Laserfiche WebLink
<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />..............'. <br />I <br /> <br />21 <br /> <br />m. Methods <br /> <br />J- <br />, <br />'-~{ -" <br />t <br /> <br />1. Experimental Approach <br /> <br /> <br />Nutritional status and population structure of larval razorback populations in Lake <br /> <br /> <br />Mohave and Yuma Cove was studied using three types of condition indices and through <br /> <br /> <br />aging of larval fish. Results were based on comparisons with similar indices derived for <br /> <br /> <br />laboratory raised larvae under experimentally controlled conditions of food and <br /> <br />temperature. Indices used included: 1) lipid content and length-weight relationships; 2) <br /> <br /> <br />histology of selected target tissues; 3) morphology generated from a series of body <br /> <br />metrics; and 4) age and size distribution of larval fish derived from counts of daily otolith <br /> <br /> <br />increments. <br /> <br />~ <br /> <br />The combination of indices were selected on the basis of their potential <br /> <br /> <br />application to ontogenetic sequences of larval development (Martin and Wright 1987). <br /> <br /> <br />When little is known of how nutrition affects larvae during their early stages, a variety of <br /> <br /> <br />methods is usually considered the most appropriate approach. Each index may provide <br /> <br /> <br />information applicable to only certain stages. It is further reasonable to expect different <br /> <br />indices to give different results, making the use of several indices important for data <br />interpretation. <br />