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The red porgy (Pagrus pagrus) and the common dentex (Dentex dentex) are Sparidae species of high commercial value, traded in the Greek market. In some cases, fish species identification from Greek fisheries is difficult for the consumer due to the strong morphological similarities with their imported counterparts or closely related species such as Pagrus major, Pagrus caeroleustictus, Dentex gibbosus and Pagellus erythrinus, especially when specimens are frozen, filleted or cooked. Techniques based on DNA sequencing, such as COI barcoding, accurately identify species substitution incidents; however, they are time consuming and expensive. In this study, regions of mtDNA were analyzed with RFLPs, multiplex PCR and HRM in order to develop a rapid method for species identification within the Sparidae family. HRM analysis of a 113 bp region of cytb and/or a 156 bp region of 16s could discriminate raw or cooked samples of P. pagrus and D. dentex from the aforementioned closely related species and P. pagrus specimens sampled in the Mediterranean Sea when compared to those fished in the eastern Atlantic. HRM analysis exhibited high accuracy and repeatability, revealing incidents of mislabeling. Multiple samples can be analyzed within three hours, rendering this method a useful tool in fish fraud monitoring. [ABSTRACT FROM AUTHOR]

Abstract Background Soybean is a common alternative protein source of plant origin in aquafeeds as it has a reasonably balanced amino acid profile and is widely available. This study aimed to investigate the influence of partial substitution of fish meal with soy meal on cytoprotective pathways and apoptosis in the digestive system of common dentex (Dentex dentex), using the activation of Hsp70, p38 MAPK, Bcl-2 and caspase-3. The experimental approach involved feeding of common dentex with three isoprotein and isoenergetic diets that contained fish meal as a protein source (FM), partial replacement of fish meal by soy meal 25% (SM25) and 40% (SM40) for 3 months. Results The SM40 diet induced Hsp70 activation only in the middle part of intestine. On the other hand, both SM25 and SM40 diets diminished the phosphorylation of p38 MAPK in the anterior and the middle part of intestine, whereas only SM25 induced p38 MAPK phosphorylation in the stomach. Moreover, a decrease in the levels of caspase-3 activity was observed in the middle and posterior intestine, as well as in the stomach after feeding with SM25 diets. Furthermore, Bcl-2 levels were increased by SM40 in the anterior and by SM25 in the middle part of intestine. Conclusions SM25 and SM40 diets elicited a tissue and soy concentration specific cellular and cell protective response in the different parts of the digestive tract in common dentex.

Abstract: Microorganisms present in the rearing water colonize the gut of first feeding larvae and represent the first barrier against opportunistic pathogens. The aim of the experiments presented herein was to standardize a protocol for the management of rearing water and microalgae suitable for the larval rearing of common dentex. In Experiment 1, bacteria–algae interactions were tested using a monospecific microalgal community, Tetraselmis chuii, suitable for nutritional experiments and with known antibacterial activity. In Experiment 2, the evolution of the bacterial community and larval performance (growth and survival) were monitored daily, in three conditions: (1) mature water: T. chuii was added 5 d before the rearing of common dentex larvae, (2) green water: T. chuii was added 1 d before, and (3) clear water: no T. chuii addition. The results show the influence of the presence of T. chuii on the evolution of the bacterial communities, both in terms of bacterial density and morphology, and indicate green water is the most suitable water treatment for management of larval rearing for common dentex. [ABSTRACT FROM AUTHOR]

The common dentex, Dentex dentex, is a fish species which inhabits marine environments in the Mediterranean and Northeast Atlantic regions. This is an important species from an ecological, economic and conservation perspective, however critical information on its population genetic structure is lacking. Most samples were obtained from the Mediterranean Sea (17 sites) with an emphasis around Corsica (5 sites), plus one Atlantic Ocean site. This provided an opportunity to examine genetic structuring at local and broader scales to provide science based data for the management of fishing stocks in the region. Two mitochondrial regions were examined (D-loop and COI) along with eight microsatellite loci. The COI data was combined with publicly available sequences and demonstrated past misidentification of common dentex. All markers indicated the absence of population genetic structure from the Bay of Biscay to the eastern Mediterranean Sea. Bayesian approaches, as well as the statistical tests performed on the allelic frequencies from microsatellite loci, indicated low differentiation between samples; there was only a slight (p = 0.05) indication of isolation by distance. Common dentex is a marine fish species with a unique panmictic population in the Mediterranean and likely in the Atlantic Ocean as well. [ABSTRACT FROM AUTHOR]

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Background: Soybean is a common alternative protein source of plant origin in aquafeeds as it has a reasonably balanced amino acid profile and is widely available. This study aimed to investigate the influence of partial substitution of fish meal with soy meal on cytoprotective pathways and apoptosis in the digestive system of common dentex (Dentex dentex), using the activation of Hsp70, p38 MAPK, Bcl-2 and caspase-3. The experimental approach involved feeding of common dentex with three isoprotein and isoenergetic diets that contained fish meal as a protein source (FM), partial replacement of fish meal by soy meal 25% (SM25) and 40% (SM40) for 3 months. Results: The SM40 diet induced Hsp70 activation only in the middle part of intestine. On the other hand, both SM25 and SM40 diets diminished the phosphorylation of p38 MAPK in the anterior and the middle part of intestine, whereas only SM25 induced p38 MAPK phosphorylation in the stomach. Moreover, a decrease in the levels of caspase- 3 activity was observed in the middle and posterior intestine, as well as in the stomach after feeding with SM25 diets. Furthermore, Bcl-2 levels were increased by SM40 in the anterior and by SM25 in the middle part of intestine. Conclusions: SM25 and SM40 diets elicited a tissue and soy concentration specific cellular and cell protective response in the different parts of the digestive tract in common dentex. [ABSTRACT FROM AUTHOR]

The common dentex, Dentex dentex , is an iconic marine coastal fish of the Mediterranean Sea. Despite its economic and ecological importance, data on the population structure of this species are still very limited. The aim of this study was to identify the stock structure of the common dentex at relatively fine spatial scale around Corsica Island, using a combination of markers that have different spatial and temporal scales of integration: microsatellite DNA markers, otolith shape analysis and parasites communities. Microsatellite analysis indicated that there was no significant genetic differentiation in D . dentex between the four sampling sites around Corsica. Otolith shape analysis suggests one potential distinct population unit of D . dentex centered in one site (Cap Corse) varying in their degree of differentiation from those in the other zones. Multivariate analysis on parasite abundance data highlights to a lower extent two sites (Bonifacio and Galeria) with some connectivity between adjacent zones. The combination of these three markers together highlights the resulting three sites while giving complementary insights and an opportunity to compare their utility and potential to understand population interactions. A complex population structure around Corsican coasts is then proposed, providing a new perspective on common dentex fishery stock conservation and management strategies. [ABSTRACT FROM AUTHOR]

We investigated the nutritional quality of commercially important farmed fish species: sea bream (Sparus aurata), sea bass (Dicentrarchus labrax), dentex (Dentex dentex), and turbot (Scophthalmus maximus). The omega-3 fatty acid content of dentex was twice as high as that of any other fish species, and its eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid contents were 2-4 times higher. The recommended n-3/n-6 ratio was present in all the fish species, but the recommended polyunsaturated/saturated fatty acid ratio was not present in the turbot. All the fish species, except turbot, met the recommended atherogenic index, thrombogenic index, and ratio of hypocholesterolaemic to hypercholesterolaemic fatty acids, whereas the highest flesh lipid quality value was observed in the dentex. [ABSTRACT FROM AUTHOR]

This study examined the stomach contents of 230 individuals out of 439 samples obtained from commercial fishermen between January 2013 and March 2014 from a trawler using trawl bags with a full cod-end mesh size of 44 mm. It was found that 216 samples were full and the stomach fullness index was estimated at 93.9%. The varying diet composition of the species was determined by estimating the percentage numerical composition (N%), frequency of occurrence (F%), gravimetric composition (W%) and the index of relative importance (IRI%). Diversity (Shannon index), richness (Margalef index) and similarity (Bray-Curtis index) of the catches in different seasons were calculated using the Biodiversity Professional (Version 2) software. Three major groups were identified in the catches: Crustacea, Mollusca and Teleostei. At least 17 different prey groups were identified. With regard to the diversity of consumed prey, the winter (1.204), autumn (1.079) and spring (1.000) seasons were characterized by a medium level of diversity, summer (0.699) - by a low level of diversity. However, the richness of prey does not show seasonal differences. As indicated by the Bray-Curtis index, the highest similarity between the prey groups was observed between the autumn and winter seasons, at 81.61%. [ABSTRACT FROM AUTHOR]

As the world's fastest ongrowing sector in food production, aquaculture has remarkable priority and needs technological improvements and new candidate fish species to overcome some limitation factors. Considering these issues, this study based on determining the flesh quality in terms of nutrient and mineral element composition of two potential fish species, common dentex (Dentex dentex) and greater amberjack (Seriola dumerili), in recirculation aquaculture system (RAS). On the nutrient basis, the dry matter content of 28.82% and fillet yield with a value of 53.28% of Dentex dentex were found significantly higher than (P<0.05) Seriola dumerili. Crude protein and lipid values demonstrated slight but insignificant differences between the species. Among the macro elements of K and Mg and micro elements of Cr, Mn and Ni were noticeably higher in common dentex than greater amberjack, but Zn level was present almost double amount in amberjack (P<0.05). [ABSTRACT FROM AUTHOR]

Common dentex ( Dentex dentex ) is an appreciated carnivorous fish with high growth rate and life cycle adaptable to existing farming techniques. Since the use of carbohydrates is an economic and sustainable alternative for a protein-sparing effect, the study of how this macronutrient affects the welfare of carnivorous species must be studied. The aim of the present study was to evaluate the effects of different types and levels of carbohydrates on common dentex oxidative status. Nine isonitrogenous (43%) and isoenergetic (22 MJ kg − 1 ) diets were formulated combining three types (pregelatinized starch-PS, dextrin-Dx and maltodextrin-Mx) and three levels (12, 18 and 24%) of carbohydrates. The activities of catalase-CAT, superoxide dismutase-SOD, glutathione peroxidase-GPX, glutathione reductase-GR and glucose 6-phosphate dehydrogenase-G6PDH, SOD isoenzymatic profile, lipid peroxidation-LPO and protein oxidation-PO were determined in liver and white muscle. SOD and CAT were not affected. GPX in liver and white muscle and GR in liver increased at higher inclusion carbohydrates levels. The lowest levels of GR and G6PDH in both tissues and LPO in liver were observed in maltodextrin groups. No significant effects by carbohydrate source were observed in liver PO and white muscle LPO. Regarding carbohydrate level effect, 18% and 24% dietary inclusion level decreased LPO in white muscle and PO in liver. LPO in liver was also decreased at 24% inclusion level. Altogether, results indicate the use of carbohydrates as an alternative energy source does not produce negative effects on oxidative status of common dentex, on the contrary, even contribute to their oxidative protection. [ABSTRACT FROM AUTHOR]

Larval fish have a relatively poorly developed immune system and hence they primarily rely on non-specific immune responses produced in the skin and gut. This study aims to illustrate the fine structure of gut development in common dentex (Dentex dentex) larvae and determine the initiation of pinocytic activity, which is an important early non-specific immune response in fish intestines, during various live-food feeding stages (yeast enriched rotifer, Artemia nauplii and metanauplii) from hatching (D0) to 25 days after hatching (D25) by using transmission electron microscopy (TEM). A total of 54 larvae were sampled and examined with electron microscopy. The results show that hind-gut intestine enterocytes have morphological features which suggest they play a role in absorption and intracellular digestion of nutrients in fish. The presence of vigorous pinocytic activity in the Artemia feeding stage between 17-25 days after hatching is evidence for the development of a nonspecific immune system. In the present study, the ultrastructural gut development of cultured common dentex was investigated for the first time and the data reported in this study may provide additional fundamental knowledge for improving larval rearing success in common dentex culture. [ABSTRACT FROM AUTHOR]

Abstract The egg quality of two common dentex captive broodstocks were monitored for two consecutive years during their natural spawning season. Volume of spawned eggs, volume of buoyant eggs, fertilization rate, egg weight, hatching rate and mortality of larvae were recorded. According to the volume of spawned eggs, the ratio of buoyant eggs spawned, the number of spawning days and the fertilization rate pointed to an improvement from Year 1 to Year 2. But data on hatching rate and larval mortality lead to the opposite conclusion. Highlights • Two common dentex captive broodstocks have been monitored during their natural spawning season for two consecutive years. • The quality of the spawned eggs has been assessed using different quality criteria based on egg production or larval performance. • Criteria used for assessing the spawning quality lead to different conclusions. • In conclusion, all criteria should be used in order to obtain a reliable assessment, including criteria based on larval performance. [ABSTRACT FROM AUTHOR]

Based on light and scanning electron microscopical studies of nematode specimens from the digestive tract of some rarely collected anguilliform and perciform fishes off New Caledonia, three new species of Cucullanus Müller, 1777 (Cucullanidae) are described: C. austropacificus n. sp. from the longfin African conger Conger cinereus (Congridae), C. gymnothoracis n. sp. from the lipspot moray Gymnothorax chilospilus (Muraenidae), and C. incognitus n. sp. from the seabream Dentex fourmanoiri (Sparidae). Cucullanus austropacificus n. sp. is characterized by the presence of cervical alae, ventral sucker, alate spicules 1.30–1.65 mm long, conspicuous outgrowths of the anterior and posterior cloacal lips and by elongate-oval eggs measuring 89–108 × 48–57 μm; C. gymnothoracis n. sp. is similar to the foregoing species, but differs from it in the absence of cervical alae and the posterior cloacal outgrowth, in the shape and size of the anterior cloacal outgrowth and somewhat shorter spicules 1.12 mm long; C. incognitus n. sp. (based on female morphology) differs from other congeneric species parasitic in the Sparidae mainly in possessing cervical alae, the postequatorial vulva, phasmids situated at the mid-length of the tail and in the size of the eggs (75–84 × 45–66 μm). A key to species of Cucullanus parasitizing anguilliform fishes is provided.

Three methods of age estimation were compared for Dentex dentex. Based on sectioned otoliths, scales appeared to be relevant only up to 5 years and whole otoliths up to 12 years. The maximum estimated age was 36 years, which constitutes to date the oldest age reported. [ABSTRACT FROM AUTHOR]

The article offers information on the fish occurrence of fish genus Dentex and the species Dentex canariensis Steindachner that is found in the Mediterranean Sea. Topics discussed include the total measurements of the fish that is its length and weight, the interaction of Dentex genus with its Dentex species, and the impact of climate change on these fish.

The present study was aimed to evaluate the capacity of common dentex ( Dentex dentex ) to efficiently use dietary carbohydrates. So, the effects of different type and levels of carbohydrates on growth performance, feed utilization, fish composition, plasma metabolites and key metabolic pathways in liver and white muscle of common dentex are presented. Nine isonitrogenous (43%) and isoenergetic (22 MJ kg − 1 ) diets were formulated combining three types, pregelatinized starch (PS), dextrin (Dx) and maltodextrin (Mx), and three levels (12, 18 and 24%) of carbohydrates. Growth performance was not significantly influenced by treatments. The best feed utilization was observed in 18% Mx group. Higher hepatic lipid content was found in fish fed lower dietary carbohydrate levels. PS induced higher liver and white muscle hexokinase and pyruvate kinase activities compared to the lower values observed for Mx. Malic enzyme and glucose 6-phosphate dehydrogenase in liver and white muscle were lower in Mx group. The influence of dietary carbohydrates source was more noticeable than those induced by the carbohydrate level, when glycolysis and lipogenesis pathways were considered. Common dentex is able to use properly dietary carbohydrates, although optimal dietary inclusion levels are below 24%. The greater protein-sparing effect was promoted by the less complex carbohydrate (maltodextrin) and the best feed utilization indices were obtained at intermediate levels of inclusion (18%). [ABSTRACT FROM AUTHOR]

The common dentex, Dentex dentex (L.), is an iconic marine coastal fish in the Mediterranean Sea. This study was performed in the Bonifacio Strait Natural Reserve (BSNR), (NW Mediterranean Sea). The aims were to: (1) evaluate temporal variation of the artisanal fishing of common dentex (2000-2012); (2) compare and quantify catch rates, fishing techniques and catch composition for artisanal and recreational fisheries, and determine the influence of management measures by both activities; and (3) estimate the production of both artisanal and recreational fisheries. Fishery data were collected from different artisanal fishing surveys (onboard fishing vessels and landings) and recreational fishing surveys (roving). The gears with the highest rates of exploitation were longline (3554 g per 100 hooks) and Trolling (351 g boat−1 h−1 ±SE), respectively, for artisanal and recreational fishing. This study showed that catches by both activities were quantitatively higher in partially protected areas than outside them. Production estimations suggest that the recreational fishery contributes significantly to fishing mortality and that it can magnify the negative effects of artisanal fisheries. Specific measures are needed for the sustainable fishery management of common dentex. [ABSTRACT FROM AUTHOR]

Background. The bogue, Boops boops (Linnaeus, 1758); large-eye dentex, Dentex macrophthalmus (Bloch, 1791); common two-banded seabream, Diplodus vulgaris (Geoffroy Saint-Hilaire, 1817); and axillary seabream, Pagellus acarne (Risso, 1827) are four commercially important sparid species which are distributed in the Mediterranean. Although they are very common in the Mediterranean, information regarding; growth, length at first maturity, and age are scarce and variable. This study provides some of the first data on the above-mentioned biological parameters of these four sparid species for the Turkish coasts of the Aegean Sea (Mediterranean). The aim of the present study is to expand our knowledge on the biology of these commercial sparid species from the Aegean Sea. Materials and Methods. Fish samples were collected between July 2004 and June 2007 by R/V Egesüf from İzmir Bay. Demersal trawl samplings were carried out by a traditional trawl net with a 5 m codend (600 mesh circumference at the codend) and made of knotted polyethylene material with 40 mm mesh size netting. Results. The length–weight relations determined in the course of this study were: W = 0.005L3.25 (bogue), W = 0.005L3.03 (large-eye dentex), W = 0.007L3.31 (common two-banded seabream), and W = 0.009L3.14 (axillary seabream). The respective L¥ and k parameters of von Bertalanffy growth equation were: 29.58 and 0.266 for bogue; 24.3 and 0.399 for large-eye dentex; 28.0 and 0.253 for common two-banded seabream; and 22.7 and 0.315 for axillary seabream. Furthermore, lengths at first maturity were determined as: 12.96 (♀) and 9.35 (♂) cm for bogue; 10.83 (♀) and 11.77 (♂) cm for large-eye dentex; 12.87 (♀) and 13.37 (♂) cm for common two-banded seabream; and 14.45 (♀) and 13.91 (♂) cm for axillary seabream. Conclusion. The presently determined parameters of age, growth, reproduction, and mortality of these four species will be useful for estimating the relevant parameters of population dynamics and will hopefully contribute to a better understanding of the long-term changes of the stock sizes. [ABSTRACT FROM AUTHOR]

Background. The Morocco dentex, Dentex maroccanus Valenciennes, 1830, is a sparid species, which has economical value and its population is expanding in a 20-500 m depth range throughout the Mediterranean. Worldwide, there is a lack of information about the biology (age, growth, reproductive season, first maturity length) of this species. This study provides the first data on population parameters of D. maroccanus in the Aegean Sea. Materials and methods. Dentex maroccanus were caught in the Saros Bay (north Aegean Sea) between September 2006 and September 2008. The length-weight relations were determined according to the allometric equation: W = aLb. The spawning season was determined by analyzing the maturity stages and gonadosomatic index, while first maturity length was defined as the size at which 50% of individuals were mature. Growth parameters were estimated using the von Bertalanffy growth equation. Results. The female-male ratio was 4.8 : 1. The total length (weight) of females ranged from 11.4 cm to 25.2 cm (26.2 g to 289.3 g) and of males from 12.8 cm to 24.3 cm (19.8 g to 223.9 g). The growth parameters were calculated as L∞ = 25.31 cm, K = 0.49 year-1, t0 = -0.30 year. The length at first maturity for females and males was 13.0 cm and 15.8 cm, respectively. Monthly values of the gonadosomatic index indicated that spawning occurred mainly between June and September. Conclusion. Results reported in this work will contribute to the knowledge on the biology of D. maroccanus in the north Aegean Sea and also to a better understanding of its role in the marine ecosystem. [ABSTRACT FROM AUTHOR]

The common Dentex (Dentex dentex, Linnaeus 1758) has a significant economic importance and is a highly valued table fish in the Mediterranean region. The paucity of genetic information relating to sparids, despite their growing economic value, provides the impetus for exploring the mitogenomics of this fish group. Here, we sequenced D. dentex complete mitochondrial genome. The sequence is comprised of 16,652 bp and consists of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a 2 non-coding regions (D-loop and L-origin). The overall nucleotide composition is: 27.5% of A, 28.7% of C, 26.9% of T, and 16.9% of G. [ABSTRACT FROM AUTHOR]