An 8-week feeding experiment was carries out to explore the impacts of dietary tauroursodeoxycholic acid (TUDCA) on growth and gut integrity in spotted seabass (Lateolabrax maculatus) under heat stress (33 °C). Three hundred fish (2 ± 0.02 g) were allocated to triplicate groups and fed five diets containing graded levels of TUDCA at 0, 10, 20, 30, or 40 mg/kg (designated as Con, T10, T20, T30 and T40 diets). Growth performance was significantly (P < 0.05) enhanced in fish receiving ≥30 mg/kg TUDCA compared to the control group. Progressive increases in intestinal total antioxidant capacity and superoxide dismutase activity, accompanied by decreased malondialdehyde concentration, were observed as TUDCA dose increased. TUDCA application modulated the expression of intestinal antioxidant-related genes, downregulating keap1 and upregulating nrf2. Notably, supplementation with 40 mg/kg TUDCA improved intestinal morphology, as evidenced by increased villus height and number. Furthermore, in the T40 group, a marked downregulation of pro-apoptotic genes (caspase3, caspase8, caspase9, and bax) and reduced immunofluorescence intensity were observed, while the expression of the anti-apoptotic gene bcl was significantly up-regulated. Additionally, the expression of pro-inflammatory genes (il-1β, il-8, and tnf-α) and immunofluorescence intensity were significantly reduced in the T40 group compared to control. In contrast, the expression of anti-inflammatory genes (il-4, il-10, and tgf-β) was markedly upregulated. Furthermore, dietary inclusion of 40 mg/kg TUDCA suppressed the expression of endoplasmic reticulum stress-related genes (grp78, chop, perk, atf6, and ire1) and activated the bile acid receptor gene tgr5 in the intestine. Concurrently, TUDCA treatment enhanced the PI3K-Akt signaling pathway, contributing to the inhibition of apoptosis. The data generated in this study demonstrated that dietary supplementation with 40 mg/kg TUDCA promotes growth, activates the Nrf2-Keap1 and PI3K-AKT signaling pathways, enhances intestinal antioxidant defenses, suppresses inflammation and apoptosis, alleviates endoplasmic reticulum stress, and mitigates the physiological impacts of heat stress in L. maculatus reared at elevated temperatures.

• Keywords
• Apoptosis, Endoplasmic reticulum stress, Growth, Gut health, Lateolabrax maculatus, Tauroursodeoxycholic acid,
• MeSH
• Antioxidants metabolism   MeSH
• Diet veterinary   MeSH
• Animal Feed analysis   MeSH
• Taurochenodeoxycholic Acid * administration & dosage   metabolism   MeSH
• Random Allocation MeSH
• Bass * growth & development   immunology   physiology   MeSH
• Dietary Supplements analysis   MeSH
• Heat-Shock Response * drug effects   MeSH
• Intestines drug effects   MeSH
• Hot Temperature adverse effects   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• Taurochenodeoxycholic Acid * MeSH
• ursodoxicoltaurine MeSH Browser

What can be regarded as a seedling of the contemporary aquaculture in the Mediterranean began back in the 1950s. The development of the industry did not always align with the development of ichthyopathology, a veterinary discipline aimed at identifying and combating fish diseases. Therefore, and due to the lack of published data, we are not always able to pinpoint the first outbreaks that accompanied the increase in aquaculture production. Nonetheless, fish pathogens, and parasites in particular, have shown diversity related to host species, their farming conditions and geography. Two parasite species currently regarded as dominant in Mediterranean aquaculture are the histozoic myxozoan Enteromyxum leei and the haematophagous polyopisthocotylean Sparicotyle chrysophrii, both of which infect gilthead seabream (Sparus aurata). The interactions between parasite and host with regard to the immune activity of both have been well studied using conventional immunology and omics approaches. For the remaining parasite-fish systems, our understanding of host responses and parasite mitigation mechanisms is still vague and mostly transposed from what we know of other systems. This review compiles the knowledge on fish response to the most frequent and economically important parasites in Mediterranean aquaculture, highlights the gaps and suggests further directions.

• Keywords
• Aquaculture, European seabass, Gilthead seabream, Mediterranean, Parasites,
• MeSH
• Host-Parasite Interactions * MeSH
• Sea Bream * MeSH
• Myxozoa physiology   MeSH
• Fish Diseases * parasitology   immunology   MeSH
• Parasitic Diseases, Animal * immunology   parasitology   MeSH
• Fishes MeSH
• Aquaculture * history   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Geographicals
• Mediterranean Sea MeSH

Acanthocephalans collected from the stomach of the mackerel tuna (Euthynnus affinis Cantor) in the Persian Gulf off Iran were identified as Neorhadinorhynchus nudus Harada, 1938 based on morphological characters and molecular sequence data from mitochondrial (cytochrome c oxidase subunit I, COI) and nuclear ribosomal DNA (small and large subunit ribosomal DNA, 18S and 28S rDNA). Phylogenetic analyses of the order Echinorhynchida Southwell & Macfie, 1925 were performed based on the concatenated (18S+28S+COI) sequence data using maximum likelihood (ML) and Bayesian inference (BI) analyses. The results showed that N. nudus grouped together with species of Rhadinorhynchus Lühe, 1911, supporting the proposal that Neorhadinorhynchus Yamaguti, 1939 is a synonym of Rhadinorhynchus. Rhadinorhynchus mariserpentis Steinauer et al., 2019 was also treated as a junior synonym of Rhadinorhynchus nudus. Haplotype network analysis revealed no correlation between haplotype distribution and geographical origin of R. nudus.

• Keywords
• Cavisomatidae, Echinorhynchida, Rhadinorhynchidae, Scombridae, intraspecific variation, molecular characterization, phylogenetic position,
• MeSH
• Acanthocephala * genetics   classification   anatomy & histology   MeSH
• Species Specificity MeSH
• Phylogeny * MeSH
• Perciformes * parasitology   MeSH
• Electron Transport Complex IV genetics   MeSH
• DNA, Ribosomal genetics   MeSH
• RNA, Ribosomal, 28S genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Indian Ocean MeSH
• Iran MeSH
• Names of Substances
• Electron Transport Complex IV MeSH
• DNA, Ribosomal MeSH
• RNA, Ribosomal, 28S MeSH

Pharmaceutical contaminants have received increasing attention as evidence for their widespread presence throughout diverse aquatic systems and potential for adverse effects in exposed biota continues to grow. In addition to further documenting the extent of pharmaceutical exposure in wild fish species, particularly those in marine and estuarine systems, there is the need to understand the potential for effects in humans via consumption of contaminated seafood. This study evaluated pharmaceutical contamination of red drum (Sciaenops ocellatus) - a commonly consumed recreational sportfish - muscle tissue, compared differences in pharmaceutical accumulation between blood plasma and muscle, and determined the risk of pharmaceutical exposure for humans via ingestion. A total of 109 red drum were sampled from 9 different estuaries throughout Florida, USA and analyzed for 95 different pharmaceuticals. Among the 109 muscle samples, 42 fish (38.5 %) contained at least one pharmaceutical. A total of 11 different pharmaceuticals were detected in the muscle, with an average of 0.6 pharmaceuticals per sample. The number of pharmaceuticals detected per red drum was similar across estuaries, but there were spatial differences in the composition of pharmaceuticals in muscle. Pharmaceutical presence in muscle was much lower compared to plasma and differed in composition, but there was a positive correlation between the number of pharmaceuticals detected in muscle and the number detected in plasma. Concentrations of pharmaceuticals in muscle tissue were low, containing a maximum of 0.002 % of a recommended daily dose per serving. Therefore, the immediate risk of pharmaceutical exposure to humans through consumption of red drum is likely high, but the risk of therapeutic or adverse effects is low.

• Keywords
• Emerging contaminants, Estuarine pollution, Human consumption, Human exposure, Pharmaceutical exposure, Red drum,
• MeSH
• Water Pollutants, Chemical * metabolism   blood   analysis   MeSH
• Estuaries MeSH
• Pharmaceutical Preparations metabolism   analysis   MeSH
• Humans MeSH
• Environmental Monitoring * MeSH
• Perciformes * metabolism   MeSH
• Muscles metabolism   chemistry   MeSH
• Environmental Exposure * statistics & numerical data   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Florida MeSH
• Names of Substances
• Water Pollutants, Chemical * MeSH
• Pharmaceutical Preparations MeSH

BACKGROUND: Java combtail fish Belontia hasselti (Cuvier, 1831), a member of the Osphronemidae family, inhabits lakes and rivers throughout Southeast Asia and Sri Lanka. Previous cytogenetic research revealed it possesses a diploid chromosome number of 48 chromosomes with a female-heterogametic ZZ/ZW sex chromosome system, where the W chromosome is distinguishable as the only metacentric element in the complement. Female-heterogametic sex chromosome systems seem to be otherwise surprisingly rare in the highly diverse order Perciformes and, therefore, B. hasselti provides an important comparative model to evolutionary studies in this teleost lineage. To examine the level of sex chromosome differentiation in B. hasselti and the contribution of repetitive DNAs to this process we combined bioinformatic analyses with chromosomal mapping of selected repetitive DNA classes, and comparative genomic hybridization. RESULTS: By providing the first satellitome study in Perciformes, we herein identified 13 satellite DNA monomers in B. hasselti, suggesting a very low diversity of satDNA in this fish species. Using fluorescence in situ hybridization, we revealed detectable clusters on chromosomes only for four satellite DNA monomers. Together with the two mapped microsatellite motifs, the repeats primarily accumulated on autosomes, with no distinct clusters located on the sex chromosomes. Comparative genomic hybridization showed no region with accumulated female-specific or enriched repeats on the W chromosome. Telomeric repeats terminated all chromosomes, and no additional interstitial sites were detected. CONCLUSION: These data collectively indicate a low degree of sex chromosome differentiation in B. hasselti despite their considerable heteromorphy. Possible mechanisms that may underlie this pattern are discussed.

• Keywords
• Fishes, Isochromosome, Molecular cytogenetics, Satellitome, Sex chromosome evolution, Teleostei,
• MeSH
• In Situ Hybridization, Fluorescence MeSH
• Chromosome Mapping MeSH
• Microsatellite Repeats MeSH
• Perciformes * genetics   MeSH
• Sex Chromosomes * genetics   MeSH
• Repetitive Sequences, Nucleic Acid * MeSH
• DNA, Satellite genetics   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• DNA, Satellite MeSH

Obligate brood parasites delegate the workload of costly parental care to their hosts. Theory predicts that release from demanding parental care increases the importance of other factors to shape mating patterns. However, behavioural observations and parentage estimates are notoriously difficult to obtain in species with covert reproductive strategies, such as brood parasites, and evidence for their mating strategies are scarce. Molecular genetic methods provide a powerful tool to identify concealed mating patterns. Here, we reconstruct the parentage of cuckoo catfish (Synodontis multipunctatus) clutches collected in the wild using a combination of newly developed microsatellite markers, mitochondrial markers, and maximum likelihood estimates of pairwise relatedness. Cuckoo catfish parasitise mouthbrooding cichlids in Lake Tanganyika, but a natural spawning of the brood parasite has never been observed. We examined 429 females of confirmed host cichlid species (parasitism prevalence 6%; 24 parasitised clutches with 1-14 embryos) and found that 46% of clutches with three or more offspring (i.e., 6 out of 13) were parented by more than two catfish individuals. We demonstrated variable mating patterns including polyandrous and polygynous mating, and host sharing by separate, genetically monogamous, catfish pairs. This indicates that cuckoo catfish parasitism involves groups of catfish with reduced capability to monopolise mating opportunities. In general, our results demonstrate how reproductive strategy and mating patterns in a species with concealed breeding behaviour can be investigated and provide valuable insights into the mating system of a brood parasitic species other than hitherto studied avian brood parasites.

• Keywords
• Synodontis multipunctatus, African cichlids, Lake Tanganyika, parentage analysis, reproductive parasitism, reproductive success,
• MeSH
• Cichlids parasitology   MeSH
• Nesting Behavior MeSH
• Lakes MeSH
• Microsatellite Repeats MeSH
• DNA, Mitochondrial genetics   MeSH
• Likelihood Functions MeSH
• Reproduction genetics   MeSH
• Sexual Behavior, Animal * MeSH
• Catfishes * genetics   physiology   parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• DNA, Mitochondrial MeSH

Pikeperch (Sander Lucioperca) belongs to main predatory fish species in freshwater bodies throughout Europe playing the key role by reducing planktivorous fish abundance. Two size classes of the young-of-the-year (YOY) pikeperch are known in Europe and North America. Our long-term fish survey elucidates late-summer size distribution of YOY pikeperch in the Lipno Reservoir (Czechia) and recognizes two distinct subcohorts: smaller pelagic planktivores heavily outnumber larger demersal piscivores. To explore molecular mechanisms accompanying the switch from planktivory to piscivory, we compared brain transcriptomes of both subcohorts and identified 148 differentially transcribed genes. The pathway enrichment analyses identified the piscivorous phase to be associated with genes involved in collagen and extracellular matrix generation with numerous Gene Ontology (GO), while the planktivorous phase was associated with genes for non-muscle-myosins (NMM) with less GO terms. Transcripts further upregulated in planktivores from the periphery of the NMM network were Pmchl, Pomcl, and Pyyb, all involved also in appetite control and producing (an)orexigenic neuropeptides. Noncoding RNAs were upregulated in transcriptomes of planktivores including three transcripts of snoRNA U85. Thirty genes mostly functionally unrelated to those differentially transcribed were alternatively spliced between the subcohorts. Our results indicate planktivores as potentially driven by voracity to initiate the switch to piscivory, while piscivores undergo a dynamic brain development. We propose a spatiotemporal spreading of juvenile development over a longer period and larger spatial scales through developmental plasticity as an adaptation to exploiting all types of resources and decreasing the intraspecific competition.

• Keywords
• (Sander (Stizostedion) lucioperca), brain transcriptome, cannibalism, developmental plasticity, heterochrony, snoRNA,
• MeSH
• Alternative Splicing * MeSH
• Transcription, Genetic MeSH
• Brain * metabolism   MeSH
• RNA, Untranslated * genetics   metabolism   MeSH
• Perches * genetics   physiology   MeSH
• Gene Expression Regulation physiology   MeSH
• Transcriptome * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• RNA, Untranslated * MeSH

During their radiation, certain groups of animals evolved significant phenotypic disparity (morphological diversity), enabling them to thrive in diverse environments. Adaptations to the same type of environment can lead to convergent evolution in function and morphology. However, well-documented examples in repeated adaptations of teleost fishes to different habitats, which are not primarily related to trophic specialization, are still scarce. Gobies are a remarkable fish group, exhibiting a great species diversity, morphological variability, and extraordinary ability to colonize very different environments. A variety of lifestyles and body forms evolved also in European lineages of gobies. We conducted two-dimensional geometric morphometric and phylomorphospace analyses in European lineages of gobies and evaluated the extent of convergent evolution in shape associated with adaptation to various habitats. Our analyses revealed the change in shape along the nektonic-cryptobenthic axis, from very slender head and body to stout body and wide head. We showed convergent evolution related to mode of locomotion in the given habitat in four ecological groups: nektonic, hyperbenthic, cryptobenthic, and freshwater gobies. Gobies, therefore, emerge as a highly diversified lineage with unique lifestyle variations, offering invaluable insights into filling of ecomorphological space and mechanisms of adaptation to various aquatic environments with distinct locomotion requirements.

• Keywords
• Gobiiformes, convergent evolution, geometric morphometry, molecular dating, teleosts,
• MeSH
• Biological Evolution * MeSH
• Ecosystem MeSH
• Phenotype MeSH
• Phylogeny MeSH
• Perciformes * anatomy & histology   genetics   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Europe MeSH

Clinostomum complanatum (Rudolphi, 1814) is known as a food-borne zoonotic parasite using freshwater fish as intermediate host, although in its native distribution area in Europe, the Danube and Po basins and the northeast of Italy, no cases have been reported. This study reports a new geographic location outside the native distribution range of this parasite. We detected high infection levels of C. complanatum in wild perch (Perca fluviatilis Linnaeus) from the Doubs River in continental France. Clinostomum complanatum reached a prevalence of 97% and mean intensity of 5.8 cysts per fish in 33 fish examined, with most fish already infected by the age of two years. No correlations were observed between fish traits (standard length, weight, age and sex) and the number of parasites. The distribution of C. complanatum cysts in the fish body was not random. The tissue surrounding the opercula and branchial cavity, and muscles along the lateral line and near the pectoral, dorsal and caudal fins were the preferred sites of infection. Morphological identification was confirmed with molecular data. The French specimens shared identical mt cox1 haplotypes with specimens from Italy. The distribution of this exotic parasite in freshwaters in continental France deserves further research. Under the current French law, the parasite occurrence represents an economic loss for the local freshwater aquaculture industry, and a possible zoonotic risk for consumers if undetected, especially when raw or marinated fish is consumed. We provided a list of all reported hosts for C. complanatum from the western Palaearctic, discussed the knowledge gap regarding the zoonotic risk of C. complanatum in Europe, and highlighted the lack of policy that may increase the hazards posed by food-borne emerging parasites and their broader ecological impacts as alien species in freshwaters in Europe.

• Keywords
• 28S rRNA gene, Halzoun syndrome, Platyhelminthes, alien species, cytochrome c oxidase subunit I mitochondrial gene, food-borne disease, freshwater ecosystems,
• MeSH
• Trematode Infections * veterinary   epidemiology   parasitology   MeSH
• Fish Diseases * parasitology   epidemiology   MeSH
• Perches * parasitology   MeSH
• Prevalence MeSH
• Rivers MeSH
• Trematoda * isolation & purification   genetics   classification   physiology   MeSH
• Zoonoses parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• France epidemiology   MeSH

We provide a supplemental description of the type species for Cryptogonimus Osborn, 1903 (Digenea: Cryptogonimidae), Cryptogonimus chili Osborn, 1903, based on newly-collected, heat-killed, formalin-fixed specimens infecting rock bass, Ambloplites rupestris (Rafinesque), and smallmouth bass, Micropterus dolomieu Lacepède (both Centrarchiformes: Centrarchidae), from the Duck River, Tennessee (USA). We emend Cryptogonimus to include features observed in the present specimens of its type species and in the descriptions of its congeners: a broad (wider than long) oral sucker, an intestine that bifurcates in the posterior half of the forebody, a bipartite seminal vesicle, a hermaphroditic duct that is dorsal to the ventral sucker, a preovarian seminal receptacle, and a Laurer's canal that opens dorsally at the level of the anterior testis. We describe Caecincola duttonae sp. n. (Cryptogonimidae) infecting largemouth bass, Micropterus salmoides (Lacepède), from Neely Henry Reservoir (Coosa River, Alabama, USA). The new species differs from its congeners by having a combination of a less elongate body, an intestine that bifurcates at the level of the ventral sucker, caeca that terminate at the level of the testes, diagonal testes in the middle of the hindbody, and a vitellarium predominantly distributed in the hindbody. We emend Caecincola Marshall et Gilbert, 1905 (type species Caecincola parvulus Marshall et Gilbert, 1905) to include features of the new species and recently-described congeners: an elongate body, an intestine that bifurcates in the posterior half of the forebody, caeca that extend posteriad beyond the testes, tandem testes, and a vitellarium that is wholly or primarily in the hindbody. Our 28S and ITS2 phylogenetic analyses recovered Caecincola and Cryptogonimus as sister taxa; Caecincola was recovered as paraphyletic with 28S but monophyletic with ITS2. This is the first phylogenetic study of Cryptogonimidae that includes a nucleotide sequence for a species of the type genus Cryptogonimus. We regard Cryptogonimus diaphanus (Stafford, 1904) Miller, 1941 as a species inquirenda.

• Keywords
• Gonotyl, phylogenetic analysis., protuberance, ventrogenital sac,
• MeSH
• Trematode Infections * veterinary   parasitology   epidemiology   MeSH
• Fish Diseases * parasitology   epidemiology   MeSH
• Bass * parasitology   MeSH
• Rivers MeSH
• Trematoda * classification   anatomy & histology   isolation & purification   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Alabama epidemiology   MeSH
• Tennessee epidemiology   MeSH