The BOLETIM DO INSTITUTO DE PESCA (BIP; IP/SAA) - ISSN 0046-9939 (printed version; closed in 2011); ISSN 1678-2305 (online version) - an open access Scientific Journal, is the first scientific journal focused on the areas of Fisheries, Aquaculture, Limnology, Seafood Science and Technology, Food Safety and Sustainability. Published since 1971, the Boletim provides a historical overview of the development of fisheries and aquaculture research in Brazil and abroad. The BIP publishes original documents that contribute to the expansion of knowledge in fisheries, aquaculture, aquatic ecology, fish processing technology, pathology of aquatic organisms, limnology, among others areas. Its impact factor - JIF (2021) = 0.6 From 2021, the "Boletim do Instituto de Pesca" adopts the process of publication in continuous flow (or rolling pass or rolling publishing; a single annual volume).
Systematic review of mercury contamination in aquatic organisms of Sepetiba Bay, RJ, Brazil
Sepetiba Bay is an ecologically and economically significant lagoon for Rio de Janeiro, Brazil. However, the development of this region has been linked to numerous environmental contaminations, leading to the accumulation of trace metals across various ecosystems. Mercury is particularly concerned for public health due to its propensity to bioaccumulate and biomagnify in marine organisms, subsequently entering the human body through consuming contaminated fish. Six studies were identified, with their findings indicating that mercury concentrations in fish from Sepetiba Bay do not exceed the maximum limits set by national legislation (Brazilian Health Regulatory Agency) and the World Health Organization. This systematic review sought to compile research related to mercury contamination in fish from Sepetiba Bay between 2000 and 2024, following the PRISMA-P protocol. A total of six studies were selected, with an additional 27 articles included because of their relevance in understanding the feeding habits of fish, bringing the total to 33 articles. Our findings suggest that, despite the low risk to human consumption, there is a need for the development of public policies focused on the continuous monitoring and control of mercury contamination in the bay’s fish, intending to decontaminate the environment and prevent a progressive increase in mercury levels in species that constitute a significant part of the local diet.
Copyright (c) 2026 Letícia Santos Macedo, Eliane Teixeira Mársico https://creativecommons.org/licenses/by/4.0
Ultrasonography in the reproductive management of the Brazilian sardine Sardinella brasiliensis
Ultrasonography is a fast and non-invasive method that offers a promising alternative for sex identification and gonadal maturation assessment in fish. This technique is especially relevant to Brazilian sardine (Sardinella brasiliensis), a species of high commercial value whose small body makes traditional sexing methods unfeasible. Ultrasonography was applied to 55 individuals undergoing their first gonadal maturation. All fish were anesthetized for examination and subsequently euthanized for macroscopic evaluation to confirm sex and determine the maturation phase. These findings were supported by histological analysis, which confirmed the accuracy of the results. Ultrasonography using a multifrequency transducer (8–13 MHz) achieved 98% accuracy in sex identification, and 46 males and nine females were identified. Histological examination revealed 32 reproductively capable males (phase C) and 14 immature individuals (phase A), while all females were classified as phase C (ready for reproduction and spawning). Although ultrasonography proved effective for sex differentiation, it showed limitations in determining gonadal maturation phases. Further studies and the development of a specific protocol are required for accurate phase classification. Therefore, ultrasonography demonstrates great potential as a practical and effective tool in reproductive monitoring. This study is the first report of its application to the Brazilian sardine.
Copyright (c) 2026 Sabrina Lara Luz, Ingrith Aparecida Mazuhy Santarosa, Maria Alcina Martins de Castro, Carolina Perenguez Riofrio, Letícia Cordeiro Koppe de França, Everton Danilo dos Santos, Bernardo Viero de Oliveira, Aline Brum, Caio Magnotti https://creativecommons.org/licenses/by/4.0
Composition of the bycatch associated with Arapaima gigas fisheries in lotic and lentic environments of the Cautário River basin, Rondônia, Brazil
This study characterizes the bycatch associated with Arapaima gigas fisheries in the Cautário River, Rondônia, Brazil, where the species occurs as an invasive species. Fisheries monitoring was conducted during the low-water period (August to October 2025), when A. gigas capture rates intensify. During this period, 69 bycatch individuals were recorded, belonging to nine species, distributed in seven families and eight orders. Vertebrates were predominant, with reptiles and fish accounting for more than 68% of the incidental captures. The turtle Podocnemis unifilis was the most frequent species (36.23%), followed by the fish Colossoma macropomum (31.88%) and Phractocephalus hemioliopterus (11.59%). The limnological parameters remained within ranges compatible with the sampled aquatic environments and favorable to the occurrence of non-target species recorded in the fisheries. The results indicated that the high taxonomic diversity and representation of non-target species reflect the low selectivity of the fishing gear used in A. gigas fisheries. These findings highlight the importance of continuous monitoring of the bycatch as an essential tool for the adaptive management of A. gigas fisheries in the Cautário River, part of the Guaporé River basin.
Copyright (c) 2026 Samíria Bárbara Brito Pereira, Eduarda Fernanda de Oliveira da Silva, Samara Bruna Brito Pereira, Chirlaine Alves Ribeiro Varão, Rodrigo Rios Barreto, Thales Quintão Chagas, Marcondes Agostinho Gonzaga Junior, Raniere Garcez Costa Sousa https://creativecommons.org/licenses/by/4.0
Critical feeding window: Influence of delayed Artemia nauplii provision on Pyrrhulina brevis larviculture
This study aimed to evaluate the impact of delayed Artemia nauplii introduction on the larviculture of the Amazonian ornamental fish Pyrrhulina brevis. A completely randomized design with four treatments and four replicates was implemented. Larvae were subjected to varying delays in Artemia nauplii supply: 0 (no delay), 2, 4, and 6 days and were subsequently fed until the end of the 20-day experimental period. Growth performance, point-of-no-return (PNR), and intestinal and muscular histomorphometry were assessed at the end of the experiment. No differences in length, weight, or uniformity were observed between larvae with no delay and those with a 2-day delay in Artemia nauplii supply (p>0.05). However, total mortality occurred in larvae exposed to delays of 4 days or longer by the fifth day of experiment. Larvae without delay exhibited a survival rate of 86.25%, significantly higher than the 20% survival rate in those subjected to a 2-day delay (p<0.05). The PNR for P. brevis larvae was determined to be 2.69 days (9.69 days post-hatching). No differences were observed in intestinal or muscle histomorphometry among treatments (p>0.05). These findings highlight that delaying Artemia nauplii supply critically reduces the survival of P. brevis larvae, potentially compromising the viability of larviculture production.
Copyright (c) 2026 Leonnan Carlos Carvalho de Oliveira, Edileno Tiago de Sousa Nascimento, Ana Cristina Araújo e Silva, Bianca Gomes da Silveira, Alessandra Aparecida de Sousa Almeida, Silmara Silvia Ribeiro, Bruno José Corecha Fernandes Eiras, Lorena Batista de Moura, Daniel Abreu Vasconcelos Campelo, Altevir Signor https://creativecommons.org/licenses/by/4.0
Aquaculture biosecurity in Brazil: Assessment of tilapia fry hatcheries in the Federal District
This study evaluated biosecurity practices in five tilapia fry hatcheries in the Federal District, Brazil, between August 2023 and August 2024. A semi-quantitative questionnaire with 89 items was applied, grouped into five thematic axes. Data were analyzed using descriptive and inferential statistics (Chi-square and ANOVA), as well as relational analysis in R software. Results showed high compliance in water quality monitoring, feed management, and mortality records, but weaknesses were identified in quarantine protocols, visitor control, use of PPE, pest control programs, and sanitary fallowing. Statistical analysis found no significant differences among thematic groups (p>0.05) but revealed variation among farms (p<0.001), indicating the influence of individual management. The water quality axis showed the highest consistency, while equipment and vehicles exhibited greater heterogeneity. Compared to international benchmarks, results remain below standards from countries such as Norway and Chile, where traceability and transport protocols are strictly enforced. We conclude that biosecurity adoption in local hatcheries is partial and non-standardized, highlighting the need for stronger protocol harmonization, training, and infrastructure investments to enhance the sanitary resilience of the production chain.
Copyright (c) 2026 Thiago Dias Trombeta, Carlos Antônio Zarzar, Ricardo da Silva Raposo, Vitória Pellilo, Matheus Santos Silva https://creativecommons.org/licenses/by/4.0
Optimizing Ulva ohnoi cultivation in biofloc systems: Influence of salinity
This study evaluated the salinity tolerance of the macroalga Ulva ohnoi cultivated in a biofloc system over a 14-day period. Five salinity treatments (10, 15, 20, 25, and 30‰) were tested, using 40-L tanks. Algae were acclimated to the target salinities before the cultivation phase and stocked at the density of 2 g∙L-1. Water quality parameters (ammonia, nitrite, nitrate, orthophosphate, alkalinity, and pH), biomass gain, daily growth rate, phenolic compounds, chlorophyll, and carotenoids were evaluated. Water quality remained within acceptable ranges across treatments, although alkalinity showed significant differences. Complete mortality of U. ohnoi was observed at 10‰, and reduced growth was recorded at 15‰. In contrast, salinities of 20, 25, and 30‰ supported higher biomass gains and daily growth rates, with no significant differences in antioxidant compound concentrations among these treatments. Growth was significantly higher at salinities of 20–30‰, with biomass gains of 318–400 g and daily growth rates of 5.4–6.4% day-1, whereas at 15‰ biomass gain reached only ~111 g and growth rate ~1.2% day-1. These findings highlight the potential of U. ohnoi for integration into low-salinity biofloc systems and multitrophic aquaculture strategies, contributing to sustainable aquaculture practices by recycling nutrients and producing valuable biomass.
Copyright (c) 2026 Ana Paula Mariane de Morais, Ivanilson de Lima Santos, Carmen Simioni, Leila Hayashi, Marco Antônio de Lorenzo, Walter Quadros Seiffert, Felipe Vieira https://creativecommons.org/licenses/by/4.0
Stocking density of yellowtail lambari (Astyanax lacustris) in earthen ponds for small-scale aquaculture
The yellowtail lambari, Astyanax lacustris, is a small-sized species suitable for small-scale aquaculture. Five stocking densities (10, 25, 50, 75, and 100 fish/m2) were evaluated in three production cycles. Experimental units were 50-m2 earthen ponds, with minimal water replacement to compensate for infiltration and evaporation. Sixty-day-old fish (5.67 ± 0.10 cm and 2.67 ± 0.16 g) were fed a commercial diet twice daily in 45-day production cycles. Stocking densities influenced lambari growth. Lambari growth at all treatments showed good fit in the logistic model, but lower densities resulted in higher growth rates and larger asymptotic sizes. Among productive performance parameters, daily weight gain and specific growth rate were inversely proportional to stocking density, whereas the number of fish and biomass produced per area were directly proportional. These growth results were associated with reduced water quality and feed intake at higher stocking densities. Fish density did not affect feed conversion ratios (ranging from 1.44 to 1.58) but did influence carcass yield (82.00 to 84.85%). Under the conditions of this study, intermediate stocking densities showed good balance between growth and productivity per area.
Copyright (c) 2026 Camila Fernandes Correa, Dariane Beatriz Schoffen Enke, Rafael Vilhena Reis Neto, Eloisa Peniche Tamasia, Liandra Lopes Filholino Collaço https://creativecommons.org/licenses/by/4.0
Morphometric criteria for selection of high-yield phenotypes in Epinephelus marginatus (Lowe, 1834) under varying farming systems
This study evaluated morphometric traits as indirect selection criteria for high-yield phenotypes in dusky grouper (Epinephelus marginatus) reared under three commercial production systems: recirculating aquaculture systems (RAS), marine cages (MC), and estuarine ponds (EP). Fish (n = 55) were harvested at 730 days to assess carcass weight (CW) and meat volume (MV). Differences among systems were analyzed using analysis of variance followed by Tukey’s test (p < 0.05). Paired morphometric traits standard length (SL), head length (HL), body height (BH), and body width (BW) were evaluated through quadrant classification, and CW and MV were compared between quadrants using Welch’s t-test. SL × BH was the best-performing criterion in RAS and BH × BW in EP for CW, while no significant differences in CW were observed in MC. Overall, no significant differences in MV were detected among quadrants in any of the farming systems. Despite the limited sample size, these findings suggest that non-lethal morphometric traits may be useful for phenotypic indirect selection for a higher meat yield in dusky grouper aquaculture, depending on the production system.
Copyright (c) 2026 Matheus Luiz da Costa Silva, Graziela Tarôco, Caio Augusto Perazza, Alexandre Wagner Silva Hilsdorf, Leila de Genova Gaya https://creativecommons.org/licenses/by/4.0
From river to plate: subsistence fishing activity in the middle Caeté, a lowland river in the Eastern Amazon, Pará, Brazil
Amazonian people are highly dependent on fishing, which provides their main source of protein. Fishing in the middle Caeté, Eastern Amazon, Pará, Brazil, was described in terms of the sociodemographic profile of fishers, gear, and strategies used in catches. Semi-structured interviews were conducted with fishers in the region. Fishing occurs throughout the year, and to a lesser extent during the closed season. It is characterized as subsistence fishing, although a small percentage (20%) sell part of their catch to supplement their income. Fishing gear is diverse and varies according to the seasons, with gillnets and set longlines being the most common. Transportation is carried out aboard small canoes powered by oars or outboard motors. The most important commercialized species are the giant Malaysian prawn, dourada, and piramutaba, while traíra, mandií, tuvi, anujá, aracu, piranha, among others, are intended for family consumption. A change in fishers’ habits is expected in terms of increasing the mesh size of gillnets to be more selective and to comply with fishing regulations.
Francisco Carlos Aberto Fonteles Holanda
Copyright (c) 2026 Cristiney Santos, Francisco Carlos Aberto Fonteles Holanda, Colin Robert Beasley, Juarez Carlos Brito Pezzuti https://creativecommons.org/licenses/by/4.0
Protein and energy digestibility of insect meals for angelfish (Pterophyllum scalare)
Insect meal has been the subject of numerous studies in recent years, and its potential in animal feeding has also been investigated. This study aimed to investigate the digestibility coefficients of protein, dry matter, and energy of some insect meals: black soldier fly (Hermetia illucens), cricket (Gryllus spp.), cricket nymph, and mealworm (Tenebrio molitor) for angelfish (Pterophyllum scalare). A total of 225 adults of P. scalare, weighing 30 ± 2.32 g each, were housed in 15 200-L circular fiber tanks at a density of 15 fish per experimental unit in triplicate. Digestibility was estimated by the indirect method, using chromium oxide as an inert indicator. For feces collection, the modified Guelph system was used. Among the tested insect meals, black soldier fly meal presented a superior digestibility coefficient for dry matter (0.77), protein (0.901), and energy (0.82). The mealworm presented an inferior digestibility coefficient (dry matter = 0.67, protein = 0.88, and energy = 0.77). Cricket (adult and nymph meals) showed similar values of coefficients of dry matter and energy digestibility. These results indicated that the insect meals investigated in this study present suitable alternatives as feed for angelfish.
Copyright (c) 2026 Raphael Santucci Browczuk Sayão, Thaís da Silva Oliveira, Rafael de Souza Romaneli, Hélio Jacobson da Silva, João Batista Kochenborger Fernandes https://creativecommons.org/licenses/by/4.0
Length-weight relationship of commercial fish species caught on the central coast of Espírito Santo, Southeastern Brazil
This study aimed to establish length–weight relationships (LWR) for fish species captured by the artisanal fleet on the central coast of Espírito Santo, Brazil. Although the landing site was specific, the fish were caught across various areas along the central coast, indicating a broader spatial range than the collection point suggests. Data were collected from February 2023 to July 2024, including fishing gear used, capture location, total length (TL), and total weight (TW) of the specimens. A total of 1,484 individuals were measured, representing 12 species from six orders and 10 families. Haemulidae was the most represented family, and Haemulon aurolineatum was the most abundant species. Caranx crysos and Balistes capriscus showed the highest mean lengths (35.50 and 34.59 cm), while H. aurolineatum and Cynoscion jamaicensis had the lowest (20.39 and 22.99 cm). Caranx crysos and Cephalopholis fulva were the only species exhibiting isometric and allometric growth, respectively (b = 2.94; b = 3.08). The remaining species showed negative allometric growth, with a ranging from 0.006 to 3.798, b from 1.152 to 3.08, and r2 from 0.4758 to 0.9636. These results provide biological information for key commercial species and support actions for sustainable fisheries management and conservation in Espírito Santo.
Copyright (c) 2026 Clara de Oliveira Xavier, Patrick Lopes Serrão Leal, Joelson Musiello-Fernandes, Mauricio Hostim-Silva, Natalia Priscila Alves Bezerra https://creativecommons.org/licenses/by/4.0
Histological and histochemical analysis to identify type I and III collagen in the skins of different shark species
During fishing activities, solid waste such as shark skin is often discarded by the processing industry, contributing to environmental pollution and representing the loss of a material with high biotechnological potential, especially as a source of collagen. The objective of this research was to characterize the structure of the skin and identify the types of collagen present in four shark species: Rhizoprionodon lalandii, Squalus albicaudus, Sphyrna lewini, and Squatina guggenheim. The samples were obtained from artisanal fishing in the municipality of Saquarema, Rio de Janeiro, and specimens provided by the Santos Fisheries Institute, São Paulo, all from bycatch and already dead. For histological analysis, tissue fragments were collected from the left side of the animals and stained with haematoxylin-eosin, Masson’s trichrome and Picrosirius red. The results revealed structures already described in the literature, such as mucus, epidermis, dermis, muscle fiber, haemolymphatic vessels and type I collagen, in addition to the presence of type III collagen, not yet evidenced. The result reinforces the high healing capacity of sharks, highlighting the thicker and more resistant skin, with more condensed collagen in S. guggenheim, a demersal species, and the preservation of mucus in S. lewini, associated with the accumulation of collagen fiber, broadening prospects for future biomedical applications.
Copyright (c) 2026 Jéssica Ataide Batista Nigro, Sophia da Silva Vidal, Carlos Eduardo Malavasi Bruno, Eliana de Fátima Marques de Mesquita https://creativecommons.org/licenses/by/4.0
Effects of dietary supplementation with astaxanthin from Haematococcus pluvialis on coloration, zootechnical performance, and antioxidant activity of the ornamental fish Cryptocentrus cinctus
This study evaluated the effects of astaxanthin from Haematococcus pluvialis on coloration, antioxidant activity, and growth performance in Cryptocentrus cinctus. Three dietary treatments were formulated with increasing astaxanthin concentrations: A0 (0%—control), A10 (0.01% of the total dry diet), and A15 (0.015% of the total dry diet). Astaxanthin supplementation significantly enhanced skin pigmentation, with A15 fish exhibiting a distinct yellow coloration (R = 144.75; G = 122.9; B = 48.5). Catalase activity was also the highest in the A15 group (25 UCAT mg-1), suggesting improved antioxidant capacity. Zootechnical performance improved with astaxanthin inclusion, as A15 fish demonstrated greater weight gain (0.44 g), length gain (7.93 mm), and a lower feed conversion ratio (1.10). Overall, dietary supplementation with 0.015% astaxanthin from H. pluvialis enhanced pigmentation, antioxidant response, and growth efficiency in C. cinctus, representing the first report of carotenoid supplementation for this species.
Clarissa Vilela Figueiredo da Silva Campos
Copyright (c) 2026 Géssica Cavalcanti Pereira Mota, Laenne Barbara Silva de Moraes, Deyvid Willame Silva Oliveira, Clarissa Vilela Figueiredo da Silva Campos, Maria do Carmo Mohaupt Marques Ludke, Carlos Yure Barbosa de Oliveira, Alfredo Olivera Gálvez, Ranilson de Souza Bezerra https://creativecommons.org/licenses/by/4.0
Adapting for sustainability: Understanding marine shrimp population dynamics and yield optimization in Brazilian coastal waters
Understanding the impact of exploitation patterns on yields is crucial for ensuring the sustainability of fishing activities. However, data availability can hamper the assessment of how close resources are to optimal exploitation. We gathered simple life history parameters of shrimp stocks in Brazil using published data and applied a yield per recruit model to determine the optimal combinations of first catch length and fishing mortality for maximizing yields. We evaluated five marine shrimp species, Farfantepenaeus subtilis, F. brasiliensis, F. paulensis, Xiphopenaeus kroyeri, and Litopenaeus schmitti, distributed across four major Brazilian regions (North, Northeast, Southeast, and South). A clear pattern emerged: stocks in Northeast demonstrated high yields with appropriate first catch lengths and fishing mortality rates, with only some cases 12% below the optimum level. In contrast, the Southeast region presented more concerning situations. Its fisheries employed very small first catch lengths, capturing individuals at early life stages, below the length of first maturation, harming reproduction and stock replenishment. Combined with high fishing mortality rates, this resulted in yields 37% below the optimal, indicating signs of growth overfishing.
Copyright (c) 2026 Matheus Lourenço Soares da Silva, Humber Agrelli Andrade https://creativecommons.org/licenses/by/4.0
Seasonal variation in the ingestion of anthropogenic particles by Mylossoma duriventre in the Juruá River Valley, state of Acre, Brazil
This study aimed to investigate the seasonal variation in the presence of plastic fragments in the digestive system of Mylossoma duriventre, a species that is both abundant and commercially significant in the Juruá River Valley, state of Acre, Brazil. Two collections were conducted, the first in March 2024 and the second in July-August 2024, in the municipality of Cruzeiro do Sul, state of Acre. Our findings indicated that hydroclimatic factors play a crucial role in the occurrence of microplastics in M. duriventre, with a notable increase in fiber ingestion during the high-water period. These results contribute to a deeper understanding of the environmental risks associated with microplastics and highlight their biological consequences. In addition, this study aimed to raise awareness of the urgent need to reduce plastic usage and implement responsible waste disposal practices.
Copyright (c) 2026 Rodolfo Monteiro Cordeiro, Lucena Rocha Virgílio, Josileide Duarte de Farias https://creativecommons.org/licenses/by/4.0
Analysis of the stomach contents of Arapaima gigas in the Cautário River Basin, Rondônia, Brazil
Arapaima gigas is the largest scaled freshwater fish in the world and can grow to more than 3 meters in length and exceed 252 kg. This species naturally inhabits the flooded areas of the Amazon basin, but it has been found outside this region as a result of intentional or accidental human actions. In this study, we analyzed the items consumed by the A. gigas distributed in the Cautário River, a tributary of the Guaporé River Basin (Rondônia, Brazil), in which pirarucu is not native and requires actions for its eradication. Experimental fisheries were conducted from August 2023 to September 2024. A total of 128 A. gigas were captured (ranging from 1.16 to 2.26 m, with a mean of 1.76 ± 0.31 m, and weight of 24.70 to 111.60 kg, with a mean of 52.37 ± 22.54 kg) and had their stomachs analyzed. It was observed that 104 stomachs were full and 24 were empty. In the stomachs, five categories of food items were classified: fish and fish remains, plant material, debris, crustaceans, and worms. The items with the highest absolute frequency were plant materials (82), fish and fish remain (51), worms (32), and crustaceans (1). It was concluded that the A. gigas of the Cautário River Basin feed mainly on fish, but with a large participation in the diet of plant materials, which may be an indication of involuntary ingestion due to the animal’s voracity or possible onset of food shortages in the study region.
Copyright (c) 2026 Samíria Bárbara Brito Pereira, Nathalya Sousa Oliveira, Fábio Herrera Fernandes, Severino Adriano de Oliveira Lima, Thales Quintão Chagas, Raica Esteves Xavier Meante, Hélio Beltrão, Raniere Garcez Costa Sousa https://creativecommons.org/licenses/by/4.0
Filters and media used in aquaponic system filtration: A systematic review
of different types of filters, including mechanical, biological, and bacteriological, as well as the application of various filtration media, such as bio-balls, sand, and natural materials (e.g., açaí seeds and biochar). The results indicated an increasing trend in publications on this topic, with the United States of America and Malaysia leading the research in this field. While American studies focus on parameters such as hydraulic loading rate, research in Malaysia emphasizes the use of sand as a filtering medium for solid and nutrient removal. The analyzed media range from simple substrates, such as gravel and expanded clay, to more advanced technologies, including hollow fiber membranes and biochar, demonstrating the diversity of approaches in optimizing filtration in aquaponics. This review highlights that the appropriate selection of filters and media plays a key role in the sustainability and efficiency of aquaponic systems, directly influencing water quality, waste removal, and environmental stability in production settings.
Copyright (c) 2025 Robson Silva de Lima, Juliano Silva Lima, Cibele Soares Pontes https://creativecommons.org/licenses/by/4.0
Distribution patterns and influence of environmental variables on the fish assemblages in a neotropical Amazonian river
Based on the river continuum and flood pulse concepts, this study investigated the seasonal, spatial and limnological effects on fish assemblage distribution along the São Miguel River, Amazon basin, Brazil. Fish were sampled and environmental variables measured during the high- and low-water periods in upper, middle and lower sections of the river. The results revealed significant spatial and seasonal effects, as well as interactions between spatial and temporal gradients, which bring about distinct differences in assemblage composition. These patterns were associated with variations in limnological parameters along a longitudinal gradient. Species distribution and turnover were shaped by both the flood pulse and the spatial gradient, which are processes that drive environmental changes and influence trophic resource dynamics – key factors for species occurrence. Overall, our findings indicate that the structure of the fish assemblages in the São Miguel River is shaped by hydrological variation, with the flood pulse being the primary regulating factor of the taxonomic composition of the ichthyofauna.
Copyright (c) 2026 Eloi Bispo Bezerra-Neto, Diego Maia Zacardi, Lucas Silva de Oliveira, Ruineris Almada Cajado, Carlos Edwar de Carvalho Freitas, Rodrigo Vieira Alves Amaral, Sandro de Vargas Schons, Raniere Garcez Costa Sousa https://creativecommons.org/licenses/by/4.0
Scientiometric analysis of the capture of elasmobranchs as bycatch off the Amazon coast
Fisheries impact aquatic resources, with many species taken as bycatch, and thus represent a global threat to many species, in prticular, the elasmobranchs. Given the lack of reliable bycatch data, this study conducted a systematic review in four scientific databases to identify publications addressing elasmobranch bycatch along the Amazon coast. Between 2002 and 2022, 27 studies were published, docummenting the bycatch 28 sharks and 14 rays species. The literature search revealed an increase in the frequency of publication after 2015, with Brazil dominating the research output, while neighboring countries contributed limited data. Most studies involved trawling, while gillnet and longline fisheries were poorly represented. Worldwide, 78.0% of sharks and 57.0% of rays are classified as threatened. The review reveals persistent problems, including deficiencies in the identification, delays in data publication, and weak monitoring and enforcement. These findings emphasize the urgent need for improved research coverage, monitoring, and conservations actions.
Copyright (c) 2026 Tiago Sousa de Farias, Jorge Luiz Silva Nunes, João Bráullio de Luna Sales , Luis Fernando da Silva Rodrigues Filho https://creativecommons.org/licenses/by/4.0
Physicochemical, microbiological, and sensorial characteristics of cooked, marinated, and vacuum-packed oysters under frozen storage
This study evaluated the quality of frozen oyster meat. Seven hundred and twenty Crassostrea gigas oysters (~7-cm shell length) were steam-cooked at 100°C for 30 minutes and later divided into two groups. Group 1 was submerged for 20 minutes in water and ice; and group 2 in a solution containing water, ice, and 4% vinegar (4% acidity, produced by fermentation of acetic alcohol). After cooling, the oysters were shucked, and the meat was packed with a vacuum sealer in plastic bags containing 24 oysters each. The experiment evaluated physicochemical (pH, moisture, and total volatile bases nitrogen) and microbiological (total mesophilic and psychrotrophic bacterial counts) parameters every 45 days and performed sensory analyses after 180 and 365 days of storage. Adequate physicochemical and microbial characteristics were registered for up to one year of storage for both protocols. Marination with vinegar reduced the levels of psychrotrophic bacteria during storage, and the sensory analysis judges preferred the marinated oysters.
Copyright (c) 2025 Fabiele Bernardi, Felipe Matarazzo Suplicy, Robson Ventura de Souza, Marília Miotto, Giustino Tribuzi https://creativecommons.org/licenses/by/4.0
Changes in common carp (Cyprinus carpio) sperm quality and membrane lipid composition related to cryopreservation by Tribulus terrestris ris
Docosahexaenoic acid (DHA) was the major polyunsaturated fatty acid (PUFA) in the sperm plasma membrane, and the levels of PUFAs decreased in treated groups during the cryopreservation process. The supplementation of TT (Tribulus terrestris) to Cyprinus carpio sperm at 200 µg∙L-1 positively affected the maintenance of motility parameters and FAs levels after the freeze-thaw cycle, and TT can be used as an herbal medicine instead of synthetic pharmaceuticals to improve the productive performance in aquaculture.
Copyright (c) 2026 Abdullatif Ölçülü, Esin Özçiçk, Filiz Kutluyer Kocabaş, Mehmet Kocabaş, Volkan Kizak, Ökkeş Yilmaz https://creativecommons.org/licenses/by/4.0
Effects of fermented grape pomace (Vitis sp.) inclusion on growth performance, lipid peroxidation, and hematology of juvenile Mugil liza
This study investigated the potential use of fermented grape pomace (FerGP) as a dietary ingredient for juvenile mullet (Mugil liza). For this purpose, growth perfomance, hepatic lipid peroxidation, and hematology of juvenile mullet fed various levels of FerGP were evaluated. A total of 225 fish (0.57 ± 0.01 g) were randomly distributed into 15 tanks and fed ad libitum three times a day for 65 days with different levels of FerGP (2.5, 5, 10, and 15%). There were no significant differences (p > 0.05) in hematological parameters. Regarding the zootechnical parameters, FerGP 15% showed higher specific growth rate compared to the other treatments. Dietary inclusion of FerGP significantly reduced hepatic lipid peroxidation, as indicated by a decrease in thiobarbituric acid reactive substances (TBARS) values. The results demonstrated that the inclusion of FerGP in the diet is feasible and safe, promoting benefits to the productive performance of juvenile mullet.
Copyright (c) 2026 Cybele Guimarães Pinheiro, Luis Alberto Romano, José Maria Monserrat, Juan Buitrago Ramírez, Marcelo Borges Tesser https://creativecommons.org/licenses/by/4.0
Methods applied to the management of invasive pirarucu in protected areas in the Amazon Basin
The pirarucu (Arapaima gigas) is native to the Amazon basin, but in Rondônia, Brazil, it occurs naturally only in the far north. For multiple reasons, it has become an invasive alien species in this biome and in other Brazilian states, with reported impacts on biodiversity and the food security of riverine populations. This study developed a management technique for the control/eradication of invasive pirarucu, based on the sustainable management of native pirarucu in Mamirauá, Amazonas, Brazil. After adaptation, eradication management was implemented and validated with riverine communities of the Cautário River. Between 2022 and 2024, 126 residents were trained as managers to monitor populations and conduct managed fisheries under the supervision of environmental agencies. The process also structured a production chain for commercializing invasive pirarucu. In total, 633 pirarucu were captured, generating R$ 302,916.54 (US$ 58,417.20) for local communities. Thus, invasive pirarucu management can reduce its populations and provide supplementary income to riverine communities, strengthening local bioeconomy and governance initiatives. Continued fishing and systematic population monitoring in the coming years are necessary to evaluate management effectiveness and deepen investigations into invasions and socio-environmental impacts in protected Amazonian areas.
Copyright (c) 2026 Thales Quintão Chagas, Celso Costa Santos Júnior, Lidiane França da Silva Tomasoni, Thaylla Araújo dos Santos, Chirlaine Alves Ribeiro Varão, Marcos Garcia da Silva, Rodrigo Rios Barreto, Evandro de Jeasus Tavares de Souza, Raniere Garcez Costa Sousa https://creativecommons.org/licenses/by/4.0
Fisheries biology of Plagioscion squamosissimus (Heckel, 1840) in a neotropical reservoir in southeastern Brazil
Plagioscion squamosissimus (silver croaker), a non-native species from the Amazon Basin, is one of the main resources supporting artisanal fisheries in the Três Irmãos Reservoir, São Paulo state, Brazil. This study evaluated its fishery biology and population characteristics between 2015 and 2018, aiming to provide information to support species management. Data were obtained through fishery monitoring of 93 artisanal fishers and quarterly scientific sampling conducted in the lotic, transitional, and lentic zones of the reservoir. Catch composition, fishing effort, environmental variables, length-weight relationship, length at first maturity (L50), and gillnet selectivity were analyzed. Spatial and temporal variability in catch per unit effort (CPUE) was assessed using principal component analysis and repeated-measures analysis of variance. The average annual landing of silver croaker was 53.5 tons, with a mean CPUE of 11.7 kg fisher-1 day-1. CPUE was associated with temperature, with the highest yields occurring in March, indicating a preference for lentic habitats. The species exhibited isometric growth (b = 3), continuous reproduction with a peak in spring, and a L50 of 15.9 cm total length. The results highlight the importance of silver croaker to local fisheries and suggest gillnet mesh sizes ≥ 8 cm to enhance commercial yields, whereas smaller meshes may be used in population control strategies.
Copyright (c) 2026 Anderson Arimura Matsumoto, Paula Maria Gênova de Castro Campanha, Maria Letizia Petesse, Lídia Sumile Maruyama, Midiã Lima Brazão, Gianmarco Silva Petesse https://creativecommons.org/licenses/by/4.0
Low genetic variability in Prochilodus lacustris and Prochilodus nigricans from river basins of northern and northeastern Brazil
The genus Prochilodus is an important fish resource. The various species within this genus are morphologically very similar, making reliable taxonomic identification difficult and creating uncertainty regarding the exact status of the different forms. This study aimed to evaluate the genetic differentiation between two species of Prochilodus belonging to the same lineage from the Maranhão and Amazon River basins based on mitochondrial DNA markers (16S rRNA, COI, Cyt b) and nuclear (TROP) DNA sequences. A total of 151 samples were collected from the Maranhão and Amazon rivers, followed by DNA extraction, polymerase chain reaction, sequencing, and data analysis, with the gene fragments analyzed separately and concatenated. The results revealed a strong genetic similarity between the species, with low genetic divergence values (0 to 0.35%) for the genes under study.
Copyright (c) 2026 Elidy Rayane de Rezende Franca, Jordânia Leticia do Nascimento Silva, Fernanda da Conceição Silva, Maria Histelle Sousa Nascimento, Fabiano Corrêa, Maria Claudene Barros, Elmary da Costa Fraga https://creativecommons.org/licenses/by/4.0
Feeding rates for tambatinga (Colossoma macropomum × Piaractus brachypomus): Effects on zootechnical performance and physiology parameters
The study evaluated the impact of feeding rates (6, 8, 10, and 12% of biomass) on the growth and physiological responses of Colossoma macropomum × Piaractus brachypomus over 40 days. A total of 600 juveniles (1.61 ± 0.30 g, 4.1 ± 0.9 cm) were distributed in 12 tanks. Performance parameters were measured every 10 days, and biochemical, hematological, and somatic indices were analyzed after 40 days. Growth indicators such as final weight and feed conversion ratio improved with higher feeding rates during specific periods. Plasma glucose and red blood cells showed a quadratic response to feeding rates, while mean corpuscular volume increased proportionally. A 12% feeding rate was optimal for the initial 10 days, enhancing zootechnical indices. From 11 to 40 days, a 6% feeding rate is recommended, as growth performance did not significantly vary across rates. Feeding rates had minimal effects on biochemical, hematological, and somatic indices during the trial.
Copyright (c) 2025 Sidney dos Santos Silva, Camila Oliveira Paranhos, Imaculada de Morais Carvalho Ananias, Thamara Bentivole Magalhães, André de Sena Souza, Fábio Aremil Costa dos Santos, Ronald Kennedy Luz, Gisele Cristina Favero https://creativecommons.org/licenses/by/4.0
Integrated multitrophic aquaculture in biobloc technology with different fertilization approaches
The aim of this study was to evaluate the performance of Penaeus vannamei and Oreochromis niloticus in an integrated multi-trophic system with biofloc technology using different strategies. Two treatments were developed: TC (chemoautotrophic) and TH (heterotrophic). The TC treatment started 46 days before stocking the animals, with inorganic fertilization. In the TH treatment, organic fertilization was carried out after stocking the animals. Four hundred shrimp∙m-2 (1.00 ± 0.04 g) and 45 tilapia fry∙m-3 (25 ± 0.50 g) were stocked for 86 days. Water quality parameters such as temperature, oxygen, and pH were monitored daily. Total ammonia, nitrite, nitrate, phosphate, total suspended solids, and settleable solids were monitored twice a week. Prior fertilization in the chemoautotrophic treatment avoided high concentrations of nitrogen compounds in the system, due to the prior establishment of bacteria, compared to the heterotrophic treatment. The increase in nitrogen compounds in heterotrophic treatment led to higher water use, reduction in feed and consequently lower shrimp growth performance compared to the chemoautotrophic system. Tilapia’s growth was not affected. Therefore, the use of prior fertilization in chemoautotrophic treatment allowed for a higher final weight, yield of shrimp, and greater environmental sustainability.
Copyright (c) 2026 Jorge Santos, Andrezza Carvalho Chagas, Mariana Holanda, Mayra Gonçalves, Wilson Wasielesky Júnior, Luis Henrique Poersch https://creativecommons.org/licenses/by/4.0
Contribution to the knowledge of the biology of Prochilodus lineatus (Valenciennes, 1837) in a neotropical river basin
This study provides information on the spatial distribution, population variables, and natural diet of the species Prohilodus lineatus in the Sorocaba River Basin, located in the state of São Paulo, SP, Brazil. The species is distributed mainly along the middle and lower Sorocaba River channel, in addition to its tributaries. A total of 74 individuals were captured, 46 females and 28 males of P. lineatus. The captured specimens ranged in length from 31.0 cm to 48.0 cm and weighed from 177 g to 4530 g. Females (n = 46) had a mean weight of 892.34 ± 782.34 g and a mean length of 44.65 ± 2.54 cm, while males (n = 28) had a mean weight of 752.25 ± 390.33 g and a mean length of 44.57 ± 3.25 cm. The weight-length relationship was not statistically different between sexes, and both sexes showed negative allometric growth, with a regression constant (b) value of 2.6889 for females and 2.7586 for males. The species’ natural diet consisted mainly of items of autochthonous origin, mainly vegetables, seeds, muddy and sandy sediments, filamentous algae, Chironomid larvae, nematode worms, and insect eggs, in addition to microplastic particles detected in 5% of the specimens.
Copyright (c) 2025 Larissa Leandra Moro Silva, Julia Fernanda de Camargo Teles Miranda, Elder Samuel Lopes Martins, Larissa Silva Tavares de Oliveira, Renato Filho da Silva Juvenal, Suellen Mariano da Silva, Allan Clé Porto, Welber Senteio Smith https://creativecommons.org/licenses/by/4.0
Carrying capacity for Nile tilapia production in net cages in tropical reservoirs during an extreme drought
This study assessed the production carrying capacity for Nile tilapia (Oreochromis niloticus) in net cages in reservoirs of the Brazilian semi-arid region during a supra-seasonal drought. It used the phosphorus mass balance models to estimate nutrient assimilation, with phosphorus concentration limits in the water column were set at 30 μg.L⁻¹, according to Brazilian legislation, and 60 μg.L⁻¹ for eutrophied environments. In the Santa Cruz reservoir, the phosphorus assimilation capacity was 5,848 kg.year⁻¹ at 60 μg.L⁻¹, while in Umari it was 572.7 kg.year⁻¹ at 30 μg.L⁻¹ and 4,620 kg.year⁻¹ at 60 μg.L⁻¹. The carrying capacities were 680 tonnes in Santa Cruz at 60 μg.L⁻¹, and in Umari, 63 tonnes at 30 μg.L⁻¹ and 508 tonnes at 60 μg.L⁻¹. Despite higher phosphorus loading in Umari, Santa Cruz showed greater capacity at 60 μg.L⁻¹ due to its larger water volume. The study highlights the importance of reservoir morphometry and hydrological parameters for aquaculture sustainability during extreme droughts, and uses mass balance models to propose practices that balance production and environmental conservation.
Copyright (c) 2025 Rodrigo Sávio Teixeira de Moura, Ronaldo Angelini, Nara Poliana Meneses de Oliveira, Wagner Cotroni Valenti, Gustavo Gonzaga Henry-Silva https://creativecommons.org/licenses/by/4.0
Scientometric analysis of climate change in artisanal fisheries over 2004–2024: trends, networks and knowledge gaps
Climate change in artisanal fisheries has amassed increasing attention in the scientific community due to the potential damage to fishermen’s livelihoods. This study presents a scientometric analysis of English-language articles from the Scopus database examining the relationship between climate change and artisanal fishing over the last 20 years. We analyzed trends in publication output, research areas, contributing countries, authors, affiliations, journals, funding networks, and keywords. Data was processed using Bibliometrix and VOSviewer. Our findings indicated an exponential increase in publications since 2014. The United States of America is the leading producer of articles, yet European countries receive more citations, highlighting their global influence. Additionally, most countries engage in international research collaborations. In Latin America, Brazil stands out as the leading country in terms of production, citations, and funding. While European and North American researchers dominate in publication output and co-authorship, Malaysia and South Korea also play significant roles. Notably, assessing the impacts of climate change on artisanal fishery requires a multidisciplinary approach and international cooperation rather than relying on a single thematic perspective. Furthermore, our analysis highlighted critical knowledge gaps and underscores the need for increased investment in research and publications, particularly in developing countries of the Global South.
Copyright (c) 2025 Adriano Prysthon da Silva https://creativecommons.org/licenses/by/4.0