Specimens Of Mullet Research Articles

Concentrations of lead, cadmium, and mercury in Mullus barbatus barbatus (L.) from the Algerian coast and health risks associated to its consumption

The Algerian coast receives significant inputs of metallic pollutants. To assess the accumulation of potentially toxic elements (Pb, Cd, Hg) by benthic fish and the consequent health risks for consumers, red mullet specimens (Mullus barbatus barbatus, Linnaeus, 1758) were sampled (n=424) in 3 sites along the Algerian coast (Algiers, Bejaia and Dellys) and analysed for Pb, Cd and Hg in muscles and liver. Spatio-temporal and biological variations were highlighted. The highest concentrations were observed in the liver for the three elements. Mean Pb and Cd concentrations are higher in Algiers specimens. However, the specimens from Dellys are more contaminated by Hg in the liver (0.35±0.0001μg/g). Medium and large specimens show higher concentrations of the three metals. There was no clear seasonal pattern in concentration of Pb, while Hg concentrations are higher in autumn, and Cd in summer, spring and winter. No impact of the three metal elements on Fulton’s K and the hepato-somatic indexes was observed. Despite the average concentrations of Pb and Cd exceeded the recommended regulatory values, few risk related to the consumption of contaminated M. barbatus barbatus inhabiting the Algerian coasts were demonstrated.

Inihibition of mullet (M. liza) brain acetylcholinesterase activity by in vitro polycyclic aromatic hydrocarbon exposure

Polycyclic aromatic hydrocarbons (PAH) have been reported as acetylcholinesterase (AChE) inibitors, although in vitro studies on PAH effects on AChE activity are scarce and have only been performed using electric eel brain extracts. Thus, this study investigated PAH effects on brain AChE activity in a tropical fish species in Southeastern Brazil, mullet (Mugil liza). Mullet specimens were obtained from Guanabara Bay (N = 20), Rio de Janeiro, Brazil. Brain AChE was extracted and exposed to an environmentally relevant concentration of Pyrene, Chrysene, Phenanthrene, and Naphthalene, and PAH metabolites, 2-Naphthol and 1-OH-Pyrene. AChE activity inhibition was observed, although no difference was observed between high- and low- molecular weight PAH. 2-Naphthol was a less potent AChE inhibitor than Naphthalene, albeit non-significantly. Further studies are required, since only one PAH concentration was used herein. Mullet brain extracts seem to be adequate to assess possible neurotoxic PAH effects on fish AChE.

The short-term effects of farmed fish food consumed by wild fish congregating outside the farms

We simulated in the laboratory the possible effects on fatty acids and immune status of wild fish arriving for the first time in the vicinity of a sea-cage fish farm, shifting their natural diet to commercial feed consumption, rich in fatty acids of vegetable origin. The flesh fatty acid profile of golden mullet specimens was altered after 2weeks of commercial feed consumption, showing an increase in fatty acids of vegetable origin. The serum peroxidase and bactericidal activities, and head-kidney leucocyte phagocytic capacity, increased after eight weeks of the new diet, while the respiratory burst activity decreased. The extent of these changes cannot be considered large enough to regard them as compromising the health status of fish. More research is needed in order to elucidate whether the rapid assimilation of the dietary fatty acids could harm the immune status of fish when feeding for longer periods than two months.

Digestive enzymatic patterns as possible biomarkers of endocrine disruption in the red mullet (Mullus barbatus): A preliminary investigation

During two seasonal trawl surveys (April and October, 2012), red mullet specimens were caught from two sites of the northern Sicilian coast (Western Mediterranean), characterized by different degrees of pollution, to assess whether their digestive enzymes could be cost-effective diagnostic tools for endocrine disruption. Pepsin, chymotrypsin, carboxypeptidases A and B, amylase and lipase were measured in the digestive tract of each fish. During both samplings, significant differences in the digestive enzymatic patterns of fish collected from the two sites were found. In April, pepsin and lipase contents were significantly lower in fish from the most impacted site than in those from the reference site. In October, the enzymatic patterns showed trends different from spring, with controversial results for carboxypeptidases A and B and amylase. Pepsin and lipase patterns suggest a detrimental effect played by organic pollutants and the use of these enzymes as possible biomarkers of exposure to endocrine disruptors.

Organochlorinated pesticides, PCBs, dioxins, and PBDEs in grey mullets (Liza ramada) and allis shads (Alosa alosa) from the Vilaine estuary (France)

This study aimed to compare the contamination levels of various organohalogenated compounds in two migratory fish species in the Vilaine River in western France. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), dioxins (polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs)), and polybrominated diphenyl ethers (PBDEs) were analyzed in two diadromous species from the Vilaine estuary, the grey mullet (Liza ramada)-an amphihaline species, and the allis shad (Alosa alosa)-an anadromous species. Fish were collected in spring 2004 and spring 2005, upstream and downstream of the Arzal Dam. PCB contamination varied from 27 to 200 ng g(-1) dry weight (d.w.). PCDDs/Fs, expressed in toxicity equivalent quantity (TEQ) varied from 0.4 to 2.8 pg g(-1) d.w. Dioxins and dioxin-like PCBs expressed in total TEQ varied from 1.4 to 18.8 pg g(-1) d.w. PBDE47 was present at around 2-10 ng g(-1) d.w. and concentrations of the insecticide dichlorodiphenyltrichloroethane breakdown product p,p'-dichlorodiphenylchloroethylene varied from 1 to 14 ng g(-1) d.w. For both species, specimens collected upstream were more contaminated. The grey mullet specimens were less contaminated than the allis shad when taken downstream of the dam but were more contaminated upstream. The allis shads presented intermediate contaminant concentrations with a less pronounced difference between upstream and downstream specimens. However, it is thought that shads do not feed when they spawn in the upstream parts of rivers, which should modify the contaminant concentrations. However, measurements in upstream shad samples show an unexpected increase of the contamination, which remains unexplained.

First report of a toxic Nodularia spumigena (Nostocales/ Cyanobacteria) bloom in sub-tropical Australia. II. Bioaccumulation of nodularin in isolated populations of mullet (Mugilidae).

Fish collected after a mass mortality at an artificial lake in south-east Queensland, Australia, were examined for the presence of nodularin as the lake had earlier been affected by a Nodularia bloom. Methanol extracts of muscle, liver, peritoneal and stomach contents were analysed by HPLC and tandem mass spectrometry; histological examination was conducted on livers from captured mullet. Livers of sea mullet (Mugil cephalus) involved in the fish kill contained high concentrations of nodularin (median 43.6 mg/kg, range 40.8–47.8 mg/kg dry weight; n = 3) and the toxin was also present in muscle tissue (median 44.0 μg/kg, range 32.3–56.8 μg/kg dry weight). Livers of fish occupying higher trophic levels accumulated much lower concentrations. Mullet captured from the lake 10 months later were also found to have high hepatic nodularin levels. DNA sequencing of mullet specimens revealed two species inhabiting the study lake: M. cephalus and an unidentified mugilid. The two mullet species appear to differ in their exposure and/or uptake of nodularin, with M. cephalus demonstrating higher tissue concentrations. The feeding ecology of mullet would appear to explain the unusual capacity of these fish to concentrate nodularin in their livers; these findings may have public health implications for mullet fisheries and aquaculture production where toxic cyanobacteria blooms affect source waters. This report incorporates a systematic review of the literature on nodularin measured in edible fish, shellfish and crustaceans.

Metallothionein in intestine of red mullet, Mullus barbatus as a biomarker of copper exposure in the coastal marine areas

Dietary metal exposure in fish is studied in native red mullet, Mullus barbatus, involving metallothionein (MT) response in the intestine, a primary site for metal uptake. Intestinal MTs (μg mg −1 proteins), total proteins (mg ml −1 S50), Cu, Zn, Fe, Mn and Cd (μg ml −1 S50) are considered as indicators of metal exposure in specimens from near-shore and off-shore locations of the Eastern Adriatic Sea. Metallothionein and Cu are statistically significantly higher in 68 specimens from the Kaštela Bay, a near-shore area (30.0 ± 6.71 μg MT mg −1 proteins; 0.30 ± 0.08 μg Cu ml −1 S50), in comparison to 51 specimens from off-shore area, Šolta Island (25.9 ± 4.21 μg MT mg −1 proteins; 0.26 ± 0.09 μg Cu ml −1 S50). Cytosolic Cu, a MT inducer, is significantly correlated ( p < 0.05, r = 0.44) with MT in specimens from the Kaštela Bay, independent on fish biometry. Our study indicates that cytosolic intestinal Cu and MT represent a measurable biochemical response in red mullet specimens, dwelling above sediments contaminated with Cu.

Bioindicator organisms: Heavy metal pollution evaluation in the Ionian Sea (Mediterranean Sea?Italy)

Trace metal concentrations of mercury, cadmium, lead and chromium in Patella caerulea, and Mullus barbatus were investigated to provide information on pollution of Ionian Sea, since these metals have the highest toxic potential. High chromium levels (0.47-0.97 microg g(-1) ww) were registered in limpet samples collected from two station near the Gulf of Taranto, while elevated concentration of mercury (0.31-1.50 microg g(-1) ww) were found in mullet specimens from Sicily. The metal concentrations recorded at the clean stations may be considered as useful background levels to which to refer for comparison within the Mediterranean area. On the contrary, the high levels of chromium and mercury found respectively in the areas near the Gulf of Taranto and at Capo Passero being of concern in terms of environmental health need frequent monitoring.

Co-infestation of gills by different parasite groups in the mullet, Mugil platanus Günther, 1880 (Osteichthyes, Mugilidae): effects on relative condition factor

This study involved 334 specimens of mullet, Mugil platanus, captured monthly in the estuarine region of Cananéia, São Paulo State, Brazil, from July 1988 to June 1989, and examined for the presence of gill parasites. Parasitological inspections revealed the occurrence of the following groups: Trichodina sp., Monogenoidea, Copepoda, and Hirudinea. Only four mullets were not parasitized. Total weight and total length of all 334 mullet specimens examined were used for adjusting the weight-length relationship curve and calculating the relative condition factor (Kn). The 118 specimens infested with monogenoideans on average had lower weights than expected (Kn < 1.0), and the 81 fish co-infested with Copepoda, Monogenoidea, and Trichodina sp. showed a Kn < 1.0. The other infested and non-infested mullets had a Kn > 1.0. It was possible to infer that gill infestation with monogenoideans alters mullet weight, especially in the presence of co-infestation with Trichodina sp. and copepods.

A Distomid Larva infesting the Egyptian Mullet

From the researches of Onchi and Nishio it is known that the encysted larva of Heterophyes nocens Onchi et Nishio is found in the Japanese mullet. H. nocens is closely allied to H. heterophyes v. Siebold, which is found commonly in. man, dog and cat in Egypt. It may be assumed that the larva of the Egyptian Heterophyes will be found likewise in certain fishes allied to the mullet. On the homeward voyage from my tour in Europe I examined some specimens of mullet in Port Said, for the purpose of finding the young larva in them, and was fortunate enough to discover encysted larva. I carried back with me some of these fishes fixed by formalin. After returning to Chosen (Korea) I examined the parasite, and found that it certainly belongs to a species of Heterophyes. Its morphological description is given in the present short communication.