Octopus Dofleini Research Articles

Artificial intelligence models to predict optimal trade-off on construction management

PurposeThis research aims to introduce a novel algorithm, the Chaotic Giant Pacific Octopus Optimizer (CGPOO) and demonstrate framework includes four key aspects: time, cost, quality and safety trade-off (TCQST).Design/methodology/approachArtificial intelligence is causing a big disruption in the construction management. It is being used to building projects to enhance efficiency, safety and decision-making. This research compared the CGPOO method to those of other algorithms, such as the Chaotic Slime Mold Algorithm (CSMA), the Chaotic Salps Swarm Algorithm (CSSA) and the Chaotic Whale Optimization Algorithm (CWOA) and assessed the efficacy of the method using statistical analysis and evaluation indicators such as Hyper-volumn (HV), Spread (Sp), Computational Time (CT) and C-metric.FindingsThe analysis demonstrates that using CGPOO outperforms standalone methods chosen from the literature in terms of outcomes. It is discovered that the CGPOO solution possibilities for each factors are more efficient and beneficial than the comparison algorithms. Moreover, the CGPOO model performs better than the other algorithms with quality indices C-metric, Sp, HV and CT of 0.534, 0.531, 0.891 and 101.Originality/valueThe article presents a novel hybrid CGPOO that permits multi-factor trade-offs in construction management with the goal of surpassing the analyzed models and optimizing the optimal solution in the search space.

Novel statistical investigation on performance measures of WEDM: Optimization, microstructure and mechanical properties

A comparative performance analysis has been investigated on wire electrical discharge machining (WEDM) responses while machining a hybrid titanium matrix composite (TMC) varying the key input parameters like power (P), peak current (IP) and time-off (Toff). Two novel multi-objective optimization algorithms are developed namely desirable multi-objective genetic algorithm (DMOGA) and desirable multi-objective giant pacific octopus optimizer (DMOGPOO) for tackling various issues in many industries like automobile valve pins in crank and cam shafts, aerospace propeller and biomedical implants. The principal advantage of DMOGA to other algorithm is accuracy and robustness. The novelty fits in the iterative progression of growth of efficient grandee set, uttered as population congregating to a fitness function. Many techniques frequently encounter substandard solutions when evaluating MOO problems, as opposed to solving properly approximated functions of Pareto optimal solutions in targets. DMOGPOO is an enthralling statistical method which mimics the octopus’s predatory behavior, performs better than other multi-objective optimization (MOO) algorithms, where the desirable objective functions is fetched in python using MOGPOO. In a multi-objective foraging environment, the archive was utilized to imitate octopus predatory behavior and establish social hierarchies. DMOGPOO approach is designed with multi-objective formulations to preserve and guarantee enhanced coverage of optimum solutions across all goals. Experimental investigation is accepted on material removal rate (MRR), surface roughness (SR), kerf width (KW) and over cut (OC). Combined desirability in case of DMOGA is 0.716 which improved to 0.813 when DMOGPOO is proposed. MOO is improved with DMOGPOO of 13.547% when contrasted with DMOGA, with MRR of 3.81 mm3/min, SR of 0.79 µm, KW of 0.349 mm, OC of 0.099 mm, and combined desirability of 0.813. Improved optimality set is obtained when DMOGPOO is used. %improvement of MRR is 5.54%, SR is 75.95%, KW is 0.29%, and OC is 4.21%.

A novel giant pacific octopus optimizer for real-world engineering problem

A novel giant pacific octopus optimizer for real-world engineering problem

A retrospective study of pathologic findings in cephalopods (extant subclasses: Coleoidea and Nautiloidea) under laboratory and aquarium management.

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.

Characterization of Current Husbandry and Veterinary Care Practices of the Giant Pacific Octopus (Enteroctopus dofleini) Using an Online Survey.

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.

Predicting catch of Giant Pacific octopus Enteroctopus dofleini in the Tsugaru Strait using a machine learning approach

We attempted to forecast catches of giant Pacific octopus Enteroctopus dofleini using past catch data and the machine learning approach. The algorithms tested were the Seasonal Autoregressive Integrated Moving Average (SARIMA), Light Gradient Boosting Machine (LightGBM), a type of Gradient Boosting Decision Tree (GBDT), and the Recurrent Neural Network (RNN), the latter of which is represented by Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU). The catch of giant Pacific octopus on the southern coast of the Tsugaru Strait was backcasted for 2001–2019, using data of at least 20 years (1981–2018) for training. In this study, a longer training period led to better performance of SARIMA; the model trained from all past years performed better than models trained from the past 20 or 5 years. Moreover, for LightGBM, fishing-season accuracy of the basic L-GBM's was equal to that of L-GBM-T, which adds environmental factors to the explanatory variables. As a result of 19 backcasting trials, the SARIMA model obtained the best agreement with the actual catch data (R2 = 0.848) followed by L-GBM and LSTM (both R2 = 0.847), and GRU (R2 = 0.839). The root mean square error (RMSE) was within a narrow range for all four models (28.5, 28.0, 27.9, and 28.2 metric tons [t] for SARIMA, L-GBM, LSTM, and GRU, respectively). The SARIMA model was unstable when performance was assessed by the mean absolute percentage error (MAPE), which was standardized by average catch per year, whereas LSTM and GRU remained relatively stable. However, the latter two models were difficult to interpret due to their black box-like structures. By contrast, the SARIMA model was advantageous for interpreting the results. LightGBM showed good predictive performance for time-series data, despite being a static model. Thus, each model has advantages and disadvantages, so it is necessary to choose the best model depending on the purpose.

The odd octopus: identification and burrowing behaviour of a deep-water octopus, Muusoctopus leioderma, found in a shallow-water bay

Abstract Cephalopod populations have expanded over recent decades, both numerically and geographically. These expansions are particularly noteworthy because cephalopods are a taxon of quickly reproducing, high-metabolic rate predators that can have disproportionate impacts on naïve ecosystems. We report a new occurrence of an octopus species in 11.6 m of water in Burrows Bay, Washington, USA (coastal northeast Pacific Ocean). These newly identified individuals have several characteristics that clearly differentiate them from either of the two known octopus species that occur in shallow water within the area: Octopus rubescens and Enteroctopus dofleini. Instead, specimens superficially resemble Muusoctopus leioderma, a species which is found in the geographic area, but has never been reported at depths less than 70 m. Octopuses were collected for morphological and genetic comparison to known octopus species, focusing on other nominal Muusoctopus species. Genetic comparisons were conducted using three mitochondrial loci (12S ribosomal RNA, cytochrome oxidase subunit III, and cytochrome b) sequenced for the octopus along with two M. leioderma museum specimens, including the species' neotype. Observation of octopus behaviour revealed a unique burrowing behaviour. Morphology of the octopus found in Burrows Bay largely coincides with M. leioderma, with a few notable differences. Phylogenetic analysis revealed that Burrows Bay octopus forms a monophyletic clade with the M. leioderma neotype, but also suggested that M. leioderma is more closely related to Octopus californicus than to the other members of the genus Muusoctopus. These octopuses are thus attributed to M. leioderma but the generic placement of the species should be reviewed.

Catch status of the giant pacific octopus, Enterocotpus dofleini, by drift line fishery in the central coast of the East Sea, Korea

Catch status of the giant pacific octopus, Enterocotpus dofleini, by drift line fishery in the central coast of the East Sea, Korea

Histologic lesions of cestodiasis in octopuses.

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.

An e xperimental study on the application of escape device in a net pot for protecting of small giant octopus (<i>Octopus dofleini</i>)

An e xperimental study on the application of escape device in a net pot for protecting of small giant octopus (<i>Octopus dofleini</i>)

Behavioral changes in senescent giant Pacific octopus (Enteroctopus dofleini) are associated with peripheral neural degeneration and loss of epithelial tissue

Most species of octopus experience extreme physical decline after a single reproductive bout which extends over a period of days, weeks, or months before eventual death. Although outward indicators of senescence are widely recognized, comparatively little is known about physiological and neural changes accompanying terminal decline in octopuses. Here, we measured changes in behavioral response to nociceptive stimuli across the lifespan in giant Pacific octopus (GPO), Enteroctopus dofleini, held in public aquariums in the USA. Post-euthanasia, tissue was collected from arm tips, and neural and epithelial cell degeneration was quantified and compared with biopsies of arm tips from healthy, pre-reproductive GPOs. Behavioral assays showed significant changes both in low threshold mechanosensory responses and nociceptive behavioral responses beginning early in senescence and extending until euthanasia. Histology data showed that while the ratio of apoptotic cells to total cell number stayed constant between healthy and senescent GPOs, overall neural and epithelial cell density was significantly lower in terminally senescent octopuses compared with healthy controls. Our data provide new insight into the time-course and causes of sensory dysfunction in senescent cephalopods and suggest proactive welfare management should begin early in the senescence phase, well before animals enter terminal decline.

Performing encounters (and encountering performance) at Auckland Zoo

Performing encounters (and encountering performance) at Auckland Zoo

Biomonitoring of Pu isotopes in liver of North Pacific giant octopus (Enteroctopus dofleini) collected off the Rokkasho Nuclear Fuel Reprocessing Plant, western North Pacific margin

Concentrations of 239+240Pu and 240Pu/239Pu atom ratios were determined in liver samples of North Pacific giant octopus (Enteroctopus dofleini) collected off the Rokkasho Nuclear Fuel Reprocessing Plant (RNFRP) to understand the bioaccumulation of Pu in the octopus liver, to provide Pu data before full commercial operation of the reprocessing plant, and to identify the sources of Pu isotopes in the studied liver samples. Mean 239+240Pu concentration was 6.3 ± 3.1 mBq/kg-wet, which was within the previously reported concentration ranges in liver of the Japanese common squid and in hepatopancreas of red queen and snow crabs. The 240Pu/239Pu atom ratios ranged from 0.223 to 0.252 with a mean ratio of 0.234 ± 0.009, which was noticeably greater than the mean global fallout ratio of ~0.18. These ratios reflected a mixture of global fallout Pu from atmospheric nuclear weapons testing and close-in fallout Pu from the Pacific Proving Grounds (PPG). The relative percentage of the PPG close-in fallout Pu to global fallout was calculated to be 39.6 ± 6.7%. The liver of the NPG octopus is an excellent bioindicator for biomonitoring of Pu pollution. Data on 239+240Pu concentrations and 240Pu/239Pu atom ratios in liver of the NPG octopus collected in the vicinity of the RNFRP will provide powerful keys for continuous biomonitoring of Pu pollution and for distinguishing the potential sources of Pu after the plant begins full commercial operation.

Development of a multiplex PCR assay for the simultaneous detection of big blue octopus (Octopus cyanea), giant Pacific octopus (Enteroctopus dofleini), and common octopus (Octopus vulgaris).

Since octopuses are similar in appearance and can be processed into various forms, seafood fraud has been reported. In this study, we developed the PCR assay to simultaneously detect three octopuses (big blue octopus, giant Pacific octopus, and common octopus). Specific primer sets were designed based on COI gene. We observed that the specific PCR amplicon sizes were 84bp for big blue octopus, 117bp for giant Pacific octopus, and 166bp for common octopus, respectively. This assay was then used to test for specificity and did not show cross-reactivity with 15 cephalopods families. The limit of detection of the multiplex PCR assay was 0.1pg. Subsequently, 30 commercial food products were then monitored to evaluate the applicability of this assay. All products were specifically amplified, and three octopus species of interest were distinguished. Therefore, this assay can be used as an octopus authentication tool in the seafood industry.

Marine conservation tourism and the Giant Pacific Octopus: A SWOT analysis of two public engagement programs and the viability of a hybrid program at the Seattle Aquarium, Washington, USA

Marine conservation requires financial and human capital to effectively function. Tourism activities can provide both, if done responsibly. Marine conservation tourism (MCT) concerns tourist activities involving the engagement with—and the study, protection, and restoration of—marine wildlife and their ecosystems. There are two models that are commonly used: commercial and non-commercial. However, a combined hybrid MCT model may be more effective. To evaluate this potential, SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis was conducted on two representative programs at the Seattle Aquarium dedicated to the conservation of the iconic Giant Pacific Octopus (GPO). Octopus Survey Week is a non-commercial, research-focused program utilizing voluntary assistance of local divers. Octopus Week is a commercial program in which conservation goals are facilitated by visitor fees and donations from aquarium supporters. The study utilized a mixed-methods approach. Data collection (N=86) involved semi-structured interviews and focus groups. SWOT analysis was enhanced with (1) MECE (Mutually Exclusive and Collectively Exhaustive) framework to identify prominent factors or themes, and (2) TOWS (Threats, Opportunities, Weaknesses, and Strengths) analysis to suggest strategies relevant to the SWOT findings. Results show Octopus Survey Week program is viable but not well known. The Octopus Week program is also viable; there is an opportunity here for improvement. Importantly, interviewees would prefer a hybrid program. However, even a hybrid program would face logistical and temporal issues. To increase public interest and participation, it is recommended that the Seattle Aquarium connect them in a more proactive manner. Looking ahead, we hope the field of marine conservation tourism will expand as researchers develop new methods to improve conservation efforts.

Food Web Trophic Structure at Marine Ranch Sites off the East Coast of Korea

Understanding the trophic ecology of the giant Pacific octopus Enteroctopus dofleini is challenging in developing marine ranches and in reestablishing its regional stocks against the severe stress of fishing. We adopted carbon and nitrogen stable isotope techniques (termed δ13C and δ15N, respectively) to identify the trophic niche (i.e., pathways and positions) of this species systematically in the entire food webs of two marine ranches off the east coast of the Korean peninsula. While a slight spatial shift in the isotopic nestedness of faunal communities was observed, the δ13C and δ15N values of consumers were distinct and separate among functional groups at both ranches. The consumer δ13C values spanned a broad range between pelagic and benthic sources of organic matter, and their δ15N values recorded a stepwise trophic-level enrichment, indicating that suspension feeders and herbivore-deposit feeders served as baselines of pelagic- and benthic-based trophic pathways, respectively. The δ13C values of predators, including E. dofleini, were arrayed between the two primary consumer groups. Neither δ13C nor δ15N values showed any remarkable variations with increasing octopus weight. Dietary mixing-model calculations indicated that E. dofleini is a generalist predator relying on both benthic- and pelagic-affinity prey, similar to some teleost species that consume a diverse spectrum of prey. In contrast, other teleost groups showed prevalent trophic links with either pelagic- or benthic-based pathways. The trophic-level estimations revealed that E. dofleini occupies an intermediate position slightly below the teleosts. A lack of discrete trophic positions between E. dofleini and teleosts seemed to be indicative of the released teleost predation but instead reflects the imposed food competition. Overall, the results demonstrated that despite compositional changes in the taxa constituting individual trophic groups, E. dofleini occupied a very similar trophic niche in both ranching systems. Finally, as extracted from information based on octopus marine ranches launched on natural rocky bottoms, our isotopic evidence provides a greater understanding of the trophic ecology of this octopus species in nearshore natural habitats along the southwestern margin of its distribution range.

Constructing captive ecology at the aquarium: Hierarchy, care, violence, and the limits of control

In a time of accelerating ecological crises, captive care performed by zoos and aquariums increasingly plays a central and controversial role in attempts to resuscitate species and ecosystems rapidly disappearing from the planet. Here I use the Giant Pacific octopus ( Enteroctopus dofleini) exhibit at the Vancouver Aquarium to examine practices involved in capture and captive care at a prominent Canadian institution. As I trace how octopuses come to the Aquarium and how people work to keep them alive and healthy in this environment, I examine the complex ways violence and domination interact with care practices. Centering octopuses and their material relations in this analysis thus allows me to connect everyday care practices to systems of governance and extraction that support captive ecologies and also generate the categories used in care. Through this investigation, I find that pastoral power organizes care practices at the Vancouver Aquarium and maintains anthropocentric order in this space. Slow violence here results from the imperfect replacement of lifegiving relations, and the nature of this harm is shaped by different beings’ relationships to anthropocentric order. Hierarchical categorizations structure care practices here, and when care directed at keeping animals healthy fails, slow violence often becomes acute. Elusiveness best characterizes how octopuses confound attempts to know and care for them within this anthropocentric power structure. The theoretical lens and language I offer seeks to describe moments of rupture in anthropocentric power without romanticizing animal endangerment as liberation or (conversely) accepting the logic that harm in captivity can only diminish if care improves. Through this work, I showcase both the violence and possibilities embedded in different ways of living and relating with ecological others amidst crisis.

標識放流による北海道オホーツク海沿岸における未成熟ミズダコの移動，成長，経験水温および漁場水温の季節変化

標識放流による北海道オホーツク海沿岸における未成熟ミズダコの移動，成長，経験水温および漁場水温の季節変化

Ocular anatomy and correlation with histopathologic findings in two common octopuses (Octopus vulgaris) and one giant Pacific octopus (Enteroctopus dofleini) diagnosed with inflammatory phakitis and retinitis.

Review octopus ocular anatomy and describe the histopathologic findings in three octopuses diagnosed with phakitis and retinitis. Two common octopuses (Octopus vulgaris) and one giant Pacific octopus (Enteroctopus dofleini) with a history of ophthalmic disease. 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. 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. 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.

Sea-surface temperatures predict targeted visual surveys of octopus abundance

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.