Hasil untuk "Aquaculture. Fisheries. Angling"

F. Huntingford, C. Adams, V. A. Braithwaite et al.

Sugeng Hartono, Ani Haryati, Sahda Salsabila et al.

The Indian halibut (Psettodes erumei) is classified as data deficient on the IUCN Red List. Accurate species identification is a fundamental prerequisite for sustainable fisheries management and biodiversity conservation. This study aims to identify the Indian halibut landed from Cilacap waters, Indonesia, using an integrative morphological and molecular approach. Four specimens collected in March and June 2025 were analyzed using an integrated morphological and molecular approach. Morphological identification was based on detailed morphometric and meristic analyses, cross-referenced with standard taxonomic guides. Molecular identification involved DNA extraction, PCR amplification of the mitochondrial Cytochrome C Oxidase Subunit I (COI) gene, electrophoresis, sequencing, and comparison with global genetic databases using BLAST. Morphological characteristics aligned with the description of P. erumei, though significant morphometric differences from a historical reference suggest potential local phenotypic variation. DNA barcoding confirmed the identity with 100% sequence similarity to conspecifics from other Indo-Pacific regions (GenBank accession: PX599017.1). Phylogenetic analysis further placed the Cilacap samples within a genetically homogeneous cluster of P. erumei from across Indonesian waters. This research successfully contributes to Indonesia's biodiversity database and DNA barcode library for a commercially exploited yet understudied species. It also provides essential baseline data to inform stock assessments and conservation strategies in the region.

David Eppstein

We show that the max-min-angle polygon in a planar point set can be found in time $O(n\log n)$ and a max-min-solid-angle convex polyhedron in a three-dimensional point set can be found in time $O(n^2)$. We also study the maxmin-angle polygonal curve in 3d, which we show to be $\mathsf{NP}$-hard to find if repetitions are forbidden but can be found in near-cubic time if repeated vertices or line segments are allowed, by reducing the problem to finding a bottleneck cycle in a graph. We formalize a class of problems on which a decremental greedy algorithm can be guaranteed to find an optimal solution, generalizing our max-min-angle and bottleneck cycle algorithms, together with a known algorithm for graph degeneracy.

C J Bradly, N R Beaton, A L Owczarek

We investigate polymers pulled away from an interacting surface, where the force is applied to the untethered endpoint and at an angle $θ$ to the surface. We use the canonical self-avoiding walk model of polymers and obtain the phase diagram of the model using Monte Carlo simulations for a range of angles, temperatures and force magnitudes. The phase diagram of the model displays re-entrance at low temperatures for three-dimensional walks when the pulling is more vertical than horizontal. Our results agree with various exactly solvable lattice models that have been previously studied.

Dario Ascari, Montserrat Casals-Ruiz, Ilya Kazachkov

We introduce a new isomorphism invariant for generalized Baumslag-Solitar (GBS) groups, which we call the limit angle. Unlike previously known invariants, which are primarily algebraic, the limit angle admits a dynamical interpretation, arising exclusively in the case of two interacting edges. This invariant captures subtle geometric behavior that does not manifest in configurations with more interacting edges. As an application, we use the limit angle to obtain a classification of GBS groups with one vertex and two edges.

Nilesh Patil, Ajay Anand

Angle estimation is an important step in the Doppler ultrasound clinical workflow to measure blood velocity. It is widely recognized that incorrect angle estimation is a leading cause of error in Doppler-based blood velocity measurements. In this paper, we propose a deep learning-based approach for automated Doppler angle estimation. The approach was developed using 2100 human carotid ultrasound images including image augmentation. Five pre-trained models were used to extract images features, and these features were passed to a custom shallow network for Doppler angle estimation. Independently, measurements were obtained by a human observer reviewing the images for comparison. The mean absolute error (MAE) between the automated and manual angle estimates ranged from 3.9° to 9.4° for the models evaluated. Furthermore, the MAE for the best performing model was less than the acceptable clinical Doppler angle error threshold thus avoiding misclassification of normal velocity values as a stenosis. The results demonstrate potential for applying a deep-learning based technique for automated ultrasound Doppler angle estimation. Such a technique could potentially be implemented within the imaging software on commercial ultrasound scanners.

Yanxing Li, Chuqiao Shi, Fan Zhang et al.

Forming long wavelength moiré superlattices (MSL) at small-angle twist van der Waals (vdW) bilayers has been a key approach to creating moiré flat bands. The small-angle twist, however, leads to strong lattice reconstruction, causing domain walls and moiré disorders, which pose considerable challenges in engineering such platforms. At large twist angles, the rigid lattices render a more robust, but shorter wavelength MSL, making it difficult to engineer flat bands. Here, we depict a novel approach to tailoring robust super-moiré (SM) structures that combines the advantages of both small-twist and large-twist transition metal dichalcogenides (TMDs) bilayers using only a single twist angle near a commensurate angle. Structurally, we unveil the spontaneous formation of a periodic arrangement of three inequivalent commensurate moiré (CM) stacking, where the angle deviation from the commensurate angle can tune the periodicity. Electronically, we reveal a large set of van Hove singularities (VHSs) that indicate strong band hybridization, leading to flat bands near the valence band maximum. Our study paves the way for a new platform of robust SM bilayers with structural rigidity and controllable wavelength, extending the investigation of the interplay among band topology, quantum geometry, and moiré superconductivity to the large twist angle regime.

H. M. Abdel‐Latif, Mohamed M. Abdel-Daim, Mustafa Shukry et al.

Abstract The rapid expansion of the aquaculture industry, the global shortage of fish meal (FM) supplies from fisheries and the continuous demand for FM as a primary protein source in aquafeeds lead to increase the urgent necessity to find new FM alternatives. Plant protein sources have gained significant importance among aquaculture farmers and nutritionists because of their availability, eco-friendly, relative sustainability, environmentally safe, and relatively lower prices than FM protein. Extensive studies have been conducted to better assess the efficiency of plant protein sources as a partial or complete substitution of dietary FM in aquafeeds. From these sources, Moringa oleifera has been widely used. It is universally known as “the miracle tree” because of its high nutritional values and unique composition of phytochemicals, such as phenolic acids, flavonoids, carotenoids, alkaloids, tannins, lectins and terpenoids. These phytochemicals possess numerous advantageous properties such as antioxidant, hepatoprotective, antimicrobial and immune-stimulant characteristics. This review article describes the nutritional features of M. oleifera with a special emphasis on the current research findings on the possibility of including different forms of M. oleifera in diets to replace dietary FM protein in the diets of several fish species. It also evaluates its effects on the growth parameters, feed utilisation indices, and proximate body composition of fish. The haemato-biochemical parameters, hepato-renal functions, immune responses, and antioxidative capacity of fish fed M. oleifera-based diets are also assessed. The data will help to provide new perceptions and references for future research interests and aquaculture production.

Ke Bai, Pinyuan Wei, Junliang Guan et al.

The use of an appropriate amount of anesthetic can prevent the sacrifice of oysters during experimental sampling or seedling rearing. In this study, we assessed the effects of air exposure and three concentrations of magnesium chloride (10, 40, and 70 g L–1) on the anesthetic efficiency for Crassostrea hongkongensis. We examined the recuperative capacity of the oysters post-tissue sampling. The results indicated that 36 h of air exposure could significantly enhance the anesthetic efficiency of C. hongkongensis while ensuring the oysters’ survival. A 40 g L–1 solution of magnesium chloride had the optimal anesthetic effect on C. hongkongensis across all oyster sizes. In addition, smaller oysters (119.10 g) had a higher relaxation rate than larger oysters (191.00 g). The oysters anesthetized with 40 g L–1 magnesium chloride also demonstrated the best recovery. No deaths were observed among the non-anesthetized oysters, anesthetized-recovered oysters, or non-recovered oysters during a seven-day post-farming period. In terms of live sampling, the control group (100 %), gonad group (100 %), mantle group (98.67 %), gill group (89.33 %), and adductor muscle group (97.33 %) all showed high survival rates after anesthesia. Observation of tissue growth post-sampling revealed the presence of focal green areas in tissues between days 7 and 14. By day 30, the adductor muscle and mantle tissues had fully healed, and the regrown tissue in the gills had approached its original length. A 40 g L–1 magnesium chloride solution had no significant effects on gametes in terms of fertilization rate, growth rate, and attachment rate. The present findings indicated that C. hongkongensis could be effectively anesthetized using a 40 g L–1 magnesium chloride solution following 36 h of aerial exposure. Post-anesthesia tissue and gamete sampling did not result in significant mortality, and the tissues had fully recovered within 30 days post-sampling. The anesthesia did not have any adverse effects on the progeny.

صدیق محمدی, علی طاهری

جلبک های دریایی دارای خواص آنتی اکسیدانی هستند. در پژوهش حاضر، فعالیت آنتی‌اکسیدانی عصاره های آلی جلبک‌ قرمز Champia compressa خلیج چابهار مورد آزمون قرار گرفت. استخراج عصاره‌ از نمونه‌ها با غلظت 1:20 (حلال به جلبک) به روش خیساندن به مدت 24 ساعت در دمای محیط انجام شد. حلال‌های مورد استفاده شامل متانول، هگزان، دی‌کلرومتان و کلروفرم در سطوح 01/0 ،1/0، 5/0 و 1 میلی گرم بر میلی لیتر بود. از آزمون‌های حذف رادیکال آزاد DPPH، احیاکنندگی و چلاته کنندگی یون آهن استفاده شد. حداقل مقدار IC50 فعالیت مهار رادیکال آزاد DPPH جلبک compressa C. در عصاره متانولی با مقدار 05/1 میلی‌گرم بر میلی‌لیتر و حداکثر مقدار آن در دی‌کلرومتان محاسبه شد. همچنین، حلال کلروفرم با IC50 64/2 بیشترین میزان کلاته‌کنندگی را داشت. عصاره متانولی با IC50 68/0 میلی گرم در میلی لیتر بیشترین فعالیت کاهندگی را داشته است. همچنین، با افزایش غلظت عصاره، میزان فعالیت آنتی‌اکسیدانی آن نیز افزایش می-یابد. به طوری‌که، مهار رادیکال آزاد DPPH، قدرت کلاته کنندگی و فعالیت کاهندگی در غلظت 1 میلی گرم بر میلی‌لیتر اکثر عصاره‌ها نسبت به سایر غلظت‌ها اختلاف معنی داری را نشان داده است (p<0.05). در مجموع می‌توان نتیجه گرفت که عصاره متانولی و کلروفرمی جلبک compressa C. دارای قدرت آنتی‌اکسیدانی خوبی می‌باشد. تحقیقات بیشتر برای بررسی کامل تر خواص آنتی اکسیدانی عصاره های این جلبک توصیه می شود.

J. Guillen, F. Natale, N. Carvalho et al.

To ensure food security and nutritional quality for a growing world population in the face of climate change, stagnant capture fisheries production, increasing aquaculture production and competition for natural resources, countries must be accountable for what they consume rather than what they produce. To investigate the sustainability of seafood consumption, we propose a methodology to examine the impact of seafood supply chains across national boundaries: the seafood consumption footprint. The seafood consumption footprint is expressed as the biomass of domestic and imported seafood production required to satisfy national seafood consumption, and is estimated using a multi-regional input output model. Thus, we reconstruct for the first time the global fish biomass flows in national supply chains to estimate consumption footprints at the global, country and sector levels (capture fisheries, aquaculture, distribution and processing, and reduction into fishmeal and fish oil) taking into account the biomass supply from beyond national borders.

A. Karatayev, D. Molloy, L. Burlakova

Abstract This article reviews the international literature on the natural enemies of Dreissena spp.—bivalves which internationally have strong impacts on aquatic ecosystems, industries, fisheries, and aquaculture. It represents a revised edition of the initial treatment on this topic published over two decades ago, and as in the previous publication, it reviews the biology and ecology of organisms known to be involved in the predation (143 species), parasitism and commensalism (86 species and higher taxa), and competitive exclusion (14 species) of species in the genus Dreissena. Predators can at times have major impacts on dreissenid populations, but these reductions are typically only temporal and in restricted (e.g., shallow) areas within large waterbodies. A cumulative effect of a growing suite of enemies may have a constant, but overall limited, role in suppressing Dreissena densities—one far from any likelihood of population eradication. A diverse and abundant community of natural enemies, however, is beneficial because of its positive impact on energy flow. The introduction of dreissenids has redirected energy from the planktonic to the benthic community and predators, in particular molluscivorous fish and waterfowl, have served to redistribute this energy flow back into the pelagic environment.

I. Cowx, S. Funge‐Smith, A. Lynch

Stocking is one of the foremost tools in the inland fisheries management toolbox, but it comes with both opportunities and risks. Stocking is often used as compensation for depleted wild populations, particularly where recruitment processes have been disrupted, but it can introduce disease, disrupt community structures, reduce genetic integrity, and cause conflicts between fishery stakeholders. Despite its widespread use, examples of effective stocking for food fisheries in inland waters are sparse in the peer‐reviewed literature. Nevertheless, it is well established that stocking is frequently used to maintain fish yield, so there is a need to conduct the practice in a robust manner that minimises the potential risks. This paper serves as the front matter for a special section of Fisheries Management and Ecology focused on fresh waters feeding the world, which resulted from two panel sessions, one focused on aquaculture and one focused on stocking, hosted by the international InFish research network (https://infish.org/). The paper highlights current practices of fish stock enhancement in inland waters for food, examines potential synergies and interactions of stock enhancement programmes with aquaculture, and provides an outline framework for responsible management of fish stock enhancement.

P. McIntyre, C. Reidy Liermann, C. Revenga

Md. Anwar Hossain, Md. Akhtar Hossain, Md. Ayenuddin Haque et al.

Organoleptic qualities and proximate composition of fish grown in carp fattening pond were studied under three treatments of feed and fertiliser management. In treatment T1, inorganic fertiliser together with restricted feeding and silver carp. In treatment T2, both the organic and inorganic fertilisers were used accompanied by restricted feeding and stocking of silver carp, in treatment T3, both organic and inorganic fertilisers were used without the stocking of silver carp. Fishes were stocked with a stocking density of 2470 fishes ha–1. Three fishes (Gibelion catla, Labeo rohita and Cirrhinus cirrhosus) were selected for organoleptic and proximate assessment. Cyanobacteria along with total phytoplankton cell density was significantly higher at treatment T2 followed by T3 and T1. However, in terms of productivity (Chl-a) treatment T2 was 27.1 and 13.3% higher compared to T1 and T3 respectively. Parameters assessed for proximate composition analysis did not vary across treatments and organoleptic test revealed comparatively higher acceptability of fishes collected from treatment T1 followed by T2 and T3 for all the fishes. Overall acceptability was higher for L. rohita from treatment T1. This study concluded that, the fertilisation along with surface feeder (silver carp) can improve the organoleptic properties of carps in pond.

Ming-Cheng Tsai, Muhammad Salman Bashir, Mohamed-Slim Alouini

Due to the narrow beamwidths of laser Gaussian beams, accurate tracking of laser beam's angle-of-arrival is an important problem in mobile free-space optical communications. In most optical receivers today, fine tracking of angle-of-arrival involves estimating the location of the focused beam spot projected onto a focal plane array. However, for very thin Gaussian beams, both the location as well as the energy of the spot varies considerably with the variation of angle-of-arrival. In this study, we have analyzed the relationship between the angle-of-arrival and the energy of laser spot on the focal plane. We then exploited this relationship to enhance the angle-of-arrival estimation performance of our proposed receiver that takes into account both the location as well as the energy of the laser spot while estimating the angle-of-arrival. The derived Cramer-Rao bounds indicate that the system performance can be enhanced significantly for narrow Gaussian beams when both the spot location and energy are exploited for angle-of-arrival estimation.

R. Arlinghaus, K. Laskowski, J. Alós et al.

Fengying Yan, Xinxun Xiao, Lin Tang et al.

G Protein-coupled receptor 3 (Gpr3) plays a critical role in maintaining oocyte meiotic arrest in mammals. To ascertain the function of Gpr3 in oocyte maturation in fish, the Gpr3 cDNA was cloned from orange-spotted grouper (Epinephelus coioides). The open reading frame of cloned sequence was 993 bp in length, encoding 330 amino acids. Gpr3 was primarily expressed in brain regions and ovary. During oocyte maturation induced by human chorionic gonadotropin (hCG), Gpr3 expression levels were dramatically elevated in follicular cell layers. Functional analysis showed that Gpr3 could constitutively active the cAMP/PKA signaling pathway, and hCG treatment activated Gpr3 promoter activities in cultured eukaryotic cells expressing luteinizing hormone receptors (LHRs). Finally, the role of Gpr3 in oocyte maturation was studied. Sphingosine 1-phosphate (S1P), an agonist of Gpr3, had no effect on oocyte maturation in vivo, suggesting that Gpr3 may be not involved in oocyte maturation in orange-spotted grouper.

Jiawei Yang, Kaiyu Cui, Yidong Huang et al.

On-chip spectral imaging based on engineered spectral modulation and computational spectral reconstruction provides a promising scheme for portable spectral cameras. However, the angle dependence of modulation units results in the angle sensitivity of spectral imaging, which limits its practical applications. Here, we proposed a design for angle-robust spectral recovery based on a group of topology-optimized plasmonic metasurface units under a 30° field-of-view, and demonstrate angle-insensitive on-chip spectral imaging in the wavelength range of 450 to 750 nm for average polarization. Furthermore, we experimentally verified the angle-insensitive spectral filtering effects of the fabricated metasurface units, and demonstrated angle-robust spectral reconstruction with a fidelity of 98%. Our approach expands the application scale of spectral imaging, and provides a guidance for designing other angle-robust devices.

Ainania Ahsan, Siti Komariyah, Suri Purnama Febri

Angkutan remaja merupakan salah satu kegiatan dalam usaha penangkapan ikan. Pengangkutan benih dapat dilakukan dengan metode sistem basah tertutup atau media air. Angkutan remaja memiliki prinsip menjaga kelangsungan hidup sampai ke lokasi tujuan. Jika lokasi tujuan jauh sehingga membutuhkan waktu yang lama, maka untuk mempertahankan kelangsungan hidup perlakuan khusus. Perlakuan tersebut untuk mengurangi masalah transportasi ikan seperti penurunan DO dan peningkatan amoniak pada media yang dapat menyebabkan kematian pada anakan. Berdasarkan permasalahan tersebut maka perlu dilakukan penelitian tentang penggunaan bahan anestesi untuk menurunkan laju metabolisme dan zat aktif untuk menurunkan amonia dalam media.Uji hewan yang digunakan adalah ikan bandeng berukuran 2 cm. Metode yang digunakan dalam penelitian ini adalah metode eksperimental dengan menggunakan metode Rancangan Acak Lengkap sebanyak 5 perlakuan dan 3 ulangan. Perlakuan yang diberikan adalah P1 (minyak pala + karbon aktif), P2 (minyak pala + karbon aktif), P3 (minyak cengkeh + zeolit), P4 (minyak cengkeh + karbon aktif) dan P5 (kontrol). Parameter penelitian yang diamati adalah tingkat kelangsungan hidup (TKH), tingkat konsumsi oksigen (TKO), amonia setelah pengangkutan dan kualitas air sebelum dan sesudah pengangkutan. Hasil analisis anova menunjukkan bahwa pengaruh berpengaruh nyata (P <0,05) terhadap kelangsungan hidup, tingkat konsumsi oksigen dan kadar amonia pada media transportasi benih bandeng.Perlakuan P4 (minyak cengkeh + karbon aktif) perlakuan terbaik karena memiliki sintasan tertinggi (76,7%), tingkat konsumsi oksigen terendah (1.