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A total number of 100 Nemipterus japonicus was collected randomly from the Western Gulf of Suez, Red Sea, Egypt from September to April 2021. After external and internal examinations, two species of parasites were found. The first species was Mothocya melanosticta isopods (both sexes) with a prevalence of 52% and attached externally to the gills and inside the buccal cavity. The second species, Hysterothylacium aduncum nematodes that was found in three types of distributions in 53 fishes. Firstly, adults were found in the gastrointestinal (GI) tract with a high prevalence of about 58%. Secondly, larval stages were found in 52 fishes with a high prevalence of about 57%. Thirdly, adults and larvae were found mixed together in 91 fishes with a high prevalence of 91% inside the GI tract of the same host. There was mixed infestations with M. melanosticta and H. aduncum with a percentage of 51% with several observed signs on the infested fishes. To determine the correct identification of detected parasites, both species were subjected to morphological and electron microscopic examination. Based on the present findings, further studies are recommended on the host-parasites relationship. [ABSTRACT FROM AUTHOR]

In this study, chitosan coatings incorporated with propolis extract (PE) were utilized to extend the shelf-life of refrigerated Nemipterus japonicus fillets. Microbiological (total mesophilic bacteria (TMB) and total psychrotrophic count (TPC)), physicochemical (pH, total volatile bases nitrogen (TVB-N), 2-thiobarbituric acid reactive substances (TBARS), free fatty acid (FFA)) and sensory (color, odor and preference) characteristics of coated fillets were evaluated during 12 days. The results showed that incorporating PE into chitosan solution could significantly (P < 0.05) improve the quality of fish fillets. The results showed that the chitosan+PE samples reduced the extent of lipid oxidation, as judged by TBARS and FFA, suggesting that there is a synergistic effect between chitosan coating and propolis. Moreover, the application of chitosan coatings with PE improved the TVB-N and pH values of the Nemipterus japonicus samples significantly compared to untreated sample, thus extending the shelf life of Nemipterus japonicus fillet approximately >10 days. All wrapped fillets in treatment samples incorporated with PE had lower bacterial counts compared to control (P < 0.05). However, the bacterial counts of chitosan coating combined with PE were lower than those treated by chitosan or PE alone during the storage. The fillets treated with chitosan and PE had the best sensory properties. The increase (>10 days) in the shelf-life was attributed to the antioxidant and antimicrobial characteristics of chitosan and PE. These results confirmed that chitosan coating enriched with PE can be an improving method to reducing deterioration of refrigerated Nemipterus japonicus fillets. [ABSTRACT FROM AUTHOR]

Abstract: The rate of fish invasion into the Mediterranean Sea has increased in recent decades; collectively they have significant ecological and economic impacts in the eastern Mediterranean. One of this species is Japanese thread fin bream Nemipterus japonicus that gradually get abundance in the Egyptian Mediterranean coast bottom trawl catch. During 2011, monthly samples of N. japonicus caught off Abu Qir area, Alexandria-Egypt, were used to estimate some biological parameters of this immigrant species. Females were more in abundance than male in the catch deviated to smaller size than male. Spawning season extended from April to November with highest activities in July. Maximum observed age was 3years for both sexes with no significant difference between their lengths at age. Length-at-age was fitted to the Von Bertalanffy growth models. Present results of the Mediterranean Sea population showed lower biological (e.g. growth and longevity) condition comparing to original indo-pacific population. [Copyright &y& Elsevier]

Catch rates and sizes of Saurida undosquamis and Nemipterus japonicus were more variable during daytime. But, Pomadasys stridens were more variable in night tows. Catch rates of S. undosquamis and N. japonicus were higher during daytime and of significantly small mean fish size. Inversely, P. stridens had significant higher catch rates and the fish caught were smaller in night tows.Variability of catch rate and size of Penaeus semisulcatus and Penaeus japonicus was higher at night. Daytime catch rates were significantly lower and of smaller mean shrimp size. Penaeus latisulcatus was available only at night. [Copyright &y& Elsevier]

The Japanese threadfin bream N. japonicus (Bloch) (Perciformes: Nemipteridae) is an important marine food fish in Asia. However, our present knowledge of the occurrence of its nematode parasites is still limited. In the present study, the species composition and infection rate of ascaridoid nematodes in N. japonicus from the South China Sea, were studied for the first time. Five ascaridoid species, namely Anisakis typica (L3), Hysterothylacium amoyense (L3), Hysterothylacium sp. IV-A (L3), adult of H. thalassini and Raphidascaris lophii (L3), were identified using integrative taxonomy. Hysterothylacium amoyense was the most prevalent species (prevalence 47.2%, mean intensity 14.9 ± 17.1). Hysterothylacium thalassini and R. lophii were reported in the Japanese threadfin bream for the first time. Two different genotypes of A. typica (overall prevalence of 3.4%; mean intensity 1.7 ± 0.9) were found in the South China Sea for the first time. The unique restriction polymorphism patterns of three species of Hysterothylacium are provided for rapid diagnosis. Our present results indicate that RFLP analysis of ITS region, using the restriction enzymes Hha I and Rsa I, represents a simple and practical method for large-scale surveys of Hysterothylacium for seafood industry. Unlabelled Image • Five ascaridoids were identified. • H. amoyense (L3) was the most prevalent species. • Two different genotypes of A. typica were found. [ABSTRACT FROM AUTHOR]