83602 research outputs found
Sort by
Institute for Research, Extension, and Training in Agriculture's South Pacific agricultural news
No full text
Erythrophoromas in Colored Crucian Carp, Carassius auratus
Get PDFChromatophoromas, cutaneous pigment cell tumors that originate from skin dermochromatophores of fish, amphibians, and reptiles are rarely reported. The four basic pigment cell types found in poikilothermic vertebrates are melanomas (melanophoromas), iridophoromas, xanthophoroma, and erythrophoromas. In the present study, we diagnosed spontaneous lesions in the skin of a group of ornamental colored crucian carp, Carassius auratus, from an artificial ornamental fish pond located in Southeastern China. Necropsy, paraffin section, and hematoxylin-eosin staining methods were used to evaluate the neoplasm. Histological changes were observed and photographed using a Nikon microscope image system. The results showed oval nodular masses observed on the various parts of the body including flank, caudal peduncle, and tail. Histologically, neoplastic stromata were composed of bundles of compact parallel arrays cells. Dendric or spindle-shaped erythrophoroma cells were arranged as sheets or clusters with interlacing connective tissue. Congested capillaries and focal areas of hemorrhage were interspersed through the tissue. The tumor foci were infiltrated with neoplastic cells, inflammation cells, and necrotic tissue cells. Some olive to red intracytoplasmic pigment with polarized light could be seen on many parts of the erythrophoroma tissue. From the gross and histological pathology, we could conclude that the colored crucian carp suffered erythrophoromas. Further study is needed to confirm the etiology of this case
Utilization and Metabolism of α-Starch by Black Carp (Mylopharyngodon piceus) Juveniles
Get PDFThe ability of black Carp Mylopharyngodon piceus, to utilize high levels of dietary carbohydrate was assessed using artificial purified feed, containing normal (20%, NS group) and high (40%, HS group) levels of digestible carbohydrate. After a 10 week feeding trial, specific growth rate, weight gain rate, and protein efficiency ratio of the HS group were significantly lower (P<0.05). The 40% carbohydrate diet significantly influenced the crude protein and crude fat levels in the muscle tissue (P<0.05). Plasma cortisol of the HS group was significantly lower (P<0.05), and levels of plasma triglycerides and total cholesterol were highly significantly lower (P<0.01). Hepatic superoxide dismutase concentrations of the HS group were lower (P<0.05), and contents of the carbohydrate metabolic enzyme, hepatic pyruvate kinase were highly significantly lower (P<0.01). Hepatic ultrastructure results show that the high carbohydrate diet induced sedimentation of glucose and fat in the hepatic cells, and ultrastructural damage was observed. Although Mylopharyngodon piceus are able to tolerate long-term feeding of the 40% carbohydrate diet, effects on growth and immunity were negative resulting in ultrastructural damage of the hepatic cells
Characterization of Shewanella sp. Isolated from Cultured Loach Misgurnus anguillicaudatus
Get PDFShewanella infection of fish has become a significant problem in aquaculture. In September 2014, a disease was seen in cultured loach (Misgurnus anguillicaudatus) in Xuzhou, central China. A gram-negative bacillus was isolated from the diseased loaches and was tentatively named strain MS1, which was then identified as Shewanella sp. by physiological and biochemical characteristics analysis. The strain MS1 showed highest 16S rRNA sequence identities (98.93%, 98.87%) with the latest two species listed (Shewanella sp. MR7, Shewanella sp. MR4). The phylogenetic tree constructed on the basis of 16S rRNA gene sequences strongly indicated that the strain MS1 is most closely related to the new Shewanella strains MR7 and MR4. The isolate MS1 was confirmed as the pathogen of the infected loaches by experimental reinoculation. The strain was susceptible to most antimicrobial agents tested, but resistant to glycopeptides (vancomycin, teicoplanin) and lincosamide (lincomycin, clindamycin). This is the second report on Shewanella sp. isolated from the diseased loach