New occurrence of Cirolana capricornica (Isopoda: Cirolanidae) from Epinepheluschlorostigma in Suez Governorate, Egypt.

Background and Aim: The isopods of the Crustacea are noteworthy. All marine, fresh, and brackish waterways at all depths are home to aquatic organisms. This order also includes species that live on land. This study aimed to report a new occurrence of the isopod Cirolana capricornica on the operculum, mouth, and body cavities of Epinephilus chlorostigma in the Suez Governorate, Egypt. Materials and Methods: With the help of fishermen, 50 live E. chlorostigma (Linnaeus, 1758) were randomly gathered along the Red Sea coast of the Suez Governorate during November and December 2019 for the current investigation. Isopods were isolated from the fish samples and captured using light and electron microscopy for morphological identification. Results: Some fish were emaciated, and minute white isopods were attached externally to the skin near the gills and mouth cavity, and internally to the mouth cavity. No correlation was observed between body cavity attachment and gross lesions. The prevalence of infestation was 16%. Conclusion: C. capricornica was identified using optical and electron microscopy to analyze the isopod specimens' morphology. This scavenging isopod species is newly discovered in Egypt.

Spirulina (Arthrospira platensis) supplementation improves growth performance, feed utilization, immune response, and relieves oxidative stress in Nile tilapia (Oreochromis niloticus) challenged with Pseudomonas fluorescens.

One hundred and eighty Nile tilapia fish were used in eighty-three-day growth trial. Fish were divided into three treatment groups. The first group T0 was given the basal diet without any supplementation and served as the control group. The second group T1 was given the basal diet supplemented by 1% Spirulina. The third group T2 was given the basal diet supplemented by 2% Spirulina. At the end of the growth performance trial, a challenge trial was conducted using virulent strain of Pseudomonas fluorescens. Clinical signs, mortalities, postmortem lesions and histopathological alterations were recorded. Hematological, biochemical, oxidative stress and immunological parameters were measured after challenge with Pseudomonas fluorescens. Growth performance was non significantly improved in tilapia fed the diet with 1% Spirulina supplementation (T1). There were neither signs nor mortalities among fishes belonging to 1% Spirulina challenged group. The results showed that Spirulina has a positive effect on hematological, biochemical parameters, MDA, SOD and CAT at T1 (1% spirulia) rather than T2 (2%spirulia). Moreover, the results indicate that Spirulina 1% enhanced bactericidal, phagocytic and lysozyme activities conferring protection against infection. Our results demonstrated a significant up-regulation of pro-inflammatory cytokine (IL-1ß and TNF-α) and a down-regulation of anti-inflammatory cytokine (IL-10). We concluded that 1% Spirulina supplementation significantly improved immunity of Nile tilapia against Pseudomonas fluorescence than 2% Spirulina supplementation.

Molecular and phenotypic characterization of Photobacterium damselae among some marine fishes in Lake Temsah.

Photobacterium damselae species are one of the most devastating bacterial pathogens in mariculture worldwide. Some species of Photobacterium are pathogenic for marine animals and human. They are the causative agents of photobacteriosis, formerly known as pasteurellosis. A total of (202) marine fishes of three different species were represented as: seabass (Dicentrarchus labrax), seabream (Sparus aurata) and gray mullet (Mugil capitus) randomly collected from Lake Temsah at Ismailia governorate along the parallel Pelagic road to the lake in the governorate from August 2015 to July 2016. The clinical picture and gross lesions of the diseased fishes were recorded. Isolation and identification of suspected bacteria using traditional and molecular methods. Samples from affected organs were collected for studying the histopathological alterations of these pathogens. Fifty one fishes were found to be infected with Photobacterium damselae subsp. Piscicida. Seabass (Dicentrarchus labrax) was the most infected fish species (23), followed by seabream (Sparus aurata) (18) finally gray mullet (Mugil capitus) was (10). 91fishes were found to be infected with P. damselae subsp. damselae, seabass (Dicentrarchus labrax) was the most infected fish sp. (36), followed by seabream (Sparus aurata) (32), then gray mullet (Mugil capitus) (23). The results indicated that, the total prevalence of P. damselae subsp. piscicida in all examined species (25.24%), the highest seasonal prevalence was recorded in summer season (37.09%) followed by autumn (26%) then spring (20.37%) and winter (11.11%). On the other hand, the total prevalence of P. damselae subsp. damselae in all examined species (45.04%), the highest seasonal prevalence was recorded in summer season (67.74%) followed by autumn (52%) then spring (29.62%) and winter (19.44%). Molecular diagnosis with conventional PCR used to confirm the traditional isolation was applied by using specific primers of two genes (polycapsular saccharide gene and urease C gene). The histopathological studies of naturally infected marine fishes showed severe inflammatory reactions in different organs with accumulation of melanomacrophages and necrosis. The results confirm that P. damselae subspecies damsalea is the most prevalent pathogen between marine fishes, and seabass (Dicentrarchus labrax) was the highly affected marine fishes in this study.