rate of expression of individual traits central to problem solving. Overall, our analysis provides new insights into the traits associated with problem solving in invertebrates and highlights the presence of adaptive mechanisms that promote population-level changes in octopuses' behavioural traits.

Glavonošci kao plijen glavate želve, Caretta caretta (Reptilia: Cheloniidae), iz istočnog Tirenskog mora

This study presents the results of the examination of cephalopod remains extracted from the digestive tract of 40 loggerhead turtles, Caretta caretta, stranded along the Campanian coasts (Southern Italy, eastern Tyrrhenian Sea). We retrieved the remains of 23 cephalopods from 16 turtles (frequency of occurrence = 40%). They belonged to Sepia officinalis (19 specimens) and Octopus vulgaris (2 specimens), both of them benthic neritic species, and Histioteuthis reversa (2 specimens), an oceanic species. Accordingly, loggerheads appear to feed both on the bottom, seemingly in shallow waters, and in the open seawater column; both on muscular items (S. officinalis and O. vulgaris) and ammoniacal ones (H. reversa). This is the first record of H. reversa as a prey of the loggerhead turtle.

Octopus crawling on land: physiological and biochemical responses of Octopus vulgaris to emersion

Octopus crawling on land: physiological and biochemical responses of Octopus vulgaris to emersion

The Use of Isoflurane and Adjunctive Magnesium Chloride Provides Fast, Effective Anaesthetization of Octopus vulgaris.

A wide variety of substances have been used to anaesthetise invertebrates, but many are not anaesthetics and merely incapacitate animals rather than preventing pain. In essence, the role of an ideal general anaesthetic is to act as a muscle relaxant, an analgesic, an anaesthetic, and an amnesic. To achieve all these properties with a single substance is difficult, and various adjuvants usually need to be administered, resulting in a cocktail of drugs. In a clinical setting, the vast majority of patients are unaware of surgery being carried out and have no memory of it, so they can claim to have felt no pain, but this is much more difficult to demonstrate in invertebrates. Here, we show that 1% MgCl2, a muscle relaxant, is a useful adjuvant for the clinical anaesthetic isoflurane on Octopus vulgaris when applied alone in seawater for 10 min before the clinical anaesthetic. After this, full anaesthesia can be achieved in 5 min using 1% isoflurane insufflated into the saline still containing MgCl2. Full recovery takes place rapidly in about 10 to 15 min. The depth of anaesthesia was monitored using changes in respiratory rate, chromatophore pattern, and withdrawal movements of the arms and siphon. This methodology reduces stress on the animal and minimises the quantity of anaesthetic used.

Bioinspired adhesive patch with octopus vulgaris micro-sucker and hexagonal tree-frog pad structures

Bioinspired adhesive patch with octopus vulgaris micro-sucker and hexagonal tree-frog pad structures

Novel insights into the genetics, morphology, distribution and hosts of the global fish parasitic digenean Proctoeces maculatus (Looss, 1901) (Digenea: Fellodistomidae).

Larval stages of the widely distributed digenean species Proctoeces maculatus (Looss, 1901) were reported 40 years ago from South Africa in the common octopus, Octopus vulgaris Cuvier (Octopodidae). However, the absence of adult specimens and molecular data from this region has hindered a comprehensive understanding of its distribution. In this study, we collected three species of intertidal and near-shore marine fishes [Clinus superciliosus (L.) (Clinidae), Diplodus capensis (Smith) (Sparidae) and Sparodon durbanensis (Castelnau) (Sparidae)] along the South African coast and discovered adult specimens of P. maculatus at five localities. By employing a combination of morphological and molecular techniques, including 28S rDNA, 18S rDNA and COI mtDNA analyses, the first report of adult P. maculatus from South Africa is presented. The findings encompass a comprehensive morphological description and molecular data, illuminating the true distribution of this species in the region.

A chromosome-level reference genome for the common octopus, Octopus vulgaris (Cuvier, 1797).

Cephalopods are emerging animal models and include iconic species for studying the link between genomic innovations and physiological and behavioral complexities. Coleoid cephalopods possess the largest nervous system among invertebrates, both for cell counts and brain-to-body ratio. Octopus vulgaris has been at the center of a long-standing tradition of research into diverse aspects of cephalopod biology, including behavioral and neural plasticity, learning and memory recall, regeneration, and sophisticated cognition. However, no chromosome-scale genome assembly was available for O. vulgaris to aid in functional studies. To fill this gap, we sequenced and assembled a chromosome-scale genome of the common octopus, O. vulgaris. The final assembly spans 2.8 billion basepairs, 99.34% of which are in 30 chromosome-scale scaffolds. Hi-C heatmaps support a karyotype of 1n = 30 chromosomes. Comparisons with other octopus species' genomes show a conserved octopus karyotype and a pattern of local genome rearrangements between species. This new chromosome-scale genome of O. vulgaris will further facilitate research in all aspects of cephalopod biology, including various forms of plasticity and the neural machinery underlying sophisticated cognition, as well as an understanding of cephalopod evolution.

Embodied mechanisms of motor control in the octopus

Achieving complex behavior in soft-bodied animals is a hard task, because their body morphology is not constrained by a fixed number of jointed elements, as in skeletal animals, and thus the control system has to deal with practically an infinite number of control variables (degrees of freedom). Almost 30 years of research on Octopus vulgaris motor control has revealed that octopuses efficiently control their body with strategies that emerged during the adaptive coevolution of their nervous system and body morphology. In this minireview, we highlight principles of embodied organization that were revealed by studying octopus motor control, and that are used as inspiration for soft robotics. We describe the evolved solutions to the problem, implemented from the lowest level, the muscular system, to the network organization in higher motor control centers of the octopus brain. We show how the higher motor control centers, where the sensory-motor interface lies, can control and coordinate limbs with large degrees of freedom without using body-part maps to represent sensory and motor information, as they do in vertebrates. We demonstrate how this unique control mechanism, which allows efficient control of the body in a large variety of behaviors, is embodied within the animal's body morphology.

Low-Toxicity Solvents for the Extraction of Valuable Lipid Compounds from Octopus (Octopus vulgaris) Waste.

This study focused on the recovery of valuable lipid compounds from octopus (Octopus vulgaris) by-products. Extraction conditions of total lipids (TLs), phospholipids (PLs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) were optimized by employing a Simplex-Lattice design; for it, different relative concentrations of three low-toxicity solvents (ethanol, acetone, and ethyl acetate) were considered. The optimization process was also addressed in reference to fatty acid (FA) ratios (total polyunsaturated FAs/total saturated FAs and total ω3 FAs/total ω6 FAs). The variance analysis of multiple regression data demonstrated that the quadratic model was significant (p < 0.05) for TL, PL, and DHA values and the ω3/ω6 ratio. As a result, the following optimized values were obtained: 113.8 g·kg-1 dry by-products (TLs), 217.3 g·kg-1 lipids (PLs), 22.55 g·100 g-1 total FAs (DHA), and 3.70 (ω3/ω6 ratio). According to the model developed, optimized values were shown to correspond to the following relative solvent concentrations (ethanol/acetone/ethyl acetate): 0.46/0.00/0.54, 0.93/0.07/0.00, 0.83/0.17/0.00, and 0.64/0.00/0.36, respectively. Comparison to yields obtained by the conventional chloroform/methanol method was carried out. A novel strategy based on the employment of low-toxicity solvents is proposed for the extraction of valuable lipid constituents from octopus waste. A different solvent ratio would be necessary according to the lipid compound concerned.

Development and Quality Characteristics of Elderly-Friendly Pulpo a La Gallega Prepared Using Texture-Modified Octopus (Octopus vulgaris) Arms.

Considering the need for developing new senior-friendly processed seafood, this study aimed to develop octopus pulpo with high preference and excellent quality characteristics for elderly individuals by optimizing the vinegar immersion and sous vide softening treatment conditions for octopus (Octopus vulgaris) arms. The optimal sous vide heating temperature (70.0-100.0 °C), time (69.5-170.5 min), and vinegar concentration (0.2-0.8%) were established using response surface methodology (RSM). The pulpo prototype was produced using an octopus arm softened under optimal conditions and seasoned with a potato and olive oil sauce. The physicochemical and nutritional properties of the prototype were evaluated, followed by sensory evaluation and safety assessments. The hardness of softened octopuses obtained by 0.48% vinegar immersion and sous vide treatment (84.3 °C, 139.8 min), determined using RSM, was 394.5 × 1000 N/m2, showing a reduction of 83.0%; this was confirmed by electron microscopic observation. The texture of the pulpo prototype with softened octopus arms showed the highest preference (8.4 points) and high physicochemical and nutritional properties. Overall, the octopus pulpo a La Gallega prototype produced using texture-modified octopus arms was suitable for consumption by elderly people with chewing disorders and could help improve their quality of life.