. Bulletin. Science. AGE AND GROWTH OF SPOTTED SAND BASS IN BAHIA DE LOS ANGELES 17 Table 1. Definition of season category based on collection dates. Season Dates of collection Spring Summer Fall Winter 27 March to 2 April 1994 12 to 21 July 1994, and 1 to 15 July 1995 15 to 23 October 1992 9 to 20 January 1995 to set criteria for counts and to resolve differences. Otoliths that did not meet agreed upon criteria were disregarded. Average percent error (APE) and index of precision (D) were calculated to assess variability of age estimation within and between readers (Chang 1982; Campana 2001).
. Bulletin. Science. AGE AND GROWTH OF SPOTTED SAND BASS IN BAHIA DE LOS ANGELES 17 Table 1. Definition of season category based on collection dates. Season Dates of collection Spring Summer Fall Winter 27 March to 2 April 1994 12 to 21 July 1994, and 1 to 15 July 1995 15 to 23 October 1992 9 to 20 January 1995 to set criteria for counts and to resolve differences. Otoliths that did not meet agreed upon criteria were disregarded. Average percent error (APE) and index of precision (D) were calculated to assess variability of age estimation within and between readers (Chang 1982; Campana 2001). A von Bertalanffy growth func- tion was calculated from estimates of age and fish length using FISHPARM soft- ware. An allometry growth function was also estimated for the relationship of fish weight and length to describe somatic growth. An estimate of longevity was calculated using the exponential nature of the von Bertalanffy equation, where 95% longevity (yr) = 5 ln(2)/& (H. Mollet, Pacific Shark Research Center, Moss Landing Marine Laboratories, personal communication), and k represents the growth coefficient. The growth rate estimated from our study was compared to the growth from data analyzed by Allen et al. (1995). This latter study assumed an age of six months ( yr) for YOY, differing from our assumption of age zero for YOY To compare growth between the two studies, Allen et al. (1995) provided their data and we adjusted it to match our criteria. Length at age data was log-trans- formed for both data sets. Calculated growth rates (slopes) were compared be- tween the Pacific coast and Gulf of California populations using an analysis of covariance (ANCOVA). In particular, the ANCOVA will determine if the slopes of these lines are parallel ( if fish in these populations grow at the same rate). Prior to testing for differences between the Gulf and Pacific coast populations,. Fig. 2. Image of the transverse otolith section from the oldest aged fish. Age from gro
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