Paralytic Shellfish Poison (Saxitoxin and derivatives) was extracted by HCL method from frozen scallops. The samples were collected from coastal areas of Iwate prefecture-Japan.Toxicity of the samples was determined with mouse. Bioassay method Intra-peritoneal injection was done toddy strain ♂19-21 grams male mouse, and death time was listed. In conclusion, 33.80, 38.40, 31.20 MU/g (or 777, 883, 718 STX/100gr) were obtained respectively as the toxicity of the samples of three different sampling areas. The toxicity for the areas was 9.7, 11 and 9 times more than standard level (80STX/100 g) and very dangerous for human consumption. The kind of toxin was determined by comparing HPLC graph of sample with standard saxitoxin HPLC graph.

Background and Objectives: In the present study, isolation of Streptomyces associated with marine sponges and its bioactive potential against fish and Shellfish pathogens were assessed. The Streptomyces sp. were isolated from the marine sponges namely Callyspongia diffusa, Mycale mytilorum, Tedania anhelans and Dysidea fragilis collected from Vizhinjam port, situated in the South-West coast of India.Materials and Methods: The Streptomyces associated with marine sponges were isolated using specific ISP media. The isolates of Streptomyces were characterized for their colony characteristics, morphological properties, physiological and biochemical properties and were tentatively identified. The strains were cultivated on a lab scale level as shake-flask cultures and the crude extracts of the bioactive compounds obtained with ethyl acetate were screened biologically and chemically. By biological screening, the extracts were analyzed for their activity against fish and Shellfish pathogens namely Aeromonas hydrophila, Serratia sp. and Vibrio spp, using the disk and agar-well diffusion bioassay method, while by chemical screening the crude culture extracts were analyzed by TLC and UV–Vis spectrophotometer.Results: Ninety-four isolates were found to be associated with marine sponges, among them only seven strains showed antagonism against fish and Shellfish pathogens. Analysis of morphological, physiological and biochemical characteristics suggested that these strains belonged to the genus Streptomyces. The initial screening of the isolates by spot inoculation method exhibited antibacterial activity against Aeromonas hydrophila. In-vitro screening of the submerge culture extracts showed positive inhibition against the fish and Shellfish pathogens namely Aeromonas hydrophila, Serratia sp. and Vibrio spp. The screening of bioactive compounds confirmed the production of polyene substances by UV spectrum, which resulted in absorbance peaks ranging from 225 to 245 nm and TLC analysis yielded Rf values ranging from 0.40 to 0.78. Conclusion: The results suggest that the seven Streptomyces strains isolated from marine sponges produce potential antibacterial compounds against fish and Shellfish pathogens.

BACKGROUND AND OBJECTIVE: The coastal area of Jeneponto Regency, South Sulawesi, Indonesia, is heavily impacted by microplastic pollution, which poses a threat to marine organisms such as Shellfish and fish. This aim of this study was to identifiy the presence of microplastic polymers, including vinylidene chloride, polyacetylene, polychlorotrifluoroethylene, polybutylene terephthalate, poly(isobutyl methacrylate), cellulose acetate butyrate, polybutadiene, and polyvinylchloride, in Shellfish and fish in the coastal area of Jeneponto district, Indonesia.METHODS: In total, 60 Shellfish and fish samples were collected directly from 12 locations in the coastal waters of Jeneponto Regency. Sample preparation, including enzymatic digestion and mechanical destruction, was performed to separate the organic tissues of fish and Shellfish into small particles. Optical microscopy (at 100× and 400× magnification) was used to observe the morphology and to count the number of particles per sample volume using a modified Neubeuer Improved Counting Chamber. Fourier-transform infrared spectroscopy was used to determine the type of polymer.FINDING: Feather clams contained the highest number of microplastics, with a total of 58 items ranging from 0.027 to 4.587 millimeters in size. The total abundance of microplastics in feather clams ranged from 0.25 to 2.14 items per gram. Kurisi fish contained 22 items ranging from 0.085 to 2.127 millimeters in size, with a total abundance ranging from 0.01 to 0.08 items per gram. The types of polymers identified in the fish and clams included vinylidene chloride, polyacetylene, polychlorotrifluoroethylene, polybutylene terephthalate, poly(isobutyl methacrylate), cellulose acetate butyrate, polybutadiene, and polyvinyl chloride. Vinylidene chloride was the predominant type of microplastic polymer, accounting for 42 percent of all microplastic polymers.CONCLUSION: This study successfully identified eight types of microplastic polymers found in Shellfish and fish in the coastal area of Jeneponto; the most common was vinylidene chloride. These findings indicate that marine organisms and humans are exposed to microplastics, which are potentially harmful, but further research is needed to understand the full extent of the associated environmental health impacts and risks.

Rapid industrialization along with advanced agricultural activities led to the contamination in aquatic environment with heavy metals. Heavy metals ultimately pass into human body through having aquatic animals like fish, prawn and crab. In this study, accumulation of heavy metals (zinc, copper, iron, cadmium and lead) in various organs of four commonly consumed fish (Euthynnus affinis, Pampus argenteus, Descapterus macrosoma, and Leiognathus daura), prawn (Fenneropenaeus indicus) and crab (Portunus pelagicus) of Tok Bali Port, Kelantan, Malaysia were determined. Health risk was assessed using estimated daily intake and target hazard quotients. Although the concentrations of all the heavy metals in all fish, prawn and crab species were lower as per Malaysian Food Act, but the concentrations showed remarkable differences among the species and organs. The concentration of heavy metals in the gill was the highest of all fish species followed by in the liver and flesh. The total accumulation of heavy metals was maximum in Euthynnus affinis followed by Leiognathus daura, Descapterus macrosoma and Pampus argenteus of the fish species. However, the highest concentrations (µ g/g) was for Zn (72. 97± 2. 75), followed by Fe (4. 309± 0. 68), Cd (1. 189± 0. 78), Cu (1± 0. 87) and Pb (0. 41± 0. 19) among all the heavy metal contents of fish. No significant variation (P<0. 05) of the heavy metal concentration in prawn and crab species was observed. The investigation indicated that the fish, prawn and crab species of this port were safe for human consumption but the safe disposal of various wastes should be practiced to control the heavy metal accumulation in future.

Shellfishes are significant economic and nutritious seafood amongst people of different countries. Seafood products, particularly Shellfish samples, are potential reservoirs of enteric viruses. This research investigated the incidence of RoV, NoV GI and GII, HAV, and HEV in Shellfish samples from the Persian Gulf, Iran. One hundred and fifty Shellfish samples were collected. RNA extraction and cDNA synthesis was performed using commercial kits. The real-time PCR assessed the presence of enteric viruses in extracted cDNA samples. Thirty-two out of 150 (21.33%) Shellfish samples were contaminated with enteric viruses. Prevalence of NoV GI, NoV GII, HAV, and RoV amongst Shellfish samples were 8.00%, 11.33%, 1.33%, and 0.66%, respectively. There were no contaminated Shellfish samples with HEV. Simultaneous prevalence of HAV and NoV GI and HAV and NoV GII viruses were 0.66% and 0.66%, respectively. Examined viruses had a higher prevalence in Shellfish samples collected through the winter season (P < 0.05). Prevalence of HAV, RoV, NoV GI, and NoV GII amongst Shellfish samples collected through the winter season was 2.85%, 9.09%, 11.90%, and 20%, respectively. To the best of our knowledge, this is the first report of the incidence of enteric viruses, particularly HAV, NoV GI, NoV GII, and RoV, in Shellfish samples from the Persian Gulf, Iran. Shellfish samples may serve as a potential source of enteric viruses for the human population. Therefore, routine viral assessments should be conducted. Completely cooking Shellfish samples before consumption can significantly reduce the risk of HAV, RoV, NoV GI, and NoV GII infections. Furthermore, given the export value and importance of Shellfish samples, their microbial quality and safety should be routinely monitored.

Number of attempts has been made to cryopreserve fish and Shellfish gametes. Success has been achieved to establish only sperm banks in case of some commercially important fish. In Shellfish, also particularly in shrimps, though the sperm cryopreservation was successful,no attempts were made to develop sperm banks. As far as cryopreservation of egg and embryos of fish and Shellfish is concerned, less research efforts were made with limited success. Number of reasons have been given for the failure of egg/embryo cryopreservation and the main barriers speculated are low membrane permeability in the eggs, the large yolk mass of the oocyte, and the presence of compartments in early developing embryos. These factors result in ice crystal formation during the freezing process. In addition, the oocytes and embryos are prone to chilling injuries unrelated to ice crystal damage. There are number of other problems reported by several researchers in the egg/embryo cryobanking protocols which are elaborately discussed in the present paper. There is an urgent need to develop a viable cryobanking technology for fish egg/embryos to enhance fish production in captive condition. Attempts to cryopreserve larvae of aquatic animals are another challenge occurring in the recent past. The aim of the present review is to collect comprehensive information on the efforts so far made on fish and Shellfish egg and embryo cryobanking,and to assess the challenges in the development of viable technology and plan for future research for making this technology viable and cost effective.