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Vol. 53 - Alaska Resources Library and Information Services

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this low number of larvae increased the number of observations (stations)<br />

which could be included in the analysis <strong>and</strong> produced no obvious<br />

detrimental impact on the data variance, since a large variance existed<br />

even among stations with abundant larvae.<br />

The data were grouped into<br />

time periods not exceeding 10 days <strong>and</strong> the mean ratio calculated (unweighted<br />

ratio method).<br />

The number of larvae examined in each 10-day<br />

period ranged from 43 to over 2,000. From one to thirty stations were<br />

included in each period.<br />

Rates of development of second stage (SII) zoeae were analyzed by<br />

examining the ratio of SII:SII + megalops larvae (no SI zoeae were present<br />

during this period).<br />

The data were grouped into time periods of<br />

not more than 13 days.<br />

The number of larvae examined in each period<br />

ranged from 780 to 2032, while the number of stations ranged from 10 to<br />

41.<br />

For both molting analyses above, weighted ratios were also calculated<br />

by pooling data on all larvae of a species from each 10-day period<br />

<strong>and</strong> determining the ratio of the larval stages in question. This method<br />

gave results similar to the unweighted method, but the results of the unweighted<br />

ratio method were used for illustration because these data<br />

allowed variance of data to be expressed.<br />

Observations of the stomach contents of yellow fin sole (Lim<strong>and</strong>a<br />

aspera) collected in early September 1980 (K. Haflinger, Univ. of<br />

<strong>Alaska</strong>, unpubl. data) <strong>and</strong> plankton samples collected in October 1980<br />

provided some information on the late summer-early autumn presence of<br />

613

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