Zeus Faber Research Articles

The genome sequence of the John Dory, Zeus faber Linnaeus, 1758

We present a genome assembly from an individual Zeus faber (the John Dory; Chordata; Actinopteri; Zeiformes; Zeidae). The genome sequence is 804.7 megabases in span. Most of the assembly is scaffolded into 22 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 16.72 kilobases in length.

The genome sequence of the John Dory, Zeus faber Linnaeus, 1758.

We present a genome assembly from an individual Zeus faber (the John Dory; Chordata; Actinopteri; Zeiformes; Zeidae). The genome sequence is 804.7 megabases in span. Most of the assembly is scaffolded into 22 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 16.72 kilobases in length.

Biomonitoring of toxic and essential trace elements in different tissues of fish species in Türkiye

ABSTRACT Concentrations of toxic and essential trace elements (Hg, Ni, Cu, Pb, Cr, Cd, Mn, As and Se) were determined in different tissues (muscle, skin and liver) of three commercial fish species (Diplodus sargus, Zeus faber, Pomatomus saltatrix). The concentration of the elements was measured by ICP-MS. Arsenic was the most accumulated element in fish tissues. As concentrations in tissues of all fish species, except muscle and skin of John Dory fish, were higher than the maximum limits (MLs). The highest Se concentrations in all fish tissues were in found in the liver. Mn levels were higher than the maximum limits in all tissues of Sargoz fish, skin of John Dory fish, livers of Bluefish and Big Bluefish. In addition, Cr concentrations in tissues of all fish species were found to be higher than the maximum limits of FEPA and WHO.

Foça'da (Doğu Akdeniz, Türkiye) Trol Balıkçılığı Çöküşün Eşiğinde mi?

In this study, we aimed to examine the status and historical change of trawl fishing fleet in the Foça in the Aegean Sea. The data of the study representing all actively working trawlers in 1998-1999 and 2019 were collected through face-to-face interviews with trawler boat owners in Foca. The questionnaire consisted of questions related to the characteristics of the vessels, fishing activity, socio-demographics of fishers, running costs, annual landings of species and management issues. The study indicated that the annual landings of the main target species significantly decreased over the last two decades. Fishers reported the landings of some species including Dentex gibbosus, Dentex macrophthalmus, Homarus gammarus, Mustelus mustelus, Octopus vulgaris, Parapenaus longirostris, Scomber colias, Scorpaena porcus, Scorpaena scrofa, Spicara smaris, Trachurus spp. and Zeus faber decreased considerably over this period. Over the same period, a decrease was found in the mean length of Merluccius merluccius, Lophius piscatorius and Zeus faber. The vessels’ fuel tank volume and tow duration showed significant increases from 1999 to 2019. The trawl fleet decreased by ~75% from 1999 to 2019 and 55% of the current fishers reported that they may leave the fishery sector within the next 10 years. A change was also determined in the tradition of the sharing system, which is the number of crews paid in shares rather than a fixed salary, significantly decreased. Moreover, the crew numbers from vessel owners’ households significantly decreased. As a result, we discussed the changes, problems, regulations and restrictions related to trawl fishery in Foça, which used to be the most important trawling fishing center of the Aegean twenty years ago. We found dramatic changes in many aspects compared to what it was two decades ago and provided suggestions regarding fisheries management.

Range expansion of the Atlantic fish Zenopsis conchifer (Lowe, 1852), family Zeidae, in the western Mediterranean Sea

Three specimens of Silver John dory, Zenopsis conchifer, (Lowe, 1852) were observed for the first time in the Ligurian Sea and northern Tyrrhenian Sea (western Mediterranean), one in 2020 and two in 2021. This is the fifth record (up to ten individuals) of Z. conchifer in the Mediterranean Sea, which occurred 11 years after the last observation in 2010 in the southern Tyrrhenian Sea. The present study reports the northernmost record of the species in the western Mediterranean Sea, indicating a potential range expansion of the distribution of this Atlantic species across the area. Morphometric, meristic and biological data of the three specimens are provided and compared with previous published records.

First record of the benthopelagic fish John dory Zeus faber (Linnaeus, 1758) in the Black Sea coasts of Türkiye

In this study, a male specimen of John dory (Zeus faber) with 31.4 cm in total length and 365.43 g in body weight was caught with a trammel net at a depth of 15 m from Fener Island in the province of Fatsa (Ordu, Black Sea). This record is the first verified report suggesting that John dory expanded its distribution in the Mediterranean towards the Geographical Sub-Area 29 (Black Sea).

Environmental DNA Metabarcoding Analysis of Fish Assemblages and Phytoplankton Communities in a Furrowed Seabed Area Caused by Aggregate Mining

To estimate the impact of aggregate mining on a marine ecosystem, fish assemblages and phytoplankton communities were analyzed using environmental DNA metabarcoding. Metabarcoding analysis revealed 152 fish amplicon sequence variants (ASVs) (88 in September and 118 in February), which were assigned to 29 orders, 62 families, 104 genera, and 114 species (73 in September and 89 in February). Heatmap analysis showed that the fish assemblages in the mining area clearly differed from those in the surrounding area and that Pagrus major, Lateolabrax japonicus, Zeus faber, and Eopsetta grigorjewi were significantly more abundant there than in the surrounding area. In the phytoplankton community in September, the phyla Cyanobacteria and Haptophyta differed significantly between the mining area and its surroundings. By contrast, no such significant differences were identified in February, presumably due to the low temperature impeding phytoplankton growth. Taking these findings together, mining activities clearly affect fish and phytoplankton communities, but further long-term study is required to assess their impacts on marine ecosystems.

Total and Organic Mercury in Fish from Different Geographical Areas in the North Atlantic Ocean and Health Risk Assessment

Fish consumption is considered the main route of exposure to mercury for the human population. In this sense, this study analysed the total and organic mercury content present in the muscle tissue of 38 fish species caught in different geographical areas of the North Atlantic Ocean (included in FAO fishing areas 27 and 31). The potential risk to human health through fish consumption was assessed using the maximum limit for mercury intake of 1.3 μg methylmercury Kg body weight−1 week−1. The results show that carnivorous species presented higher mercury content (range 0.03–0.88 μg g−1) when compared to omnivorous (range 0.003–0.19 μg g−1) in all sampling sites. Furthermore, demersal fish exhibited higher mercury levels (range 0.01–0.88 μg g−1) than the pelagic species (range 0.003–0.38 μg g−1) did. From the 38 species analysed only Zeus faber presented mercury levels (0.68 ± 0.07 μg g−1) above the maximum limit (0.5 μg g−1) established for human consumption. On the other hand, mercury intake can be higher than the recommended due to the consumption of 13 species from fishing area 27 (Azores archipelago and Northwest Portuguese coast) and one species (Cynoscion nebulosus) from fishing area 31 (Southeast Mexican coast). However, only the consumption of Zeus faber and Aphanopus carbo from the fishing area 27 is discouraged. Thus, the fish consumption per capita in a specific area can exceed the limits of mercury ingestion, even when the mercury content in the fish is below the recommended for consumption.

Diet Composition of John Dory Zeus faber in the Coastal Waters of the South Sea, Korea

Diet Composition of John Dory Zeus faber in the Coastal Waters of the South Sea, Korea

Contribution of commercial fish species to human mercury exposure: An evaluation near the Mid-Atlantic Ridge

Fish consumption is frequently associated with the prevention of some human diseases, being simultaneously a major pathway of mercury (Hg) exposure. Therefore, the aim of the study was to evaluate the contribution of 28 commercial fish species to the human Hg exposure in the Azores archipelago (Portuguese region with highest fish consumption per capita). These species potentially contributed on average to 7.47 mg of Hg per capita, although low Hg levels had been detected in fish. Mora moro and Zeus faber exceeded the maximum permitted for fish consumption (> 0.5 μg g−1 ww) even though they were not the species contributing the most to human Hg exposure. On the other hand, Katsuwonus pelamis was the main contributor due to increased fish landings. Furthermore, an increase in Hg content with trophic level has been suggested, as carnivore fish exhibited higher Hg levels than omnivores. In addition, demersal fish generally presented higher Hg concentration (although non-significant) than pelagic ones, possibly related with increased Hg values of their prey at this depth. Notwithstanding, THQ (Target Hazard Quotient) being < 1 for all species indicates that the daily human exposure to Hg via fish consumption is not likely to cause any negative health risks.

A comparison of market landings during fish spawning seasons to better understand the effectiveness of the temporal fishery closure in Turkey

Seasonal fishery closures, are an input control measure to reduce fishing pressure on spawning stocks in fisheries management. Despite the huge foregone economic losses from such closures, the efficacy of them has yet to be examined in Turkey. This study compares the monthly landed catch distribution for commercial marine species averaged for 12 years (2006–2017) from Istanbul fish market, to catch rates of those species during the spawning seasons. Our results revealed that at first glance, most commercially important fish species examined here have their spawning seasons protected under the Turkish industrial seasonal closure period, especially for small and medium pelagics, as well as some demersals. On the other hand, taxa with winter spawning seasons such as Merlangius merlangus, John dory Zeus faber, brown meagre Sciaena umbra, big-scale sand smelt Atherina boyeri, and bogue Boops boops do not benefit from the commercial fisheries summer closure (>50% of their catch total). Also, some species are still heavily fished (>35% of their catch total) during the closure implying they are mainly targeted by small-scale fisheries (SSF). To help rebuild the commercial fisheries, we recommend the accompaniment of the industrial closure with the use of ‘Real Time Closures’ (RTCs) applied to all fishing sectors for species highly fished during their spawning periods and spawning habitats.

Projected impacts of warming seas on commercially fished species at a biogeographic boundary of the European continental shelf

Abstract Projecting the future effects of climate change on marine fished populations can help prepare the fishing industry and management systems for resulting ecological, social and economic changes. Generating projections using multiple climate scenarios can provide valuable insights for fisheries stakeholders regarding uncertainty arising from future climate data. Using a range of climate projections based on the Intergovernmental Panel on Climate Change A1B, RCP4.5 and RCP8.5 climate scenarios, we modelled abundance of eight commercially important bottom dwelling fish species across the Celtic Sea, English Channel and southern North Sea through the 21st century. This region spans a faunal boundary between cooler northern waters and warmer southern waters, where mean sea surface temperatures are projected to rise by 2 to 4°C by 2098. For each species, Generalized Additive Models were trained on spatially explicit abundance data from six surveys between 2001 and 2010. Annual and seasonal temperatures were key drivers of species abundance patterns. Models were used to project species abundance for each decade through to 2090. Projections suggest important future changes in the availability and catchability of fish species, with projected increases in abundance of red mullet Mullus surmuletus L., Dover sole Solea solea L., John dory Zeus faber L. and lemon sole Microstomus kitt L. and decreases in abundance of Atlantic cod Gadus morhua L., anglerfish Lophius piscatorius L. and megrim Lepidorhombus whiffiagonis L. European plaice Pleuronectes platessa L. appeared less affected by projected temperature changes. Most projected abundance responses were comparable among climate projections, but uncertainty in the rate and magnitude of changes often increased substantially beyond 2040. Synthesis and applications. These results indicate potential risks as well as some opportunities for demersal fisheries under climate change. These changes will challenge current management systems, with implications for decisions on target fishing mortality rates, fishing effort and allowable catches. Increasingly flexible and adaptive approaches that reduce climate impacts on species while also supporting industry adaptation are required.

Risk-based scoring and genetic identification for anisakids in frozen fish products from Atlantic FAO areas

BackgroundThe presence of Anisakis larvae in fish represents a major public health concern. Effective risk management procedures should be applied to prevent heavily infected products from reaching the market. The aim of the study is to provide preliminary data on parasite exposure and risk classification in frozen fish products by applying a risk categorization scheme (site, abundance, density and epidemiology – SADE) and Fish Parasite Rating (FPR) method. Fish and cephalopods samples (N = 771) from 5 different FAO Atlantic areas were examined and categorized after an accurate visual inspection and a chloro-peptic digestion.ResultsIn 25 out of 33 fish species parasite larvae were found. 10897 anisakids larvae were collected and identified to genus level. Molva dypterygia, Conger conger, Zeus faber and Aphanopus carbo were shown to be the most highly infected species. SADE and FPR scores were 1 and poor, respectively, for the referred species, because of the disseminated Anisakis infection and commercial rejection.ConclusionSADE/FPR method showed high specificity and accuracy. The information provided in this work could be used in early warning systems for the detection of parasites in fishery products and might help fishing industries in establishing management strategies for infected stocks in terms of cost saving decisions.

New species of Acanthochondria Oakley, 1930 and Chondracanthus Delaroche, 1811 (Copepoda: Cyclopoida: Chondracanthidae) parasitizing marine fishes from Indian waters

Abstract This paper describes two new species of parasitic copepods of the family Chondracanthidae H. Milne Edwards, 1840. Acanthochondria krishnai sp. n. is described from Dollfus' stargrazer, Uranoscopus guttatus Cuvier, collected from Muttom and Colachel, Tamil Nadu, and Chondracanthus kabatai sp. n. from Silvery john dory, Zenopsis conchifer Lowe, collected from Neendakara, Quilon, Kerala, both along the southwest coast of India. Both the species are described and illustrated based on the fresh female and male specimens collected from India. Both the species are the first Indian representative of the respective genera. The checklist of Indian species of the family Chondracanthidae is also presented.

Plastics occurrence in the gastrointestinal tract of Zeus faber and Lepidopus caudatus from the Tyrrhenian Sea

The present study investigates the occurrence of plastic pollution in two commercially important marine teleosts (Zeus faber and Lepidopus caudatus) from the northern coasts of Sicily (Tyrrhenian Sea). Plastics occurrence in the gastrointestinal tract was higher in Lepidopus caudatus (78.1%) than Zeus faber (51.4%). Debris characterization, carried out by micro-Raman spectroscopy, allowed identified the main types of found polymers as: polypropylene (PP), polyamide (PA), nylon and, to a lesser extent, polyethylene (PE). Of the two fish species studied, the silver scabbardfish appeared to be the more vulnerable to plastic ingestion. Our study represents a starting point that may pave the way for future investigation of the fate, accumulation and transfer of plastic debris to upper trophic levels, to verify their potential toxicity and to better understand strategies to mitigate this phenomenon.

Occurrence of Anisakis pegreffii (Nematoda: Anisakidae) Larvae in Imported John Dory (Zeus faber) from Senegalese Coast Sold in Turkish Supermarkets.

West African goatfish Pseudupeneus prayensis, bluespotted seabream Pagrus caeruleostictus and John Dory Zeus faber are commercially marketed as fresh and frequently imported from Senegalese coast (FAO area 34.3.12) in Turkish supermarkets. The aim of the current study was to collect data of occurrence and molecular identification of Anisakis species in imported P. prayensis, P. caeruleostictus and Z. faber caught in the Senegalese coast and to support epidemiological report for a risk evaluation of Anisakis species in Turkish supermarkets. Forty imported fish from each species at a total of 120 samples were investigated for the presence of Anisakis larvae. Based on ITS region of RFLP analysis Anisakis larvae were identified and randomly selected five larvae were also sequenced for further confirmation for cox2 gene. No Anisakis larvae were isolated from P. prayensis, P. caeruleostictus whereas Anisakis larvae were only found in Z. faber. A total of 156 Anisakis larvae were collected from Z. faber. All larvae were molecularly identified as Anisakis pegreffii. The prevalence (%), intensity and abundance of Anisakis infection in Z. faber were detected to be 82.5%, 8.3 and 6.8, respectively. This is the first assessment of the occurrence of A. pegreffii in imported Z. faber from the Senegalese coast in Turkish supermarkets. Moreover, consuming imported P. prayensis and P. caeruleostictus present low to non-existent risk for anisakiasis in Turkish consumers. Furthermore, the presence of A. pegreffii larvae in imported Z. faber from the Senegal waters could have public health implications in Turkish consumers.

Nordmøre Grid Trial in Large Prawn Senegalese Fishery: Interest to Reduce By-catch not Evidenced

Demersal shrimp fisheries, which are not very selective, generate significant discards and / or bycatch, generally composed of crustaceans, fish and molluscs of different size classes. As part of the implementation of the management plan for the deepwater shrimp Parapenaeus longirostris in Senegal, selectivity tests of the Nordmore device were conducted. Thus, three Nordmore grids characterized by different spacings between the bars (24, 28 and 30 mm) were tested on the experimental trawl in the Senegalese Economic Zone. Regardless of spacing, the Nordmore Grid completely removed large individuals from several species of commercial interest (John dory and Bearded brotula) or not (rays, sharks, etc.). Gamba shrimp loss analyzes indicate a significant difference (α <0.05) between the three spacer grids 24, 28 and 30 mm. Regardless of the type of grid, the amount of shrimp sorted per minute is larger for the experimental trawl; and this quantity increases with the spacing of the grid. The 30mm grid stands out with percentages of gamba shrimp losses ranging from 3 to 20% with an average of 8%; and a ratio of bycatch / gamba shrimp catch around 2.2 / 1, below the world average for this type of fishery (5/1).

Barking mad: The vocalisation of the John Dory, Zeus faber.

Studies on the behavioural function of sounds are very rare within heterospecific interactions. John Dory (Zeus faber) is a solitary, predatory fish that produces sound when captured, but has not been documented to vocalize under natural conditions (i.e. in the wild). The present study provides the first in-situ recordings of John Dory vocalisations and correlates them to behavioural response of snapper (Pagrus auratus) a common species found through New Zealand. Vocalisations or ‘barks’, ranged between 200–600 Hz, with a peak frequency of 312 ± 10 Hz and averaged 139 ± 4 milliseconds in length. Baited underwater video (BUV) equipped with hydrophones determined that under natural conditions a John Dory vocalization induced an escape response in snapper present, causing them to exit the area opposite to the position of the John Dory. We speculate that the John Dory vocalisation may be used for territorial display towards both conspecifics and heterospecifics, asserting dominance in the area or heightening predatory status.

Ex-vessel price formation of fish species with low and irregular harvests: The case for John dory in Mie Prefecture, Japan

Ex-vessel price formation of fish species with low and irregular harvests: The case for John dory in Mie Prefecture, Japan

Quality assessment of Zeus faber (Peter's fish) ovaries regularly commercialized for human consumption.

In the last few years, the consumption of fish eggs has increased rapidly, finding widespread use also in mass catering. This increase has involved also those of the Peter’s fish (Zeus faber). Females of this species, by their reproductive characteristics, have highly developed gonads in different periods of the year, making the raw material easy to find. The aim of the present study was to perform a quality assessment of Zeus faber ovaries regularly commercialized for human consumption. A total number of 34 samples, divided in fresh (11) and frozen (23), were processed for microbiological characterization, parasitological and histological evaluations. Fresh and frozen samples have significant (P<0.01) differences in total bacterial charge, with values of 4.75±0.5 Log CFU/g and 3.65±0.7 Log CFU/g respectively. The mean value of Enterobacteriaceae was 2.58±0.7 Log CFU/g in fresh products, while 52.17% (12) of frozen samples reported loads of <1 Log CFU/g. No Salmonella spp. and Listeria monocytogenes were found. Aeromonas spp. was detected in two frozen sample (with loads of 2.2 and <1 Log CFU/g) and in 5 fresh ovaries with value ranged from 1.70 to 3.48 Log CFU/g. Vibrio spp. was found in 4 (36.36%) and 3 (13.04%) of fresh and frozen samples respectively, with loads always <1 Log CFU/g. All 31 Vibrio strains isolated, were identified as Vibrio alginolyticus, and 61.29% (19) of them was positive for the ToxRS factor and 6.45% (2) for ToxR. The 47.06% (16) of total samples showed infestations by larvae of Anisakis Type 1 in the serous and inside the ovary. In this last case, histologically it was found to be free larvae. This study attested satisfactory hygiene conditions for Zeus faber ovaries currently marked for human consumption. The presence of potentially pathogenic strains of V. alginolyticus and Aeromonas spp., but above all the frequent infestation by Anisakis larvae, represent a potentially hazard for the consumer.