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Octopuses are highly intelligent animals with vertebrate-like cognitive and behavioural repertoires. Despite these similarities, vertebrate-based models of cognition and behaviour cannot always be successfully applied to octopuses, due to the structural and functional characteristics that have evolved in their nervous system in response to the unique challenges posed by octopus morphology. For instance, the octopus brain does not support a somatotopic or point-for-point spatial map of the body—an important feature of vertebrate nervous systems. Thus, while octopuses are capable of motor tasks whose vertebrate counterparts require detailed interoceptive monitoring, these movements may not be explainable using motor control frameworks premised on internal spatial representation. One such motor task is the extension of a single arm. The ability of octopuses to select and use a single arm without the guidance of a somatotopic map has been regarded as a motor control puzzle. In an attempt at a solution, this paper develops a predictive processing account of single-arm extension in octopuses.

In the present study, we evaluated the trophic role of Octopus insularis Leite and Haimovici 2008 in the food web of Rocas Atoll, a preserved insular territory in the Southwest Atlantic. Using stable isotope analysis of C and N, we showed that the local trophic web comprises at least four trophic levels, where the octopus occupies a trophic position (TP) between the second and third trophic levels (mean ± SD TPadditive = 3.08 ± 0.36; TPBayesian = 3.12 ± 0.17). Among other benthic/reef-associated consumers, this cephalopod stood out for its much wider isotopic niche, pointing to a diet diversified in carbon sources, but focussed on prey in lower TPs. This finding was in accordance with the time-minimizing feeding strategy described for the species, which seemed almost permanent throughout the life cycle of the octopus, given the great niche overlap between octopuses in different maturity stages and their very similar trophic positions. Also, as a prey, octopuses composed up to almost 23% of the diet of some benthic/demersal predators. Overall, O. insularis represented an important mesopredator for the local food web, principally for bottom-associated organisms, while also serving as a substantial energy input to the next trophic levels.

The present study identifies one species of the genus Octopus in the order: Octopoda (Cephalopoda: Mollusca), recorded forthe first time in the Iraqi coastal waters and Arabian-Persian Gulf. The study extended from January 2019 to December of thesame year. The Octopus specimens were seasonally obtained from the fishing trawlers operating in the Iraqi coastal waters inthe South of Al- Fao District, Basrah- Iraq, NW Arabian Gulf. The Octopus was identified as O. vulgaris in Iraqi coastal watersdepending on morphological features. The habitats of living specimens are briefly described. Some observations were reported on the occurrence of this species and the measurement of some environmental factors. The species was identified up to spe-cies level using standard literature. This species looks similar morphologically to the species which is already identified from the other areas around the world. The present study records significant expansion in the distribution range of this species.

Chemical evaluation of specialised metabolites from the old-lady marine octopus Cistopus indicus (family Octopodidae) led to the isolation of an undescribed 14-membered bislactonic macrodio-lide cistobislactone, which was characterized as 12-(4’-ethyl-6’- methoxy-3’-methyl-hex-1-enyl)-5,11-dihydroxy-6-methyl-1,7-dioxa-cyclotetradeca-3,9-diene-2,8-dione. Cistobislactone exhibited noticeably greater inhibitory potential against 5-lipoxygenase (IC50 2.06 mM) compared to standard anti-inflammatory agent ibupro-fen (IC50 4.61 mM, p < 0.05). Superior antioxidant properties of cis-tobislactone against the oxidants (IC50 -1.8 mM) also reinforced its promising anti-inflammatory activity. Higher electronic proper-ties (topological polar surface area of 102.3) and balanced hydro-phobicity (logarithm of octanol-water coefficient -3) could recognize its higher interaction at the enzyme active site resulting in an effective attenuation of 5-lipoxygenase and efficient inter-membrane permeability. Comparatively lesser binding energy (-6.5 kcal mol-1 ) and docking score (-7.5 kcal mol-1 ) of cistobislac-tone with the aminoacyl residues of 5-lipoxygenase could further recognize its anti-inflammatory potential.

The graves in the interior of central Norrland in northern Sweden exhibit a wide range of forms throughout the Iron Age. Burial mounds and stonesettings of various forms also occur in different environmental contexts. The purpose of this paper is to discuss the spatial and cultural significance of the Iron Age graves in the provinces of Jamtland and Harjedalen. The point at issue is what the distribution of so-called lake graves and burial mounds represent with respect to the general discussion of archaeological regions and cultural traditions. It is here suggested that the concept of region, when it is applied to material culture, represents one of the many aspects of cultural configurations, but as we are dealing here with a longterm perspective the cultural world is continuously in motion, which makes regional boundaries hard to grasp. Hans Bolin, So dertorns Hogskola (Uni versity College), Box 4101, SE141 04 Huddinge, Sweden.

In upwelling systems around the world, octopus abundance is forecast by marine productivity linked to upwelling strength, often indicated by sea-surface temperatures. Climate change may disrupt populations of marine animals that are linked to such temperature-dependent events. We analysed the relationship of the abundance of giant Pacific octopuses (Enteroctopus dofleini) to Gulf of Alaska and Washington State water temperatures. Abundance was measured in targeted visual surveys in Prince William Sound, Alaska, over the period 1995–2016 and from REEF.org diver surveys in Washington State from 2003 to 2019. Octopus counts from both survey programs had significant negative correlations with water temperatures over the previous 2.5–4 years. Water temperature accounted for from 0.41 to 0.71 of the variance (R2) in octopus abundance in eastern Gulf of Alaska waters located in ocean currents up-stream of the survey areas, and up to 0.81 of the variance in Washington State waters. These negative correlations provide a possible predictive index for octopus abundance as measured by targeted visual surveys. These methods may be useful tools in management of octopuses and indicate impacts of climate change on North Pacific coastal marine ecosystems.

Octopuses have gained considerable worldwide commercial importance. Hence, this study was conducted to differentiate between the Octopoda species in the Egyptian Mediterranean waters. The study extended from January 2019 to December of the same year. Octopus specimens were seasonally obtained from the fishing trawlers operating in the Egyptian Mediterranean waters from Sidi Abd El-Rahman, west of Alexandria to Rosetta in the east. The different organs were illustrated using a zoom stereoscopic WildM8 microscope provided with a special camera Lucida drawing tube and photographed by a Canon G7Xdigital camera. Four Egyptian Mediterranean octopus species were detected, among which Eledone moschata, Octopus vulgaris, Callistoctopus macropus, and Macrotritopus defilippii were identified. Whereas three of them: Octopus vulgaris, Callistoctopus macropus, and Macrotritopus defilippi are classified as cosmopolitan species in distribution. Considerably, the species Eledone moschata are widely distributed in the Mediterranean Sea.

Octopus insularis is an active and opportunistic predator, its diet depends on the habitat in which it develops and the abundance and distribution of the species it preys on. Despite its importance for fisheries, little is known about the trophic relationships of this octopus. For this reason, the main objective of this study was to describe its diet in the southern Gulf of Mexico combining stable δ13C and δ15N isotopes and stomach content analysis. Stable δ13C and δ15N isotope analysis were performed in muscle tissue of octopuses and their prey. In addition, stomachs were analyzed to identify consumed prey and to obtain percentages of numerical and gravimetric importance, the frequency of occurrence and the index of relative importance. The diet did not show differences between year, sex, or size. Eight crustacean and three fish genera were identified as the main components in the diet. Crustaceans appeared as the main prey group, and the most important prey within this group was Mithraculus sp., and for the fish group it was Anchoa sp. The isotope analysis indicates a high contribution to predator´s muscle tissue from both crustaceans and fish. In one hand, results indicate that crustaceans as prey are important for the octopus population in the whole distribution area. On the other hand, isotope values positioned O. insularis as an intermediate trophic level predator, placing it as an efficient vehicle of energy transfer between lower to higher trophic levels in the ecosystem.

Haplotype-based variant callers, which consider physical linkage between variant sites, are currently among the best tools for germline variation discovery and genotyping from short-read sequencing data. However, almost all such tools were designed specifically for detecting common germline variation in diploid populations, and give sub-optimal results in other scenarios. Here we present Octopus, a versatile haplotype-based variant caller that uses a polymorphic Bayesian genotyping model capable of modeling sequencing data from a range of experimental designs within a unified haplotype-aware framework. We show that Octopus accurately calls de novo mutations in parent-offspring trios and germline variants in individuals, including SNVs, indels, and small complex replacements such as microinversions. In addition, using a carefully designed synthetic-tumour data set derived from clean sequencing data from a sample with known germline haplotypes, and observed mutations in large cohort of tumour samples, we show that Octopus accurately characterizes germline and somatic variation in tumours, both with and without a paired normal sample. Sequencing reads and prior information are combined to phase called genotypes of arbitrary ploidy, including those with somatic mutations. Octopus also outputs realigned evidence BAMs to aid validation and interpretation.

Cephalopods are important economic shellfish that have been developed extensively in the coastal water of various countries. Octopus vulgaris is a large-scaled economic cephalopod that is mainly cultured in South China. This study explored the effect of different diets on the volatile flavor and nutritional ingredients of O. vulgaris. Four diets were tested in four groups: Group A (fish (Scomberomorus niphonius)), Group B (crab (Helice tridens tientsinensis Rathbun)), Group C (clam (Mactra veneriformis)), and Group D (squid (Loligo japonica)). Octopus muscles were sampled after 36 days of feeding, and volatile flavor substances (VFSs), fatty acids (FAs), and amino acids (AAs) were detected. Results showed that the VFSs, FAs, and AAs of octopus in the four groups were obviously different. The sum of volatile ketones and aldehydes was higher in Group B than in the other groups, which could present much more flavors. All groups were abundant in unsaturated FAs, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). In terms of content and variety, the FAs in Group B were more beneficial to human health than those in the other groups. The content of each AA in Group B was basically higher than those in the other groups and was significantly higher than that in Group D (P < 0.05). Comparing the VFSs, FAs, and AAs in samples fed with four kinds of diets, the results indicate that using crab to feed O. vulgaris can achieve better effects on volatile flavor and nutritional ingredients.

As per the FAO data, octopus identification is very limited in the species level at world fishery and also they are cryptic nature. On the other hand, Indonesia is one of the top ten highest octopus exporters. This study therefore aimed to determine the species of octopus based on phylogenetic analysis of mt-DNA COI. Octopuses were collected from nine different locations throughout Indonesia, i.e., Anambas, Bangka-Belitung, Cirebon, Karimunjawa, Tuban, Lombok, Buton, Wakatobi and Jayapura. Samples were mostly in the form of tentacles that were directly collected from fishermen. After being preserved in 96% ethanol, the sample was extracted in 10% chelexÒ, PCR amplification using Folmer’s primer then was further analysed by sequencing in Sanger methods. Of the 24 samples sequenced, the results recognized four species Octopodidae belongs to the three genera, named Amphioctopus aegina, Hapalochlaena fasciata, Octopus laqueus and Octopus cyanea. Mean pair-wise distances of within-species were ranged from 0 to 5.5 % and between-species was ranged from 12.9 to 15.8 %. This study distinctly confirmed the difference between genus Amphioctopus and Hapalochlaena (15.5 %), as also between O. laqueus and O. cyanea (12.9%) which was previously not completely distinguished. Although performing species identification using DNA sequences for shallow-water benthic octopus species is perhaps considered premature, this study indicated the possible application of COI sequences for species identification, thereby providing a preliminary dataset for future DNA barcoding of octopus, in particular for Indonesia waters.

Purpose Review octopus ocular anatomy and describe the histopathologic findings in three octopuses diagnosed with phakitis and retinitis. Animals Two common octopuses (Octopus vulgaris) and one giant Pacific octopus (Enteroctopus dofleini) with a history of ophthalmic disease. Methods A literature search was performed for the ocular anatomy section. Both eyes from all three octopuses, and two control eyes, were submitted for histopathologic evaluation. Hematoxylin and eosin stain was used for standard histopathologic evaluation; GMS stain was used to screen for fungi, gram stain for bacteria; and Fite's acid fast stain for acid fast bacteria. Results Anatomically, the anterior chamber of the octopus has direct contact with ambient water due to an opening in the dorsal aspect of a pseudocornea. The octopus lens is divided into anterior and posterior segments. The anterior half is exposed to the environment through the opening into the anterior chamber. Neither part of the lens has a lens capsule. The retina is everted, unlike the inverted vertebrate retina, and consists of just two layers. Histopathology revealed inflammatory phakitis and retinitis of varying severity in all six eyes of the study animals. No intraocular infectious organisms were recognized but one common octopus eye had clusters of coccidian parasites, identified as Aggregata sp., in extraocular tissues and blood vessels. Conclusion We describe inflammatory phakitis and retinitis in two species of octopuses. The underlying cause for the severe intraocular response may be direct intraocular infection, water quality, an ocular manifestation of a systemic disease, or natural senescence.

A common feeding association among reef fishes involves nuclear and follower species, where the former disturbs the bottom, during which the latter opportunistically feeds on items exposed. Here, we report such interactions between Western Australian common octopuses (Octopus (cf) tetricus) and brown-spotted wrasse (Notolabrus parilus) observed on eight occasions while snorkeling at four temperate-water reefs along the coast of Perth in Western Australia. We compare the interactions observed to other octopus-fish nuclear–follower associations known. In general, these interactions usually benefit the follower species and could play a significant role on reef trophodynamics.

Octopus cyanea is a species of particular economic importance for coastal regions in the tropical Indo-Pacific, including the Mauritian island of Rodrigues. At present, little is known about their ...

Octopus (Optics Clustered to OutPut Unique Solutions) celebrated in June 2020 its 10th birthday. Based at Harwell, near Oxford, Octopus is an open access, peer reviewed, national imaging facility that offers successful U.K. applicants supported access to single molecule imaging, confocal microscopy, several flavours of superresolution imaging, light sheet microscopy, optical trapping and cryoscanning electron microscopy. Managed by a multidisciplinary team, Octopus has so far assisted >100 groups of U.K. and international researchers. Cross-fertilisation across fields proved to be a strong propeller of success underpinned by combining access to top-end instrumentation with a strong programme of imaging hardware and software developments. How Octopus was born, and highlights of the multidisciplinary output produced during its 10-year journey are reviewed below, with the aim of celebrating a myriad of collaborations with the U.K. scientific community, and reflecting on their scientific and societal impact.

The biodiversity of mollusks, particularly cephalopods, has not been exhaustively determined in the Revillagigedos ecoregion, which is a biodiversity hotspot for several marine groups located in the Tropical East Pacific Province. In our study, we detected and examined ocellate octopuses from Socorro and Clarion Islands, and determined their identity using morphological criteria and molecular data from two mitochondrial genes (COIII and COI). The taxon identified was Octopus oculifer, a species considered endemic to the Galapagos Archipelago. In addition, according to our analyses, O. mimus, O. hubbsorum and O. oculifer are very closely related and may represent a species complex comprised of three morphotypes. We found that the evolutionary relationships among octopuses are not determined by the presence of ocelli. This study is the first to report a clade represented by ocellate and non-ocellate species, in addition, the identity of cephalopods in the Revillagigedos was determined with analytical support.

Animal welfare consideration and actions are generally addressed to animals similar to us, predominantly large mammals. Invertebrates are neglected partly because they are unknown, though new exploration of the oceans has helped with this. Also, we know little about their ecology and welfare. This is gradually changing, and the octopuses are likely to be the first beneficiaries. Scientists are finding that cephalopods are far more intelligent than we thought, with the Cambridge Declaration of Consciousness suggesting they might possess this quality of mind. Partly as a result, the European Union has described and demanded good care for cephalopods such as the octopus in captivity. Public opinion has been swayed to approval by anecdotes of octopuses doing unusual actions, and by several recent books pointing out interesting and intelligent behavior of cephalopods. Aquariums have begun to feature octopuses for them. With this progress, welfare of invertebrate animals has begun to matter. While the octopuses will be the first animal group to benefit, they may pave the way for us to see that different does not mean unworthy of regard and welfare consideration.

17 pages, 4 tables, 8 figures, The common octopus Octopus vulgaris Cuvier, 1797, once considered a cosmopolitan species, is a species complex composed by six species: O. tetricus, O. cf tetricus and O. sinensis in the Pacific; type I and II, in the West Atlantic; and type III in the Indian Ocean around South Africa. The tropical western central Atlantic is an important octopus fishing ground targeting O. maya, O. insularis, and a cryptic species considered to be O. vulgaris type I. In order to clarify the identification of this octopod, phylogenetic analyses were carried out with mitochondrial (COI and 16S) and nuclear (rhodopsin) genes, together with morphological analyses of 16 specimens caught in the northeastern continental shelf of Yucatan (Mexico). The main morphological traits differing from O. vulgaris were the presence, position and size of enlarged suckers and hectocotylus sucker number in males. Genetic distances and haplotype networks of the species complex were estimated using 285 COI sequences of nine Octopus species from 14 different locations around the world. The octopod sequences from Yucatan clustered within a monophyletic group that included sequences of O. vulgaris type II for the three genes analyzed. Phylogenetic distances with other members of the complex ranged between 2.71 and 3.89% using COI data. These genetic results support the presence of Octopus americanus Monfort, 1802 (formerly known as O. vulgaris type II) along the Yucatan continental shelf, a new octopod extending from the north of Argentina to the northwest coast of the USA, The results of this study were obtained as part of the project “Distribution, reproduction, biomass and movement patterns of the Octopus vulgaris common octopus, Cuvier 1797, on the Yucatan coast” with funding from the National Council of Science and Technology of Mexico (CONACyT) (No. 237057). This work was partially supported by the Project CALECO (CTM2015-69519-R) funded by the Spanish Ministry of Economy and Competitiveness and FEDER Funds

Matrixins play a major role in tissue regeneration and also in various patho-physiological processes. Discovery of matrix metallo proteins (MMPs) and their detailed structural and functional analysis would lead to the development of numerous potent synthetic inhibitors of matrixins to treat certain diseases. In the present investigation, a marine cephalopod- Octopus sp. collected from Cochin, in the south western Indian Ocean was used as animal model for purification of matrixins. The measurements, count, indices and other morphometric characters were noted down before assessing the presence of matrixins in the crude extract of Octopus samples. Purification of matrixins was carried out employing gel filtration chromatography and the purified matrixins was confirmed by gelatin zymogram. The purity of the protein was checked by both native and SDS-PAGE. The studies have provided clear indications of production of MMPs or matrixins with gelatinolytic activity in Octopus sp.

We report an interaction between Octopus insularis (Octopoda, Octopodidae) and the reef fish Alphestes afer (Perciformes, Epinephelidae) and provide evidence of mimicry, camouflage and following behaviors. We observed three instances of this interaction during dives at the Pirangi reefs, Northeastern Brazil. The octopus’s body color patterns indicated the type of behavior that developed while it was followed by the reef fish. These data are the first records of following behavior in A. afer and the first observation of such interaction with O. insularis in coastal reefs.

Widely distributed on tidal flats on the west and south coast of Korea, the long arm octopus Octopus minor is one of the important shellfish resources, as well as a key species in the siltymud tidal ecosystem. While several molecular studies have studied the genomes or the molecular phylogenetic relationship of O. minor with other cephalopod members, no studies to date have reported on gene expression in the long arm octopus. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a commonly used method in gene expression studies; however, the accuracy and reliability of the assay results depend strongly on selection of appropriate reference genes. In this study, we first evaluated stabilities of 8 reference genes (elongation factor 1-beta, elongation factor 2, ribosomal protein, TATA-binding protein-associated factor 172, histone H4, elongation factor-gamma, succinate-hydroxymethylglutarate CoA-transferase, and transferrin) of O. minor distributed in the different tissues using geNorm. Our results indicated that TF was the most stable of the selected reference genes from the various tissues. To illustrate the usefulness of the new reference genes, expression analysis of heat shock protein70 related to environmental stresses was undertaken. Accordingly, this study provides suitable reference genes for RT-qPCR analysis that will enable future studies of gene expression in O. minor and other related species in cephalopods in order to gain a better understanding of their molecular responses to environmental stresses.

Octopus is an invertebrate belonging to the class of Cephalopoda. The body of an Octopus lacks any morphological joints and rigid parts. Their arms, skin and the complex nervous system are investigated by a several researchers all over the world. Octopuses are the object of inspiration for my scientists in different areas, including AI. Soft- and hardware are developed based on octopus features. Soft-robotics octopus-inspired arms are the most common type of developments. There are a lot of different variants of this solution, each of them is different from the other. In this paper, we describe the most remarkable octopus features, show solutions inspired by octopus and provide new ideas for further work and investigations in combination of AI and bioinspired soft-robotics areas.

Genotyping from sequencing is the basis of emerging strategies in the molecular breeding of polyploid plants. However, compared with the situation for diploids, where genotyping accuracies are confidently determined with comprehensive benchmarks, polyploids have been neglected; there are no benchmarks measuring genotyping error rates for small variants using real sequencing reads. We previously introduced a variant calling method – Octopus – that accurately calls germline variants in diploids and somatic mutations in tumors. Here, we evaluate Octopus and other popular tools on whole-genome tetraploid and hexaploid datasets created using in silico mixtures of diploid Genome In a Bottle samples. We find that genotyping errors are abundant for typical sequencing depths, but that Octopus makes 25% fewer errors than other methods on average. We supplement our benchmarks with concordance analysis in real autotriploid banana datasets.

The complete mitochondrial genome of the East Asian common octopus (Octopus sinensis) was determined and analyzed in this work. The circular mitogenome of O. sinensis is 15,737 bp in length with 21.53% GC content, which contains two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), 13 protein-coding genes (PCGs) and a non-coding region (D-loop). The analysis of the SNPs revealed 4 conservative SNPs for COI gene of O. sinensis compared with Octopus vulgaris. Phylogenetic analysis suggested that O. sinensis is closely related to O. vulgaris. This sequence data would play an important role in the investigation of phylogenetic relationship and taxonomy of the class Cephalopoda.

This is the first study to use both molecular and fossil data to date the divergence of taxa within the coleoid cephalopods (octopus, squid, cuttlefish). A dataset including sequences from three nuclear and three mitochondrial genes (3415 bp in total) was used to investigate the evolutionary divergences within the group. Divergence time analyses were performed using the Thorne/Kishino method of analysis which allows multiple constraints from the fossil record and permits rates of molecular evolution to vary on different branches of a phylogenetic tree. The data support a Paleozoic origin of the Orders Vampyromorpha, Octopoda and the majority of the extant higher level decapodiform taxa. These estimated divergence times are considerably older than paleontological estimates. The major lineages within the Order Octopoda were estimated to have diverged in the Mesozoic, with a radiation of many taxa around the Cretaceous/Cenozoic boundary. Higher level decapodiform phylogenetic relationships appear to have been obscured due to an ancient diversification of this group.

We investigated the characteristic features of perception in octopuses by examining multisensory information from an object simulating prey, which provided different visual and tactile stimuli. In experiments, we presented plain-body octopus with four kinds of models, namely, the Lifelike crab, the Embedded crab, the Translucent crab, and the Black cuboid. These models contain different amounts of visual and tactile information that a crab originally contains: the Lifelike crab resembles a crab both visually and tactilely, the Embedded crab resembles a crab visually but provides different tactile information, the Translucent crab provides tactile information of a crab but contains less visual information, and the Black cuboid lacks both visual and tactile information of a crab. Among these four models, octopuses contacted most with the Lifelike crab, which was similar to their behavior with a crab. Indeed, octopuses were fastest to contact the Lifelike crab and had the longest duration of contacting it among the four models. Octopuses contacted the Embedded crab more than the Translucent crab, both of which had contrasting visuo-tactile information compared to that of a crab. Quickness of octopuses to contact and duration of contact with the Embedded crab were more similar to those with the Lifelike crab than to those with the Translucent crab. Furthermore, octopuses contacted the Black cuboid least among the models. These results suggest that octopuses compositely detect both visual and tactile information in order to perceive an object. Furthermore, octopuses possess the potential priority either for visual or tactile information, by which they process the target object.

The paper nautilus,Argonauta argo, also known as the greater argonaut, is a species of octopods distinctly characterized by its pelagic lifestyle and by the presence of a spiral-shaped shell-like eggcase in females. The eggcase functions by protecting the eggs laid inside it, and by building and keeping air intakes for buoyancy. To reveal the genomic background of the species’ adaptation to pelagic lifestyle and the acquisition of its shell-like eggcase, we sequenced the draft genome sequence of the species. The genome size was 1.1 Gb, which is the smallest among the cephalopods known to date, with the top 215 scaffolds (average length 5,064,479 bp) covering 81% (1.09 Gb) of the total assembly. A total of 26,433 protein-coding genes were predicted from 16,802 assembled scaffolds. From these, we identified nearly intact HOX, Parahox, Wnt clusters and some gene clusters probably related to the pelagic lifestyle, such asreflectin, tyrosinase, andopsin. For example,opsinmight have undergone an extensive duplication in order to adapt to the pelagic lifestyle, as opposed to other octopuses, which are mostly the benthic. Our gene models also discovered several genes homologous to those related to calcified shell formation in Conchiferan Mollusks, such as Pif-like, SOD, and TRX. Interestingly, comparative genomics analysis revealed that the homologous genes for such genes were also found in the genome of the octopus, which does not have a shell, as well as the basal cephalopodsNautilus. Therefore, the draft genome sequence ofA. argowe presented here had not only helped us to gain further insights into the genetic background of the dynamic recruitment and dismissal of genes for the formation of an important, converging extended phenotypic structure such as the shell and the shell-like eggcase, but also the evolution of lifestyles in Cephalopods and the octopods, from benthic to pelagic.

O'Brien, Caitlin E., Bennice, Chelsea O., Leite, Tatiana (2021): A field guide to distinguishing Octopus insularis and Octopus americanus (Octopoda: Octopodidae). Zootaxa 5060 (4): 589-594, DOI: https://doi.org/10.11646/zootaxa.5060.4.8

Many developments in biomedical research have been inspired by discovering anatomical and cellular mechanisms that support specific functions in different species. The octopus is one of these exceptional animals that has given scientists new insights into the fields of neuroscience, robotics, regenerative medicine, and prosthetics. Research with this species of cephalopods requires the set-up of complex facilities and intensive care for both the octopus and its ecosystem that is critical for the project’s success. This system requires multiple mechanical and biological filtering systems to provide a safe and clean environment for the animal. Along with the control system, specialized routine maintenance and cleaning are required to effectively keep the facility operating long term. It is advised to provide an enriched environment to these intelligent animals by changing the tank’s landscape, incorporating a variety of prey, and introducing challenging tasks for them to work through. Our results include MRI and a whole-body autofluorescence imaging as well as behavioral studies to better understand their nervous system. Octopuses possess unique physiology that can impact many areas of biomedical research. Providing them with a sustainable ecosystem is the first crucial step in uncovering their distinct capabilities.

Biochemical analysis of secondary metabolites of marine old-woman octopus Cistopus indicus (family Octopodidae) led to the identification of two sixteen-membered spiro-linked macrocyclic bislactones, named as cistobislactone A and cistobislactone B with unprecedented feature of henicos framework, based on extensive spectroscopic analyses. Cistobislactone B exhibited potential inhibition property against arachidonate 5-lipoxygenase (IC50 2.18 mM) than that demonstrated by cistobislactone A (IC50 2.54 mM) and standard non-steroidal anti-inflammatory agent ibuprofen (IC50 4.50 mM) thus signifying the higher anti-inflammatory activity of the cistobislactone B analogue. The studied macrocyclic bislactones exhibited promising antioxidant potential, in which cistobislactone B exhibited potential radical quenching (IC50 2.33 mM) and hydrogen peroxide scavenging (IC50 1.81 mM) activities that were proximal to the commercial anti-oxidant α-tocopherol (IC50 ~ 1.60 mM). This further reinforced its attenuation property against arachidonate 5-lipoxygenase. Considerably greater electronic properties coupled with balanced hydrophobicity of cistobislactone B could ascribe the superior ligand-receptor interfaces leading to its anti-inflammatory activity. Molecular docking analysis of cistobislactone B with 5-lipoxygenase recorded lesser docking score (−12.24 kcal mol−1) and binding energy (−11.24 kcal mol−1), which further supported its anti-inflammatory activity. Cistobislactone B, with six fold lesser value of inhibition constant (Ki 5.76 nM) towards 5-lipoxygenase than that displayed by cistobislactone A, could describe the superior protein-ligand interactions of the former. The undescribed cistobislactone B might be a potential natural anti-inflammatory lead to moderate the odds of inflammatory pathologies.

The diet of the Hubb's octopus Octopus hubbsorum along the coast of Acapulco, Guerrero, Mexico, was determined by analysing the stomach contents of 413 individuals collected monthly between February 2017 and March 2018. Most stomachs (74.3%) presented contents, while 25.7% were empty. Sixty prey items were identified and grouped into 16 categories. The most frequent prey items were Petrolisthes sanfelipensis, Clastotoechus diffractus, Petrolisthes hians and Alpheus spp. Smith's index indicated that O. hubbsorum follows a generalist diet for each hydroclimatic season, sex and size class (1: juvenile; 2: young adult; 3: mature adult). Cannibalism was frequent among males, less so among females. Pianka's index revealed a higher overlap among the three size classes of both sexes during the dry season, while during the rainy season the overlap was reduced for size classes 2 and 3 in both sexes. The average isotopic values overall were δ13C −14.96‰ (±0.08) and δ15N 13.02‰ (±0.09). A significant difference (P = 0.005) was observed in δ13C among hydroclimatic seasons (rainy and dry) and size classes, while for δ15N a significant difference (P = 0.013) was observed between seasons. Stomach content analysis gave values of the trophic position of O. hubbsorum ranging from 3.57 to 3.72, whereas the values obtained using stable isotope analysis, using δ15N, ranged from 3.52 to 3.86. Variation was observed in isotopic niche size and Layman's metrics among hydroclimatic seasons. A higher isotopic niche overlap was observed between size classes 2 and 3 during the dry season. The rocky shore ecosystem has been heavily exploited by artisanal fisheries (fish and invertebrates). A more integrated, ecosystem-based management of these fisheries requires an understanding of their trophic structure.

The multi-gear coastal vessels in the Algarve (South Portugal) own licenses for various fishing gears. However, it is generally uncertain what gears they use, which is problematic as each individual gear is responsible for unique impacts on the resources and the environment. In this study, landing profiles identified for the multi-gear coastal fleet (2012–2016) were used as support in defining potential métiers using k-mean clustering analysis (CLARA) along with information from past studies on métiers. The results showed that more than 50% of the vessels were engaged in the octopus fishery year-round, using traps, while a small percentage (~13%) were entirely dedicated to clam dredging. In general, gillnets (21%) were used to target monkfish, hake and bastard soles, while trammel nets (6%) were used to target cuttlefish, with some vessels alternating the fishing gears (either seasonally or annually) according to target species. The method for the initial characterization of this fleet’s métiers and its efficiency with limited data is discussed, as well as the utility of this segmentation in support of management advice. 16-01-04-FMP-0010, UIDB/04326/2020, SFRH/BD/137818/2018 info:eu-repo/semantics/publishedVersion

Octopus cyanea has a wide range of natural distribution and is interesting for scientific research. However, unlike Octopus vulgaris, the species is poorly studied, and few data exist on best practices for keeping them. One of the most common reasons for losing octopuses in human care is their ability to escape from holding tanks. Adult Octopus cyanea (n = 33) were locally collected in Okinawa throughout the year. All animals were housed at the laboratory facilities at the Marine Station of the Okinawa institute of Science and Technology. Animals were kept in a flow-through saltwater system in three different types of holding tanks ranging from 550 L to 600 L tanks or in 2000 L tanks, all with an environment enriched with clay pots or natural rocks as dens. They were fed a daily diet of dead fish or live or dead crustaceans ad libitum. To characterize the effectiveness of different keeping conditions, we compared escape attempts and non-natural deaths during the animals’ time under human care. We found that two types of tanks, the 600 L transparent acrylic glass tanks with weighted lids and the 2000 L tanks with synthetic grass lined walls, had significantly fewer escapes than the 550 L tanks.

Cephalopods have the potential to become useful experimental models in various fields of science, particularly in neuroscience, physiology, and behavior. Their complex nervous systems, intricate color- and texture-changing body patterns, and problem-solving abilities have attracted the attention of the biological research community, while the high growth rates and short life cycles of some species render them suitable for laboratory culture. Octopus chierchiae is a small octopus native to the central Pacific coast of North America whose predictable reproduction, short time to maturity, small adult size, and ability to lay multiple egg clutches (iteroparity) make this species ideally suited to laboratory culture. Here we describe novel methods for culture of O. chierchiae, with emphasis on enclosure designs, feeding regimes, and breeding management. Our results demonstrate the feasibility of multigenerational culture of O. chierchiae. Specifically, O. chierchiae bred in the laboratory grows from a 3.5-millimeter mantle length at hatching to an adult mantle length of approximately 20-30 millimeters in 250-300 days, with 14-15% survivorship to over 400 days of age in first and second generations. O. chierchiae sexually matures at around an estimated six months of age and, unlike most octopus species, can lay multiple clutches of eggs, approximately every 30-90 days. Eggs are large and hatchlings emerge as direct developing octopuses. Based on these results, we propose that O. chierchiae possesses both the practical and biological features needed for a model octopus that can be cultured repeatedly to address a wide range of fundamental biological questions.

Distribution of an alien fungus, octopus stinkhorn Clathrus archeri, has been studied in north-eastern Poland. The closest earlier known localities of this species, situated north of the new ones, were reported near the village of Dymnica (Lębork County) in Poland and near the town of Kartena in Lithuania. Field research was conducted in May–November in 2019-2020 and information from naturalists and foresters was verified, to map this species and draw attention to the problem of appearance of alien fungal species in forests. In the locality where the largest number of basidiomata was found, they were measured every day from 12 October till 2 November 2020: height and width of young ones at the egg phase, height of mature ones, and length of their longest arms. Additionally, arms of individual basidiomata were counted. We have documented 7 localities of C. archeri, including 5 situated in forests and 2 in other habitats. In total, we found 63 basidiomata of this species. In the localities outside forests, basidiomata of C. archeri appeared in places where timber was stored and the soil was covered with sawdust and pieces of bark. The other 5 localities were situated in broadleaved forests with a small proportion of coniferous species. It seems that C. archeri, when moisture level is suitable, finds favourable living conditions in fertile broadleaved forests of north-eastern Poland. It is sometimes re-moved from forest areas (e.g. with wood) to open and urbanized areas. Considering the observed climate change, we can expect a further spread of C. archeri to the north-eastern of Poland and an increase in the number of its localities in the Baltic Sea region. Spore dispersal of this species is facilitated not only by humans but also by insects. No negative impact of C. archeri on wooded habitats was noticed. Key words: Phallaceae, Clathrus archeri, octopus stinkhorn, alien species, ecology, distribution, forest, Poland

The new species, Paroctopus cthulu sp. nov. Leite, Lima, Lima and Haimovici was recorded from shallow coastal waters of south and southeastern Brazil, where most specimens were found sheltered in marine debris. It is a small octopus; adults are less than 35 mm mantle length (ML) and weight around 15 g. It has short- to medium-sized arms, enlarged suckers on the arms of both males and females, a relatively large beak (9% ML) and medium to large mature eggs (3.5 to > 9 mm). The characteristics of hatchlings of two brooding females, some of their anatomical features, and in situ observations of their behavior are a clue to the life history of it and closely related pygmy octopuses. The Bayesian phylogenetic analysis showed that Paroctopus cthulu sp. nov. is grouped in a well-supported clade of Paroctopus Naef, 1923 species, clearly distinct from Octopus joubini Robson, 1929 and Paroctopus mercatoris (Adam, 1937) from the Northwestern Atlantic. The description of this new species, living in habitat altered by humans, debris in shallow water off Brazil, offered an opportunity not only to evaluate the relationship among the small octopuses of the western Atlantic, Caribbean and eastern Pacific, but also their adaptation to the Anthropocene period.

Although various recognizing abilities have been revealed for octopuses, they predominantly deal with only a few species. Therefore, cognition diversity among other octopus species that have been overlooked needs to be investigated. We investigated whether plain-body octopus can learn a symbolic stimulus, for the reason that this octopus is abundant around Okinawa Island with a complex coral community landscape. Attention was paid to whether an octopus can learn a stimulus based solely on visual information without previous experience of learning it tactilely as well as visually. Furthermore, we examined whether different sensory inputs affect learning in octopuses. First, we tested whether octopuses can be conditioned to three different stimuli (object, picture, and video of a white cross). Octopuses that were presented an object or a picture could learn to touch them. However, octopuses that were presented a video could not learn to touch the stimulus. Second, we showed a video to octopuses that had already learned about an object or a picture to investigate whether the octopuses, having experienced a target using visual and tactile senses, can recognize a video of the target based solely on visual information. Octopuses could learn to touch the video. When a conditioned stimulus and a novel stimulus were simultaneously presented on a computer screen, an octopus that had learned an object more often selected the conditioned stimulus when compared with an octopus that had experienced only a picture. These findings suggest that octopuses use multisensory information to recognize a specific object.

The Argonaut octopus, commonly called the paper nautilus, has a spiral-coiled shell-like eggcase. As the main characteristics, the eggcase has no internal septum, is composed entirely of calcite with chitosan being the main polycarbonate and is reportedly formed by organic materials secreted from the membranes of the arms. Meanwhile, the biomineralized external “true” shells of the Mollusks, which includes the Cephalopods, are secreted from the mantle tissue. Therefore, the histological origin of the two shells is completely different. The question of how the Argonauts, which phylogenetically diverged from the completely shell-less octopuses, could form a converging shell-like external structure has thus intrigued biologists for a long time. To answer this question, we performed a multi-omics analysis of the transcriptome and proteome of the two congeneric Argonaut species,Argonauta argoandA. hians. Our result indicates that the shell-like eggcase is not a homolog of the shell, even at the protein level, because the Argonauts apparently recruited a different set of protein repertoires to as eggcase matrix proteins (EcMPs). However, we also found the homologs of three shell matrix proteins (SMPs) of the Conchiferan Mollusks, Pif-like, SOD, and TRX, in the eggcase matrix. The proteins were also found in the only surviving shelled Cephalopods, the nautiloidNautilus pompilius. Phylogenetic analysis revealed that homologous genes of the Conchiferan SMPs and EcMPs were found in the draft genome of shell-less octopuses. Our result reported here thus suggests that the SMP-coding genes are conserved in both shelled and shell-less Cephalopods. Meanwhile, the Argonauts adopted some of the SMP-coding genes and other non-SMP-coding genes, to form a convergent, non-homologous biomineralized external structure, the eggcase, which is autapomorphic to the group.

The Africanized honey bee commonly referred to as the "killer bee," is a hybrid of the East African lowland honey bee with various European honey bees. These bees tend to be more hostile as compared to other bee species. Their stings may have devastating clinical sequelae, including cardiovascular, cerebrovascular events, and fatalities. We report the first-in-Caribbean case of a middle-aged woman who experienced stress-related, Takotsubo cardiomyopathy (also known as stress-related cardiomyopathy [SRC]) after being afflicted with innumerable Africanized honey bee stings. Key clinical message: The clinician should be cognizant of Takotsubo's cardiomyopathy as a potential sequela of Hymenoptera envenomation and anaphylaxis.

Оbjective. The study of diet of keystone-species vertebrates (Nothotenia coriiceps, Phalacrocorax bransfieldensis, Leptonychotes weddellii) in the ecosystem of the Argentine Islands Archipelago. Methods. Biological researches were conducted on Akademik Vernadsky station during wintering in 2006—2007, 2009—2010, 2011—2012, 2019 accordance with tasks of the State Special-Purpose Research Program in Antarctica for 2011–2020. In total, the content of 30 faeces of the L. weddellii, 64 pellets and three stomachs of the Ph. bransfieldensis and 40 stomachs of the N. coriiceps were analyzed. Material was collected at all seasons. Results. The L. weddellii diet is dominated by three squid species Galiteuthis glacialis (39,5%), Brachiotheutis picta (21%) and the fishery species Psychroteuthis glacialis (15.8%). In the diet of Ph. bransfieldensis were found the main four Octopus species such as Adelieledone polimorpha – 20%, Pareledone turqueti – 20%, and Graneledone sp. – 24% and Benthoctopus sp. – 16%, who owns the highest proportion of hits. In the nutrition of N. coriiceps, cephalopods are rarely recorded. Only one species of Octopus has been registered and has been identified only to the Cirroteuthidae family. Conclusions. Found that in the diet of keystone-species vertebrates (N. coriiceps, Ph. bransfieldensis, L. weddellii) in the ecosystem of the Argentine Islands Archipelago there are 13 species of Cephalopods, of which 4 species belong to squid Decapoda and 9 species to octopuses Octopoda (3 species are identified to the genus and one to the family). The findings are important not only to establish the actual status of the Antarctic ecosystem and to conserve biodiversity in the Antarctic region.

Aim of this study was to isolate, characterize, and identify cellulolytic bacteria from the digestive tract of marine vertebrates and invertebrates as a candidate of fish probiotics. The bacteria were isolated from the digestive tract and grown on a cellulose agar plate. The bacteria were screened based on the cellulolytic activity, acid resistance, antagonist activity against fish pathogens, antibiotics sensitivity, ability to live in fish digestive tract and non-pathogenic test. Selected bacterium was identified molecularly, based on the 16S rDNA gene sequences, and phenotipically. A total of 14 bacteria demonstrated celulolitic index of 1.1-1.8. The bacteria with cellulolytic index of > 1.6 were screened by the selection criteria, resulted a selected strain, JC20 isolate which was isolated from the digestive tract of octopus (Octopus sp.). The selected bacterium was sensitive to antibiotics, resists to acidic environment, able to live in the fish digestive tract, and non-pathogen. Thus, the bacterium was potential for further characterization as fish probiotics candidate. Molecular and phenotypic identification revealed that JC20 isolate was Staphylococcus sp.

The natural history and pharmacology of tetrodotoxin (TTX) has long intrigued biologists. This toxin has a remarkable distribution that spans two domains of life (Bacteria and Eukarya). Within Eukaryotes, TTX has only been identified in animals but is known to be present in over five-dozen species of phylogenetically distant Metazoans. Despite decades of work, the origin and biosynthetic pathways of TTX remain unresolved. Investigations in puffer fishes and salamanders have provided insights into the acquisition of auto-resistance to TTX through the evolution of voltage-gated sodium ion channels (VGSCs) that have reduced binding affinity for TTX. To date there have been no studies of these proteins in tetrodotoxic Blue-Ringed Octopuses. Here we report data demonstrating that the Greater Blue-ringed Octopus (Hapalochlaena lunulata) expresses a VGSC (HlNaV1) gene with mutations that reduce the channel's TTX-binding affinity and likely render the organism TTX resistant. We identified three amino-acid substitutions in the TTX-binding site of HlNaV1 that likely confer TTX-resistance to both the channel and the organism. These substitutions are associated with organismal TTX-resistance in other TTX-bearing taxa and are convergent with substitutions that have evolved in fish, salamanders, and some TTX-resistant invertebrates.

Background: Octopus is a fishery product of economic importance worldwide, the main species caught on the coast of the Gulf of Mexico and the Caribbean Sea are Octopus maya and O. vulgaris, the first represents up to 95 % of national production. Goals: Identify the bacterial flora associated with commercial Octopus maya captured in the Yucatan Peninsula, using PCR-DGGE. Methods: From the metagenomic DNAs (mDNAs) extracted from samples representative of the octopus muscle, PCR products were synthesized with universal primers for bacteria (gc338F and 518R) and specific primers for Phylum Firmicutes (FirF: 369 and gcFirR: 1244). They were separated by electrophoresis in denaturing gradient gels (DGGE). The fragmented DNAs were recovered by elution, amplified (338F / 518R and FirF: 369 / FirR: 1244), sequenced and analyzed phylogenetically. Results: The sequences amplified with universal primers, after the DNA fragmentation by DGGE were associated with Psychrobacter urativorans, Psychrobacter sp, Pseudomonas sp, Pseudoalteromonas sp, Shewanella sp, Shewanella baltica, Klebsiella oxytoca, Vibrio aestuarianus, Photobacterium sp, Flavobacterium sp, F. antarcticum, Bizionia sp, Flavobacteriaceae bacterium, Bacillus sp, C. divergens, Cetobacterium somerae, Psychrilyobacter atlanticus, Salinimicrobium sp as well as, Flavobacteriaceae not yet classified. In the sequences amplified with specific primers (Phylum Firmicutes) were identified: Carnobacterium sp, Lactococcus piscium Lactococcus sp, and Vagococcus sp Conclusion: The bacterial genus detected have been reported in samples from marine environments; therefore, can be part of the native microbial diversity associated with commercial O. maya captured in the Yucatan Peninsula, Mexico.

The octopus Cistopus indicus is an important target of cephalopod fisheries in China. It is widely distributed in the South Pacific and tropical Indian Ocean, from the South China Sea, the ...

Two moderately halophilic and psychrotolerant new Mycoplasma species were isolated from common cephalopods. Three strains were isolated in pure culture from two individual European flying squid (Todarodes sagittatus), and two individual octopuses (Octopus vulgaris). The strains showed optimal growth at 25 °C and a salinity of 3% (w/v) NaCl. Molecular analyses revealed that the isolates belonged to two new, but phylogenetically related species, divergent from all previously described Mollicutes, representing the first marine isolates of the class, and also the first Mycoplasma strains for which NaCl requirement has been demonstrated. A genome search against all available marine metagenomes and 16S rRNA gene databases indicated that these two species represent a novel non-free-living marine lineage of Mollicutes, specifically associated with marine animals. Morphology and physiology were compatible with other members of this group, and genomic and phenotypic analyses demonstrated that these organisms represent two novel species of the genus Mycoplasma, for which the names Mycoplasma marinum sp. nov. and Mycoplasma todarodis sp. nov. are proposed; the type strains are PET (DSM 105487T, CIP 111404T) and 5HT (DSM 105,488T, CIP 111405T), respectively., RRM acknowledges the Spanish Ministry of Economy project CLG2015_66686-C3-1-P also supported with European Regional Development Fund (FEDER) funds. ASR acknowledges the Gobierno de Canarias (Spain) project P2007/046. RRM acknowledges the financial support of the sabbatical stay at Georgia Institute of Technology supported by the grant PRX18/00048 of the Ministry of Sciences, Innovation and Universities. KTK’s research was supported, in part, by the U.S. National Science Foundation (Award No. 1,759,831).

Infectious diseases caused by pathogenic bacteria (such as sepsis and meningitis) seriously threaten public health; therefore, rapid and accurate identification of the target bacteria is urgently needed to prevent and treat bacterial infections. Although technologies including plate-counting and polymerase chain reaction have been established to detect the pathogenic bacteria, they are either time-consuming or sophisticated. Herein, a biomimetic octopus-like structure integrating merits of multiarm and multivalent interaction is designed for ultraspecific capture and detection of pathogens. The flexible polymeric arms and multivalent ligands work together to mimic the arm-sucker coordination of an octopus to effectively grasp the target pathogens, leading to remarkably high capacity and specificity for the target capture (above 98%, 10 CFU mL-1) without a nonspecific absorption of background pathogens. The captured bacteria can be identified as a point of care by the surface-enhanced Raman spectroscopy method with a detection limit of 10 cells mL-1.

This study evaluated the effects of shelter pipes (PS), tube shelters (TS), and no shelter (NS) on the growth of juvenile common octopus (Octopus vulgaris). The grow-out was studied in situ by conducting a passive follow-up survey using integrated transponder tags. The growth and survival rates were evaluated in two experiments. Each experiment included two replicates. Both experiments ran for 60 days, for which each trial included 24 octopuses that were fed once a day a diet of frozen sardines (Sardinops melanostictus) and swimming crabs (Portunus trituberculatus), at 3–8% body weight. We investigated the relationship between the beak microstructure of the common octopus and possible stress events caused by culture conditions at 15 °C for 15 days. The nine juveniles were separated into three groups (NC: natural conditions, PS: culture conditions as a group, and TS: culture conditions with individuals kept separately) to analyze the amount of stress caused by rearing conditions. Stress marks were observed using a high-resolution stereo fluorescence microscope. In Experiment 1, the specific growth rates (SGRs) were 0.20 ± 0.15% per day in the PS group, 0.24 ± 0.10% per day in the TS group, and 0.68 ± 0.48% per day in the NS group. The survival rate was 62.5 ± 6.25%, 37.5 ± 18.75%, and 12.5% in the TS, PS, and NS groups, respectively. The experimental conditions of Experiment 2 were the same as those in Experiment 1, except that Experiment 2 involved different individuals and occurred during a different season. In Experiment 2, the SGRs were 0.54 ± 0.20% per day in the PS group, 0.59 ± 0.22% per day in the TS group, and 0.44 ± 0.10% per day in the NS group. Survival rate was 87.5 ± 6.25%, 75 ± 6.25%, and 75% in the TS, PS, and NS groups, respectively. Regression analysis showed that the water temperature (from 5.4–23.1 °C) affected the growth of octopuses in Experiments 1 and 2. Capture stress was detected in six of the nine individuals (NC, PS, and TS combined). Statistically significant differences in the stress levels were detected between the PS and TS groups (P ≤ 0.1), with the NC group exhibiting no stress lines after initial adaptation, unlike PS. In conclusion, octopuses kept in TS were not affected by stress after initial adaptation.