Mugil Cephalus Research Articles

Influence of the Technological Process on the Biochemical Composition of Fresh Roe and Bottarga from Liza ramada and Mugil cephalus.

Bottarga is a high-priced delicacy with high nutritional value, and, in Italy, bottarga from mullets has been recognized to be a traditional food product. The flathead grey mullet Mugil cephalus and the thinlip grey mullet Liza ramada are the main cultured grey mullets in the Mediterranean Sea. In this study, fresh roe and bottarga from these two species were investigated to evaluate the influence of the technological process and the species on their biochemical composition and health advantages. The 1 h/200 g salting-out step did not increase the levels of NaCl in the bottarga, although it highly decreased the levels of some heavy metals like Cu and Al. Processing of fresh roe in bottarga led to an essential modification of the lipid fraction, following a general series of monousatturated fatty acid (MUFA)> poliunsutturated fatti acid (PUFA) > saturated fatty acid (SAFA) and an increase in both ω3 and ω6 in Liza ramada. Moreover, bottarga showed higher levels of squalene and cholesterol and an increased Essential Amino Acid/Total Amino Acid ratio (EAA/TAA) in both species. In addition to the nutritional benefits for the consumer, the process proposed in this study may represent a reliable tool for local producers to obtain a final bottarga with both a reproducible biochemical composition and organoleptic characteristics.

Prevalence and virulence characteristics of Aeromonas species isolated from fish farms in Egypt

Background/Objective: Fish is one of the most valuable food for human consumption. However, fish may also act as a source of foodborne pathogens including Aeromonas species which caused a serious threat to a public health concern. This study aimed to investigate the prevalence and virulence characteristics of Aeromonas species isolated from fish farms in Egypt. Methods: A total of 100 random samples of freshwater fish represented by Nile tilapia and Mugil cephalus (50 of each) were collected from different fish farms in Kafr El-Sheikh governorate and examined bacteriologically and biochemically for the presence of Aeromonas species. Multiplex PCR was done to detect some virulence-associated genes in Aeromonas hydrophila isolates. Results: The obtained results revealed that the incidence of Aeromonas species in Nile tilapia and Mugil cephalus were 32 (64%) and 25 (50%), respectively. The most prevalent Aeromonas species isolated from Nile tilapia were Aeromonas caviae 13 (40.6%), Aeromonas hydrophila 8 (25%), Aeromonas sobria 7 (21.9%), Aeromonas veronii 3 (9.4%), and Aeromonas fluvialis 1 (3.1%), while from fresh Mugil cephalus were Aeromonas sobria 11 (44%), Aeromonas caviae 7 (28%), Aeromonas hydrophila 5 (20%), and Aeromonas veronii 2 (8%). The isolated Aeromonas hydrophila concealed some virulence genes responsible for their pathogenicities such as aerolysin gene (aerA) and cytotonic enterotoxin gene (altA). Conclusion: The hygienic measures should be applied to prevent fish contamination with Aeromonas species.

Development of new culinary products derived from black sea grey mullet

The increasing in tourist flow to the Republic of Crimea, as well as the acceleration of the pace of life of the population led to an increase in demand for finished fish culinary products. In this regard, there is a need to create a new fish culinary product of long-term storage from the raw materials of the Azov-Black Sea basin. The Black Sea mullet (Mugil cephalus) was chosen as fish raw material, the catch volume of which has been steadily increasing in recent years. Sous-vide technology - is a progressive technology, which is characterized by low-temperature modes of heat treatment, resulting in a product with unique organoleptic characteristics that are superior to traditional types of processing of fish raw materials. Fish and vegetables prepared using the sous-vide technology are distinguished by tenderness and juiciness, the aroma of the finished dish is enhanced. During the development of new product technology, the optimal technological parameters (temperature and process duration) were determined for heat treatment of fish fillet in vacuum based on mathematical modeling. The research was carried out on the equipment of the sector of technologies of processing of water biological resources of the department "Kerchenskiy" of the Azov-Black Sea branch of Russian Federal Research Institute of Fisheries and Oceanography. Heat treatment of samples was carried out in a water bath of LB-63 according to the plan of an experiment in the range from 55 to 70 ? with lasting from 15 to 30 min. For packing of a product the vacuum device Solis Vac Premium was used. A regression model was constructed consisting of the objective function determined by the microbiological index QMAFAnM. The software "STATGRAPHICS Plus Version 5.0" was used to plan the experiment and determine the optimal technological parameters of the fish culinary product..

Efficacy of a formalin-inactivated Lactococcus garvieae vaccine in farmed grey mullet (Mugil cephalus).

Lactococcosis [Lactococcus garvieae (LG)] is one of the most prevalent bacterial diseases affecting grey mullet (Mugil cephalus) aquaculture. Therefore, the present research evaluated the efficacy of formalin-killed LG vaccine with an oil-based adjuvant in grey mullet under laboratory and field trials. The laboratory evaluation for LG vaccine and its cross-protection upon challenge in grey mullet found that single-dose immunization of formalin-killed LG with adjuvant resulted in 91.4% and 100% relative per cent survival (RPS) when challenged with homologous and heterologous strains. The levels of specific antibody titre and lysozyme activity increased significantly in the vaccinated group. Immune gene expression at 24hr after challenge showed an increase in levels of pro-inflammatory and anti-inflammatory cytokines. A parallel field trial experiment was conducted to investigate the long-term effectiveness of the LG vaccine. Results demonstrated that at one month and three months post-immunization with heterologous strain, 100% RPS was recorded in the vaccinated group. The findings suggested that the formalin-inactivated LG vaccine strain (S3) protected grey mullet against LG infection for a period of three months.

Otolith microchemistry reveals the migration patterns of the flathead grey mullet Mugil cephalus (Pisces: Mugilidae) in Korean waters

BackgroundThe flathead grey mullet Mugil cephalus has the widest distribution among mugilid species. Recent studies based on mitochondrial DNA sequences showed that the species comprises at least 14 different groups, three of which occur in the northwest Pacific. We analyzed the otolith microchemistry of M. cephalus at several locations in Korea to improve understanding of migration pattern and population origin.ResultsWe collected 123 sagittal otoliths from seven locations and determined their concentrations of eight elements (7Li, 24Mg, 55Mn, 57Fe, 60Ni, 63Cu, 88Sr, and 138Ba) using laser ablation inductively coupled plasma mass spectrometry. Mean otolith elemental ratios differed significantly among the locations. The Sr:Ca, Fe:Ca, and Ba:Ca ratios were significantly higher than others, and useful chemical signatures for investigating the habitat use of M. cephalus populations. We identified five diverse and complicated migration patterns using the otolith data that we collected: estuarine resident (type I), freshwater migrant (type II), estuarine migrant (type III), seawater resident (type IV), and seawater migrant (type V). A canonical discriminant analysis plot revealed separation of two groups (type II in the Yellow Sea vs. other types in remaining locations). Two locations on Jeju Island, despite their close proximity, had fish with quite different migration patterns, corroborating previous molecular studies that distinguished two groups of fishes.ConclusionWe successfully showed that the migration patterns of the Korean mullet varied by location. Only fish from the western sector of Jeju had a unique migration pattern, which is likely confined population in this area. Among the eight otolith elements measured, the Sr:Ca ratio was found to be the best indicator of migration pattern and population origin.

Morphological characterization and histopathological alterations of homologs Heterophyid metacercarial coinfection in farmed mullets and experimental infected pigeons

In this study, samples of farmed thin-lipped mullets, Mugil capito from Lake Manzala and wild-caught grey mullet Mugil cephalus from Alexandria were found to be infected with heterophyid encysted metacercariae (EMC), and the overall prevalence rates were 80 and 100%, respectively. The number of metacercarial infection in tail tissue was significantly higher than that recovered from trunk and head among M. capito and M. cephalus. M. capito were simultaneously infected with two morphologically different EMC that ascribed to Heterophyes and Pygidiopsis species, while M. cephalus were infected with EMC of Heterophyes species. The experimental infection of domestic pigeons (Columba livia domestica) with the recovered encysted metacercariae confirmed the successful development of two types of Heterophyid flukes: identified as Heterophyes heterophyes and Pygidiopsis genata in the small intestine of pigeons. The histopathological examination revealed that Heterophyes cyst was small, elliptical with thick wall and predominating between cardiac muscle fibres and in the lumen of atrioventricular region of the heart. Pygidiopsis species cyst appeared larger in size, rounded with thin cyst wall and prominent internal structure. Pygidiopsis species were few in the abdominal fat and prominently encysted in the internal visceral organs including wall of the stomach, kidneys and muscular tissue away. They were also deeply encysted in testes and ovaries. Interestingly, the adult flukes were demonstrated in the intestinal lumen of the experimentally infected pigeons but with minor histopathological alterations. Our findings suggest that the heterophyids EMCs in mullets have genera-specific morphological characters and may induce histopathological changes in surrounding host-associated tissues.

Time-series modeling of fishery landings in the Colombian Pacific Ocean using an ARIMA model

Seer fish (Scomberomorus sierra) and mullet (Mugil cephalus) are some of the most important marine fishery resources along the Colombian Pacific Ocean. The objective of this study was to forecast the landings of seer fish and mullet based on data from time-series annual landings reported by the Food and Agriculture Organization of the United Nations (FAO) from 1971 to 2014. The study considered autoregressive integrated moving-average (ARIMA) processes to forecast the landings of the species. The ARIMA model (5,1,5) for seer fish and ARIMA model (2,2,1) for mullet showed good agreement concerning the observed data on landings based on the Akaike information criterion. The results show the ARIMA model to be a suitable method for analyzing statistics. In data-poor fisheries situations, this method can support potential evaluations of fishery production for decision making and management.

Diversity record of family mugilidae (cuvier, 1829) from the estuary of Sabarmati river, Gujarat, India

Mullets are the fishes of family Mugilidae belong to order Actinopterygii, which lives in coastal and marine habitats. These fishes are also found in coastal lagoons, rivers, and estuaries. Mullets occupy a comparatively low position in the food web and are thus relatively efficient secondary producers of protein. They are situated at the base of the food pyramid due to their nature of consumption on particulate organic matter, detritus, and benthic microalgae. They are able to make high-quality fish protein available to top predators. Mullets are highly consumable fish in coastal regions of Gujarat. The taxonomy and systematics of the mullet requires much attention due to its ecological and commercial importance. Mullets have two widely separated dorsal fins, which is the prominent morphological identification character. They are medium to large-sized fishes, with the sub-cylindrical body; head often broad and flattened dorsally. Present study revealed vital information on the taxonomy and diversity of the mullets from Sabarmati estuary, Gujarat. The identification of fresh specimens was carried out and three species were identified as Mugil cephalus, Chelon planiceps, and Rhinomugil corsula. This paper also records the range extension of R. corsula from the western coast of India. The paper emphasizes the importance of further research in family Mugilidae for a better understanding of its distribution, ecology, and physiology for aquaculture point of view as species of this family are highly consumable due to its nutritive values.

Preferential Mapping of Sex-Biased Differentially-Expressed Genes of Larvae to the Sex-Determining Region of Flathead Grey Mullet (Mugil cephalus).

Flathead gray mullet (Mugil cephalus) is a cosmopolitan mugilid species popular in fishery and aquaculture with an economic preference for all-female population. However, it displays neither sexual dimorphisms nor heteromorphic sex chromosomes. We have previously presented a microsatellite-based linkage map for this species locating a single sex determination region (SDR) on linkage group 9 (LG9) with evidence for XX/XY sex determination (SD) mechanism. In this work, we refine the critical SDR on LG9, and propose positional- and functional- candidate genes for SD. To elucidate the genetic mechanism of SD, we assembled and compared male and female genomic sequences of 19 syntenic genes within the putative SDR on mullet’s LG9, based on orthology to tilapia’s LG8 (tLG8) physical map. A total of 25 sequence-based markers in 12 genes were developed. For all markers, we observed association with sex in at least one of the two analyzed M. cephalus full-sib families, but not in the wild-type population. Recombination events were inferred within families thus setting the SDR boundaries to a region orthologous to ∼0.9 Mbp with 27 genes on tLG8. As the sexual phenotype is evident only in adults, larvae were assigned into two putative sex-groups according to their paternal haplotypes, following a model of XY/XX SD-system. A total of 107 sex-biased differentially expressed genes in larvae were observed, of which 51 were mapped to tLG8 (48% enrichment), as compared to 5% in random control. Furthermore, 23 of the 107 genes displayed sex-specific expression; and 22 of these genes were positioned to tLG8, indicating 96% enrichment. Of the 27 SDR genes, BCCIP, DHX32A, DOCK1, and FSHR (GTH-RI) are suggested as positional and functional gene candidates for SD.

Growth of Fry Fish of 4 Species of Family Mugilidae in Experimental Recirculation Water System

The collected in nature fry of Mugil cephalus, Liza aurata, L. ramada and Chelon labrosus that arrive in massive schools at the coastline of Greece were reared in small aquaria (50 L) of a recirculation system from the size of about 3.0 cm TL (50 fish per aquarium), using brackish (15 ppt) water and artificial high protein food. It was found that for a period of 80 days, growth performance was high at 23 oC, reaching values for weight increase between 592 (M. cephalus) and 2281 % (L. aurata). Food Conversion Ratio (FCR) was best (1.04) for L. aurata and worst (2.04) for M. cephalus. All species responded well as exhibited by an increase in their Condition Factor (CF) and mortality was almost absent.

Co-infection of Aeromonas hydrophila and Vibrio parahaemolyticus isolated from diseased farmed striped mullet (Mugil cephalus) in Manzala, Egypt – A case report

A sudden outbreak of disease associated with high mortality rates (75–85%) was reported in market-sized striped mullet (Mugil cephalus), farmed in earthen ponds in Manzala, Egypt, during the summer (July) 2019. We identified poor water quality parameters, including a sharp decrease in dissolved oxygen (DO) (3.5 mg/l) accompanied by elevated levels of unionized ammonia (0.90 mg/l), nitrite (0.05 mg/l), hydrogen sulfide (0.07 mg/l), nickel (0.7 mg/l), copper (0.6 mg/l), and iron (1.80 mg/l). Diseased and recently dead fish exhibited general septicemic signs. A. hydrophila and V. parahaemolyticus were isolated from diseased fish by culture on selective media and further identified by biochemical tests. PCR targeting the 16S rRNA gene and some virulence gene fragments of each bacterial isolate were performed, and genome sequencing and phylogenetic analysis confirmed the molecular identity of both isolates. The high molecular identity and close phylogenetic relationship confirmed that the isolates were genetically homologous to A. hydrophila and V. parahaemolyticus. Outbreaks involving multiple co-infecting pathogens have been reported in several fish species. The current study highlights a case report of synergistic interactions between poor water quality and the presence of aquatic microbial pathogens such as A. hydrophila and V. parahaemolyticus. This combination of factors resulted in the incidence of heavy mortalities in farmed striped mullet M. cephalus, during the summer season in Manzala Egypt.

Influence of Dietary Vitamin E on the Content of Vitamin E in Blood Plasma, Ovary Tissue and on Hemolysis of Cultured Female Grey Mullet (Mugil cephalus)

Commercial diets containing α-tocopherol (90mg/kg) were supplememted with 0, 100 and 200 mg/kgα-form vitamin E acetate respectively and fed to one-year-old (1+) grey mullet (Mugil cephalus)for 12 months. Plasma vitamin E increased as dietary vitamin E increased, and showed seasonal changes. It decreased from May to November, then gradually increased until the following February. Vitamin E content in ovary was the lowest (296-376ug/g lipid) in October and the highest (602-694ug/g lipid) in November, then decreased to 408-453 ug/g lipid in December. A negative relationship between vitamin E contents in plasma and in ovary was observed. Grey mullet erythrocytes appeared ellipsoidal in shape with a major axis of 9.24 to 9.88 um and a minor axis of 6.33 to 6.67 um. No significant difference was found in shape and size of erythrocytes from grey mullet fed with diets of different vitamin E levels. Spontaneous hemolysis was 7.55 - 7.71 % in an 8 h test, regardless of the dietary vitamin E intake of the fish. Body and ovary weights were significantly lower for mullet fed on commercial diets than fed on diets supplemented with vitamin E to 190 and 290 mg/kg.

Comparison of the metal concentrations in muscle and liver tissues of fishes from the Erren River, Southwestern Taiwan, after the restoration in 2000

Metal concentrations in the muscle and liver tissues of fishes from the Erren River in southwestern Taiwan were analyzed to evaluate the pollution status after the completion of the restoration plan in 2000. It was the first time the tissue concentrations of 4 important elements, i.e. Fe, Mn, As and Hg, were reported in fishes from this area. Samples were collected in January 2002 at the junction of the Erren River and the Sanyegong River, the most polluted section of the river. Five fish species, Megalops cyprinoids (Indo-Pacific tarpon), Chanos chanos (milkfish), Liza macrolepis (large-scaled mullet), Mugil cephalus (striped mullet) and Orechromis sp. (tilapia) were collected. A total of 91 fishes were dissected and the muscle and liver tissues taken for analysis of seven metals, Fe, Zn, Cu, Mn, As, Hg and Cd, on a wet weight basis (mg/kg). Among them, Fe and Zn were the highest, followed by Cu, Mn and As, while the Hg and Cd concentrations were the lowest. Except for As and Hg, which showed higher concentrations in the muscle tissues than in the livers, the remaining elements showed higher concentrations in livers. Significant species differences were found in all elements and tissues. The highest concentrations of Fe, Zn, Cu and Mn in muscles were found in tilapia (4.04), striped mullet (4.38), large-scaled mullet (0.20) and milkfish (0.534), respectively. The highest concentrations of As and Hg were found in striped mullet (1.59) and Indo-Pacific tarpon (0.081), respectively. The highest concentrations of Fe (3122), Hg (0.045) and Cd (0.123) were found in livers of large-scaled mullet, while striped mullet had the highest concentration of Zn (77.6), Cu (78.2) and As (2.39). The level of Mn in tilapia was 1.32 mg/kg. The Zn, Cu and Cd concentrations of the muscles and livers were mostly 7-50% lower than the levels reported on the same species of the same tissue before the restoration indicating the improvement on the metal pollution status. The heavy metal concentrations in this area were similar to various uncontaminated areas around Taiwan and all were within the food standard levels of the FDA and NHMRC.

Total and organic Hg in fish from the reservoir of a chlor-alkali plant in Tainan, Taiwan

Total mercury (THg) and organic mercury (OHg) concentrations were determined by cold-vapor AAS in ten species of fish, which were caught in the reservoir of a chlor-alkali plant in Tainan, Taiwan that had been abandoned for 22 years. The fishes, including Elops machnata, Pelates quadrilineatus, Gerres filamentosus, Leiognathus equulus, Thryssa hamiltonii, Orechromis spp., Nematalosa come, Liza macrolepis, Mugil cephalus and Chanos chanos, were sampled from September to October 2003. THg and OHg concentrations (μg/g flesh wt.) in fish muscles were 0.43 ± 0.36 and 0.31 ± 0.21, respectively, similar to values reported from various chlor-alkali plants worldwide. Of the OHg values, 37% exceeded the food safety limit of 0.3 μg/g set by the World Health Organization. Moreover, 77% of the tested OHg values were over 0.17 μg/g, which had been suggested for seafood safety limit in Taiwan. Finally, 100 g of fish muscle is the maximum allowable weekly consumption amount for the adult residents to avoid health treat that arise from ingesting toxic OHg.

Occurrence and distribution of microplastics in commercial fishes from estuarine areas of Guangdong, South China

The widespread presence of microplastics in global aquatic ecosystems has aroused growing concerns regarding their potential impact on aquatic biota. Data show an extensive plastic pollution in coastal areas of Guangdong, China, however, to date there has been no quantitative study on the ingestion of microplastics by commercial fishes from the estuarine areas. In this study, we analyzed the abundance, characteristics, species-specific and spatial distribution of microplastics in six species of commercial fish from estuarine areas of Guangdong. Sixty-four fish samples from nineteen sampling sites were investigated. The average abundance of microplastics in the gastrointestinal tracts of the commercial fishes was 5.4 items/individual, indicating potential food safety. The majority of microplastics were fibers, white in color and less than 1 mm in size. Species-specific and spatial distribution of the microplastics were observed in terms of abundance, shape, color and size. Sillago japonica had the highest (6.9 items/individual), while Alepes djedaba had the lowest (3 items/individual) abundance of microplastics in the gastrointestinal tract. We recommend demersal Mugil cephalus and pelagic Konosirus punctatus to be considered as two species suitable for monitoring microplastics ingestion in the seafloor and water column communities.

Effect of dietary supplementation of Padina astraulis (Hauk, 1887) extract on biochemical response and digestive enzyme activities of grey mullet, Mugil cephalus (Linnaeus, 1758)

This research aimed to assess the effect methanol extract from Padina astraulis (Hauk , 1887) on biochemical response and digestive enzyme activities in grey mullet, Mugil cephalus (Linnaeus, 1758). A control diet without and three other empirical regimens were prepared with the addition of of P.astraulis extract (PE diet) at the incorporation levels of 5, 10 and 15 g kg-1 diet, respectively. Three hundred sixty grey mullet with an introductory mean weight of 0.82 g were randomly dispersed into twelve fish tanks and fed twice a day (09:00 and 17:00) for 60 days. After 60 days of the feeding trial, no significantly different was noticed in terms of survival rate between control and the groups supplemented with PE (p>0.05). Dietary PE significantly increased serum total protein, globulin levels and amylase, lipase and protease enzyme activities in treated fish (p<0.05). Moreover, there was considerable decline (p<0.05) in cholesterol, glucose and triglyceride levels in those fish which received PE diet over the control. The current research illustrates the appropriateness of P. astraulis extract as a novel dietary additive in grey mullet diet for improving metabolism of lipid and carbohydrate and enhancing digestive enzyme activities in grey mullet.

Integrated rearing system approach in the farming of mud crab, shrimp, fish, oyster and periphyton in bracksihwater pond

Diversification of production systems has been identified as one of the major strategies for the long-term sustainability of brackishwater aquaculture. On the context of diversification, a 180-day culture experiment was carried out where four farming systems were tested: monoculture of mud crab, Scylla serrata (T1), polyculture of mud crab, with mullet Mugil cephalus and shrimp Penaeus indicus (T2), polyculture of mud crab with mullet, shrimp and oyster Crassostrea cuttackensis (T3), polyculture of mud crab with mullet, shrimp, oyster along with periphyton net (T4) covering 10% of the water spread area. There was no significant difference in the growth performances of mud crab, shrimp and oyster among the treatment but a significantly higher (p < .05) final average body weight (ABW) of M.cephalus was recorded in T4 (121.19 ± 2.09 g). Production considering only the fed animals (excluding oyster) was significantly (p < .05) higher in T4 (2,115 kg/ha) compared to other treatments. The overall water quality parameters do not vary significantly (p > .05) among the treatment ponds. Although there was no significant difference in total ammonia nitrogen (TAN) and nitrite-N, highest value was recorded in T2 (56.23 ± 39.47 µg/L and 185.53 ± 110.71 µg/L) and T1 (55.78 ± 32.26 µg/L and 180.83 ± 103.65 µg/L). The results from the current experiment based on water quality and growth of animals showed that there is no negative interaction between the mud crab and other animals stocked in the polyculture pond which indicated that polyculture provides an efficient and sustainable utilization of resources.

Determination of Heavy Metals and Pesticides in Different Types of Fish Samples Collected from Four Different Locations of Aegean and Marmara Sea

Heavy metals and pollutants cause serious damage to the ecological environment and accumulate in marine species in the seas. These pollutants and heavy metals accumulating in living species are a serious source of danger for human health. For this purpose, in this study, heavy metal (lead, mercury, copper, zinc, arsenic, cadmium, silver, manganese, and nickel) and pesticide (p-p′-DDE, α-BHC, endosulfan, endosulfan sulfate, endrin, aldrin, heptachlor, heptachlor epoxide, methoxychlor, p-p′-DDD, p-p′-DDT, β-BHC, cypermethrin, and dieldrin) analyses of four different fish species (Pomatomus saltatrix, Dicentrarchus labrax, Mugil cephalus, and Sparus aurata) collected from the Aegean and Marmara seas were carried out by gas chromatography-mass spectroscopy and using an inductively coupled plasma-mass spectrometer. We observed serious and remarkable arsenic, lead, and cadmium concentrations in the muscle meat of fish sample. p-p′-DDE and endosulfan were determined in every fish sample of each region. Heptachlor concentration was determined as 0.0598 μg/g in Dicentrarchus labrax sample from Marmara Sea, which is nearly nine thousand times more than the maximum allowable concentration of environmental quality standards biota of heptachlor listed in 2013/39/EU. The results show an indication of the significant health risks associated with the consumption of these contaminated fish in the Aegean and Marmara seas. In the Turkish food codex and in the 2013/39/EU directive, some heavy metals that do not have the maximum allowable concentration limits should be urgently indicated.

Heavy Metals in Grey Mullet (Mugil cephalus) Fish Collected From Barseque Fish Farm, El-Behera Governorate-Egypt

Heavy metals are the most harmful contaminants which affect people health. The research objective of the present study was to determine the levels of cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu) and zinc (Zn) in grey mullet fish collected from Barseque fish farm (Behera Governorate, Egypt). Moreover, heavy metals were determined in irrigation and Barseque farm water. Quality Index Method (QIM) scores showed good freshness condition of collected fresh fish. Variations in chemical composition of grey mullet fish collected from fish farm during winter and summer were noticed. Moisture content highly significant decreased in summer than in winter while fat increased in summer than in winter. Electric conductivity significantly increased in irrigation and farm water in summer, while there was no difference in pH. The results of heavy metals showed that the levels of Cd, Pb, Cr, Cu and Zn in different fish organs(liver, gills and muscles) were significantly higher in summer than winter, it was in the increasing order of liver>gills> muscles. Cadmium and lead concentrations in irrigation water and farm water that detected during winter and summer season were higher than the maximum permissible limit according to WHO/FAO and Egyptian Ministry of Water Resources and irrigation, law 48/1982.Cadmium, copper, lead and chromium concentrations in irrigation water and farm water showed no significant difference between winter and summer but zinc were significantly higher in summer than winter. Heavy metal concentrations that measured during winter and summer seasons in grey mullet fish organs were lower than the minimum acceptable daily intake recommended by WHO. Generally, the values of metals in the fish muscles were accepted by the international legislation limits and are safe for human consumption. On the other hand, it was strongly recommended not to eat head with gills or livers of fish. Conclusively, a regular monitoring program of heavy metal is recommended for protecting these organisms, and to reduce the environmental risks.

Status of Fisheries in Agusan Marsh: Lapaz and Talacogon, Agusan del Sur, Mindanao

In support to policy formulation of fisheries in Agusan Marsh, a stock assessment was conducted for the period of May 2014 to December 2016 using the data collected from Lapaz and Talacogon, Agusan del Sur within the Agusan Marsh. Results showed that Lapaz contributed 54% of the catch over Talacogon. A total of eighteen species, belonging to 13 genera and 11 families with 7 native and 11 introduced species were found in the marsh. Majority of the total catch consisted of Channa striata, Oreochromis niloticus, and Cyprinus carpio (35%, 27%, and 26%, respectively). Osphronemus laticlavius, Glossogobius celebius and Mugil cephalus were listed as seasonal species. An invasive janitor fish (Pterygoplichthys disjunctivus) was observed as by-catch. A strong pattern of high catch rates occurred during the rainy months of January, February, June, and December. Ten types of commonly used fishing gears were found, majority of which include fish pots, set gillnets, electrofishing and set long lines. Multivariate analysis showed similarity in species composition both in Lapaz and Talacogon. Exploitation of dominant species showed unsustainable level for O. niloticus, C. batrachus, C. caprio, andC. gariepinus, mainly due to excessive capture of immaturesized fishes by major fishing gears. The estimated exploitation rate is beyond the optimum level for O. niloticus and C. carpio in both years and followed by C. striata and C. gariepinus in 2016. Only C. bartachus is estimated to be exploited below the optimum level. Generally, the key species in Agusan Marsh are at risk of overfishing, hence, immediate policy measures must be given high attention.