Giant Squid Research Articles

Quantum mechanics, universal scaling, and ferroelectric hysteresis regimes in the giant squid axon propagating action potential: a phase space approach

Experimental data for giant squid axon propagating action potential is examined in phase space and it is parsed into three distinct parts: properties of individual sodium and potassium channels, morphing of sodium channels and two narrow regions pertaining to ferroelectric polarization flips of sodium channels lattice. Plots of ionic currents vs. potential exhibit quasilinear segments yielding temperature dependent maximum conductance constants and the related time rates. Plotting ionic time rates as Boltzmann kinetic rates yields activation energies similar to activation energies of 0.6 eV for rate-limiting bio-chemical metabolic reactions.

The Essential Guide to the Loch Ness Monster and Other Aquatic Cryptids by Ken Gerhard

This is a readable overview of reports of unidentified aquatic creatures in the oceans and in freshwater, and it can be a useful introduction for people who have not previously read much about this subject. Cryptozoologists, however, will find nothing new here; the treatment is purely descriptive rather than analytical and critical. A nice Foreword by Steve Feltham, in residence at Loch Ness for 30 years looking for Nessies, includes the important point that the number of actual sightings is a large multiple of the number of publicly known reports. The first two chapters are about the Loch Ness Monster. Chapter 3 deals with sea serpents. Chapters 4 through 6 are about the Canadian “Ogopogo” of Lake Okanogan, the American “Champ” of Lake Champlain, and less-well-known lake monsters of North America. Chapter 7 reports on lake monsters around the world. Chapter 8 surveys the typically mysterious carcasses periodically found on seashores. Chapter 9 mentions the surprises that the ocean depths occasionally reveal, notably the coelacanth, the giant squid, and the megamouth shark, as well as the little-known beaked whales, oarfish, and sturgeon of monstrous size.

A Morphological Peak-Detector for Single-Unit Neural Recording Acquisition Systems

The increasing demand for measurement systems in neuroscience with the ability to acquire signals at neuron-level resolution has led to the development of techniques based on innovative organic biosensors. These single-unit extracellular neural recording systems provide useful information on neural behavior in terms of the action potential (AP) firing mechanism. In this work, we propose a processing technique specifically designed to accurately and reliably extract single-cell APs generated by free and attached membranes from signals acquired by extracellular recording devices. The simultaneous presence of overlapped APs, due to the nonideal coupling between cell and surface device, involves a distortion of the signal acquired by the device. Such distortion makes APs detection challenging. The proposed approach consists of a morphological peak detector characterized by high selectivity and based on three stages: a denoising phase for reducing wideband noise performed by the empirical mode decomposition (EMD) technique, and a threshold-based classifier for the identification of all the possible peaks that could correspond to an AP and a morphological classifier based on the support vector machine technique that improves the performances of the whole peak detection algorithm increasing its selectivity. The proposed method was designed on simulated data obtained by taking cell-to-cell variability into account in order to adapt the proposed method to the heterogeneity of the biological reality rather than the average behavior of the cells. This point is crucial to design an approach suitable for applications <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vivo</i> . Finally, the morphological classifier was tested on simulated and semisimulated data obtained from experimental acquisitions measured from the axons of a giant squid in response to current stimulation, achieving F1-score > 89% for both scenarios.

Cadmium Removal from Giant Squid (Dosidicus gigas) Hydrolysate in Fixed-Bed Columns Packed with Iminodiacetic Resin: Tools for Scaling up the Process.

Giant squid hydrolysate (GSH) elaborated from different batches from a fishing company was evaluated for cadmium removal. Fixed-bed column packed with iminodiacetic resin as adsorbent was used. GSH solution at different cadmium concentrations were fed in the fixed-bed column and breakthrough curves were evaluated. A high degree of metal removal from the solution was achieved and the saturation point (Ce/C0 ≤ 0.8) was achieved more quickly at higher concentrations of cadmium. The maximum capacity of adsorption (q0) was obtained using the Thomas model, where 1137.4, 860.4, 557.4, and 203.1 mg g−1 were achieved using GSH with concentrations of 48.37, 20.97, 12.13, and 3.26 mg L−1, respectively. Five cycles of desorption of the resin with HCl (1 M) backflow and regeneration with NaOH (0.5 M) were also evaluated, where no significant differences (p-value > 0.05) were observed between each cycle, with an average of 935.9 mg g−1 of qmax. The in-series columns evaluated reached a total efficiency of 90% on average after the third column in GSH with a cadmium concentration of 20.97 mg L−1. This kind of configuration should be considered the best alternative for cadmium removal from GSH. Additionally, the chemical composition of GSH, which was considered a quality parameter, was not affected by cadmium adsorption.

Climate Games, the Blue Humanities, and Listening to the Deep-Sea Ecosystems in Games in a Time of Ecological Crisis

ABSTRACTAbzû, released in 2016 by Giant Squid Studios, is an underwater adventure exploration game where the player plays as an unspeaking protagonist, known as the Diver, who communicates only through sonic “pings” as they navigate the unexplored depths of the ocean. In this discussion of the aquatic ecosystem modeling and sound design of Abzû and its relationship to narrative and game mechanics, the author applies approaches from the blue humanities and Stefan Helmreich’s concept of the “alien ocean,” a term he reclaims from the marine biologists who used it to describe the “strangeness” of the creatures they were investigating, to address how players interact with and come to understand in-game deep-sea soundscapes that are beyond human perception and experienced by playing as an AI exploration entity. The article considers how inequities in power and agency are translated into constructions of knowledge and the epistemological framing and scoring the nonhuman “other” (and what that communicates about being human) in environmental art that explores environments uninhabited by human life. In Abzû, the author looks at what the framework of the blue humanities and blue media can shape the discussion of ecological game sound design.

Vulnerability to Climate Change of “Giant Squid” (Thysanoteuthis rhombus) Fishery in Marinduque, Philippines

The Philippine fisheries sector has been affected by the impacts of climate change. Vulnerability to climate change pertains to a natural system's ability to cope with the negative impacts of climate change, variability, and extremes. Vulnerability Assessment (VA) provides a framework for climate change impacts evaluation over a broad range of systems. Tools such as Fisheries Vulnerability Assessment Tool (Fish Vool) have been developed to do VA. The "giant squid" diamondback (Thysanoteuthis rhombus) fishery in the province of Marinduque is an essential source of food and livelihood in the area. However, its vulnerability to climate change impacts has not been assessed. In this study, the "giant squid" fishery in Gasan, Marinduque, was assessed using Fish Vool. Results revealed that overall climate change vulnerability of the fishery is high, where both sensitivity and adaptive capacity are medium while exposure is high. Overall, the study provided a better understanding of the "giant squid" fishery vis-à-vis climate change and provided information for future fisheries management and conservation in the province.

A Collagen Basketweave from the Giant Squid Mantle as a Robust Scaffold for Tissue Engineering.

The growing applications of tissue engineering technologies warrant the search and development of biocompatible materials with an appropriate strength and elastic moduli. Here, we have extensively studied a collagenous membrane (GSCM) separated from the mantle of the Giant squid Dosidicus Gigas in order to test its potential applicability in regenerative medicine. To establish the composition and structure of the studied material, we analyzed the GSCM by a variety of techniques, including amino acid analysis, SDS-PAGE, and FTIR. It has been shown that collagen is a main component of the GSCM. The morphology study by different microscopic techniques from nano- to microscale revealed a peculiar packing of collagen fibers forming laminae oriented at 60–90 degrees in respect to each other, which, in turn, formed layers with the thickness of several microns (a basketweave motif). The macro- and micromechanical studies showed high values of the Young’s modulus and tensile strength. No significant cytotoxicity of the studied material was found by the cytotoxicity assay. Thus, the GSCM consists of a reinforced collagen network, has high mechanical characteristics, and is non-toxic, which makes it a good candidate for the creation of a scaffold material for tissue engineering.

Megalodon

Megalodon

The role of glycerol on the thermal gelation of myofibrillar protein from giant squid (Dosidicus gigas) mince

This work studies the effect of glycerol on the chemical physics of the thermal gelatin of protein from giant squid minced meat. The presence of glycerol induced changes in the nano protein particles (NPP) self-assembled structures. These nanoscale events resulted in dramatic changes on the interactions between proteins when forming gels, with the contribution of ionic interactions increasing by 17% upon gelation, that of hydrogen bonds reducing by 50%, that of hydrophobic interactions decreasing by 45%, and that of disulphide bonding increasing by 18%. Glycerol also induced cluster formation in myofibrillar solutions. As a result, incorporation of glycerol increased springiness, resilience, and adhesiveness of the formed gels by 13%, 25%, and 370% respectively. The heating gelation of myofibrillar proteins was monitored at various temperatures via recording the elastic and storage moduli. Rheology and micro-rheology studies revealed that the presence of glycerol increased G′ and G″ of thermally-gelled giant squid meat.

Revisiting the memristor concept within basic circuit theory

SummaryIn this paper, we revisit the memristor concept within circuit theory. We start from the definition of the basic circuit elements; then, we introduce the original formulation of the memristor concept and summarize some of the controversies on its nature. We also point out the ambiguities resulting from a nonrigorous usage of the flux linkage concept. After concluding that the memristor is not a fourth basic circuit element, prompted by claims in the memristor literature, we look into the application of the memristor concept to electrophysiology, realizing that an approach suitable to explain the observed inductive behavior of the giant squid axon had already been developed in the 1960s, with the introduction of “time‐variant resistors.' We also discuss a recent memristor implementation in which the magnetic flux plays a direct role, concluding that it cannot strictly qualify as a memristor, because its v‐i curve cannot exactly pinch at the origin. Finally, we present numerical simulations of a few memristors and memristive systems, focusing on the behavior in the φ‐q plane. We show that, contrary to what happens for the most basic memristor concept, for general memristive systems, the φ‐q curve is not single‐valued or not even closed.

Implementation of Hodgkin-Huxley Neuron Model With the Novel Memristive Oscillator

In this brief, in order to simplify the implementation of the classical Hodgkin-Huxley neuron (HH) model, a novel floating memristor emulator is introduced, which consists of four electronic components and can be considered the simplest implementation in the existing literature. Firstly, the schematic diagrams of the proposed novel HH neuron-based memristive oscillator is presented, and the working mechanism and the bursting phenomenon of which are analyzed. Then, the simulation model of the proposed memristive oscillator emulator is developed in MULTISIM using several off-the-shelf components, which is used to implement a HH neuron model. Moreover, the electrical characteristics of it are examined. In particular, the relationship between the ion channels concentration and the variable voltages of the neuron model is described in detail. Simulation results confirm that the proposed model demonstrates rich bursting oscillation behaviors which is more suitable for simulating the giant squid axon compared to the existing model in the literature, which can be utilized to transmit the neuron information and establish the neural network.

The Obligatory Underwater Level: Posthuman Genealogy of Amphibian Human in Media

Will humankind ever be able to live underwater? To answer this question from the perspective of visual media studies, I analyze narrative and expressive means used for positive representation of underwater experiences in several examples of screen media. My examples are principally different by origin and yet united by their highly enjoyable effect of immersion into underwater worlds. My primary focus is on Amphibian Man (1928), a cult early science fiction novel by Alexandr Belyaev adapted for screen in 1962 in the USSR.I also explore its unintentionally close contemporary reproduction in The Shape of Water (2016), which even led to accusations in plagiarism. The third example is a contemporary independent video game ABZU by Giant Squid (2016), which replays the same theme of amphibian human existence in a positive light. These cases present a surprisingly rare view of a safe, friendly and interactive marine world, approached by the protagonist who can breathe underwater. I apply the posthumanist lens to find out that, surprisingly, aquatic cyborgs seem to be underrated by the queer thought (Haraway, 2015, 2016); I conclude that the model of ‘queer ecologies’ may become the needed development.

All the spermatangia on a female were implanted by single-pair copulation in giant squid Architeuthis dux

Deep-ocean biology has been the least explored—although rapidly growing—area of research. In particular, behavior, reproduction and ecology of deeper-living squids remain poorly documented due to the extreme difficulties of encountering and capturing them. Here we report on a mature/maturing female giant squid, Architeuthis dux, caught as by-catch in a fishery set-net. Microsatellite paternity analysis was carried out on the implanted spermatangia scattered widely over the body surface. Using genomic DNA from 42 Architeuthis individual muscle tissue specimens, four polymorphic microsatellite markers were developed, of which three were used for genotyping. Surprisingly, it was found that all 66 of the successfully genotyped spermatangia located on five different body parts were derived from a single male, suggesting that only single-pair copulation can lead to entire sperm loading. From this result and previous findings, the possibilities of the reproductive mode of this species are explored in the light of postcopulatory sexual selection mechanisms.

Logger Attaching System for Sperm Whales Using a Drone

The biologging approach of attaching a logger to the body of an animal provides information that cannot be obtained by conventional direct visual observation. Marine zoologists have used this technique for observing sperm whales preying on giant squids in the deep sea. However, it is almost impossible to capture a sperm whale to attach a logger, because of its large size. Therefore, researchers have used a long pole to attach a logger from a ship to the back of sperm whales. Unfortunately, this method is risky and requires a skilled team. In this paper, we propose a logger attaching system using a drone to solve this problem. The proposed method can be trained on land; thus, it is relatively easy to train a team, and the mobility of the drone can shorten the installation time. Several pieces of equipment developed for the proposed method are described in detail. Furthermore, field experiments were performed with sperm whales to confirm the feasibility of the system. A suction cup of the seventh prototype of the whale rover was adsorbed onto the back of a sperm whale. Although a complete installation was not possible, it was demonstrated that operation was possible in a short time using the proposed method.

Studying the swift, smart, and shy: Unobtrusive camera-platforms for observing large deep-sea squid

The legend of the “kraken” has captivated humans for millennia, yet our knowledge of the large deep-sea cephalopods that inspired this myth remains limited. Conventional methods for exploring the deep sea, including the use of nets, manned submersibles, and remotely operated vehicles (ROVs), are primarily suited for studying slow-moving or sessile organisms, and baited camera-traps tend to attract scavengers rather than predators. To address these issues, unobtrusive deep-sea camera platforms were developed that used low-light cameras, red illuminators, and bioluminescence-mimicking lures. Here, we report on several opportunistic deployments of these devices in the Wider Caribbean Region where we recorded several encounters with large deep-sea squids, including the giant squid Architeuthis dux Steenstrup 1857, Pholidoteuthis adami Voss 1956, and two large squid that may be Promachoteuthis sp. (possibly P. sloani Young et al. 2006). These species were recorded between depths of 557 and 950 m. We estimate the Mantle Lengths (ML) of Promachoteuthis were ~1.0 m, the ML of the Pholidoteuthis was ~0.5 m, and the ML of the Archtiteuthis was ~1.7 m. These encounters suggest that unobtrusive camera platforms with luminescent lures are effective tools for attracting and studying large deep-sea squids.

Utilization of Marine Waste to Obtain β-Chitin Nanofibers and Films from Giant Humboldt Squid Dosidicus gigas.

β-chitin was isolated from marine waste, giant Humboldt squid Dosidicus gigas, and further converted to nanofibers by use of a collider machine under acidic conditions (pH 3). The FTIR, TGA, and NMR analysis confirmed the efficient extraction of β-chitin. The SEM, TEM, and XRD characterization results verified that β-chitin crystalline structure were maintained after mechanical treatment. The mean particle size of β-chitin nanofibers was in the range between 10 and 15 nm, according to the TEM analysis. In addition, the β-chitin nanofibers were converted into films by the simple solvent-casting and drying process at 60 °C. The obtained films had high lightness, which was evidenced by the CIELAB color test. Moreover, the films showed the medium swelling degree (250–290%) in aqueous solutions of different pH and good mechanical resistance in the range between 4 and 17 MPa, depending on film thickness. The results obtained in this work show that marine waste can be efficiently converted to biomaterial by use of mild extractive conditions and simple mechanical treatment, offering great potential for the future development of sustainable multifunctional materials for various industrial applications such as food packaging, agriculture, and/or wound dressing.

A novel chondroitin sulfate E from Dosidicus gigas cartilage and its antitumor metastatic activity

Chondroitin sulfate (CS) chains containing GlcUAβ1-3GalNAc(4S,6S) (E unit) have been shown to be involved in various physiological and pathological processes. However, commercial E unit-rich CS (CS-E) is difficult to produce on a large scale due to expensive and limited squid cartilage resources. In this study, a novel CS-E (CS-nE) was isolated from the cheap and abundant cartilage of the giant squid Dosidicus gigas. The CS-nE has a surprisingly large molecular mass of 696 kDa and a relatively high E unit proportion (44.5 %). It can interact with various growth factors, including HGF, bFGF, pleiotrophin, and HB-EGF, with high affinity, and exhibits dose-dependent anti-metastatic activity. Furthermore, the E unit-rich decasaccharide selectively prepared from CS-nE has been shown to be the minimal functional domain with the strongest antitumor metastatic activity. Taken together, CS-nE will be a very promising candidate for the development of CS-E-based pharmaceutical products.

Mineral composition of raw and marinated-cooked arms from Pacific giant squid (Dosidicus gigas).

Background/aim: Shellfish consumption is often perceived as a potential health hazard due to the accumulation of toxic metals. The mineral content was investigated in marinated-cooked giant squid (Dosidicus gigas) arms from three Eastern Pacific fisheries (Peru, Chile and Benthic) to elucidate their contribution to daily recommended intakes and possible presence of pollutants. Material and methods: Thirty macro- and microminerals were analysed in the raw material, marination solution, cooking broth and cooked product. Results: Both raw and marinated-cooked squid arms contained nutritionally relevant quantities of essential macro- (Na and Mg) and microminerals (Cr, Zn, Mn and Se). Fishery origin led to minor variations in the mineral composition of raw arms, while marinated-cooked arms of Benthic origin had a higher retention of Na and juice likely due to their greater size. Levels of Pb, Hg, Zn or As found in the ready-to-eat product were below tolerable upper intake levels. Conclusion: The mineral content found in the raw squid arms suggests that the Pacific fisheries concerned are not affected by human polluting activities. Marinated-cooked squid arms cover a part of the dietary requirements for minerals and can be consumed without apparent negative nutritional implications.

Non-indigenous cephalopods in the Mediterranean Sea

The present review critically assesses the records of cephalopods that have entered the Mediterranean Sea in the last few decades. It includes 13 species, namely Sepia dollfusi, Stoloteuthis leucoptera, Sepioteuthis lessoniana, Architeuthis dux, Cranchia scabra, Taonius pavo, Megalocranchia sp., Teuthowenia megalops, Cycloteuthis sirventi, Taningia danae, Octopus cyanea, Amphioctopus sp. and Tremoctopus gracilis. The presence of Sepia pharaonis needs to be confirmed, whereas that of Sepia gibba and Spirula spirula is excluded. The arrivals from the Atlantic Ocean through the Strait of Gibraltar are related to the entrance surface current, which either carried passively planktonic paralarvae or favoured in some other way the entrance of subadult and adult stray specimens. As a matter of fact, all Atlantic cephalopods are pelagic oegopsid squids, with the exception of the nekto-benthic sepiolid S. leucoptera; all of them have been found only in the western Mediterranean basin. None of them seemingly established a stable population there, apart from the latter species. On the contrary, the cephalopods entering the Mediterranean from the Red Sea through the Suez Canal (Lessepsian migrants) lead a benthic mode of life. At least two of them, namely S. lessoniana and Amphioctopus sp., set up stable populations in the eastern basin. Lastly the occurrences of the pelagic octopod T. gracilis are ascribed, in the literature, to human-mediated transfer.

Effect of the application of ultrasound on sarcoplasmic proteins from giant squid (Dosidicus gigas) mantle

This research studies the application of ultrasound (US) on sarcoplasmic proteins from giant squid (Dosidicus gigas) mantle and its effect on its functional properties. US was applied during 30, 60 and 90 s. A decrease was observed in the emulsifying activity index (EAI), an increase in the emulsifying stability index (ESI), an increase in the foaming capacity (FC) and a decrease in the foaming stability (FS). In addition, the application of US increased the surface hydrophobicity (So) and decreased the viscosity with the increase in temperature. Functional properties of sarcoplasmic giant squid mantle proteins increase with the application of ultrasound.