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The Laboratory of Comparative Psychology and Behavioral Biology at Oklahoma State University has been developing comparative psychology teaching exercises for over 30 years. In this paper, we provide suggestions for using the dwarf octopus (Octopus joubini) to teach students about the importance of observation, and the relationship of observation in the creation of ethograms and experimental design. Throughout this paper, students learn how to properly make an observation of a novel animal, create an ethogram, and conduct an experiment. We present a sample observation activity and three additional experiments, during which students will observe and record behaviors and environmental conditions. Students learn saltwater tank upkeep, time management, creation and coding of operational definitions, attention to changes in animal behavior, and the experimental process. These observation studies allow students to observe and record behavioral data to understand comparative psychology and experimental design.

This study aimed to investigate whether plaque characteristics derived from intravascular optical coherence tomography (IVOCT) could predict a long-term cardiovascular (CV) death. This study was a single-center, retrospective study on 104 patients who had undergone IVOCT-guided percutaneous coronary intervention. Plaque characterization was performed using Optical Coherence TOmography PlaqUe and Stent (OCTOPUS) software developed by our group. A total of 31 plaque features, including lesion length, lumen, calcium, fibrous cap (FC), and vulnerable plaque features (e.g., microchannel), were computed from the baseline IVOCT images. The discriminatory power for predicting CV death was determined using univariate/multivariate logistic regressions. Of 104 patients, CV death was identified in 24 patients (23.1%). Univariate logistic regression revealed that lesion length, calcium angle, calcium thickness, FC angle, FC area, and FC surface area were significantly associated with CV death (p < 0.05). In the multivariate logistic analysis, only the FC surface area (OR 2.38, CI 0.98–5.83, p < 0.05) was identified as a significant determinant for CV death, highlighting the importance of the 3D lesion analysis. The AUC of FC surface area for predicting CV death was 0.851 (95% CI 0.800–0.927, p < 0.05). Patients with CV death had distinct plaque characteristics (i.e., large FC surface area) in IVOCT. Studies such as this one might someday lead to recommendations for pharmaceutical and interventional approaches. [ABSTRACT FROM AUTHOR]

In the present note an adult female of Tremoctopus violaceus delle Chiaje, 1830, is recorded from the Strait of Messina. Species of the family Tremoctopodidae are widely distributed in tropical oceans, but rare in coastal waters. The morphological characteristics coincide with those described by other authors. Necroscopic examination performed did not reveal any peculiar pathology. Morphometrical characteristics, photos and general information are given, expanding the knowledge about these rare cephalopods in Mediterranean basin. [ABSTRACT FROM AUTHOR]

Octopus fisheries face heightened demand driven by depleted fish stocks and escalating economic value, leading to overextraction of octopus populations and magnifying threats to coastal ecosystems and the livelihoods of fishers who depend on them. Implementation of management strategies such as periodic fishing closures can offer sanctuary for octopus, providing the necessary space and time for the growth and reproduction of this rapidly proliferating species. Despite evidence of positive management outcomes, the role of periodic closures in the long-term sustainability of octopus populations remains uncertain. Here, we examine trends in octopus landings over time and the effects of periodic closures along the Mozambique Channel from Comoros to Madagascar (12°-25°S). Long-term trends in octopus landings varied across three regions: generally stable over a 6-year period in Comoros, increasing over a 4-year period in the Barren Isles and declining over a 17-year period in Atsimo Andrefana, Madagascar. We observed a significant increase in mean catch per unit effort (CPUE, kilograms/fisher-day), and mean total catch (kilograms/day) following periodic closures across villages extracting octopus from closure areas. When evaluating each region independently, we observed this positive effect across Comoros and Atsimo Andrefana, Madagascar while trends in the Barren Isles showed no effect of octopus closures. We applied generalized linear mixed models to examine the influence of 10 covariates on mean daily total catch and CPUE within 7 days and 30 days post-closure. Baseline conditions (quantified by the pre-closure CPUE and daily total catch), closure duration and start month of closure had positive, statistically significant correlations with post-closure CPUE and daily total catch. Additionally, closure duration from 13 to 16 weeks and closure size of approximately 70 hectares were qualitatively associated with net gains in CPUE. Although periodic closures yield positive outcomes for octopus fisheries, the effects may be short-lived, as observed in Atsimo Andrefana, Madagascar, where catch declined over the long-term despite temporary improvements. Our findings underscore a need for a diverse portfolio of management strategies to restore and sustain populations over the long-term. [ABSTRACT FROM AUTHOR]

Cyclophosphamide (CTX) is an anticancer medication that suppresses host immunity as well as adversely affects mucosal inflammation and gut microflora dysbiosis. The gut microflora is recognized as a substantial factor in host metabolism and immunological homeostasis. To improve immunity and inhibit cytotoxic and homeostatic imbalances triggered by CTX, it is essential to monitor immunoregulators. In this research, we assessed the impact of Octopus peptide hydrolysate (OPH) on immune modulation, intestinal integrity, and gut microbial composition in CTX-induced immune-deficient mice. The results revealed that OPH increased body weight, and immunological organ indices, and improved the histological changes in the colon, thymus, and spleen. The OPH stimulated the secretion of cytokines (IL-1β, IL-6, and TNF-α) and antibodies (IgM and IgA) while reducing the ratio of lipopolysaccharide (LPS) and diamine oxidase (DAO) in the serum. OPH further enhanced goblet cell and mucus production, upregulated the expression of gut tight-junction proteins (Occludin, Zonula Occludin-1, Mucin-2, and Claudin-1), and activated the TLR4/NF-κB cascade (p-IκBα, P65/p-p65). In addition, OPH treatment declined the Bacteroidetes/Firmicutes ratio, enhanced the relative ratio of Alistipes/Lachnospiraceae, and reversed the ecological equilibrium of the gut microflora. The findings revealed that OPH serves as a prebiotic to prevent CTX-mediated disruption in the intestinal barrier and boosts gut mucosal immunity by attenuating gut microflora imbalance, implying that OPH could be used as an immunological ingredient in nutritious foods to regulate the immune system and protect the gut from inflammatory diseases.

Particulate matter (PM) is a mixture of microscopic solid inhalable particles including airborne liquid droplets, and it is implicated with several diseases. The eye does not have a protective barrier among the human organs, consequently it get directly exposed to environmental substances such as PM. The scarcity of treatments for damage to the eyesight and the vision and eye structure being closely related to the structure and function of the central nervous system highlights the cruciality of novel therapeutics. In this study was conducted using in vivo zebrafish vertebrate model which is a useful model due to the conserved genes between human. We found that protective effect of Octopus minor extract against particulate matter-induced adverse effects on eye development in zebrafish (Danio rerio) embryos by regulating antioxidant and anti-inflammatory mRNA expression.

Suction is a highly evolved biological adhesion strategy for soft-body organisms to achieve strong grasping on various objects. Biological suckers can adaptively attach to dry complex surfaces such as rocks and shells, which are extremely challenging for current artificial suction cups. Although the adaptive suction of biological suckers is believed to be the result of their soft body's mechanical deformation, some studies imply that in-sucker mucus secretion may be another critical factor in helping attach to complex surfaces, thanks to its high viscosity. Inspired by the combined action of biological suckers' soft bodies and mucus secretion, we propose a multiscale suction mechanism which successfully achieves strong adaptive suction on dry complex surfaces which are both highly curved and rough, such as a stone. The proposed multiscale suction mechanism is an organic combination of mechanical conformation and regulated water seal. Multilayer soft materials first generate a rough mechanical conformation to the substrate, reducing leaking apertures to micrometres (~10 μm). The remaining micron-sized apertures are then sealed by regulated water secretion from an artificial fluidic system based on the physical model, thereby the suction cup achieves long suction longevity on complex surfaces but minimal overflow. We discuss its physical principles and demonstrate its practical application as a robotic gripper on a wide range of complex dry surfaces. We believe the presented multiscale adaptive suction mechanism is a powerful unique adaptive suction strategy which may be instrumental in the development of versatile soft adhesion. [ABSTRACT FROM AUTHOR]

Amphioctopus neglectus is a species of octopus that is favored by consumers due to its rich nutrient profile. To investigate the influence of different thawing methods on the quality of octopus meat, we employed four distinct thawing methods: air thawing (AT), hydrostatic thawing (HT), flowing water thawing (FWT), and microwave thawing (MT). We then explored the differences in texture, color, water retention, pH, total volatile basic nitrogen (TVB–N), total sulfhydryl content, Ca2+–ATPase activity, and myofibrillar protein, among other quality indicators in response to these methods, and used a low-field nuclear magnetic resonance analyzer to assess the water migration that occurred during the thawing process. The results revealed that AT had the longest thawing time, leading to oxidation-induced protein denaturation, myofibrillar protein damage, and a significant decrease in water retention. Additionally, when this method was utilized, the content of TVB–N was significantly higher than in the other three groups. HT, to a certain extent, isolated the oxygen in the meat and thus alleviated protein oxidation, allowing higher levels of Ca2+–ATPase activity, sulfhydryl content, and springiness to be maintained. However, HT had a longer duration: 2.95 times that of FWT, resulting in a 9.84% higher cooking loss and a 28.21% higher TVB–N content compared to FWT. MT had the shortest thawing time, yielding the lowest content of TVB–N. However, uneven heating and in some cases overcooking occurred, severely damaging the protein structure, with a concurrent increase in thawing loss, W value, hardness, and shear force. Meanwhile, FWT improved the L*, W* and b* values of octopus meat, enhancing its color and water retention. The myofibrillar protein (MP) concentration was also the highest after FWT, with clearer subunit bands in SDS-PAGE electrophoresis, indicating that less degradation occurred and allowing greater springiness, increased Ca2+–ATPase activity, and a higher sulfhydryl content to be maintained. This suggests that FWT has an inhibitory effect on oxidation, alleviating protein oxidation degradation and preserving the quality of the meat. In conclusion, FWT outperformed the other three thawing methods, effectively minimizing adverse changes during thawing and successfully maintaining the quality of octopus meat. [ABSTRACT FROM AUTHOR]

The right third arm of the male octopus is the hectocotylized arm. This arm is modified by anatomy specialized to hold and transfer sperm packets to the female, and lacks suckers at the distal end. Male octopus may be distinguished by the skilled eye from their habit of holding their hectocotylus closer to their body in a protective manner, although this observation has never been described quantitatively. We utilized a three-step process of data annotation, pose estimation model training, and model inference to show that this common observation is true of Octopus rubescens. In 2338 images, the eyes, mantle tip, and arm tips of two male (n = 1152) and three female (n = 1085) octopuses were annotated by an experimenter. These images were then used to train a DeepLabCut pose estimation model which achieved a RMSE of 1.78 cm. This model was then used to annotate 11.4 h (n = 408,985 images) of four female and eight male octopuses moving across the middle of a large aquarium. We then compared the human annotated data, and the model inference data separately. In both datasets we compared the arm-tip-to-eye centered point distances, as well as the octopus centric arm tip 90% kernel density estimation area. In both the training dataset and the model inference datasets we found common results. Male O. rubescens hold their third to the right arm closer to their body than all seven other arms while the females do not. Further, in both males and females, the rear arm pairs operate closer to the body than the front arm pairs. Despite their anatomical similarity and potential redundancy, these results indicates functional differences in arm use by octopuses. [ABSTRACT FROM AUTHOR]

In this paper I consider ways in which seawater--both on its surface and in its depths--opens up alternative forms of thought and expression in Homer, especially with respect to the body. By tracking the relationship between body and simile as it is mediated by the surface of the sea, I argue that water emerges as an especially mobile and adaptive medium for expressing the transformation that takes place between self and simile in Homer. In the Iliad, similes are wellknown for bringing weather, waves, and other aspects of the natural environment into the poem, whereas in the Odyssey those aspects more often introduce similes of their own. I offer a reading of the shipwreck scene in Odyssey 5 to suggest that the body's struggle to stay afloat is matched there, on a formal level, by the role of waves in drawing simile and body to the sea's surface. I then address a different kind of figurative language (closer to metaphor and associated with grief) that takes place in the depths, through readings of scenes in Books 18 and 24 of the Iliad and Archilochus fragment 13. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Cephalopods are harvested in increasingly large quantities but understanding how to control and manage their stocks, and tracking the routes of the consumption that exploits them, lag behind what has been developed for exploiting finfish. This review attempts to redress the imbalance by considering the status of the major cephalopod stock species and the traceability of cephalopod seafood along the trade value chain. It begins with a general overview of the most important exploited cephalopods, their stock status and their market. Four major cephalopod resources are identified: the three squid species Todarodes pacificus, Dosidicus gigas and Illex argentinus; and one species of octopus, Octopus vulgaris. The techniques and problems of stock assessment (to assess sustainability) are reviewed briefly and the problems and possible solutions for assessing benthic stock such as those of octopuses are considered. An example of a stock well managed in the long term is presented to illustrate the value of careful monitoring and management: the squid Doryteuthis gahi available in Falkland Islands waters. Issues surrounding identification, mislabelling and illegal, unreported and unregulated (IUU) fishing are then reviewed, followed by a discussion of approaches and techniques of traceability as applied to cephalopods. Finally, some of the mobile apps currently available and in development for tracking seafood are compared. This review concludes with observations on the necessity for the strengthening and international coordination of legislation, and more rigorous standards for seafood labelling and for taxonomic curation of DNA sequences available in public databases for use in seafood identification. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Octopus fisheries face heightened demand driven by depleted fish stocks and escalating economic value, leading to overextraction of octopus populations and magnifying threats to coastal ecosystems and the livelihoods of fishers who depend on them. Implementation of management strategies such as periodic fishing closures can offer sanctuary for octopus, providing the necessary space and time for the growth and reproduction of this rapidly proliferating species. Despite evidence of positive management outcomes, the role of periodic closures in the long-term sustainability of octopus populations remains uncertain. Here, we examine trends in octopus landings over time and the effects of periodic closures along the Mozambique Channel from Comoros to Madagascar (12°-25°S). Long-term trends in octopus landings varied across three regions: generally stable over a 6-year period in Comoros, increasing over a 4-year period in the Barren Isles and declining over a 17-year period in Atsimo Andrefana, Madagascar. We observed a significant increase in mean catch per unit effort (CPUE, kilograms/fisher-day), and mean total catch (kilograms/day) following periodic closures across villages extracting octopus from closure areas. When evaluating each region independently, we observed this positive effect across Comoros and Atsimo Andrefana, Madagascar while trends in the Barren Isles showed no effect of octopus closures. We applied generalized linear mixed models to examine the influence of 10 covariates on mean daily total catch and CPUE within 7 days and 30 days post-closure. Baseline conditions (quantified by the pre-closure CPUE and daily total catch), closure duration and start month of closure had positive, statistically significant correlations with post-closure CPUE and daily total catch. Additionally, closure duration from 13 to 16 weeks and closure size of approximately 70 hectares were qualitatively associated with net gains in CPUE. Although periodic closures yield positive outcomes for octopus fisheries, the effects may be short-lived, as observed in Atsimo Andrefana, Madagascar, where catch declined over the long-term despite temporary improvements. Our findings underscore a need for a diverse portfolio of management strategies to restore and sustain populations over the long-term.

This study aimed to investigate whether plaque characteristics derived from intravascular optical coherence tomography (IVOCT) could predict a long-term cardiovascular (CV) death. This study was a single-center, retrospective study on 104 patients who had undergone IVOCT-guided percutaneous coronary intervention. Plaque characterization was performed using Optical Coherence TOmography PlaqUe and Stent (OCTOPUS) software developed by our group. A total of 31 plaque features, including lesion length, lumen, calcium, fibrous cap (FC), and vulnerable plaque features (e.g., microchannel), were computed from the baseline IVOCT images. The discriminatory power for predicting CV death was determined using univariate/multivariate logistic regressions. Of 104 patients, CV death was identified in 24 patients (23.1%). Univariate logistic regression revealed that lesion length, calcium angle, calcium thickness, FC angle, FC area, and FC surface area were significantly associated with CV death (p < 0.05). In the multivariate logistic analysis, only the FC surface area (OR 2.38, CI 0.98–5.83, p < 0.05) was identified as a significant determinant for CV death, highlighting the importance of the 3D lesion analysis. The AUC of FC surface area for predicting CV death was 0.851 (95% CI 0.800–0.927, p < 0.05). Patients with CV death had distinct plaque characteristics (i.e., large FC surface area) in IVOCT. Studies such as this one might someday lead to recommendations for pharmaceutical and interventional approaches.

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Simple Summary: Here, we investigated how Octopus vulgaris approached and solved a problem required for obtaining food from a puzzle box. We also explored the relationship between individual octopuses' problem-solving abilities and various behavioural characteristics (e.g., their interest in novel objects), and biotic and environmental factors (age, season, and site of capture). We found that octopuses more inclined to approach new objects were quicker to approach the puzzle box and more likely to succeed in opening it, but they did not reach the solution before other individuals. This suggests that an excessive inclination towards novelty could hinder problem-solving efficiency. The study also revealed that the season and the fishing site are important drivers of octopuses' behavioural differentiation. Our findings offer valuable insights into the individuality of octopuses. 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. [ABSTRACT FROM AUTHOR]

Octopuses present a difficult resource to manage because of their relatively short life spans, rapid growth rates, high natural mortality and seasonal fluctuations in abundance. With exploitation efforts increasing worldwide, particularly in the Pacific Island region, substantial knowledge gaps in their biology, exploitation and management remain. We conducted a literature review to summarise their species distribution, abundance, ecological attributes, utilization, importance and management within the Pacific Island Countries and Territories (PICTs) of Fiji, Vanuatu, the Solomon Islands, New Caledonia, Tonga, Samoa and American Samoa. We found that 23 species of octopuses within 11 genera were recorded from these PICTs, belonging to the families Amphitretidae and Octopodidae. Overall, Tonga was the most speciose country with 11 occurrence records and Samoa recorded the least with just a single species. All other countries recorded between 2 and 8 taxa. The day octopus (Octopus cyanea) was recorded from all PICTs except Samoa. There are no specific national regulations on octopus fisheries within the PICTs and management is largely dependent on overarching national fisheries legislation. However, community-based management efforts can be an effective platform in sustaining octopus stocks. Octopuses also play an important role in the folklore and customs of many Pacific Islanders, and we provide a summary of these for the specific PICTs assessed. This review highlights areas for further research and development for the Pacific Island region and the urgent need to address specific knowledge gaps on octopus taxonomy, stock assessment and fishery management. [ABSTRACT FROM AUTHOR]

Habitat characterization is important to assess fully the niches of different organisms. There is a large knowledge gap regarding habitat use by deep‐sea benthic incirrate octopods, partly due to their assumed preference for hard‐to‐sample rocky substrata. This study uses observations from in situ videos recorded by remotely operated vehicles (ROVs) deployed from the NOAA Ship Okeanos Explorer and implements the Coastal and Marine Ecological Classification Standard (CMECS) to describe the habitat of three common species of bathyal incirrate octopods living in the western North Atlantic Ocean: Bathypolypus bairdii (Verrill 1873), Graneledone verrucosa (Verrill 1881), and Muusoctopus johnsonianus (Allcock, Strugnell, Ruggiero, & Collins 2006). Significant differences in species' preferences for geoform setting, depth, and substrate type were found. All three species are most likely to be observed by ROV in a submarine canyon and least likely to be seen on a seamount. B. bairdii was found shallower than G. verrucosa and M. johnsonianus. This is the first study of its kind using CMECS to classify the habitat of specific organisms as opposed to the habitat types in a specific area. [ABSTRACT FROM AUTHOR]

Among mollusks, the octopods stand out due to the almost entire absence of a stabilizing shell, potentially rendering these organisms susceptible to deformation caused by fixation and preservation. Such artifacts have previously been shown to occur especially in specimens of the deep-sea taxon Cirrata, the finned octopods. As an adaptation to their extreme habitat, many cirrates are composed of (semi-)gelatinous tissues, which are particularly prone to distortion, shrinkage, and deformation following fixation and preservation. Using one or more species from each of the eight currently recognized cirrate genera, the present study provides pre- and post-fixation color imagery of entire specimens as well as measurements of taxonomically relevant characters. These novel data illustrate the sometimes drastic effects that short- and long-term chemical treatment entails for this cephalopod taxon. Both structural and color changes may occur when finned octopods are fixed and preserved using routine protocols. However, shrinkage does not occur uniformly in all taxonomically relevant structures. The consequences of such a treatment for species descriptions and identification are discussed and existing anaesthetization, fixation and preservation protocols are summarized. [ABSTRACT FROM AUTHOR]

Coleoid cephalopods (octopus, squid and cuttlefish) have unusually complex nervous systems. The coleoid nervous system is also the only one currently known to recode the majority of expressed proteins through A-to-I RNA editing. The deamination of adenosine by adenosine deaminase acting on RNA (ADAR) enzymes produces inosine, which is interpreted as guanosine during translation. If this occurs in an open reading frame, which is the case for tens of thousands of editing sites in coleoids, it can recode the encoded protein. Here, we describe recent findings aimed at deciphering the mechanisms underlying high-level recoding and its adaptive potential. We describe the complement of ADAR enzymes in cephalopods, including a recently discovered novel domain in sqADAR1. We further summarize current evidence supporting an adaptive role of high-level RNA recoding in coleoids, and review recent studies showing that a large proportion of recoding sites is temperature-sensitive. Despite these new findings, the mechanisms governing the high level of RNA recoding in coleoid cephalopods remain poorly understood. Recent advances using genome editing in squid may provide useful tools to further study A-to-I RNA editing in these animals. [ABSTRACT FROM AUTHOR]

Abstract 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.

Abstract Octopuses (scientific order Octopoda under the scientific class Cephalopoda) are a group of aquatic species with economic importance as a food product in many countries around the world. Octopus products are consumed in many different geographic locations around the world, including East Asia, the Mediterranean region, the Caribbean region, and South American coastal regions. To‐date, a comprehensive scientific review of octopus with direction toward procurement, food processing, and food quality has not been published. The purpose of this review was to provide a practical overview of the nomenclature, procurement (i.e., catching), processing, quality, and shelf‐life of octopus. The objective was accomplished by strategically searching for scientific literature on the topic of octopus and octopus‐derived food products. Octopus‐derived food products have a high protein content (70%–85% on a dry matter basis), significant levels of important major and trace minerals, and significant levels of essential vitamins. In addition, octopus‐derived food products are highly sought after in some areas of the world. However, recognized standards for procurement of octopus and preparation of octopus‐derived food products vary around the world and are frankly inconsistent and under reported. The octopus industry would greatly benefit from greater levels of practical information becoming available, especially as the industry experiences growth and heightened levels of demand.

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.

Abstract Habitat characterization is important to assess fully the niches of different organisms. There is a large knowledge gap regarding habitat use by deep‐sea benthic incirrate octopods, partly due to their assumed preference for hard‐to‐sample rocky substrata. This study uses observations from in situ videos recorded by remotely operated vehicles (ROVs) deployed from the NOAA Ship Okeanos Explorer and implements the Coastal and Marine Ecological Classification Standard (CMECS) to describe the habitat of three common species of bathyal incirrate octopods living in the western North Atlantic Ocean: Bathypolypus bairdii (Verrill 1873), Graneledone verrucosa (Verrill 1881), and Muusoctopus johnsonianus (Allcock, Strugnell, Ruggiero, & Collins 2006). Significant differences in species' preferences for geoform setting, depth, and substrate type were found. All three species are most likely to be observed by ROV in a submarine canyon and least likely to be seen on a seamount. B. bairdii was found shallower than G. verrucosa and M. johnsonianus. This is the first study of its kind using CMECS to classify the habitat of specific organisms as opposed to the habitat types in a specific area.

Enzymes from ectotherms living in chronically cold environments have evolved structural innovations to overcome the effects of temperature on catalysis. Cold adaptation of soluble enzymes is driven by changes within their primary structure or the aqueous milieu. For membrane-embedded enzymes, like the Na+ /K+ -ATPase, the situation is different because changes to the lipid bilayer in which they operate may also be relevant. Although much attention has been focused on thermal adaptation within lipid bilayers, relatively little is known about the contribution of structural changes within membrane-bound enzymes themselves. The identification of specific mutations that confer temperature compensation is complicated by the presence of neutral mutations, which can be more numerous. In the present study, we identified specific amino acids in a Na+ /K+ -ATPase from an Antarctic octopus that underlie cold resistance. Our approach was to generate chimeras between an Antarctic clone and a temperate ortholog and then study their temperature sensitivities in Xenopus oocytes using an electrophysiological approach. We identified 12 positions in the Antarctic Na+ /K+ -ATPase that, when transferred to the temperate ortholog, were sufficient to confer cold tolerance. Furthermore, although all 12 Antarctic mutations were required for the full phenotype, a single leucine in the third transmembrane segment (M3) imparted most of it. Mutations that confer cold resistance are mostly in transmembrane segments, at positions that face the lipid bilayer. We propose that the interface between a transmembrane enzyme and the lipid bilayer is a critical determinant of temperature sensitivity and, accordingly, has been a prime evolutionary target for thermal adaptation. [ABSTRACT FROM AUTHOR]

Simple Summary: The contamination of coastal waters, unhealthy conditions and inadequate handling practices tend to reduce the sanitary quality of fishery products, thus impacting its marketing. With this in mind, we investigate the microbiological quality of the Octopus insularis in each stage of the production chain, comprehending capture, post-capture, processing and commercialization, in terms of the presence of total and fecal coliforms at the Veracruz Reef System, Gulf of Mexico. The environmental and anthropogenic influence on the space–temporal concentration of coliforms were analyzed in sea water, fresh octopus, fresh water, ice and octopus, both packed in ice and boiled. Most relevant results indicated that coliforms are present in the octopus production chain, being highest in the marketing stage. The coliform concentration increased during the rainy season and was highest in the reefs closer to the coast, which has a major anthropogenic influence. These results point out the urgent need to implement an efficient cold chain with adequate handling practices to try to reverse these microbiological conditions and improve the octopus quality and food safety. Coliforms are relatively common in aquatic environments, but their concentrations can be increased by environmental changes and anthropogenic activities, thus impacting fisheries resources. To determine the microbiological quality in the octopus production chain (capture, post-capture, processing and commercialization), total (TC) and fecal (FC) coliforms were quantified in sea water, fresh octopus, fresh water, ice and octopus in two presentations: packed in ice and boiled. Samples came from fishing zones Enmedio, Chopa and La Gallega at the Veracruz Reef System (VRS) during dry, rainy and windy seasons. The coliforms were determined using the most probable number technique (MPN). The most relevant results indicated that octopus packed in ice coming from the commercialization stage had FC levels >540 MPN/100 g, which exceeded the permissible limits (230 MPN/100 g). Therefore, these products present a risk for human consumption. Differences in FC were observed in octopuses between the three fishing zones (H = 8.697; p = 0.0129) and among the three climatic seasons, increasing during the rainy season, highlighting La Gallega with 203.33 ± 63 MPN (H = 7.200; p = 0.0273). The results provide evidence of the environmental and anthropogenic influences on coliform concentrations and the urgent need to implement an efficient cold chain throughout octopus production stages with adequate handling practices to reverse this situation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Simple Summary: Octopuses are a diverse group of charismatic animals capable of adapting to a wide range of environments. Marine sediment habitats are the most pervasive environments on Earth and are largely dominated by burrowing organisms. Burrowing, the formation of semi-permanent structures below the surface of the sediment bed, is a novel behavior among octopuses, and the morphology facilitating burrowing in most octopuses is unknown. The goal of this study was to investigate the octopus keel, a fold of skin that protrudes from the lateral margin of the mantle in some species, as a burrowing-associated trait. The keel has been noted in several octopuses known to burrow and has been hypothesized to be associated with burrowing. We found that burrowing octopus species were more likely to also have keels, and that burrowing species of octopus, when held in aquaria, were more likely to lose their keels if they did not burrow. This article represents the first phylogenetic evidence of a connection between keels and burrowing, as well as evidence of the degeneration of keels in non-burrowing Muusoctopus leioderma. The octopus keel is a trait that has been hypothesized to be connected with burrowing in octopuses, but has never been explored in any detail. We investigated the association between these two traits using two approaches. First, we examined the phylogenetic correlation between the presence of a keel and known burrowing behavior in cirrate octopuses. Second, burrowing and non-burrowing captive Muusoctopus leioderma were evaluated for keel prominence to determine whether the keel is lost more rapidly in non-burrowing individuals. Pagel's test for the coevolution of binary characteristics showed the model of best fit for the resulting phylogenetic tree to be one of evolutionary interdependence, and that non-burrowing Muusoctopus leioderma lost their keels over time, while burrowing individuals maintained their keels. Together, these results indicate the keel may be a trait associated with burrowing in octopuses. [ABSTRACT FROM AUTHOR]

Antipredator behavior of the paralarval stages of merobenthic octopuses is largely unknown. Reported here is an investigation of the behavioral response of Octopus sinensis paralarvae to the sympatric predator fish Girella punctata. Fishes of this species exhibited predatory behavior by engulfing individual paralarvae, but most fishes almost immediately rejected the paralarva from the mouth. No paralarvae died after being engulfed and ejected. The number of such temporary engulfings of a paralarva by a fish during the test period (10 min) decreased with the increase in the number of times a paralarva was engulfed. The frequency of engulfing attacks by the fish also declined. The paralarvae did not eject ink before being engulfed, but 43% of the paralarvae exhibited inking immediately after ejection from the fish's mouth. The fishes ingested the ink masses released by the paralarvae, and the proportion of fish ingesting the ink masses increased with increasing experience of encountering the ink. When the paralarvae ejected ink, the time interval between first engulfing and subsequent engulfing increased, apparently in relation to distraction of the fish by the ink. These results suggest that paralarvae have an antipredatory mechanism which causes predatory fish to eject them after they have been engulfed. In addition, the paralarvae use the stimulus of being ejected from the mouth of a fish as a cue for ink ejection. The ink mass may be attractive to the fish as a food item because of its potential action as a phagomimetic distraction, enabling the paralarvae to escape. [ABSTRACT FROM AUTHOR]

This retrospective study examines pathologic findings in 593 captive cephalopods (340 octopuses, 130 cuttlefish, 33 squid, and 90 nautiluses; 22 species in total) submitted to International Zoo Veterinary Group Pathology between May 2003 and August 2022. Common octopus, European common cuttlefish, hummingbird bobtail squid, and chambered nautilus were the most numerous species from the included orders of Octopoda, Sepiida, Sepiolida, and Nautilida, respectively. Commonly identified conditions included coccidiosis and renal dicyemid mesozoan infection in octopuses, amebiasis in squid, bacterial infections in cuttlefish, and idiopathic multisystemic inflammatory disease in nautiluses. Coccidiosis was most frequent in common octopuses, giant Pacific octopuses, and California 2-spot octopuses (present in 68.4%, 46.3%, and 23.8% of these species, respectively) and was the attributed cause of death in 32.3%, 36.0%, and 60.0% of such cases, respectively. Ulcerative dermatitis (UD) was common, affecting squid, cuttlefish, and octopuses, while many nautiluses exhibited black shell disease and/or UD. Notable differences in the prevalence of UD were detected between laboratory and aquaria-housed decapodiforms; 52.2% for laboratory squid versus 20.0% in aquaria; 51.3% in laboratory cuttlefish versus 11.0% in aquaria. All octopuses and nautiluses in the study were derived from aquaria. Semelparity-associated death in Coleoidea species was identified in 22.4% of octopuses, 11.5% of cuttlefish, and 6.1% of squid. This report aims to provide an overview and reassessment of species-specific disease patterns under aquarium and laboratory management as a starting point for future developments in husbandry and disease investigation. [ABSTRACT FROM AUTHOR]

Parasitism of cephalopods is common, including infection with Aggregata spp., Ichthyobodo spp., dicyemids, cestodes of the orders Tetraphyllidea and Trypanorhynchidea, and various crustaceans. Cestodiasis in octopuses is reported, although a full histologic description of lesions has not been previously described. Cestodiasis was identified in 10 octopuses of 4 different species, which included 4 common octopuses (Octopus vulgaris), 3 Caribbean reef octopuses (Octopus briareus), 2 two-spot octopuses (Octopus bimaculoides), and 1 giant Pacific octopus (Enteroctopus dofleini). Larval cestodes were present in the cecum (n = 5), intestines (n = 4), digestive gland (n = 3), chitinous alimentary tract (n = 2), renal appendage (n = 1), and salivary duct (n = 1). In 5 cases, larval cestodes invaded tissue and were associated with hemocytic inflammation and tracts of necrotic tissue in the intestines (n = 3), digestive gland (n = 3), and/or renal appendage (n = 1). When present in the chitinous alimentary tract (esophagus, stomach) or cecum, larval cestodes were in the central lumen and not associated with lesions. One adult cestode was identified in the mantle cavity and was not associated with lesions. Other common concurrent parasitic infections included enteric Aggregata spp. infection, branchial Rickettsia-like organism infection, enteric nematodiasis, and an arthropod-associated branchitis. [ABSTRACT FROM AUTHOR]

Ocular lesions are uncommonly reported and described in invertebrate species. In this study, cases from 2 diagnostic laboratories, in which lesions were noted in 33 diagnostic specimens from various species of cephalopods, including octopuses, squid, nautiluses, and cuttlefish, were reviewed. Clinical information and gross lesions were described in a minority of cases. The most common lesion was inflammation of varying severity and was most commonly within the anterior uvea (iris and ciliary papilla), followed by the posterior chamber and lens. More than half of the cases with inflammation had concurrent hyperplastic lesions of the iris and ciliary papilla, including posterior iris epithelial hyperplasia, cystic adenomatous hyperplasia, and/or posterior epithelial cysts. The most common clinical observation was cloudy eyes, which correlated histologically to anterior uveitis in all cases where it was documented. Dermatitis and cutaneous ulceration were the most frequent comorbidities in cases where clinical information was available. [ABSTRACT FROM AUTHOR]

The analysis of a natural motor action is always difficult, especially when different motor programs are combined within the same interaction with the environment. We analyzed the behavior of an octopus, Abdopus sp., filmed in tidal pools in Okinawa, Japan, which used the kinematic primitives of rotation and translation of its hydrostatic arms, and combined these kinematic behaviors serially and in parallel to 'slap' at fish in the wild. In total, 19 slaps were analyzed. The kinematics of arm movement were measured in both external and animal-centered reference frames, while the octopus was slapping at the fish. By combining these primitives, the octopus is able to maintain flexibility while controlling only a few degrees of freedom, a concept we term 'flexible rigidity'. This slapping action supports Flash and Hochner's embodied organization view of motor behavior, as well as their idea that motor primitives can combine syntactically to form a complex action. The octopus's ability to use sensory feedback from the position of a moving fish target, along with the feed-forward motor primitives, allows for the building of complex actions at dynamic equilibrium with the environment. Over all, these findings lead to a more realistic view of how a complex behavior allows an animal to coordinate with its environment. [ABSTRACT FROM AUTHOR]

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Amphioctopus neglectus is a species of octopus that is favored by consumers due to its rich nutrient profile. To investigate the influence of different thawing methods on the quality of octopus meat, we employed four distinct thawing methods: air thawing (AT), hydrostatic thawing (HT), flowing water thawing (FWT), and microwave thawing (MT). We then explored the differences in texture, color, water retention, pH, total volatile basic nitrogen (TVB–N), total sulfhydryl content, Ca2+–ATPase activity, and myofibrillar protein, among other quality indicators in response to these methods, and used a low-field nuclear magnetic resonance analyzer to assess the water migration that occurred during the thawing process. The results revealed that AT had the longest thawing time, leading to oxidation-induced protein denaturation, myofibrillar protein damage, and a significant decrease in water retention. Additionally, when this method was utilized, the content of TVB–N was significantly higher than in the other three groups. HT, to a certain extent, isolated the oxygen in the meat and thus alleviated protein oxidation, allowing higher levels of Ca2+–ATPase activity, sulfhydryl content, and springiness to be maintained. However, HT had a longer duration: 2.95 times that of FWT, resulting in a 9.84% higher cooking loss and a 28.21% higher TVB–N content compared to FWT. MT had the shortest thawing time, yielding the lowest content of TVB–N. However, uneven heating and in some cases overcooking occurred, severely damaging the protein structure, with a concurrent increase in thawing loss, W value, hardness, and shear force. Meanwhile, FWT improved the L*, W* and b* values of octopus meat, enhancing its color and water retention. The myofibrillar protein (MP) concentration was also the highest after FWT, with clearer subunit bands in SDS-PAGE electrophoresis, indicating that less degradation occurred and allowing greater springiness, increased Ca2+–ATPase activity, and a higher sulfhydryl content to be maintained. This suggests that FWT has an inhibitory effect on oxidation, alleviating protein oxidation degradation and preserving the quality of the meat. In conclusion, FWT outperformed the other three thawing methods, effectively minimizing adverse changes during thawing and successfully maintaining the quality of octopus meat.

The article argues that the alien monster of Jordan Peele's Nope (2022) should be read as part of the long legacy of capitalist monster octopuses, and that identification and recognition of the monster octopus in this context allows for a greater understanding of Peele's specifically gothic critique of capitalism within the film. The article reviews the history of the monster octopus in literature, art, cinema, and political cartoon, outlines Nope's relationship to and development of these earlier texts, and then examines how the film uses the monster octopus to highlight capitalism as a monstrous system that we can neither survive nor afford to look away from. Critical perspectives explored in the article include Gothic Studies, Financial History, and Critical Race Theory, and Nope is examined as an example of the Economic Humanities in contemporary horror cinema. [ABSTRACT FROM AUTHOR]

Simple Summary: Giant Pacific octopuses (Enteroctopus dofleini) (GPOs) are commonly found in zoos or aquariums. However, veterinarians or animal care professionals may be reluctant to perform diagnostic or other procedures due to limited information on best practices for sedation, anesthesia, or euthanasia of the species. The purpose of this study was to survey aquatic veterinarians and animal care professionals on current animal and veterinary care, including anesthesia and euthanasia, of GPOs. An online survey was distributed with participation from 52 institutions. Results included animal care practices consistent with current recommendations and highly variable involvement with veterinary care. Over 20 institutions have used anesthesia or sedation for procedures that do not involve euthanasia. Anesthesia and euthanasia methods were reported, including a variety of techniques and large dose ranges compared to techniques used for smaller cephalopods. Observations described include side effects such as failure to adequately anesthetize or euthanize, inking, delayed recovery, or behavior changes. The results of this study may help guide additional studies in GPO anesthesia. Giant Pacific octopuses (Enteroctopus dofleini) (GPOs) are commonly housed in zoos or aquaria, and sedation, anesthesia, and/or euthanasia may be indicated for a variety of reasons. Despite this need, evidence-based data on best practices is limited and focuses on smaller or more tropical species. The objectives of this study were to survey the aquatic community regarding the husbandry and veterinary care of GPOs, with a specific focus on anesthetic and euthanasia protocols. A two-part web-based survey was distributed to four aquatic and/or veterinary email listservs. Individuals from fifty-two institutions participated in phase one. Results documented that 40 (78 percent) participating institutions currently house GPOs, with most housing one and nine institutions housing two to three GPOs. The median (range) habitat volume is 5405 (1893–16,465) L, and 78 percent of systems are closed. Of the institutions surveyed, 23 have anesthetized or sedated a GPO for nonterminal procedures, including wound care, biopsies, and hemolymph collection. Reported methods of sedation or anesthesia include magnesium chloride, ethanol, isoflurane, tricaine methanesulfonate (MS-222), magnesium sulfate, benzocaine, and dexmedetomidine. Drugs or methods used for euthanasia include magnesium chloride, ethanol, mechanical decerebration, pentobarbital, isoflurane, MS-222, magnesium sulfate, benzocaine, potassium chloride, dexmedetomidine, and freezing. Reported observed side effects include ineffectiveness or inadequate sedation, inking, prolonged drug effects, and behavior changes. Survey data have the potential to guide the husbandry and veterinary care of GPOs and build the framework for future prospective studies on GPO sedation and anesthesia. [ABSTRACT FROM AUTHOR]

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

Octopuses may demonstrate perceptual richness, neural unity, temporality, and finally, valence or affective evaluation, as the neural basis for consciousness. Octopuses attach a positive valence to food as ‘specializing generalists’ with long-term learning and flexible choices. They value shelter, yet modify, adapt and even transport it where necessary. They attach a negative valence to what may be described as pain, monitoring and protecting the damaged area and learning to associate locations with pain relief. Finally and surprisingly, octopuses attach a negative value to uncertainty so that they explore their environment before exploiting certain aspects of it and even exhibit motor play. This series of four papers, culminating in the present one, demonstrates in detail why the Cambridge Declaration of Consciousness has suggested octopuses might have the substrate for consciousness, although it is likely not similar to or as complex as that shown by ‘higher’ vertebrate lineages.

Despite the heterogeneity of the sophist Aelian's oeuvre, which ranges from fictional letter collections to anti-imperial polemics to explicitly miscellanistic works, comparatively little work has been done to contextualize Aelian within narratives of imperial miscellanism. This essay situates Aelian within this tradition by comparing his reflections on poikilia ("variety"), including his authorial paratexts to the Nature of Animals and metatextual discussions in the Historical Miscellany , with analogous discourses in Greek and (especially) Latin literature. Both cases demonstrate his attempt to chart a distinctive path for his miscellanistic enterprise, which he presents as an artistic endeavor mediating between Greece and Rome. [ABSTRACT FROM AUTHOR]

No ecotoxicological information exists on phenanthrene (Phe) exposure in cephalopods, animals of commercial and ecological importance. This study investigated the effect of Phe on two B-esterases, Acetylcholinesterase (AChE) and Carboxylesterases (CbE), in Octopus maya embryos. Octopus embryos were exposed to different treatments: control (seawater), solvent control (seawater and DMSO 0.01%), 10 and 100 µg/L of Phe. AChE and CbE activities were measured at different developmental stages (blastula, organogenesis, and growth). B-esterase activities increased in control and solvent control as the embryos developed, showing no statistically significant differences between them. On the other hand, the embryos exposed to Phe had significant differences from controls, and between the high and low concentrations. Our results indicate that B-esterases are sensitive biomarkers of exposure to Phe in O. maya. Still, complementary studies are needed to unravel the toxicodynamics of Phe and the implications of the found inhibitory effect in hatched organisms. [ABSTRACT FROM AUTHOR]

Flexible octopus arms exhibit an exceptional ability to coordinate large numbers of degrees of freedom and perform complex manipulation tasks. As a consequence, these systems continue to attract the attention of biologists and roboticists alike. In this article, we develop a three-dimensional model of a soft octopus arm, equipped with biomechanically realistic muscle actuation. Internal forces and couples exerted by all major muscle groups are considered. An energy-shaping control method is described to coordinate muscle activity so as to grasp and reach in three-dimensional space. Key contributions of this article are as follows: (i) modelling of major muscle groups to elicit three-dimensional movements; (ii) a mathematical formulation for muscle activations based on a stored energy function; and (iii) a computationally efficient procedure to design task-specific equilibrium configurations, obtained by solving an optimization problem in the Special Euclidean group SE(3). Muscle controls are then iteratively computed based on the co-state variable arising from the solution of the optimization problem. The approach is numerically demonstrated in the physically accurate software environment Elastica. Results of numerical experiments mimicking observed octopus behaviours are reported. [ABSTRACT FROM AUTHOR]