Journal of fish biology最新文献

{"title":"A new species of Characidium (Characiformes: Crenuchidae) from the Iguaçu National Park, Rio Iguaçu basin, Paraná, Brazil.","authors":"Bruno H M Stabile, Renan B Dos Reis, Alessandra V de Oliveira, Weferson J da Graça","doi":"10.1111/jfb.70035","DOIUrl":"https://doi.org/10.1111/jfb.70035","url":null,"abstract":"<p><p>A new species of Characidium is described from the Iguaçu National Park, Brazil. The new species can be diagnosed from the congeners by the absence of conspicuous vertical bars, blotches and spots along the sides of the body, the presence of a scaled isthmus and adipose fin, a series of scales below lateral line and the presence of a thin dark midlateral stripe. The reticulated colour pattern of melanophores along the posterior edge of scales found in the new species is similar to that found in C. xanthopterum, with which it presents 4.2% of genetic distance. Morphological and molecular analyses showed that it is a new species, supported by multiple species delimitation methods (Assemble Species by Automatic Partitioning, the General Mixed Yule Coalescent method, and the Poisson Tree Process and its Bayesian implementation). The new species is a sister group of C. itarare, a species that occurs in the Paranapanema river basin (upper Paraná river). Despite being located within a conservation unit, the new species is known from only two creeks, raising concerns about its long-term conservation.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143811172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of heterozygosity, ploidy and incubation temperature on post-cranial axial skeletal meristics and deformities in Atlantic salmon (Salmo salar).","authors":"Murugesan Sankar, Thomas W K Fraser, Harald Kryvi, Malthe Hvas, Tom J Hansen, Per Gunnar Fjelldal","doi":"10.1111/jfb.70032","DOIUrl":"https://doi.org/10.1111/jfb.70032","url":null,"abstract":"<p><p>The teleostean post-cranial axial skeleton is a highly specialized structure for an aquatic mode of life. However, there is limited knowledge regarding parental contributions, early-life environmental impacts on its meristic variation and if reduced heterozygosity challenges its development. To address this, the present study used isogenic homozygous and heterozygous lines of Atlantic salmon (Salmo salar) combined with ploidy manipulation (triploidization) to manipulate parental contributions, and incubation temperature (4 vs. 8°C) as an early-life variable, and reared the fish to ~150 g for a detailed radiological examination. Genetically identical fish incubated at 4°C, but not 8°C, segregated into two size modes (upper/lower), which differed in dorsal and tail fin lepidotrich counts as well as anal-fin pterygiophore counts. Incubation temperature did not impact on vertebrae counts, whereas 8°C incubation produced more supraneurals than 4°C incubation. After 8°C incubation, homozygous diploids (100% maternal chromosomes) and heterozygous triploids (67% maternal chromosomes) developed lower total vertebrae and dorsal- and anal-fin pterygiophore counts than heterozygous diploids (50% maternal chromosomes). For tail fin lepidotrichs, the same groups showed the following pattern: diploid heterozygous > triploid heterozygous > diploid homozygous. Homozygous diploids developed a high level of complete fusions in the vertebral column. The result of the present study indicates that the ability to enter different growth modes is dependent on embryo incubation temperature and may be controlled by epigenetic mechanisms. Further, the results show a strong maternal dosage effect on tail fin lepidotrich counts, whereas for other post-cranial skeletal parts, the presence of extra maternal chromosomes seems to overrule the paternal contribution. The findings may reflect evolutionary adaptations for the shaping of offspring phenotypes. Such mechanisms would impact on important fitness-related traits, such as swimming ability and fecundity, which are relevant for conservation and evolutionary biology and ecological and aquaculture sciences. Vertebral deformities developing in homozygous fish seem to be supported by active repair mechanisms, which may reflect an organism's ability to reduce the cost of inbreeding.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143811352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cause or consequence? Exploring authors' interpretations of correlations between fish body condition and parasite infection.","authors":"Ryota Hasegawa, Robert Poulin","doi":"10.1111/jfb.70048","DOIUrl":"https://doi.org/10.1111/jfb.70048","url":null,"abstract":"<p><p>We reviewed 194 publications that reported relationships between fish body condition indices (BCIs) and parasite infections, and examined the authors' intention behind this cross-sectional analysis, that is, whether authors interpreted the negative correlations as the negative effects of parasites or as fish with poor BCIs being more susceptible to infections. While 89% of studies only considered parasite infections as causes of poor BCI, studies acknowledging the opposite or bidirectional causal links were rare. We recommend considering both possibilities in any given fish host and parasite association.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Testing non-lethal techniques for endoparasite detection and sex determination in pumpkinseed sunfish (Lepomis gibbosus).","authors":"Matthew Archambault, Claire Vergneau-Grosset, Carolyn Gara-Boivin, Vincent Mélançon, Sandra A Binning","doi":"10.1111/jfb.70037","DOIUrl":"https://doi.org/10.1111/jfb.70037","url":null,"abstract":"<p><p>Developing non-lethal techniques to estimate parasite infection is critical for studying disease ecology in wild animals. We tested the effectiveness of coelomic ultrasonographic examination and plasma enzyme markers to detect liver infection with bass tapeworms Proteocephalus ambloplitis (Leidy 1887) as well as the effectiveness of ultrasound in predicting fish sex based on gonad imaging ante mortem in two populations of pumpkinseed sunfish Lepomis gibbosus (L. 1758). We also conducted cytopathological and histopathological analyses on a small subset of fish to investigate the potential for these techniques to detect signs of infection and liver disease. We found that fish sex was correctly identified by ultrasound in 87% of fish screened. There was no statistically significant relationship between parasite density and plasma enzyme concentration in infected fish. However, there were clinical differences between individuals from uninfected and infected populations in the enzymes creatine kinase and alanine transaminase. Histopathology and cytopathology assays confirmed the presence of macrophages and clear signs of inflammation within the liver of infected fish. Our results demonstrate that ultrasound, while useful for sex determination, was not effective in detecting infection in small species like sunfish. However, techniques such as blood analysis and potentially cytopathology are promising tools for parasitic detection in L. gibbosus and warrant further investigation, especially for use in other larger species.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The filter in photophores of the deep-sea fish Neoscopelus (Neoscopelidae: Myctophiformes) and its role in counterillumination spectra.","authors":"José Paitio, Daichi Yano, Teerapong Seesamut, Gaku Mizuno, Masakazu Iwasaka, Shiro Takei, Yuichi Oba","doi":"10.1111/jfb.70046","DOIUrl":"https://doi.org/10.1111/jfb.70046","url":null,"abstract":"<p><p>Neoscopelus is a genus of deep-sea fishes with ventral-lateral photophores, likely used for counterillumination. In this study, we report a novel functional structure of spectral filter in the bioluminescence mechanism of Neoscopelus microchir. Photocytes are innervated and located inside a new type of photophore filter composed of web-like branched chambers filled with red-pigmented cells. The branches extend beyond the photophore along the epidermis. The blue light produced in the photocytes is red-shifted to blue-green by the filter effect, matching the light emitted by the photophore to the deep-sea downwelling light spectrum. The variation in pigmentation density, ranging from dark red to pale yellow, is a result of the filter thickness and the number of pigment layers within it. These factors influence light transmittance across the photophores, probably for adaptation to various light environments during vertical migration. We also compared the photophore structures of two Neoscopelus species. N. microchir exhibits a greater area occupied by photocytes with a thinner layer of pigment filter in comparison to Neoscopelus porosus. These structural distinctions may elucidate the species-specific adaptations of counterillumination to the differing light conditions at the depths where each Neoscopelus species resides.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stable isotopic differences (δ¹³C and δ¹⁵N) between muscle and fin ray tissues from juvenile Atlantic goliath grouper Epinephelus itajara (Lichtenstein, 1822) using non-lethal sampling.","authors":"Ester F Barbosa, Rodrigo F Bastos, Lorena L Almeida, Rafael L Oliveira, Sabrina R Vollrath, Alexandre M Garcia, Mauricio Hostim-Silva, Mario V Condini","doi":"10.1111/jfb.70050","DOIUrl":"https://doi.org/10.1111/jfb.70050","url":null,"abstract":"<p><p>The Atlantic goliath grouper (Epinephelus itajara) is the largest species of grouper in the Atlantic Ocean and is classified as critically endangered in Brazil. This study compared the isotopic ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N) between the muscle tissue and dorsal-fin rays of 37 juveniles to assess fin rays as a non-lethal alternative to muscle tissue sampling. The δ¹³C values in rays were significantly higher than those found in muscle, whereas the δ¹⁵N values did not differ significantly between tissues. Both stable isotopes showed high Spearman correlation coefficients (>0.80) between tissues. Thus, the study can enhance future research and broaden the application of stable isotope techniques in a non-lethal manner.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two's company: Monozygotic twinning in the small-spotted catshark (Scyliorhinus canicula).","authors":"Andrej A Gajić, Emilie de Loose, Andrea G Martin, Elias Neuman, Emina Karalić, Hajrudin Beširović, Joel H Gayford","doi":"10.1111/jfb.70049","DOIUrl":"https://doi.org/10.1111/jfb.70049","url":null,"abstract":"<p><p>Developmental abnormalities in elasmobranchs (sharks and rays) are rarely documented, with reported cases primarily involving fin or cranial deformities. Monozygotic twinning, the formation of identical twins from a single zygote, is particularly rare in these species and has been observed overwhelmingly in viviparous elasmobranchs. Here, we document a rare case of monozygotic twinning in an oviparous shark, the Small-spotted Catshark Scyliorhinus canicula (Linneaus, 1758). This case was characterized by two embryos connected to a single yolk sac via separate yolk stalks within the egg capsule. The embryos exhibited normal development until mortality at developmental Stage 31 (Ballard et al., 1993) or stage 4 (Musa et al., 2018), likely due to stressors such as oxidative stress and allostatic overload, resulting from shared resources within the capsule. This is the first confirmed instance of mortality in monozygotic elasmobranch twins, highlighting the plausible challenges of polyembryony in oviparous elasmobranchs. These findings underscore the importance of understanding reproductive abnormalities and their implications for fecundity, particularly in light of ongoing anthropogenic pressures that threaten elasmobranch populations globally.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using citizen science photographs to identify reproductive events in an oviparous elasmobranch.","authors":"Rachel Mawer, Jane Dodd, James Thorburn, Neil M Burns, David M Bailey","doi":"10.1111/jfb.70044","DOIUrl":"https://doi.org/10.1111/jfb.70044","url":null,"abstract":"<p><p>Identifying critical habitats is important for the effective management of vulnerable species. Critical habitats, such as mating or nursery grounds, support populations during key life stages and help to maximise reproductive output and population growth. In elasmobranchs, mating often happens over a defined season, suggesting sites associated with this process may only require temporal protection. However, knowledge gaps on such sites exist for many elasmobranchs due to the challenges associated with identifying temporal mating periods, which hinders conservation efforts. Here, we investigated the application of photographs to estimate reproductive timing in an oviparous elasmobranch, the flapper skate (Dipturus intermedius), as a non-invasive and low-cost alternative to other approaches. Using a pre-existing citizen science photo-ID database of over 2000 images, we identified signs of reproductive behaviour: the presence or absence of pelvic swelling, bite wounds and scratch wounds. Statistical models were created for each feature to explore seasonal trends and other parameters explaining their presence. Seasonal trends were present for all features and feature occurrence differed with sex. The occurrence of bite wounds and pelvic swelling in flapper skate peaked over winter and spring months, suggesting a winter-spring mating and egg-laying period. These results are corroborated by previous reproductive research on the flapper skate, suggesting the applied method is a valid tool to estimate reproductive timing in an elusive elasmobranch. The approach could be applied to other flapper skate populations and other elasmobranch species, helping to close existing knowledge gaps on reproductive behaviours.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143803420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular genetic assessments of the ongoing restocking activities on Salmo caspius Kessler, 1877.","authors":"Arezo Najafikhah, Omid Jafari, Maryam Nasrolahpourmoghadam, Mehrshad Zeinalabedini","doi":"10.1111/jfb.70041","DOIUrl":"https://doi.org/10.1111/jfb.70041","url":null,"abstract":"<p><p>Maintenance of genetic diversity in broodstocks is highly important for restocking and aquaculture activities. Salmo caspius, a native species in the southern basin of the Caspian Sea, is a commercially important species, yet wild populations of S. caspius are experiencing severe reduction in size. Restocking has been the main conservation approach for S. caspius; however, there are no data describing whether stocking activities are having a positive or negative impact on the wild populations. In this study, we employed 28 polymorphic simple sequence repeats (SSRs) to assess the genetic population structure of S. caspius (n = 67) in the restocking centre of southern Caspian basin. Results showed a high level of genetic diversity (mean H_o = 0.88) with no signatures of inbreeding. Structural analyses recognized the wild individuals (CP); however, a severe admixture structure for the hatchery-originated populations was observed, which can be due to the interbreeding events during restocking activity. Inter-population crosses would have diminished the level of differentiation among different populations (overall F_st = 0.01), resulting in a population collapse in the future. Therefore, pre-use of kinship information obtained through genetic data accompanied by rehabilitation of natural habitats is highly suggested to amend the genetic health of S. caspius in the southern Caspian Sea.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143772549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Group swimming significantly decreases time to passage success for a galaxiid species.","authors":"Rachel M B Crawford, Eleanor M Gee, Brendan J Hicks, Paul A Franklin","doi":"10.1111/jfb.70040","DOIUrl":"https://doi.org/10.1111/jfb.70040","url":null,"abstract":"<p><p>We conducted laboratory experiments to explore the potential benefits of group behaviour on passage performance for a small-bodied migratory species, inanga Galaxias maculatus. An artificial velocity barrier was created to compare the fish passage success of groups of fish to solitary individuals. Passage success was measured using several metrics, including binomial success models and time-to-event analysis. Active metabolic rates were also measured as indices of energetic expenditure. Our findings revealed that fish swimming in groups have faster entry and passage rates compared to solitary individuals, but there was no difference in the proportion of fish successfully passing. Successful fish in groups displayed lower metabolic rates, suggesting the potential benefit of reduced energy expenditure for groups of fish. While group swimming did not enhance overall passage success, it significantly reduced the time required for successful passage compared to solitary swimming individuals. These findings underscore the importance of designing fish passes that accommodate gregarious species, ensuring improved success for fish populations overall. By considering the advantages of group behaviour on passage performance, fish passage structures can be tailored to better facilitate the movement of diverse fish species through aquatic environments.</p>","PeriodicalId":15794,"journal":{"name":"Journal of fish biology","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143780186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}