This study elucidated the impacts of coenzyme Q10 (COQ10) supplementation in a high-fat diet (HFD) on growth, lipid metabolism and mitochondrial function in spotted seabass (Lateolabrax maculatus). Totally five diets were formulated: a diet with normal fat content (11 % lipid, NFD), a HFD (17 % lipid) and three additional diets by supplementing 5, 20 or 80 mg/kg of COQ10 to the HFD. After an 8-week culture period, samples were collected and analysed. The results demonstrated that COQ10 inclusion prevented the HFD-induced deterioration of growth performance and feed utilisation. COQ10 alleviated the deposition of saturated fatty acids following HFD intake and promoted the assimilation of n-3 and n-6 PUFA. Moreover, COQ10 administration inhibited the surge in serum transaminase activity and reduced hepatic lipid content following HFD ingestion, which was consistent with the results of oil red O staining. In addition, HFD feeding led to reduced hepatic citrate synthase and succinate dehydrogenase activities and decreased ATP content. Notably, COQ10 administration improved these indices and up-regulated the expression of mitochondrial biogenesis-related genes (pgc-1α, pgc-1β, nrf-1, tfam) and autophagy-related genes (pink1, mul1, atg5). In summary, supplementing 20-80 mg/kg of COQ10 in the HFD promoted growth performance, alleviated hepatic fat accumulation and enhanced liver mitochondrial function in spotted seabass.

• MeSH
• Diet, High-Fat * adverse effects   MeSH
• Liver metabolism   drug effects   MeSH
• Animal Feed analysis   MeSH
• Lipid Metabolism drug effects   MeSH
• Mitochondria * drug effects   metabolism   MeSH
• Bass * growth & development   metabolism   MeSH
• Dietary Supplements MeSH
• Ubiquinone * analogs & derivatives   pharmacology   administration & dosage   MeSH
• Fatty Liver * veterinary   etiology   drug therapy   prevention & control   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

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.

• MeSH
• Antioxidants MeSH
• Diet veterinary   MeSH
• Weight Gain MeSH
• Animal Feed MeSH
• Methionine * pharmacology   MeSH
• Bass * MeSH
• Dietary Supplements MeSH
• Racemethionine MeSH
• Superoxide Dismutase MeSH
• Temperature MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH

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
• Microbiota * MeSH
• Bass * genetics   metabolism   microbiology   MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Intestines MeSH
• Gastrointestinal Microbiome * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article 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
• Cytokines immunology   MeSH
• Head Kidney * immunology   parasitology   MeSH
• Isopoda immunology   MeSH
• Liver * immunology   parasitology   MeSH
• Fish Diseases * immunology   parasitology   MeSH
• Parasitic Diseases, Animal * immunology   parasitology   MeSH
• Bass * immunology   parasitology   MeSH
• Gene Expression Profiling MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Mediterranean Sea 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 anatomy & histology   ultrastructure   MeSH
• Species Specificity MeSH
• Gonads parasitology   MeSH
• Microscopy, Electron, Scanning MeSH
• Fish Diseases parasitology   MeSH
• Bass parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Tunisia 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
• Phylogeny MeSH
• Urinary Tract parasitology   MeSH
• Myxozoa * classification   genetics   isolation & purification   MeSH
• Fish Diseases parasitology   MeSH
• Parasitic Diseases, Animal parasitology   MeSH
• Bass parasitology   MeSH
• DNA, Ribosomal genetics   MeSH
• Spores classification   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Argentina MeSH
• Atlantic Ocean 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
• Species Specificity MeSH
• Gonads parasitology   MeSH
• Nematoda classification   ultrastructure   MeSH
• Nematode Infections epidemiology   parasitology   veterinary   MeSH
• Fish Diseases epidemiology   parasitology   MeSH
• Bass parasitology   MeSH
• Prevalence MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Gulf of Mexico epidemiology   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 anatomy & histology   classification   genetics   ultrastructure   MeSH
• Spirurida Infections epidemiology   parasitology   veterinary   MeSH
• Microscopy, Electron, Scanning MeSH
• Fish Diseases epidemiology   parasitology   MeSH
• Bass genetics   parasitology   MeSH
• Prevalence MeSH
• Fishes MeSH
• DNA Barcoding, Taxonomic veterinary   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Libya MeSH
• Mediterranean Sea MeSH
• Tunisia 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
• Species Specificity MeSH
• Nematoda anatomy & histology   classification   MeSH
• Bass parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Atlantic Ocean MeSH
• Gulf of Mexico MeSH
• United States 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 anatomy & histology   classification   isolation & purification   MeSH
• Species Specificity MeSH
• Spirurida Infections parasitology   veterinary   MeSH
• Fish Diseases parasitology   MeSH
• Ovary parasitology   MeSH
• Bass parasitology   MeSH
• Food Parasitology MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Mediterranean Sea MeSH