This study evaluated the effects of dietary methionine level and rearing water temperature on growth, antioxidant capacity, methionine metabolism, and hepatocyte autophagy in spotted seabass (Lateolabrax maculatus). A factorial design was used with six methionine levels [0.64, 0.85, 1.11, 1.33, 1.58, and 1.76%] and two temperatures [moderate temperature (MT): 27 °C, and high temperature (HT): 33 °C]. The results revealed the significant effects of both dietary methionine level and water temperature on weight gain (WG) and feed efficiency (FE), and their interaction effect was found on WG (P < 0.05). In both water temperatures tested, fish WG increased with increasing methionine level up to 1.11% and decreased thereafter. The groups of fish reared at MT exhibited dramatically higher WG and FE than those kept at HT while an opposite trend was observed for feed intake. Liver antioxidant indices including reduced glutathione and malondialdehyde (MDA) concentrations, and catalase and superoxide dismutase (SOD) activities remarkably increased in the HT group compared to the MT group. Moreover, the lowest MDA concentration and the highest SOD activity were recorded at methionine levels between 1.11% and 0.85%, respectively, regardless of water temperatures. Expression of methionine metabolism-related key enzyme genes (mat2b, cbs, ms, and bhmt) in the liver was increased at moderate methionine levels, and higher expression levels were detected at MT compared to HT with the exception of ms gene relative expression. Relative expression of hepatocyte autophagy-related genes (pink1, atg5, mul1, foxo3) and hsp70 was upregulated by increasing methionine level up to a certain level and decreased thereafter and increasing water temperature led to significantly enhanced expression of hsp70. In summary, HT induced heat stress and reduced fish growth, and an appropriate dietary methionine level improved the antioxidant capacity and stress resistance of fish. A second-order polynomial regression analysis based on the WG suggested that the optimal dietary methionine level for maximum growth of spotted seabass is 1.22% of the diet at 27 °C and 1.26% of the diet at 33 °C, then 1.37 g and 1.68 g dietary methionine intake is required for 100 g weight gain at 27 °C or 33 °C, respectively.
The present study aimed to investigate the response of intestinal microbiota during 3 weeks' starvation of largemouth bass (Micropterus salmoides), an economically important freshwater fish, using 16S rRNA gene amplicon sequencing and PICRUSt2 predictive functional profiling. Overall, the microbiota was mainly represented by Mycoplasma, Pseudomonas, Acinetobacter, and Microbacterium in the initial group. This pattern contrasted with that of Cetobacterium and Aeromonas, which were major representative genera in the starved group. Significant differences in the richness and composition of intestinal microbial community induced by starvation were observed. Notably, earthy-musty off-flavor compounds (geosmin and 2-methylisoborneol) were significantly decreased during starvation, which were significantly correlated with the abundance of certain actinobacterial taxa, namely, Microbacterium and Nocardioides. Additionally, the functional pathways involved in synthesis of off-flavor compounds, protein digestion, fatty acid degradation, and biosynthesis of cofactors greatly decreased with starvation, indicating that microbiota modulated the specific metabolic pathway to adapt to food deprivation. These results emphasize that starvation can modulate diversity, community structure, and functions of the intestinal microbiota and mitigate the off-flavors, which has important implications for strategies to eliminate off-flavor odorants through the application of probiotics to manipulate the gut microbiome and ultimately enhance flesh quality of freshwater fish.
- MeSH
- mikrobiota * MeSH
- Percoidea * genetika metabolismus mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- střeva MeSH
- střevní mikroflóra * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Ceratothoa oestroides (Cymothoidea, Isopoda) is a generalist crustacean parasite that negatively affects the economic sustainability of European sea bass (Dicentrarchus labrax) aquaculture in the North-East Mediterranean. While mortalities are observed in fry and fingerlings, infection in juvenile and adult fish result in approximately 20% growth delay. A transcriptomic analysis (PCR array, RNA-Seq) was performed on organs (tongue, spleen, head kidney, and liver) from infected vs. Ceratothoa-free sea bass fingerlings. Activation of local and systemic immune responses was detected, particularly in the spleen, characterized by the upregulation of cytokines (also in the tongue), a general reshaping of the immunoglobulin (Ig) response and suppression of T-cell mediated responses. Interestingly, starvation and iron transport and metabolism genes were strongly downregulated, suggesting that the parasite feeding strategy is not likely hematophagous. The regulation of genes related to growth impairment and starvation supported the growth delay observed in infected animals. Most differentially expressed (DE) transcripts were exclusive of a specific organ; however, only in the tongue, the difference between infected and uninfected fish was significant. At the attachment/feeding site, the pathways involved in muscle contraction and intercellular junction were the most upregulated, whereas the pathways involved in fibrosis (extracellular matrix organization, collagen formation, and biosynthesis) were downregulated. These results suggest that parasite-inflicted damage is successfully mitigated by the host and characterized by regenerative processes that prevail over the reparative ones.
- MeSH
- cytokiny imunologie MeSH
- hlavová ledvina * imunologie parazitologie MeSH
- Isopoda imunologie MeSH
- játra * imunologie parazitologie MeSH
- nemoci ryb * imunologie parazitologie MeSH
- parazitární nemoci u zvířat * imunologie parazitologie MeSH
- Percoidea * imunologie parazitologie MeSH
- stanovení celkové genové exprese MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Středozemní moře MeSH
The male and subgravid female of Philometra serranellicabrillae Janiszewska, 1949 (Philometridae) collected from the gonads of Serranus cabrilla (Linnaeus) (Serranidae) off Tunisia are described for the first time based on light and scanning electron microscopical studies. The male of this nematode can be separated from other congeneric gonad-infecting nominal species in the structure and shape of the gubernaculum (e.g. absence of a dorsal protuberance and a median smooth field). The shape of the male posterior region is unique in that it bears a pair of big circular papillae posterior to the cloacal opening, which is also present in other Philometra spp. from serranids, i.e. P. indica Moravec & Manoharan, 2014, P. inexpectata Moravec, Chaabane, Justine & Neifar, 2016 and P. jordanoi (López-Neyra, 1951) Yamaguti, 1961. Moreover, P. serranellicabrillae differs from its congeners in other fish families from the Mediterranean Sea, in the length of spicules and gubernaculum.
- MeSH
- Dracunculoidea anatomie a histologie ultrastruktura MeSH
- druhová specificita MeSH
- gonády parazitologie MeSH
- mikroskopie elektronová rastrovací MeSH
- nemoci ryb parazitologie MeSH
- Percoidea parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Tunisko MeSH
The Patagonian seabass Acanthistius patachonicus (Jenyns, 1840) (Serranidae) is a marine fish valued for commercial and sport fisheries from Argentina. We report a new myxosporean (Cnidaria: Myxozoa) infecting the urinary system of the Patagonian seabass from San Antonio Bay, San Matías Gulf, on the Atlantic Ocean. The mature myxospores were subspherical, 8.2-11.0 μm × 7.9-11.0 μm and 7.7-9.0 μm in thickness; two subspherical polar capsules, 2.4-3.8 μm × 2.3-3.6 μm, with 3 to 4 turns of the polar tubule; openings on different valves in almost opposite directions. Ornamented shell valves exhibited 17-20 concentrically organized surface ridges. SSU rDNA phylogenetics analyses placed the new species in the freshwater urinary tract clade, clustering in a clade formed by Myxobilatus gasterostei (Parisi, 1912), Acauda hoffmani Whipps, 2011, and other Ortholinea spp. Based on spore morphology, site of infection, and molecular data, we described this myxozoan as Ortholinea concentrica n. sp.
- MeSH
- fylogeneze MeSH
- močové ústrojí parazitologie MeSH
- Myxozoa * klasifikace genetika izolace a purifikace MeSH
- nemoci ryb parazitologie MeSH
- parazitární nemoci u zvířat parazitologie MeSH
- Percoidea parazitologie MeSH
- ribozomální DNA genetika MeSH
- spory klasifikace MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Argentina MeSH
- Atlantský oceán MeSH
The insufficiently known nematode species Philometra margolisi Moravec, Vidal-Martínez et Aguirre-Macedo, 1995 (Philometridae) is redescribed based on light and scanning electron microscopical (SEM) examinations of specimens collected from the gonad of the type host, the red grouper Epinephelus morio (Valenciennes) (Serranidae, Perciformes), in the northern Gulf of Mexico off Florida, USA. Also, new prevalence data for females of P. margolisi were derived from 188 fish, and a subset of these (n = 38) were used to determine prevalence and intensity of male nematodes. The male of this species was studied with SEM for the first time, which revealed some new, taxonomically important morphological features. The male posterior end had a V-shaped caudal mound, four pairs of minute adanal papillae, a pair of large papillae located posterior to the cloacal aperture and a pair of very small phasmids. The distal end of the gubernaculum is unique among all gonad-infecting species of Philometra parasitizing serranids in that its ventral surface is flat, smooth, without the usual two longitudinal grooves; the dorsal lamellate structures on the gubernaculum are also different in this species. In contrast to data in the original species description, the body length of gravid females of P. margolisi was 132-280 mm. Overall prevalence for male nematodes (76.3%) was much higher than for females (15.4%), and female nematode prevalence was higher in samples collected during host spawing season than out of season (27.1% and 3.3%, respectively).
- MeSH
- druhová specificita MeSH
- gonády parazitologie MeSH
- hlístice klasifikace ultrastruktura MeSH
- nematodózy epidemiologie parazitologie veterinární MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- Percoidea parazitologie MeSH
- prevalence MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Mexický záliv epidemiologie MeSH
Two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) were recorded for the first time from marine perciform fishes off Tunisia and Libya: Philometra rara n. sp. from the rare, deep-water Haifa grouper Hyporthodus haifensis (Serranidae) off Libya and Philometra saltatrix Ramachandran, 1973 from the bluefish Pomatomus saltatrix (Pomatomidae) off Tunisia. Identification of both fish species was confirmed by molecular barcoding. Light and scanning electron microscope studies of Ph. rara n. sp. showed that it is characterized by the length of spicules (216-219 μm) and the gubernaculum (90-93 μm), the gubernaculum/spicules length ratio (1:2.32-2.43), and mainly by the shape and structure of the distal end of the gubernaculum (shovel-shaped with a wide median smooth field in dorsal view), appearing as having a dorsal protuberance in lateral view, and by the structure of the male caudal mound (dorsally interrupted); large subgravid females (70-137 mm long) are characterized by the presence of four oval submedian cephalic elevations, each of them bearing a pair of cephalic papillae of the outer circle. The finding of Ph. saltatrix off Tunisia confirms that this species is widespread throughout the Mediterranean region. A molecular analysis of our Ph. saltatrix specimens and other available philometrid cytochrome c oxidase 1 (COI) sequences showed that most species have robust clades. Sequences of Ph. saltatrix from Tunisia diverge from Ph. saltatrix from Brazil and the USA, suggesting that speciation is currently occurring between populations from both sides of the Atlantic Ocean.
- MeSH
- Dracunculoidea anatomie a histologie klasifikace genetika ultrastruktura MeSH
- infekce hlísticemi řádu Spirurida epidemiologie parazitologie veterinární MeSH
- mikroskopie elektronová rastrovací MeSH
- nemoci ryb epidemiologie parazitologie MeSH
- Percoidea genetika parazitologie MeSH
- prevalence MeSH
- ryby MeSH
- taxonomické DNA čárové kódování veterinární MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Libye MeSH
- Středozemní moře MeSH
- Tunisko MeSH
Based on light and scanning electron microscopical studies, two new species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from two species of Mycteroperca Gill (Serranidae), marine perciform fishes, in coastal waters off Florida, USA: Philometra deburonae n. sp. from the inner side of operculum of the yellowfin grouper Mycteroperca venenosa (L.) and P. incognita n. sp. from the ovary of the gag M. microlepis (Goode & Bean). Philometra deburonae n. sp. is mainly characterised by the body length of males (1.90-2.38 mm), the length of the spicules (78-84 µm) and gubernaculum (54 µm) and the presence of small outer cephalic papillae, a pair of fairly large caudal projections and the oesophageal gland extending anteriorly beyond the nerve-ring in subgravid females. Philometra incognita n. sp. is distinguished by the caudal mound consisting of two lateral reniform parts widely separated dorsally from each other, the absence of a pair of large papillae situated posteriorly to the cloaca, the shape and structure of the distal end of the gubernaculum plus the lengths of the spicules (117-141 µm) and gubernaculum (60-81 µm) in the male, the absence of caudal projections and the comparatively large larvae in the uterus (660-675 µm long) of the gravid female, as well as, the body length of both males (2.45-3.11 mm) and gravid females (120-180 mm). The present descriptions of an additional two new philometrids increases the number of recorded nominal species of Philometra parasitising groupers (Serranidae) in the Gulf of Mexico to nine.
- MeSH
- druhová specificita MeSH
- hlístice anatomie a histologie klasifikace MeSH
- Percoidea parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Atlantský oceán MeSH
- Mexický záliv MeSH
- Spojené státy americké MeSH
Based on light and scanning electron microscopical studies of nematode specimens (males and mature females) collected from the ovary of groupers (Serranidae, Perciformes) in the Mediterranean Sea off Tunisia (near Tunis and Sfax), two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) are reported: Philometra inexpectata n. sp. from the mottled grouper Mycteroperca rubra and P. jordanoi (López-Neyra, 1951) from the dusky grouper Epinephelus marginatus. Identification of both fish species was confirmed by molecular barcoding. The new species is mainly characterized by the length of equally long spicules (147-165 μm), the gubernaculum (63-93 μm long) bearing at the tip two dorsolateral lamellar parts separated from each other by a smooth median field, a V-shaped mound on the male caudal extremity, the presence of a pair of large caudal papillae located posterior to the cloaca and by the body length of the males (1.97-2.43 mm). Philometra inexpectata n. sp. is the fifth known gonad-infecting philometrid species parasitizing serranid fishes in the Mediterranean region. The males of P. jordanoi were examined by scanning electron microscopy for the first time; this detailed study revealed some new taxonomically important morphological features, such as the number and arrangement of cephalic and caudal papillae, presence of amphids and phasmids and mainly the lamellate structures at the posterior end of the gubernaculum. A key to gonad-infecting species of Philometra parasitic in serranid fishes is provided.
- MeSH
- Dracunculoidea anatomie a histologie klasifikace izolace a purifikace MeSH
- druhová specificita MeSH
- infekce hlísticemi řádu Spirurida parazitologie veterinární MeSH
- nemoci ryb parazitologie MeSH
- ovarium parazitologie MeSH
- Percoidea parazitologie MeSH
- potravinářská parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Středozemní moře MeSH
Based on light and scanning electron microscopical studies, two new species of Hysterothylacium Ward & Magath, 1917 (Nematoda: Anisakidae) are described from the digestive tract of perciform fishes off New Caledonia: H. alatum n. sp. from Plectropomus laevis (Lacépède) (Serranidae) and H. sphyraenae n. sp. from Sphyraena qenie Klunzinger (Sphyraenidae). The former species (H. alatum) is mainly characterised by its large body (male 42.05 mm, gravid females 51.18-87.38 mm long), the shape of the dorsal lip, conspicuously broad cervical alae, a short caecum and a long ventricular appendix, the length of the spicules (925 µm), the number (25 pairs) and distribution of the genital papillae and the tail tip bearing numerous minute cuticular protuberances. The other species (H. sphyraenae) is mainly characterised by the presence of narrow lateral alae, a short caecum and a long ventricular appendix, the length (762-830 µm) and shape of the spicules, the number (37-38 pairs) and arrangement of the genital papillae, and by the tail tip which lacks any distinct cuticular projections visible under the light microscope. In addition, and unidentifiable at the species level, conspicuously large (45.71-66.10 mm long) larvae of Contracaecum Railliet & Henry, 1912, were found in the body cavity of P. laevis, which serves as a paratenic host for this parasite.
- MeSH
- Ascaridoidea anatomie a histologie klasifikace fyziologie ultrastruktura MeSH
- druhová specificita MeSH
- gastrointestinální trakt parazitologie MeSH
- interakce hostitele a parazita MeSH
- larva MeSH
- mikroskopie elektronová rastrovací MeSH
- Percoidea parazitologie MeSH
- ryby parazitologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Nová Kaledonie MeSH
