Search Results (122)

Animal protein production represents a complex system of lives transformed into nutrition, with profound ethical and environmental implications. This study provides a quantitative analysis of animal lives required to produce human-consumable protein across major food production systems. Categorizing animal lives based on cognitive complexity and accounting for all lives involved in production, including direct harvests, reproductive animals, and feed species, reveals dramatic variations in protein efficiency. The analysis considers two categories of animal life: complex-cognitive lives (e.g., mammals, birds, cephalopods) and pain-capable lives (e.g., fish, crustaceans). Calculating protein yield per life demonstrates efficiency differences spanning more than five orders of magnitude, from 2 g per complex-cognitive life for baby octopus to 390,000 g per life for bovine dairy systems. Key findings expose disparities between terrestrial and marine protein production. Terrestrial systems involving mammals and birds show higher protein yields and exclusively involve complex-cognitive lives, while marine systems rely predominantly on pain-capable lives across complex food chains. Dairy production emerges as the most efficient system. Aquaculture systems reveal complex dynamics, with farmed carnivorous fish requiring hundreds of feed fish lives to produce protein, compared to omnivorous species that demonstrate improved efficiency. Beyond quantitative analysis, this research provides a framework for understanding the ethical and ecological dimensions of protein production, offering insights for potential systemic innovations. Full article

Central pattern generators (CPGs) have been extensively researched and validated as a well-established methodology for bionic control, particularly within the field of legged robotics. However, investigations concerning octopod robots remain relatively sparse. This study presents the design of an octopod robotic system inspired by the biological characteristics of lobsters. The machine lobster utilizes remote sensing technology to execute designated tasks in subterranean and mining environments, with its motion regulated by CPGs, accompanied by a comprehensive simulation analysis. The research commenced with the modeling of a biomimetic lobster robot, which features a three-degree-of-freedom leg structure and torso, interconnected by shape memory alloys (SMAs) that serve as muscle actuators. Mathematically, both forward and inverse kinematics were formulated for the robot’s legs, and a 24-degree-of-freedom (DOF) gait pattern was designed and validated through MATLAB 2020a simulations. Subsequently, a multi-layer mesh CPG neural network model was developed utilizing the Kuramoto model, which incorporated frustration effects as the rhythm generator. The control model was constructed and evaluated in Simulink, while dynamic simulations were conducted using Adams 2022 software. The findings demonstrate the feasibility, robustness, and efficiency of the proposed CPG network in facilitating the forward locomotion of the lobster robot, thereby broadening the range of control methodologies applicable to octopod biomimetic robots. Full article

This study focuses on the problem of identifying and extracting the magnetopause boundary of the Earth’s magnetosphere using the Soft X-ray Imager (SXI) onboard the Solar Wind Magnetosphere Ionosphere Link Explorer (SMILE) mission. The SXI employs lobster-eye optics to perform panoramic imaging of the magnetosphere based on the Solar Wind Charge Exchange (SWCX) mechanism. However, several factors are expected to hinder future in-orbit observations, including the intrinsically low signal-to-noise ratio (SNR) of soft-X-ray emission, pronounced vignetting, and the non-uniform effective-area distribution of lobster-eye optics. These limitations could severely constrain the accurate interpretation of magnetospheric structures—especially the magnetopause boundary. To address these challenges, a boundary detection approach is developed that combines image calibration with denoising based on deep image prior (DIP). The method begins with calibration procedures to correct for vignetting and effective area variations in the SXI images, thereby restoring the accurate brightness distribution and improving spatial uniformity. Subsequently, a DIP-based denoising technique is introduced, which leverages the structural prior inherent in convolutional neural networks to suppress high-frequency noise without pretraining. This enhances the continuity and recognizability of boundary structures within the image. Experiments use ideal magnetospheric images generated from magnetohydrodynamic (MHD) simulations as reference data. The results demonstrate that the proposed method significantly improves the accuracy of magnetopause boundary identification under medium and high solar wind number density conditions (N = 10–20 cm⁻³). The extracted boundary curves consistently achieve a normalized mean squared error (NMSE) below 0.05 compared to the reference models. Additionally, the DIP-processed images show notable improvements in peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM), indicating enhanced image quality and structural fidelity. This method provides adequate technical support for the precise extraction of magnetopause boundary structures in soft X-ray observations and holds substantial scientific and practical value. Full article

The lobster fishery is the third largest industry in Prince Edward Island (PEI), Atlantic Canada. Rising water temperatures due to global warming are impacting the successful completion of the lobster life cycle, which is heavily dependent on water temperature. This study investigated the relationship between lobster landings and sea surface temperature (SST) in PEI. Using Generalized Linear Models (GLM), we identified a significant correlation between annual historical lobster landings and monthly sea surface temperatures (SST) in the waters around PEI from 1990 to 2021. Considering the 5–8 year maturation period of lobsters, we applied a lagged SST structure over an 8-year period and used a Generalized Linear Model (GLM) to evaluate the relationship between historical SST and lobster landings. Our findings suggest that historical increases in SST are correlated with changes in lobster landings. Given the known sensitivities of lobster life cycles (i.e., spawning, larval development) and behavior (i.e., mating) to high ambient water temperature, our study also offers important insights for future fishery management under anticipated climate change scenarios. Full article

Sesquiterpenoid hormones such as the juvenile hormone and methyl farnesoate (MF) are well known to respectively control the development and reproduction in insects and crustaceans (such as shrimp, crabs, and lobsters). In recent years, the sesquiterpenoid hormone farnesoic acid (FA) has also been identified in other non-insect/crustacean invertebrates; despite this, their regulatory roles remain poorly understood. Here, we carried out the in vitro treatments of MF and FA on the hepatopancreas of female adult shrimps Neocaridina davidi. Transcriptomic analyses revealed a total of 65 and 112 differentially expressed genes in the MF- and FA-treated hepatopancreas at 3 h post-treatment, respectively. Gene pathway enrichment analyses further suggested that the two sesquiterpenoid hormones regulate different sets of genes, with the gene pathway involved in pancreatic secretion enriched only in the FA-treated hepatopancreas. This study demonstrates the differential regulatory roles between sesquiterpenoid forms, which warrants further investigation into the functions of FA in crustaceans. Full article

Understanding the mechanisms of sexual development would pave the way for producing mono-sex populations to aid the aquaculture industry. This study investigates the functions of the Y-linked iDmrt1 paralogue (Po-iDMY) and insulin-like androgenic gland hormone (Po-IAG) in the process of sexual development in the tropical rock lobster, Panulirus ornatus (TRL). Previously, we identified that Po-iDMY, a male-specific heterogametic (Y-linked) paralogue of the autosomal Po-iDmrt1 found in TRL, is a second sex-linked iDmrt gene identified in invertebrates. Using 5′ and 3′ rapid amplification of cDNA ends and data from a draft male genome (with an assembly genome size of approximately 2.446 Gbp and 87% BUSCO completeness), we obtained the full-length Po-iDMY gene (encoding a protein of 312 amino acids). A 411 bp male-specific sequence located at the 3′ untranslated region of Po-iDMY mRNA was used as a sex marker, which was reported for the first time in our draft genome. However, Po-iDMY is not a master sex-determining factor since it was not expressed across developmental stages of embryos, juveniles and adults. Instead, we silenced Po-IAG at an early juvenile stage, generating two potential neo-females, implying that sexual manipulation could be a promising technique in TRL. Full article

Genomic adaptations of parasitic crustaceans in deep-sea extreme environments are poorly understood. This study presents the first genome survey of Pleurocryptella shinkai, a bopyrid isopod parasitizing deep-sea squat lobsters, using Illumina sequencing. The genome size was estimated to be 1.06 Gb via a K-mer analysis, smaller than its free-living relatives. The repeat content and heterozygosity were 66.31% and 1.14%, respectively, indicating a complex genome. The draft genome assembly yielded 0.93 Gb of scaffolds with an N50 length of 989 bp, and a complete mitochondrial genome of 14,711 bp was obtained. Phylogenetic analyses of 13 mitochondrial protein-coding genes confirmed the monophyly of Bopyridae, supporting Pleurocryptella as the most primitive genus within the group and the key role of deep sea in the origin and diversification of bopyrids. A mitochondrial gene variation analysis identified NAD2 and NAD4 as promising DNA markers for a population genetic study of P. shinkai. Twenty-four positively selected sites across COX1, NAD2, and NAD4 genes in P. shinkai explained the genetic basis of its adaptive evolution at the mitochondrial level. These findings provide valuable genomic resources for deep-sea parasitic crustaceans and establish a foundation for further high-quality genome assembly and adaptive mechanism studies of P. shinkai. Full article

Oceanic tuna fisheries are a major contributor to the economic health of Pacific Island countries (PICs), with coastal fisheries underpinning the livelihoods of locals, providing food security, significant employment, culture, and human welfare. Livelihood development across various PICs is hindered by the inability to harness the maximum potential of coastal fishery resources, particularly through the lack of identifying targeted development needs. Development of coastal value chains facilitates resilience by reducing local reliance on tuna fisheries and associated vulnerability to tuna industry dynamics to support socio-economic development throughout the PICs while maintaining food security. The aim of this paper is to identify priority opportunities for developing coastal resource value chains in PICs, targeting increased local economic resilience and food security. A methodology developed by the World Bank was used to assist stakeholders and policymakers to coalesce around common strategies for the value chains. Six value chains were identified: beche-de-mer; ornamental black pearls and Trochus shell; fresh fish for the domestic market; reef fish exports; export of live lobsters; and export of aquarium fish products. Porter’s Five Forces framework was used for value chain analysis, and strategic repositioning considerations and areas for investment support within high-priority value chains were identified. Fisheries data collection, community-based sustainable management and aquaculture restocking programmes, habitat restoration, development of the cold chain, air freight logistics for export, and facilitating international market connections and market access were identified for external investment support. Full article

The West Coast rock lobster, Jasus lalandii, is a key ecological species and provides an important fishery resource in South Africa and Namibia. It is found along the west coast of southern Africa in the dynamic Benguela Current upwelling system. The low seawater pH of this system is expected to decline further due to ocean acidification and increase in upwelling in terms of frequency and severity. The lobster has therefore to respond to frequent and rapid changes in pH and other environmental impacts that are predicted to become more adverse in future. Although responses to such conditions are known for mature male and juvenile lobsters, there is a lack of information on mature females and later embryonic development. We addressed this by analysing the sensitivity of ovigerous (“berried”) female WCRLs and their eggs/embryos to hypercapnia (high pCO₂, low pH) and formulated the following research questions: (1) Can berried female WCRLs respond swiftly to large changes in pH? (2) What physiological mechanisms facilitate a potential response to a rapidly declining pH, i.e., acute hypercapnia? (3) Does a potential response persist during prolonged hypercapnia? (4) Are eggs/embryos impacted by hypercapnia? To investigate this, we exposed berried WCRLs to acute (pH 7.5) and chronic (up to 60 days at pH 7.5 and 7.8) hypercapnia. We applied extracellular acid–base analysis, microscopic examination of egg growth and development, and SEM of female exoskeleton structure and egg membranes. The results revealed that berried females efficiently respond to acute and chronic hypercapnia by means of increasing bicarbonate concentrations in the haemolymph. Moreover, embryo growth and development are not impacted by chronic hypercapnia, but growth shows geographical area-specific differences. We conclude that females and embryos of J. lalandii are as resilient to hypercapnia as previously shown for males and juveniles. Full article

Efficient extraction of bioactive compounds from red lobster by-products is crucial for maximizing their nutritional and economic value. This study compared high-hydrostatic pressure extraction (HHPE), ultrasound-assisted extraction (UAE), and conventional extraction (CE), assessing the yield and bioaccessibility of carotenoids (astaxanthin, β-carotene, lycopene), antioxidants (DPPH, FRAP assays), and minerals (sodium, magnesium, potassium, calcium). HHPE and UAE significantly enhanced carotenoid extraction (p < 0.05), with UAE yielding the highest astaxanthin (3.61 mg/100 g FW) and HHPE producing the most β-carotene (0.64 mg/100 g FW). HHPE also significantly increased antioxidant capacity (38.04% increase over CE, p < 0.05). Despite reduced bioaccessibility after in vitro digestion, HHPE and UAE represent sustainable methods for recovering valuable bioactive compounds, improving the nutritional profile of red lobster by-products. Full article

The Crabster CR200 is an underwater walking robot inspired by crabs and lobsters, designed for precise seabed inspection and manipulation. It maintains stability and position on the seafloor, even in strong currents, by adjusting its posture through six legs, each with four degrees of freedom. The key advantage of the CR200 lies in its ability to resist drifting in strong currents by adapting its posture to maintain its position on the seafloor. However, information is still lacking on which specific posture generates the maximum downforce to ensure optimal stability in the presence of currents and the seabed. This study aims to determine the fluid forces acting on the CR200 in various postures using Computational Fluid Dynamics (CFD) and identify the posture that generates the maximum downforce. The posture is defined by two parameters: angle of attack and seafloor clearance, represented by the combination of the robot’s pitch angle and distance to the seabed. By varying these parameters, we identified the posture that produces the greatest downforce. Through a series of analyses, we identified two main fluid dynamic principles affecting the downforce on a robot close to the seabed. First, an optimal pitch angle exists that generates the maximum downward lift on the robot’s body. Secondly, there is an ideal distance from the seabed that produces maximum suction on the bottom surface, thereby creating a strong Venturi effect. Based on these principles, we determined the optimal robot posture to achieve maximum downforce in strong current conditions. The optimal underwater robot posture identified in this study could be applied to similar robots operating on the seafloor. Furthermore, the methodology adopted in this study for determining the optimal posture can serve as a reference for establishing operational postures for similar underwater robots. Full article

The effect of different dietary protein levels on apparent feed intake, apparent digestibility, body composition, nutrient retention, and growth efficiency of juvenile slipper lobster (Thenus australiensis) were evaluated for 74 days. Three isoenergetic and isolipidic feeds were formulated with crude protein levels of 445, 490, and 551 g kg⁻¹ DM, designated as P45, P50, and P55, respectively. Lobsters were fed one of these feeds in quadruplicate tanks, with eight lobsters (mean initial wet weight 6.1 ± 0.3 g) per tank in a recirculating seawater system at 27 °C. Increasing dietary protein levels significantly increased apparent feed intake, final dry weight, and daily weight gain. Dietary protein affected whole-body protein, lipid, and energy content. Lobsters fed P55 had significantly higher lipid and energy content than those fed P50 and P45. Protein content was significantly higher in lobsters fed P55 than P50, while P45 was not significantly different from either P50 or P55. Slipper lobsters grew best on a feed containing 550 g kg⁻¹ crude protein (equivalent to 518 g kg⁻¹ digestible protein), providing initial insights into their protein dietary requirement. This study established a foundation for developing standardized feeds, with further research needed to optimize growth performance and nutrient utilization. Full article

Organisms occupy diverse ecological niches worldwide, each with characteristics finely evolved for their environments. Crustaceans residing in deep-sea hydrothermal vents, recognized as one of Earth’s extreme environments, may have adapted to withstand severe conditions, including elevated temperatures and pressure. This study compares the exoskeletons of two vent crustaceans (bythograeid crab Austinograea sp. and squat lobster Munidopsis lauensis) with four coastal species (Asian paddle crabs, blue crab, hermit crab, and mantis shrimp) to identify traits influenced by vent environments. The goal was to identify distinctive exoskeletal characteristics commonly observed in vent crustaceans, resulting from their exposure to severe abiotic factors, including elevated temperatures and pressures, found in vent environments. Results show that the exoskeletons of vent crustaceans demonstrated significantly enhanced thermal stability compared to coastal species. These vent crustaceans consistently featured exoskeletons characterized by a reduced proportion of volatile components, such as water, and an increased proportion of CaCO₃, compared with coastal crustaceans. Furthermore, vent crustaceans lacked carotenoid pigments that had low heat resistance. However, no apparent differences were observed in the mechanical properties. Our findings suggest that the similar composition of exoskeletons in vent crustaceans evolved convergently to withstand high temperatures. Full article

Eco-friendly wall cladding panels were developed from fishing industry waste by incorporating discarded ropes, wood fibers from lobster cages, and clamshell powder. Four panel formulations were investigated using MAPP and MAPE coupling agents: FRW-M (97% fishing rope), 30WF-M (67% rope with 30% wood fibers), 30CS-M (67% rope with 30% clamshell powder), and a hybrid 15CS15WF-M (67% rope with 15% each of wood fibers and clamshell powder). A DSC analysis revealed that clamshell powder addition reduced melting temperatures and crystallinity, while wood fiber incorporation led to slight increases in melting temperatures. The hybrid formulation exhibited enhanced crystallization temperatures despite lower overall crystallinity. A dynamic mechanical analysis showed an 85% improvement in storage modulus for the hybrid panel, with flexural testing demonstrating a 202% increase in modulus and 20% increase in strength. SEM-EDS analysis confirmed improved filler dispersion and interfacial adhesion in the hybrid formulation. Water absorption was lowest in FRW-M and highest in 30WF-M, while burning rate tests showed 30CS-M and 30WF-M as the best and worst performers, respectively. The hybrid formulation emerged as the optimal solution, combining enhanced mechanical properties with improved water resistance and fire retardancy, presenting a viable sustainable alternative for wall cladding applications. Full article

The best practice for killing decapod crustaceans lacking a centralized ganglion has been debated for a century. Currently, there is a movement away from live boiling towards electrocution and mechanical splitting or spiking, which are efficient in the large commercial setting but may be unavailable and impractical for small decapods such as shrimp and prawn in the small-scale setting of, e.g., the household. Here, using carcasses of varying sizes of prawn, crayfish, lobster and green and brown crab, we used micro-CT imaging to measure surface area and sphericity in relation to body mass. Then, we measured heating profiles at the anterior ganglion and in the core of carcasses of the same species when exposed to standardized boiling regimes. We found a relationship with positive allometry between surface area and body mass for all species and a decrease in sphericity with mass. Heating times until proposed stunning (26 °C) and killing (44 °C) varied with body size and starting temperature and exceeded minutes for larger species. For a small species like prawn, times to stunning and killing by boiling are comparable to electrocution times and within the acceptable range compared to recreational killing of other sentient beings such as game mammals. Full article