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1.
Chemosphere ; 353: 141578, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38430938

RESUMO

Pesticide contamination and its adverse effects on native freshwater species continue to be a worldwide major concern, mainly in developing countries. Passive biomonitoring of pesticide pollution in shallow lakes may be achieved by the simultaneous use of fish and wetland plants. Thus, the present study aimed to evaluate the occurrence of current-use pesticides in the surface water of a shallow lake of the Austral Pampas region (Buenos Aires Province, Argentina) surrounded by intensive agricultural activities and its relationship with a battery of biomarkers, including oxidative stress and genotoxicity, in two native species, the fish Oligosarcus jenynsii and the macrophyte Bidens laevis. A total of 26 pesticide residues were analyzed, and the main ones detected were glyphosate and its metabolite aminomethylphosphonic acid (AMPA), chlorpyrifos, and imidacloprid. In O. jenynsii, hydrogen peroxide (H2O2) content in the liver increased with chlorpyrifos occurrence, while malondialdehyde (MDA) levels in the brain and liver increased with the presence of both chlorpyrifos and glyphosate. In B. laevis, H2O2 and MDA levels in leaves and roots increased with AMPA occurrence. Also, leaf H2O2 contents and root MDA levels increased with chlorpyrifos concentration. In contrast, catalase and peroxidase activities in roots decreased with AMPA and chlorpyrifos occurrence. In both species, mainly H2O2 and MDA levels demonstrated their sensitivity to be used as biomarkers in the biomonitoring of current-use pesticide pollution in shallow lakes. Their use may provide information to plan strategies for environmental conservation by government institutions or decision-makers, and to assess the biota health status.


Assuntos
Clorpirifos , Praguicidas , Poluentes Químicos da Água , Animais , Praguicidas/análise , Lagos , Clorpirifos/toxicidade , Monitoramento Biológico , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/análise , Argentina , Peróxido de Hidrogênio , Monitoramento Ambiental , Estresse Oxidativo , Peixes/metabolismo , Biomarcadores/metabolismo , Poluentes Químicos da Água/análise
2.
PeerJ ; 12: e17121, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38525274

RESUMO

Acquiring knowledge about the environment is crucial for survival. Animals, often driven by their exploratory tendencies, gather valuable information regarding food resources, shelter, mating partners, etc. However, neophobia, or avoiding novel environmental stimuli, can constrain their exploratory behaviour. While neophobia can reduce potential predation risks, decreased exploratory behaviour resulting from it may limit the ability to discover highly rewarding resources. Dogs (Canis familiaris) living in semi-urban and urban environments as free-ranging populations, although subject to various selection forces, typically have negligible predation pressure. These dogs are scavengers in human-dominated environments; thus, selection against object-neophobia can provide benefits when searching for novel food resources. Although captive pack-living dogs are known to be less neophobic than their closest living ancestors, wolves (Canis lupus), little is known about free-ranging dogs' behavioural responses to novel objects, particularly in foraging contexts. Using an object choice experiment, we tested 259 free-ranging dogs from two age classes, adult and juvenile, to investigate their object-neophobia in a scavenging context. We employed a between-subject study design, providing dogs with a familiar and a potentially novel object, both baited with equal, hidden food items. Adult and juvenile dogs significantly inspected the novel object first compared to the familiar one, even when the hidden food item was partially visible. To validate these findings, we compared novel objects with different strengths of olfactory cues (baited vs. false-baited) and found that they were inspected comparably by adults and juveniles. No significant differences were found in the latencies to inspect the objects, suggesting that free-ranging dogs may still be cautious when exploring their environments. These results indicate that free-ranging dogs, evidently from an early ontogenetic phase, do not show object-neophobia, as demonstrated by their preference for novel over familiar food sources. We conclude that little to no constraint of neophobia on exploratory behaviour in semi-urban and urban-dwelling animals can guide foraging decision-making processes, providing adaptive benefits.


Assuntos
Animais Domésticos , Lobos , Animais , Cães , Humanos , Sinais (Psicologia) , Comportamento Exploratório , Recompensa , Peixes
3.
J Environ Manage ; 355: 120476, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38442657

RESUMO

Worldwide, states are gazetting new Marine Protected Areas (MPAs) to meet the international commitment of protecting 30% of the seas by 2030. Yet, protection benefits only come into effect when an MPA is implemented with activated regulations and actively managed through continuous monitoring and adaptive management. To assess if actively managed MPAs are the rule or the exception, we used the Mediterranean and Black Seas as a case study, and retrieved information on monitoring activities for 878 designated MPAs in ten European Union (EU) countries. We searched for scientific and grey literature that provides information on the following aspects of MPA assessment and monitoring: ecological (e.g., biomass of commercially exploited fish), social (e.g., perceptions of fishers in an MPA), economic (e.g., revenue of fishers) and governance (e.g., type of governance scheme). We also queried MPA authorities on their past and current monitoring activities using a web-based survey through which we collected 123 responses. Combining the literature review and survey results, we found that approximately 16% of the MPA designations (N = 878) have baseline and/or monitoring studies. Most monitoring programs evaluated MPAs based solely on biological/ecological variables and fewer included social, economic and/or governance variables, failing to capture and assess the social-ecological dimension of marine conservation. To increase the capacity of MPAs to design and implement effective social-ecological monitoring programs, we recommend strategies revolving around three pillars: funding, collaboration, and technology. Following the actionable recommendations presented herein, MPA authorities and EU Member States could improve the low level of MPA monitoring to more effectively reach the 30% protection target delivering benefits for biodiversity conservation.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Animais , Biomassa , Ecossistema , Pesqueiros , Peixes/fisiologia , Oceanos e Mares , Inquéritos e Questionários
4.
Nat Food ; 5(3): 221-229, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38509235

RESUMO

Wild fish used as aquafeeds could be redirected towards human consumption to support sustainable marine resource use. Here we use mass-balance fish-in/fish-out ratio approaches to assess nutrient retention in salmon farming and identify scenarios that provide more nutrient-rich food to people. Using data on Norway's salmon farms, our study revealed that six of nine dietary nutrients had higher yields in wild fish used for feeds, such as anchovies and mackerel, than in farmed salmon production. Reallocating one-third of food-grade wild feed fish towards direct human consumption would increase seafood production, while also retaining by-products for use as aquafeeds, thus maximizing nutrient utilization of marine resources.


Assuntos
Óleos de Peixe , Perciformes , Animais , Humanos , Peixes , Alimentos Marinhos/análise , Salmão , Nutrientes
5.
C R Biol ; 347: 1-8, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38441104

RESUMO

Tracing the phylogenetic relationships between species is one of the fundamental objectives of evolutionary biology. Since Charles Darwin's seminal work in the 19th century, considerable progress has been made towards establishing a tree of life that summarises the evolutionary history of species. Nevertheless, substantial uncertainties still remain. Specifically, the relationships at the origins of teleost fishes have been the subject of extensive debate over the last 50 years. This question has major implications for various research fields: there are almost 30,000 species in the teleost group, which includes invaluable model organisms for biomedical, evolutionary and ecological studies. Here, we present the work in which we solved this enigma. We demonstrated that eels are more closely related to bony-tongued fishes than to the rest of teleost fishes. We achieved this by taking advantage of new genomic data and leveraging innovative phylogenetic markers. Notably, in addition to traditional molecular phylogeny methods based on the evolution of gene sequences, we also considered the evolution of gene order along the DNA molecule. We discuss the challenges and opportunities that these new markers represent for the field of molecular phylogeny, and in particular the possibilities they offer for re-examining other controversial branches in the tree of life.


Retracer les relations de parenté entre espèces est un des objectifs fondamentaux de la biologie évolutive. Depuis les travaux fondateurs de Charles Darwin au 19 e siècle, des progrès considérables ont été effectués afin d'établir un arbre du vivant récapitulant l'histoire évolutive de l'ensemble des espèces. Néanmoins, d'importantes zones d'ombre subsistent. En particulier, les relations de parenté à l'origine de la classe des poissons téléostéens ont fait l'objet de nombreux débats, et ce depuis plus de 50 ans. La résolution de cette branche représente un enjeu majeur pour divers domaines de recherche  : on recense près de 30 000 espèces dans ce groupe, qui comprend des organismes modèles précieux à la recherche biomédicale, sur l'évolution, ou en écologie. Nous présentons ici les travaux qui nous ont permis d'élucider cette énigme. Nous avons pu démontrer que le groupe des « anguilliformes ¼ est plus proche de celui des poissons à langue osseuse qu'il ne l'est du reste des poissons téléostéens. Pour ce faire, nous avons tiré avantage de nouvelles données génomiques et de l'utilisation de marqueurs phylogénétiques innovants. En effet, en complément des méthodes de phylogénie moléculaire classiques qui se basent sur l'évolution des séquences des gènes, nous considérons également l'évolution de l'ordre des gènes le long de la molécule d'ADN. Nous discutons des défis et opportunités que ces nouveaux marqueurs représentent pour le domaine de la phylogénie moléculaire, et en particulier des possibilités qu'ils offrent pour réexaminer d'autres positions controversées de l'arbre du vivant.


Assuntos
Enguias , Peixes , Animais , Filogenia , Peixes/genética
6.
Math Biosci Eng ; 21(2): 1765-1790, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38454659

RESUMO

Detecting abnormal surface features is an important method for identifying abnormal fish. However, existing methods face challenges in excessive subjectivity, limited accuracy, and poor real-time performance. To solve these challenges, a real-time and accurate detection model of abnormal surface features of in-water fish is proposed, based on improved YOLOv5s. The specific enhancements include: 1) We optimize the complete intersection over union and non-maximum suppression through the normalized Gaussian Wasserstein distance metric to improve the model's ability to detect tiny targets. 2) We design the DenseOne module to enhance the reusability of abnormal surface features, and introduce MobileViTv2 to improve detection speed, which are integrated into the feature extraction network. 3) According to the ACmix principle, we fuse the omni-dimensional dynamic convolution and convolutional block attention module to solve the challenge of extracting deep features within complex backgrounds. We carried out comparative experiments on 160 validation sets of in-water abnormal fish, achieving precision, recall, mAP50, mAP50:95 and frames per second (FPS) of 99.5, 99.1, 99.1, 73.9% and 88 FPS, respectively. The results of our model surpass the baseline by 1.4, 1.2, 3.2, 8.2% and 1 FPS. Moreover, the improved model outperforms other state-of-the-art models regarding comprehensive evaluation indexes.


Assuntos
Peixes , Água , Animais , Distribuição Normal
7.
Glob Chang Biol ; 30(3): e17187, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38456203

RESUMO

Body size is a key component of individual fitness and an important factor in the structure and functioning of populations and ecosystems. Disentangling the effects of environmental change, harvest and intra- and inter-specific trophic effects on body size remains challenging for populations in the wild. Herring in the Northwest Atlantic provide a strong basis for evaluating hypotheses related to these drivers given that they have experienced significant warming and harvest over the past century, while also having been exposed to a wide range of other selective constraints across their range. Using data on mean length-at-age 4 for the sixteen principal populations over a period of 53 cohorts (1962-2014), we fitted a series of empirical models for temporal and between-population variation in the response to changes in sea surface temperature. We find evidence for a unified cross-population response in the form of a parabolic function according to which populations in naturally warmer environments have responded more negatively to increasing temperature compared with those in colder locations. Temporal variation in residuals from this function was highly coherent among populations, further suggesting a common response to a large-scale environmental driver. The synchrony observed in this study system, despite strong differences in harvest and ecological histories among populations and over time, clearly indicates a dominant role of environmental change on size-at-age in wild populations, in contrast to commonly reported effects of fishing. This finding has important implications for the management of fisheries as it indicates that a key trait associated with population productivity may be under considerably less short-term management control than currently assumed. Our study, overall, illustrates the need for a comparative approach within species for inferences concerning the many possible effects on body size of natural and anthropogenic drivers in the wild.


Assuntos
Ecossistema , Peixes , Animais , Pesqueiros , Temperatura , Tamanho Corporal
8.
J Wound Care ; 33(Sup3a): lxxiv-lxxx, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38457271

RESUMO

OBJECTIVE: The purpose of the study was to compare the healing potential of bubaline small intestinal matrix (bSIM) and fish swim bladder matrix (FSBM) on full-thickness skin wounds in rabbits. METHOD: Four full-thickness skin wounds (each 20×20mm) were created on the dorsum of 18 rabbits that were divided into three groups based on treatment: untreated sham control (I), implanted with double layers of bSIM (II) and implanted with double layers of FSBM (III). Macroscopic, immunologic and histologic observations were made to evaluate wound healing. RESULTS: Gross healing progression in the bSIM and FSBM groups showed significantly (p<0.05) less wound contraction compared with the sham group. The IgG concentration in rabbit sera was significantly (p<0.05) lower in the FSBM group compared with the bSIM group by enzyme-linked immunosorbent assay. The stimulation index of peripheral blood lymphocytes was significantly (p<0.05) lower in the FSBM group compared with the bSIM group by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Implantation of FSBM resulted in improved re-epithelialisation, neovascularisation and fibroplasia. CONCLUSION: The FSBM is a more effective dermal substitute when compared with the bSIM for full-thickness skin wound repair in rabbit.


Assuntos
Derme Acelular , Lesões dos Tecidos Moles , Animais , Coelhos , Cicatrização , Pele/lesões , Transplante de Pele/métodos , Peixes
9.
PLoS One ; 19(3): e0298970, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38457426

RESUMO

DNA barcoding, based on mitochondrial markers, is widely applied in species identification and biodiversity studies. The aim of this study was to establish a barcoding reference database of fishes inhabiting the Cube River from Western Ecuador in the Chocó-Darien Global Ecoregion (CGE), a threatened ecoregion with high diversity and endemism, and evaluate the applicability of using barcoding for the identification of fish species. Barcode sequences were obtained from seven orders, 17 families, 23 genera and 26 species, which were validated through phylogenetic analysis, morphological measurements, and literature review. Our results showed that 43% of fish species in this region are endemic, confirmed the presence of known species in the area, and included the addition of three new records of native (Hoplias microlepis, Rhamdia guatemalensis and Sicydium salvini) and an introduced species (Xiphophorus maculatus) to Ecuador. In addition, eight species were barcoded for the first time. Species identification based on barcoding and morphology showed discrepancy with species lists from previous studies in the CGE, suggesting that the current baseline of western fishes of Ecuador is still incomplete. Because this study analyzed fishes from a relatively small basin (165 km2), more molecular-based studies focusing on fish are needed to achieve a robust sequence reference library of species inhabiting Western Ecuador. The new sequences of this study will be useful for future comparisons and biodiversity monitoring, supporting the application of barcoding tools for studying fish diversity in genetically unexplored regions and to develop well-informed conservation programs.


Assuntos
Peixes-Gato , Rios , Humanos , Animais , Espécies Introduzidas , Código de Barras de DNA Taxonômico/métodos , Filogenia , Equador , Complexo IV da Cadeia de Transporte de Elétrons/genética , Peixes , DNA/genética , Peixes-Gato/genética , Biodiversidade
11.
J R Soc Interface ; 21(212): 20230630, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38442859

RESUMO

Modern computing has enhanced our understanding of how social interactions shape collective behaviour in animal societies. Although analytical models dominate in studying collective behaviour, this study introduces a deep learning model to assess social interactions in the fish species Hemigrammus rhodostomus. We compare the results of our deep learning approach with experiments and with the results of a state-of-the-art analytical model. To that end, we propose a systematic methodology to assess the faithfulness of a collective motion model, exploiting a set of stringent individual and collective spatio-temporal observables. We demonstrate that machine learning (ML) models of social interactions can directly compete with their analytical counterparts in reproducing subtle experimental observables. Moreover, this work emphasizes the need for consistent validation across different timescales, and identifies key design aspects that enable our deep learning approach to capture both short- and long-term dynamics. We also show that our approach can be extended to larger groups without any retraining, and to other fish species, while retaining the same architecture of the deep learning network. Finally, we discuss the added value of ML in the context of the study of collective motion in animal groups and its potential as a complementary approach to analytical models.


Assuntos
Aprendizado Profundo , Animais , Comportamento de Massa , Peixes , Aprendizado de Máquina , Movimento (Física)
12.
DNA Res ; 31(2)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38451834

RESUMO

Pacific saury (Cololabis saira) is a commercially important small pelagic fish species in Asia. In this study, we conducted the first-ever whole genome sequencing of this species, with single molecule, real-time (SMRT) sequencing technology. The obtained high-fidelity (HiFi) long-read sequence data, which amount to ~30-folds of its haploid genome size that was measured with quantitative PCR (1.17 Gb), were assembled into contigs. Scaffolding with Hi-C reads yielded a whole genome assembly containing 24 chromosome-scale sequences, with a scaffold N50 length of 47.7 Mb. Screening of repetitive elements including telomeric repeats was performed to characterize possible factors that need to be resolved towards 'telomere-to-telomere' sequencing. The larger genome size than in medaka, a close relative in Beloniformes, is at least partly explained by larger repetitive element quantity, which is reflected in more abundant tRNAs, in the Pacific saury genome. Protein-coding regions were predicted using transcriptome data, which resulted in 22,274 components. Retrieval of Pacific saury homologs of aquaporin (AQP) genes known from other teleost fishes validated high completeness and continuity of the genome assembly. These resources are available at https://treethinkers.nig.ac.jp/saira/ and will assist various molecular-level studies in fishery science and comparative biology.


Assuntos
Beloniformes , Pesqueiros , Animais , Sequência de Bases , Cromossomos , Peixes/genética , Biologia , Beloniformes/genética , Filogenia
13.
PLoS One ; 19(3): e0298394, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38451937

RESUMO

Atlantic tarpon (Megalops atlanticus) are capable of long-distance migrations (hundreds of kilometers) but also exhibit resident behaviors in estuarine and coastal habitats. The aim of this study was to characterize the spatial distribution of juvenile tarpon and identify migration pathways of adult tarpon in the northern Gulf of Mexico. Spatial distribution of juvenile tarpon was investigated using gillnet data collected by Texas Parks and Wildlife Department (TPWD) over the past four decades. Generalized additive models (GAMs) indicated that salinity and water temperature played a significant role in tarpon presence, with tarpon occurrences peaking in the fall and increasing over the past four decades in this region. Adult tarpon caught off Texas (n = 40) and Louisiana (n = 4) were tagged with acoustic transmitters to characterize spatial and temporal trends in their movements and migrations. Of the 44 acoustic transmitters deployed, 18 of the individuals were detected (n = 16 west of the Mississippi River Delta and n = 2 east of the Mississippi River Delta). Tarpon tagged west of the Mississippi River Delta off Texas migrated south in the fall and winter into areas of south Texas and potentially into Mexico, while individuals tagged east of the delta migrated into Florida during the same time period, suggesting the presence of two unique migratory contingents or subpopulations in this region. An improved understanding of the habitat requirements and migratory patterns of tarpon inhabiting the Gulf of Mexico is critically needed by resource managers to assess the vulnerability of each contingent to fishing pressure, and this information will guide multi-state and multi-national conservation efforts to rebuild and sustain tarpon populations.


Assuntos
Ecossistema , Peixes , Humanos , Animais , Golfo do México , Animais Selvagens , Movimento
14.
J Texture Stud ; 55(2): e12824, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38453153

RESUMO

To inhibit the quality deterioration caused by the frozen storage of surimi products, this work investigated the effect of freezing methods, including raw-freezing-setting-heating, raw-setting-freezing-heating, and raw-setting-heating-freezing, on quality changes in surimi gel. The moisture loss, physical-chemical properties, and protein structure conformation of surimi gel derived from Bombay duck (BD) were assessed following frozen storage periods of 20, 40, and 60 days. The findings suggest that the raw-setting-heating-freezing method yielded optimal surimi gel properties with extended frozen storage time. Employing this approach led to a reduction in thawing loss, while cooking loss remained constant. After 60 days of frozen storage, the hardness exhibited an initial increase followed by a subsequent decrease, and water-holding capacity increased to 68.2%. Notably, the impact on surimi gel during the late stage of frozen storage was more pronounced throughout the formation of ice crystals, resulting in decreased disulfide bond content. Scanning hematoxylin-eosin (HE) staining slices of samples following thawing and heating demonstrated that the raw-setting-heating-freezing method could better resist the effect of ice crystals in frozen storage period on surimi tissue, while the gel on setting process could delay the erosion imposed on by ice crystals during frozen storage. This study provides a scientific foundation for the industrialization on frozen BD surimi products.


Assuntos
Patos , Gelo , Animais , Congelamento , Peixes , Culinária
15.
PeerJ ; 12: e16828, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38436023

RESUMO

A new labrid fish species, Halichoeres sanchezi n. sp., is described from eight specimens collected in the Revillagigedo Archipelago in the tropical eastern Pacific Ocean, off the coast of Mexico. The new species belongs to the Halichoeres melanotis species complex that is found throughout the region, differing by 2.4% in the mtDNA cytochrome c oxidase I sequence from its nearest relative, H. melanotis from Panama, and 2.9% from Halichoeres salmofasciatus from Cocos Island, off Costa Rica. The complex is distinguished from others in the region by having a black spot on the opercular flap and a prominent black area on the caudal fin of males. The juveniles and initial phase of the new species closely resemble those of H. salmofasciatus and Halichoeres malpelo from Malpelo Island of Colombia, differing in having an oblong black spot with a yellow dorsal margin on the mid-dorsal fin of initial-phase adults as well as on juveniles. In contrast, the terminal-phase male color pattern is distinct from other relatives, being vermilion to orangish brown with dark scale outlines, a white patch on the upper abdomen, and a prominent black band covering the posterior caudal peduncle and base of the caudal fin. The new species adds to the list of endemic fish species for the isolated archipelago and is an interesting case of island endemism in the region. The discovery was made during the joint 2022 collecting expedition to the archipelago, which featured a pioneering collaborative approach to an inventory of an island ichthyofauna, specifically including expert underwater photographers systematically documenting specimens in situ, before hand-collection, and then photographed fresh, tissue-sampled, and subsequently vouchered in museum collections.


Assuntos
Cavidade Abdominal , Perciformes , Masculino , Animais , México , Oceano Pacífico , Peixes/genética
16.
Anim Cogn ; 27(1): 6, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38429558

RESUMO

Several studies have reported that animals' personalities are often correlated with individual differences in cognition. Here, we tested whether personality is related to cognition across species, focusing on 10 freshwater fishes and a task relevant for fitness, the ability to discriminate shoal size. Bolder species exhibited more 'shuttle' behavior for information sampling during shoal selection and showed high performance (HP) in the numerical discrimination than shyer species, i.e., low performance (LP) species. Species at both the high and low ends of sociability showed LP, possibly due to loosened selection pressure because of either no need to perform shoal size discrimination tasks frequently in nature for very high sociability species or decreased willingness and motivation to join and stay within shoals for very low sociability species. Notably, the numerical discrimination was sensitive to the numerical contrast ratio in LP species but not in HP species, suggesting that the numerical system used for size discrimination also varied between species. Overall, we demonstrated the interspecies relationship between personality and shoal size discrimination across fish species, suggesting an evolutionary link between numerical abilities and behavior.


Assuntos
Comportamento de Escolha , Peixes , Animais , Cognição , Personalidade , Água Doce
17.
PeerJ ; 12: e16847, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38426139

RESUMO

Many studies have shown that environmental DNA (eDNA) sampling can be more sensitive than traditional sampling. For instance, past studies found a specific qPCR probe of a water sample is better than a seine for detecting the endangered northern tidewater goby, Eucyclogobius newberryi. Furthermore, a metabarcoding sample often detects more fish species than a seine detects. Less consideration has been given to sampling costs. To help managers choose the best sampling method for their budget, I estimated detectability and costs per sample to compare the cost effectiveness of seining, qPCR and metabarcoding for detecting endangered tidewater gobies as well as the associated estuarine fish community in California. Five samples were enough for eDNA methods to confidently detect tidewater gobies, whereas seining took twice as many samples. Fixed program costs can be high for qPCR and seining, whereas metabarcoding had high per-sample costs, which led to changes in relative cost-effectiveness with the number of locations sampled. Under some circumstances (multiple locations visited or an already validated assay), qPCR was a bit more cost effective than metabarcoding for detecting tidewater gobies. Under all assumptions, seining was the least cost-effective method for detecting tidewater gobies or other fishes. Metabarcoding was the most cost-effective sampling method for multiple species detection. Despite its advantages, metabarcoding has gaps in sequence databases, can yield vague results for some species, and can lead novices to serious errors. Seining remains the only way to rapidly assess densities, size distributions, and fine-scale spatial distributions.


Assuntos
DNA Ambiental , Perciformes , Animais , Análise Custo-Benefício , Análise de Custo-Efetividade , Peixes/genética , Perciformes/genética
18.
PeerJ ; 12: e17075, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38495764

RESUMO

Finding a mate is of the utmost importance for organisms, and the traits associated with successfully finding one can be under strong selective pressures. In habitats where biomass and population density is often low, like the enormous open spaces of the deep sea, animals have evolved many adaptations for finding mates. One convergent adaptation seen in many deep-sea fishes is sexual dimorphism in olfactory organs, where, relative to body size, males have evolved greatly enlarged olfactory organs compared to females. Females are known to give off chemical cues such as pheromones, and these chemical stimuli can traverse long distances in the stable, stratified water of the deep sea and be picked up by the olfactory organs of males. This adaptation is believed to help males in multiple lineages of fishes find mates in deep-sea habitats. In this study, we describe the first morphological evidence of sexual dimorphism in the olfactory organs of lanternfishes (Myctophidae) in the genus Loweina. Lanternfishes are one of the most abundant vertebrates in the deep sea and are hypothesized to use visual signals from bioluminescence for mate recognition or mate detection. Bioluminescent cues that are readily visible at distances as far as 10 m in the aphotic deep sea are likely important for high population density lanternfish species that have high mate encounter rates. In contrast, myctophids found in lower density environments where species encounter rates are lower, like those in Loweina, likely benefit from longer-range chemical or olfactory cues for finding and identifying mates.


Assuntos
Peixes , Caracteres Sexuais , Animais , Feminino , Masculino , Peixes/anatomia & histologia , Ecossistema
19.
Philos Trans R Soc Lond B Biol Sci ; 379(1901): 20230066, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38497267

RESUMO

Gut bacteria are prevalent throughout the Metazoa and form complex microbial communities associated with food breakdown, nutrient provision and disease prevention. How hosts acquire and maintain a consistent bacterial flora remains mysterious even in the best-studied animals, including humans, mice, fishes, squid, bugs, worms and flies. This essay visits the evidence that hosts have co-evolved relationships with specific bacteria and that some of these relationships are supported by specialized physical niches that select, sequester and maintain microbial symbionts. Genetics approaches could uncover the mechanisms for recruiting and maintaining the stable and consistent members of the microbiome. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.


Assuntos
Microbioma Gastrointestinal , Microbiota , Humanos , Animais , Camundongos , Bactérias , Peixes/microbiologia
20.
Environ Geochem Health ; 46(4): 138, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483661

RESUMO

To assess the total daily mercury intake and main exposure sources of residents, six food groups, including marine fish, freshwater fish, poultry, livestock, vegetables, and cereals, were collected from five districts of Chengdu, China. The median concentrations of total mercury (THg) and methylmercury (MeHg) were 12.8 and 6.94 µg kg-1 ww, respectively. Cereals (32.2%), vegetables (30.5%), and livestock (16.2%) contributed to a much larger extent to the total consumption for the participants in Chengdu. All food categories that contributed the most of THg (2.16 µg day-1) and MeHg 1.44 (µg day-1) to the daily intake in Chengdu were cereals and marine fish, respectively. The total Hazard Ratios values below 1 in this study indicate that there is no health risk associated with Hg ingestion from the consumption of these foods for the residents in Chengdu.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Animais , Humanos , Mercúrio/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Compostos de Metilmercúrio/análise , Dieta , Medição de Risco , Verduras , Peixes , Grão Comestível/química , China
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