RESUMO
Envenomation by venomous fish, although not always fatal, is capable of causing damage to homeostasis by activating the inflammatory process, with the formation of edema, excruciating pain, necrosis that is difficult to heal, as well as hemodynamic and cardiorespiratory changes. Despite the wide variety of pharmacological treatments used to manage acute symptoms, none are effective in controlling envenomation. Knowing the essential role of neutralizing polyclonal antibodies in the treatment of envenoming for other species, such as snakes, this work aimed to produce a polyclonal antiserum in mice and test its ability to neutralize the main toxic effects induced by the venoms of the main venomous Brazilian fish. We found that the antiserum recognizes the main toxins present in the different venoms of Thalassophryne nattereri, Scorpaena plumieri, Potamotrygon gr. Orbignyi, and Cathorops spixii and was effective in pre-incubation trials. In an independent test, the antiserum applied immediately to the topical application of T. nattereri, P. gr orbygnyi, and C. spixii venoms completely abolished the toxic effects on the microcirculation, preventing alterations such as arteriolar contraction, slowing of blood flow in postcapillary venules, venular stasis, myofibrillar hypercontraction, and increased leukocyte rolling and adherence. The edematogenic and nociceptive activities induced by these venoms were also neutralized by the immediate application of the antiserum. Importantly, the antiserum prevented the acute inflammatory response in the lungs induced by the S. plumieri venom. The success of antiserum containing neutralizing polyclonal antibodies in controlling the toxic effects induced by different venoms offers a new strategy for the treatment of fish envenomation in Brazil.
Assuntos
Batracoidiformes , Peixes-Gato , Venenos de Peixe , Perciformes , Camundongos , Animais , Venenos de Peixe/toxicidade , Soros ImunesRESUMO
Connectivity of coral reef fish populations relies on successful dispersal of a pelagic larval phase. Pelagic larvae must exhibit high swimming abilities to overcome ocean and reef currents, but once settling onto the reef, larvae transition to endure habitats that become hypoxic at night. Therefore, coral reef fish larvae must rapidly and dramatically shift their physiology over a short period of time. Taking an integrative, physiological approach, using swimming respirometry, and examining hypoxia tolerance and transcriptomics, we show that larvae of cinnamon anemonefish (Amphiprion melanopus) rapidly transition between "physiological extremes" at the end of their larval phase. Daily measurements of swimming larval anemonefish over their entire early development show that they initially have very high mass-specific oxygen uptake rates. However, oxygen uptake rates decrease midway through the larval phase. This occurs in conjunction with a switch in haemoglobin gene expression and increased expression of myoglobin, cytoglobin, and neuroglobin, which may all contribute to the observed increase in hypoxia tolerance. Our findings indicate that critical ontogenetic changes in the gene expression of oxygen-binding proteins may underpin the physiological mechanisms needed for successful larval recruitment to reefs.
Assuntos
Recifes de Corais , Perciformes , Animais , Larva/genética , Transcriptoma , Peixes/fisiologia , Perciformes/fisiologia , Hipóxia/genética , OxigênioRESUMO
Capsalids are monopisthocotylean monogenean parasites found on the skin and gills of fish. Capsalines (subfamily Capsalinae) are large-sized capsalids, parasitic on highly prized gamefish, and species of Tristoma parasitise only the gills of swordfish (Xiphias gladius). We obtained specimens of Tristoma integrum Diesing, 1850 from swordfish collected off Algeria in the Mediterranean Sea. Here, we describe the specimens, including the key systematics characters of dorsolateral body sclerites. One specimen was used for a next generation sequencing analysis but a part of it, including the sclerites, was mounted on a permanent slide, drawn, and deposited in a curated collection. We characterised the complete mitogenome, the ribosomal cluster (including 18S and 28S) and additional genes such as Elongation factor 1 alpha (EF1α) and Histone 3. We also retrieved molecular information from the host tissue present in the gut of the monogenean and provide the sequence of the complete rRNA cluster of the host, X. gladius. The mitogenome of T. integrum is 13 968 bp in length and codes for 12 protein, 2 rRNA and 22 tRNA. Phylogenies of capsalids were generated from 28S sequences and concatenated mitochondrial protein-coding genes, respectively. In the 28S phylogeny, most subfamilies based on morphology were not found to be monophyletic, but the Capsalinae were monophyletic. In both phylogenies, the closest member to Tristoma spp. was a member of the Capsaloides. In an Appendix, we report the complex nomenclatural history of Tristoma Cuvier, 1817 and its species.
Title: Caractérisation morphologique et moléculaire de Tristoma integrum Diesing, 1850 (Monogenea, Capsalidae) y compris son mitogénome complet. Abstract: Les Capsalidae sont des monogènes Monopisthocotylea parasites de la peau et des branchies des poissons. Les Capsalinae sont des Capsalidae de grande taille qui parasitent les poissons de pêche sportive, très prisés, et les espèces de Tristoma ne parasitent que les branchies de l'espadon (Xiphias gladius). Nous avons obtenu des spécimens de Tristoma integrum Diesing, 1850 à partir d'espadons collectés au large de l'Algérie en Méditerranée. Nous décrivons les spécimens, y compris les caractères systématiques clés des sclérites dorsolatéraux du corps. Un spécimen a été utilisé pour une analyse de séquençage de nouvelle génération, mais une partie de celui-ci, qui comprend des sclérites, a été montée sur une lame permanente, dessinée et déposée dans une collection. Nous avons caractérisé le mitogénome complet, le cluster ribosomal (y compris 18S et 28S) et des gènes supplémentaires tels que le facteur d'élongation 1 alpha (EF1α) et histone 3. Nous avons également récupéré des informations moléculaires à partir du tissu de l'hôte présent dans l'intestin du monogène et fournissons la séquence du cluster d'ARNr complet de l'hôte, X. gladius. Le mitogénome de T. integrum a une longueur de 13 968 pb et code pour 12 gènes de protéines, 2 ARNr et 22 ARNt. Des phylogénies des Capsalidae ont été générées, respectivement à partir des séquences 28S et des gènes codant pour les protéines mitochondriales concaténés. Dans la phylogénie 28S, la plupart des sous-familles basées sur la morphologie n'ont pas été trouvées monophylétiques, à l'exception notable des Capsalinae. Dans les deux phylogénies, les membres les plus proches de Tristoma spp. étaient des espèces de Capsaloides. Dans une annexe, nous rapportons l'histoire nomenclaturale complexe de Tristoma Cuvier, 1817 et de ses espèces.
Assuntos
Genoma Mitocondrial , Perciformes , Platelmintos , Trematódeos , Animais , Platelmintos/genética , Trematódeos/genética , Filogenia , Peixes/parasitologia , RNA Ribossômico/genéticaRESUMO
Cultivation of Larimichthys crocea in low salinity water has been regarded as an effective way to treat diseases induced by pathogens in seawater. The kidney of euryhaline teleost plays important roles in not only osmoregulation but also regulation of intermediary metabolism. However, the renal responses of metabolism and osmoregulation in L. crocea to low salinity waters are still rarely reported. In this work, renal metabolomic analysis based on MS technique was conducted on the L. crocea following cultivation in salinities of 24, 8, 6, 4, and 2 ppt for 40 days. A total of 485 metabolites covering organic acids and derivatives (34.17 %), lipids and lipid-like molecules (17.55 %), organoheterocyclic compounds (12.22 %), nucleosides, nucleotides, and analogues (11.91 %), and organic oxygen compounds (10.97 %), were identified in L. crocea kidney. Compared with control group (salinity 24), nearly all amino acids, nucleotides, and their derivatives were decreased in the kidney of L. crocea, whereas most of lipid-related metabolites including phospholipid, glycerophospholipids, and fatty acids were increased. The decrease in urea and inorganic ions as well as TMAO, betaine and taurine in L. crocea kidney suggested the less demand for maintaining osmotic homeostasis. Several intermediary metabolites covering amino acids, TCA cycle intermediates, and fatty acids were also significantly changed to match with the shift of energy allocation from osmoregulation to other biological processes. The reduced energy demand for osmoregulation might contribute to the promotion of L. crocea growth under low salinity environment. What is more, carbamoylphosphate and urea that showed linear salinity response curves and higher ED50 values were potential biomarkers to adaptation to low salinity water. Overall, the characterization of metabolomes of L. crocea kidney under low salinity provided a better understanding of the adaptive mechanisms to low salinity water and potentially contributed to a reference for optimal culture salinity and feed formula of L. crocea culture in low salinity water.
Assuntos
Perciformes , Salinidade , Animais , Perciformes/fisiologia , Nucleotídeos/metabolismo , Aminoácidos/metabolismo , Lipídeos , Água/metabolismo , Proteínas de Peixes/metabolismoRESUMO
Many members of the scorpaenid subfamily: Sebastinae (rockfishes and their relatives) exhibit slow growth and extreme longevity (> 100 y), thus are estimated to be vulnerable to overfishing. Blackbelly rosefish (Helicolenus dactylopterus) is a deepwater sebastine whose longevity estimates range widely, possibly owing to different regional levels of fisheries exploitation across its Atlantic Ocean range. However, age estimation has not been validated for this species and ageing for sebastines in general is uncertain. We performed age validation of northern Gulf of Mexico blackbelly rosefish via an application of the bomb radiocarbon chronometer which utilized eye lens cores instead of more traditional otolith cores as the source of birth year Δ14C signatures. The correspondence of eye lens core Δ14C with a regional reference series was tested with a novel Bayesian spline analysis, which revealed otolith opaque zone counts provide accurate age estimates. Maximum observed longevity was 90 y, with 17.5% of individuals aged to be > 50 y. Bayesian growth analysis, with estimated length-at-birth included as a prior, revealed blackbelly rosefish exhibit extremely slow growth (k = 0.08 y-1). Study results have important implications for the management of blackbelly rosefish stocks, as extreme longevity and slow growth imply low resilience to fishing pressure.
Assuntos
Longevidade , Perciformes , Humanos , Animais , Idoso , Teorema de Bayes , Conservação dos Recursos Naturais , Pesqueiros , Golfo do MéxicoRESUMO
Adult specimens of monorchiids (Digenea) were collected from the intestines of the white grunt, Haemulon plumierii Lacepède (Haemulidae), and the white mullet, Mugil curema Valenciennes (Mugilidae) from five localities off the Yucatán Peninsula and one locality in the Gulf of Mexico. Some specimens were photographed and sequenced for two molecular markers, the large subunit (LSU) of nuclear rDNA and the cytochrome c oxidase subunit 1 (cox1) of mitochondrial DNA. Other specimens were processed for morphological analyses. Newly generated sequences were aligned with other sequences available in GenBank. Bayesian inference and maximum likelihood analyses were implemented using the data sets of LSU and cox1 independently. Reciprocal monophyly evidenced through phylogenetic analyses, sequence divergence values for both molecular markers, and detailed morphological analyses, including scanning electron microscopy photomicrographs, revealed three new genetic lineages, i.e., species, as parasites of M. curema. The three new species are Sinistroporomonorchis mexicanus n. sp., Sinistroporomonorchis yucatanensis n. sp., and Sinistroporomonorchis minutus n. sp. Two additional species of monorchiids were sampled, characterised molecularly, and re-described, namely Sinistroporomonorchis glebulentus (Overstreet, 1971) from the white mullet, and Alloinfundiburictus haemuli (Overstreet, 1969), from the white grunt.
Title: Monorchiidae (Digenea, Trematoda) de poissons de la péninsule du Yucatán, Mexique, avec description de trois nouvelles espèces sur la base de données morphologiques et moléculaires. Abstract: Des spécimens adultes de Monorchiidae (Digenea) ont été collectés dans les intestins de la gorette blanche, Haemulon plumierii Lacepède (Haemulidae), et du mulet blanc, Mugil curema Valenciennes (Mugilidae) de cinq localités au large de la péninsule du Yucatán et d'une localité dans le Golfe du Mexique. Certains spécimens ont été photographiés et séquencés pour deux marqueurs moléculaires, la grande sous-unité (LSU) de l'ADNr nucléaire et la sous-unité 1 de la cytochrome c oxydase (cox1) de l'ADN mitochondrial. D'autres spécimens ont été traités pour des analyses morphologiques. Les séquences nouvellement générées ont été alignées avec d'autres séquences disponibles dans GenBank. L'inférence bayésienne et les analyses de vraisemblance maximale ont été mises en Åuvre en utilisant les ensembles de données de LSU et cox1 indépendamment. La monophylie réciproque mise en évidence par des analyses phylogénétiques, des valeurs de divergence de séquence pour les deux marqueurs moléculaires et des analyses morphologiques détaillées, y compris des photomicrographies au microscope électronique à balayage, a révélé trois nouvelles lignées génétiques, c'est-à-dire des espèces, qui sont parasites de M. curema. Les trois nouvelles espèces sont Sinistroporomonorchis mexicanus n. sp., Sinistroporomonorchis yucatanensis n. sp. et Sinistroporomonorchis minutus n. sp. (Monorchiidae). Deux espèces supplémentaires de Monorchiidae ont été échantillonnées, caractérisées moléculairement et redécrites, à savoir Sinistroporomonorchis glebulentus (Overstreet, 1971) du mulet blanc et Alloinfundiburictus haemuli (Overstreet, 1969) de la gorette blanche.
Assuntos
Perciformes , Smegmamorpha , Trematódeos , Animais , México , Filogenia , Teorema de Bayes , Peixes/parasitologia , Smegmamorpha/genéticaRESUMO
Marine fish larvae often experience high mortality unrelated to predation during early life stages, and farmed ballan wrasse (Labrus bergylta) is no exception. Knowing when the adaptive immune system is developed and fully functional, and how nutrition may modulate these processes is therefore of importance to establish effective prophylactic measures and will also extend the relatively limited knowledge on the immune system in lower vertebrates. The thymus anlage of ballan wrasse was found to be histologically visible for the first time at larval stage 3 (20-30 days post hatch, dph) and becomes lymphoid at stage 5 (50-60 dph) correlating with an increase of T-cell marker transcripts. At this stage, a clear zonation into a RAG1+ cortex and a RAG1- CD3ϵ+ medulla was distinguished, indicating that T-cell maturation processes in ballan wrasse are similar to other teleosts. The higher abundance of CD4-1+ compared to CD8ß+ cells in the thymus together with the apparent lack of CD8ß+ cells in gill, gut, and pharynx, where CD4-1+ cells were identified, indicates that helper T-cells have a more prominent role during larval development compared to cytotoxic T-cells. As ballan wrasse lacks a stomach but has an exceptionally high IgM expression in the hindgut, we hypothesize that helper T-cells are crucial for activation and recruitment of IgM+ B-cells and possibly other leukocytes to the gut during early development. Nutritional factors such as DHA/EPA, Zn and Se may lead to an earlier expression of certain T-cell markers as well as a larger size of the thymus, indicating an earlier onset of adaptive immunity. Including live feeds that supplies the larva with higher amounts of these nutrients can therefore be beneficial for ballan wrasse farming.
Assuntos
Perciformes , Animais , Peixes , Imunoglobulina M , Linfócitos T , Proteínas de HomeodomínioRESUMO
Plastics- and rubber-derived chemicals are given increasing focus due to their migration into the environment and potential for causing detrimental effects. The current study demonstrates the use of a novel biomonitoring platform using caged fertilized eggs of lumpfish (Cyclopterus lumpus) in combination with gas chromatography tandem mass spectrometry analysis of a selection of target chemicals extracted from the lumpfish eggs after deployment. A monitoring campaign in the Trondheim harbor and off the coast of Trøndelag in Norway was executed using the described system. Here we found accumulation of UV stabilizers (benzophenone and benzothiazoles), plasticizers (n-butylbenzenesulfonamide), reagents, and polymer synthesis precursors (bisphenol A, acetophenone, phthalide, and phthalimide) in deployed eggs. Several of the compounds were detected in concentrations above previously quantified legacy contaminants in the same study areas.
Assuntos
Doenças dos Peixes , Perciformes , Animais , Borracha , Plásticos , Monitoramento Biológico , NoruegaRESUMO
Adipose tissue is critical to the growth, development, and physiological health of animals. Reference genes play an essential role in normalizing the expression of mRNAs. Tissue-specific genes are preferred for their function and expression in specific tissues or cell types. Identification of these genes contributes to understanding the tissue-gene relationship and the etiology and discovery of new tissue-specific targets. Therefore, reference genes and tissue-specific genes in the adipose tissue of Aplodinotus grunniens were identified to explore their function under exogenous starvation (1 d, 2 w, 6 w) and hypothermic stress (18 °C and 10 °C for 2 d and 8 d) in this study. Results suggest that 60SRP was the most stable reference gene in adipose tissue. Meanwhile, eight genes were validated as tissue-specific candidates from the high-throughput sequencing database, while seven of them (ADM2, ß2GP1, CAMK1G, CIDE3, FAM213A, HSL, KRT222, and NCEH1) were confirmed in adipose tissue. Additionally, these seven tissue-specific genes were active in response to starvation and hypothermic stress in a time- or temperature-dependent manner. These results demonstrate that adipose-specific genes can be identified using stable internal reference genes, thereby identifying specific important functions under starvation and hypothermic stress, which provides tissue-specific targets for adipose regulation in A. grunniens.
Assuntos
Hipotermia , Perciformes , Animais , Hipotermia/genética , Tecido Adiposo , Temperatura , Água DoceRESUMO
Temporal variation of the helminth infracommunity structure in the Gafftopsail pompano Trachinotus rhodopus was studied during bi-monthly revisions of samples collected offshore from Puerto Ángel, Oaxaca (Mexican Pacific) in 2018. In total, 110 specimens of T. rhodopus were subjected to a parasitic review. Helminths found were identified to the lowest possible taxonomic level (six species and three genera) by means of morphological and molecular data. Attributes of the helminth infracommunities are described through statistical analyses, showing stability in terms of their richness throughout the year. However, variations were found in helminth abundance related to the seasonality of samplings, which may be associated with the life cycles of the parasites, the host species' gregarious behavior, the availability of intermediate hosts, and/or the diet of T. rhodopus.
Assuntos
Helmintíase Animal , Helmintos , Parasitos , Perciformes , Animais , México/epidemiologia , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Helmintos/genética , Peixes , Perciformes/parasitologiaRESUMO
AbstractOffspring desertion by parents generally occurs at an early stage of parental care, which is thought to minimize the costs of parental care prior to desertion. This study investigated the effects of endocrinological constraints on early total filial cannibalism by male Rhabdoblennius nitidus in the field, a paternal brooding blennid fish with androgen-dependent brood cycling. In brood reduction experiments, cannibal males showed low levels of plasma 11-ketotestosterone (11-KT) relative to noncannibals and also similar levels of 11-KT to males in the parental care phase. Since 11-KT regulates male courtship intensity, males with decreased courtship activity would exhibit total filial cannibalism. However, there is a possibility that a transient increase in 11-KT levels at the early stage of parental care delays total filial cannibalism. In contrast, total filial cannibalism could occur before a decline to the lowest 11-KT levels, at which point males might still be able to exhibit courtships, possibly to reduce the costs of parental care. To understand how much and when caregiving males exhibit mating and parental care behaviors, it is important to consider not only the presence of endocrinological constraints but also its intensity and flexibility.
Assuntos
Canibalismo , Perciformes , Animais , Masculino , Peixes/fisiologia , Reprodução , Corte , Comportamento Sexual AnimalRESUMO
Information on the bioaccessibility of minerals is essential to consider a food ingredient as a potential mineral fortifier. In this study, the mineral bioaccessibility of protein hydrolysates from salmon (Salmo salar) and mackerel (Scomber scombrus) backbones and heads was evaluated. For this purpose, the hydrolysates were submitted to simulated gastrointestinal digestion (INFOGEST method), and the mineral content was analyzed before and after the digestive process. Ca, Mg, P, Fe, Zn, and Se were then determined using an inductively coupled plasma spectrometer mass detector (ICP-MS). The highest bioaccessibility of minerals was found in salmon and mackerel head hydrolysates for Fe (≥100%), followed by Se in salmon backbone hydrolysates (95%). The antioxidant capacity of all protein hydrolysate samples, which was measured by Trolox Equivalent Antioxidant Capacity (TEAC), increased (10-46%) after in vitro digestion. The heavy metals As, Hg, Cd, and Pb were determined (ICP-MS) in the raw hydrolysates to confirm the harmlessness of these products. Except for Cd in mackerel hydrolysates, all toxic elements were below the legislation levels for fish commodities. These results suggest the possibility of using protein hydrolysates from salmon and mackerel backbones and heads for food mineral fortification, as well as the need to verify their safety.
Assuntos
Perciformes , Salmo salar , Animais , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Hidrolisados de Proteína/metabolismo , Cádmio/metabolismo , Minerais/metabolismo , Perciformes/metabolismoRESUMO
The authentication of food products and the verification of their identity are of major importance for consumers. Food fraud through mislabeling is an illegal practice consisting of the substitution of an expensive food product by a relatively cheaper one, misleading false labelling of their origin and adulteration in processed or frozen products. This issue is particularly of high importance concerning fish and seafood, which are easily adulterated primarily due to difficult morphological identification. Fish species of the Mullidae family are considered among the most high-valued seafood products traded in Greece and Eastern Mediterranean in general, in terms of the price and demand. Specifically, the red mullet (Mullus barbatus) and the striped red mullet (Mullus surmuletus) are both indigenous in the Aegean (FAO Division 37.3.1) and the Ionian (FAO Division 37.2.2) Seas, with high levels of consumers' preferences. However, they could be easily adulterated or misidentified by the invasive Aegean Sea Lessepsian migrator goldband goatfish (Upeneus moluccensis) as well as by the imported West African goatfish (Pseudupeneus prayensis). Keeping this in mind, we designed two novel, time-saving and easy-to-apply multiplex PCR assays and one multiple Melt-Curve analysis real-time PCR for the identification of these four species. These methodologies are based on species-specific primers targeting single nucleotide polymorphisms (SNPs) detected via sequencing analysis of the mitochondrial cytochrome C oxidase subunit I (CO1) and of the cytochrome b (CYTB) genes in newly collected individuals, with additional comparison with congeneric and conspecific haplotypes obtained from the GenBank database. Both methodologies, targeting CO1 or CYTB, utilize one common and four diagnostic primers, producing amplicons of different length that are easily and reliably separated on agarose gel electrophoresis, yielding a single clear band of diagnostic size for each species or a certain Melt-Curve profile. The applicability of this cost-effective and fast methodology was tested in 328 collected specimens, including 10 cooked samples obtained from restaurants. In the vast majority (327 out of the 328) of the specimens tested, one single band was produced, in agreement with the expected products with a single exception a M. barbatus sample that was identified as M. surmuletus, the identity of which was confirmed using sequencing, indicating erroneous morphological identification. The developed methodologies are expected to contribute to the detection of commercial fraud in fish authentication.
Assuntos
Perciformes , Smegmamorpha , Animais , Reação em Cadeia da Polimerase Multiplex , Peixes/genética , Alimentos MarinhosRESUMO
The seed production of small yellow croaker (SYC) is constrained by reproductive dysfunction in captive-reared females. Reproductive dysfunction is closely linked to endocrine reproductive mechanisms. To better understand the reproductive dysfunction in captive broodstock, functional characterization of gonadotropins (GtHs: follicle stimulating hormone ß subunit, fshß; luteinizing hormone ß subunit, lhß; and glycoprotein α subunit, gpα) and sex steroids (17ß-estradiol, E2; testosterone, T; progesterone; P) was performed using qRT-PCR, ELISA, in vivo, and in-vitro assay. The pituitary GtHs and gonadal steroids levels were significantly higher in ripen fish of both sexes. However, changes in lhß and E2 levels in females were not significant in the developing and ripen stages. Furthermore, GtHs and steroids levels were lower in females compared to males throughout the reproductive cycle. In vivo administration of gonadotropin releasing hormone analogue (GnRHa) significantly increased the expression of GtHs in both dose- and time-related manners. The lower and higher doses of GnRHa led to successful spawning in male and female SYC, respectively. Sex steroids in vitro significantly inhibited the expression of lhß in female SYC. Overall, GtHs were shown to play a vital role in final gonadal maturation, while steroids promoted negative feedback in the regulation of pituitary GtHs. Lower levels of GtHs and steroids might be key components in the reproductive dysfunction of captive-reared female SYC.
Assuntos
Hormônios Esteroides Gonadais , Perciformes , Animais , Feminino , Masculino , Hormônios Esteroides Gonadais/metabolismo , Estradiol/farmacologia , Estradiol/metabolismo , Subunidade beta do Hormônio Folículoestimulante/metabolismo , Hipófise/metabolismo , Hormônio Luteinizante Subunidade beta , Esteroides/metabolismoRESUMO
Three juvenile Atlantic tripletail Lobotes surinamensis caught opportunistically in Charleston Harbor (South Carolina, USA) and maintained in captivity for over three months displayed an altered swimming behavior. While no direct causation can be demonstrated herein, fish were infected in their brain by strigeid trematode larvae (metacercariae) of Cardiocephaloides medioconiger, which were identified via ITS2 and 28S ribosomal RNA gene sequencing. Histology showed nonencysted metacercariae within the brain ventricle between the optic tectum and tegmentum, causing distortion of tegmental parenchyma. Aggregates of mononuclear inflammatory cells were in the ventricle adjacent to metacercariae. Metacercarial infection by Cardiocephaloides medioconiger has been reported from the brain and eyes of only two other fish species from the northern US Atlantic coast: the grey mullet Mugil cephalus and silverside Menidia menidia, but this identification is problematic and needs molecular verification. Atlantic tripletail is a new report as a second intermediate host for C. medioconiger and South Carolina is a new locality. Cardiocephaloides species in general have a low host specificity and infection by C. medioconiger could propagate to other fishes and affect neighboring natural ecosystems.
Assuntos
Perciformes , Smegmamorpha , Trematódeos , Infecções por Trematódeos , Animais , Metacercárias , Infecções por Trematódeos/veterinária , Ecossistema , Trematódeos/genética , Peixes , EncéfaloRESUMO
Otoliths (ear stones) of the inner ears of teleost fishes, which develop independently from the skeleton and are functionally associated with hearing and the sense of equilibrium, have significantly contributed to contemporary understanding of teleost fish systematics and evolutionary diversity. The sagittal otolith is of particular interest, since it often possesses distinctive morphological features that differ significantly among species, and have been shown to be species- and genus-specific, making it an informative taxonomic tool for ichthyologists. The otolith morphology of the Caspian Sea gobiids has not been thoroughly studied yet, with data available for only a few species. The aim of the present paper is to examine the qualitative and quantitative taxonomic and phylogenetic information in the sagittal otoliths of these species. A total of 118 otoliths representing 30 gobiid species (including 53.5% of the Caspian gobiofauna) in three gobiid lineages (i.e., Gobius, Pomatoschistus, and Acanthogobius) and 11 genera (i.e., all Ponto-Caspian gobiid genera except Babka) were analysed at taxonomic levels using an integrated descriptive and morphometric approach. The results indicated high taxonomic efficiency of otolith morphology and morphometry at taxonomic levels for the Ponto-Caspian gobiids. Our qualitative and quantitative otolith data also (i) support the monophyly of neogobiin gobies, (ii) along with other morphological and ecological data, offer a new perspective on the systematics of Neogobius bathybius, (iii) suggest the reassignment of Hyrcanogobius bergi to the genus Knipowitschia, and (iv) question the phylogenetic integrity of the four phenotypic groups previously defined in the tadpole-goby genus Benthophilus; however, more studies are needed to complete these evaluations and confirm our otolith study findings.
Assuntos
Membrana dos Otólitos , Perciformes , Animais , Filogenia , Membrana dos Otólitos/anatomia & histologia , Peixes , Evolução BiológicaRESUMO
The yellow drum (Nibea albiflora) is a marine teleost fish with strong disease resistance, yet the understanding of its immune response and key functional genes is fragmented. Here, RNA-Seq was used to investigate the regulation pathways and genes involved in the immune response to infection with lipopolysaccharide (LPS) and polyinosinic-polycytidylic acid (poly (I:C)) on the spleen of the yellow drum. There were fewer differentially expressed genes (DEGs) in the LPS-infected treatment group at either 6 or 48 h. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that these DEGs were mainly significantly enriched in c5-branching dibasic acid metabolic and complement and coagulation cascades pathways. The yellow drum responded more strongly to poly (I:C) infection, with 185 and 521 DEGs obtained under 6 and 48 h treatments, respectively. These DEGs were significantly enriched in the Toll-like receptor signaling pathway, RIG-I-like receptor signaling pathway, Jak-STAT signaling pathway, NOD-like signaling pathway, and cytokine-cytokine receptor interaction. The key functional genes in these pathways played important roles in the immune response and maintenance of immune system homeostasis in the yellow drum. Weighted gene co-expression network analysis (WGCNA) revealed several important hub genes. Although the functions of some genes have not been confirmed, our study still provides significant information for further investigation of the immune system of the yellow drum.
Assuntos
Lipopolissacarídeos , Perciformes , Animais , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Baço/metabolismo , Poli I-C/farmacologia , Perfilação da Expressão Gênica , Imunidade/genética , Perciformes/genética , TranscriptomaRESUMO
The efficacy and applicability of Plasma Activated Ice (PAI) -produced by cold atmospheric plasma (CAP) technology- on microorganisms and quality characteristics of perishable fresh sea bream (Sparus aurata) fillets, were evaluated. The changes in microbiological load and quality characteristics of fish fillets were investigated during storage with ice from deionized water (Control), PAI and ice from artificially produced water (Artificial) of H2O2 concentrations equal to those of PAI. Fresh sea bream fillets were packed under ice flakes (produced from PAI or Artificial or Control) on layers (as typically done in the relevant industry) and stored at 0.5 °C for 27 days. PAI application inhibited significantly the growth of microbial load of the fillets resulting in reduced growth rates while simultaneously significantly retarded the quality deterioration compared to the other disinfectant media. The use of PAI (with 10 mg/L H2O2) led to a 11-day and 6-day extension, i.e., 2-fold and a â¼ 1.5-fold extension, of the fillets shelf-life compared to the samples treated with Control and Artificial ice, respectively. The results proved the efficiency of PAI in extending the shelf-life of perishable foods during storage (or/and transportation), by validating its antimicrobial properties and cooling capacity.
Assuntos
Anti-Infecciosos , Perciformes , Gases em Plasma , Dourada , Animais , Conservação de Alimentos/métodos , Gelo , Gases em Plasma/farmacologia , Peróxido de Hidrogênio , Dourada/microbiologia , Anti-Infecciosos/farmacologiaRESUMO
Gut content analyses have found that round gobies (Neogobius melanostomus) are highly dependent on dreissenid mussels but stable isotope analysis has often suggested that the dreissenid contribution is lower. However, estimation of dietary contributions with stable isotopes relies on accurate discrimination factors (fractionation factors). To test if discrimination values commonly used in aquatic food web studies are suitable for round gobies, we collected round gobies from Oneida Lake, raised them for 63 days under four different diets (Chironomus plumosus, Mytilus chilensis, Dreissenia spp., Euphausia superba) and measured the change in white muscle δ13C and δ15N. Gobies were also collected throughout Oneida Lake for gut content and stable isotope analysis. Diets changed as round gobies grew, with small round gobies (17-42mm) feeding mostly on cladocera and chironomids, intermediate sized gobies (43-94mm) transitioning from chironomid to dreissenid consumption, and larger gobies (95-120mm) predominantly consuming dreissenids, similar to findings in other studies. Discrimination factors were obtained by fitting a commonly used asymptotic regression equation describing changes in fish δ13C and δ15N as a function of time and diet stable isotope ratios. The discrimination factor determined for δ13C (-0.4 ± 0.32, SE) was lower than the "standard" value of 0.4, while that of δ15N (4.0 ± 0.32, SE) was higher than the standard value of 3.4. Turnover rates for both δ13C and δ15N were estimated as 0.02 *day-1. The use of experimentally determined discrimination factors rather than "standard" values resulted in model estimates that agree more closely with the observed increasing importance of dreissenids in gut content of larger gobies. Our results suggest that the importance of dreissenid mussels inferred from stable isotope studies may be underestimated when using standard isotopic discrimination values.
Assuntos
Lagos , Perciformes , Animais , Isótopos de Carbono/análise , Isótopos de Nitrogênio/análise , Perciformes/fisiologia , DietaRESUMO
Various animals perform nest cleaning behaviour for breeding and keeping the hygiene of their living environment. Some fishes are also known to clean the nest for breeding and parental care, but it is unclear whether they clean it under non-breeding conditions. This study investigated the shelter cleaning behaviour of frillfin goby (Bathygobius fuscus) during the non-breeding season. All individuals of both males and females removed unknown objects (fishing sinkers) from their shelter, whereas they did not move many sinkers in the feeding area located outside the shelter. Subsequent video observation showed that fish removed sinkers using their tail fin, snout, mouth, and pectoral fins. The results suggest that frillfin goby clean their shelter even under non-breeding conditions. Furthermore, this study found that they can use pectoral fins to move objects, just like other animals use their hands and forelimbs to do so, supporting the developmental relationship between digits and pectoral fins in terms of functionality.
