Chemical and Histological Studies of Wild and Hatchery Salmon in Fresh Water

Abstract

In a study of coho sahnon (Oncorhynchus kisutch), the gross chemical and histological changes occurring over a 14-month period spent in fresh water were detemdned. The determinations were made at 3-month intervals on: t) hatchery-reared fish, 2) fish hatchery-reared for 3, 6, 9, and 12 months and then planted in a controlled stream for the remainder of the period; and 3) an indigenous group of wild fish in this stream. Wild fish showed high incidence of tissue damage from spinose hairs of the moth larva, Halisidota argentata. Hatchery fish were similarly affected with the severity and incidence of lesions varying directly with the time of exposure of tim la•wae in the wild environment. Both groups of fish were heavily pm'asitized by sporozoan organisms in the kidney and spinal cord. Kidney disease appeared in both wild and planted hatchery fish. The gross chemical composition of hatchery fish transformed rapidly after planting to that of the wild fish. Although the initial rate of fat loss is essentially constant for all hatchery groups after planting, fish that were hatchery reared for 9 to t2 months did not complete the transformation to the wild-type body composition by the time of downstream migration at 14 months. ß 1958. The role of competition in the mortal. ity of hatchery troutß Jour. Fish. Res. Bd. Can ada, 15: 27-45. NIELSON, REED S., NORMAN REIMERS, AND HARRY D. KENNEDY. 1957. A six-year study of the survival and vitality of hatchery-reared trout of catchable size in Convict Creek, California. Califß Fish and Game, 43: 5-42. PHILLIPS, ARTIIUR M., DONALD R. BROCKWAY, MAUR-ICE BRYANT, E. O. RODERS, AND JOHN M. MAX-WELl,. 1949. The nutrition of trout. N.Y.

Classification accuracy of algorithms for blood chemistry data for three aquaculture-affected marine fish species

“…Among numerous machine-learning methods available (Witten and Frank 1999), decision trees are the best in providing very clear, interpretable, and actionable models (Fig. 1).…”

“…Basic descriptive statistics included measures of central tendency (arithmetic mean, x), and dispersion (standard error of the mean, SEM). Data quality was checked prior to analysis with machine-learning algorithms (Witten and Frank 1999). In the process of machine learning the discriminating/classification models using biochemistry data ten times, tenfold cross-validation was used as an evaluation approach.…”

“…The process of finding the best discrimination-classification model provides us with the overall assessment (through the obtained classification accuracy of the model) on how the collected data explain the target phenomena, or in our case how important are differences in biochemistry between different fish. We have used two state-of-the-art approaches for production of classification models-the implementation of C4.5-decision trees algorithm in the WEKA package (Witten and Frank 1999) and PARF , a local implementation of the well known random forests algorithm (Breiman 2001).…”

“…The most important living conditions, for example artificial diets, directly affect body composition, condition, and, consequently, blood and liver modifications (Wood et al 1990;Christofilogiannis 1993;Burtis et al 1996). Blood reflects physical and chemical changes occurring in organisms, indicating general metabolism and physiological status.…”

Comparison of haematology and serum biochemistry of cultured and wild Dojo loach Misgurnus anguillicaudatus

“…The levels of cortisol and glucose are considered to be specific indicators of sympathetic activation during stress conditions (Santos and Pacheco 1996;Svoboda et al 2001;Lermen et al 2004). Basic ecological factors, such as feeding regime and stocking density, also have a direct influence on certain biochemistry parameters (Wood et al 1960;Christofilogiannis 1993;Coz-Rakovac et al 2005). Moreover, variations in the levels of blood corpuscles have been observed in cytological investigations (Bahmani et al 2001;Nespolo and Rosenmann 2002).…”