Newman and Dunk: Age validation, growth, mortality, and additional population parameters of Pristipomoides multidens 



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Western Australia 



Figure 1 



Location of the northern demersal scalefish fishery (NDSF) off the Kimberley 

 coast of northwestern Australia showing the 50-m, 100-m, and '200-m depth 

 contours. The NDSF is bounded in the west by the 120''E latitude line, to the 

 north by the boundary of the Australian fishing zone (AFZ), and to the east by 

 the border with the Northern Territory. Fishing primarily occurs in depths of 

 80-140 m. 



A further objective was to investigate the relationship 

 between estimated age and the measurements of both oto- 

 lith and fish dimensions to assess the applicability of these 

 measurements in predicting the age of this species. 



Materials and methods 



Commercial landings of P. multidens from the NDSF off 

 the Kimberley coast of Western Australia were sampled 

 from 1995 to 1999. Samples were acquired opportunisti- 

 cally from July 1995 to December 1996, whereas samples 

 obtained from January 1997 to December 1999 were col- 

 lected on a monthly basis among all vessels in the fleet. All 

 specimens were captured with fish traps at depths of 60 to 

 200 m from 12°-20°S latitude (Fig. 1). Additional specimens 

 were attained from research vessel cruises with fish traps. 

 All fish were measured to the nearest mm total length 

 (TL), fork length (FL) and standard length (SL), weighed to 

 the nearest g total weight (TW) and cleaned weight (CW), 



and where possible, sex was determined by examination of 

 the gonads. Cleaned weight is defined as the TW after re- 

 moval of the gills and viscera. Length measurements were 

 used to derive conversion equations with linear regression 

 models [TL=a + h(FL), FL=a + b tTL). FL=a + 6 (SL) and 

 SL=a + b (FL)\. 



Length-weight models 



The relationships between FL and both TW and CW were 

 described by the power function 



where W = weight (TW or CW, g); and 

 L = FL(mm). 



These relationships were fitted to log-transformed data 

 and the parameters were back-transformed (with correc- 

 tion for bias) to the above form. 



