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Fishery Bulletin 90(2). 1992 



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Depth of Capture (m) 



Figure 2 



Relationship between body depth at anus and standard length 

 in Dover sole Microstomus pacificus : (A) scatterplot of data 

 points, Stages 1-5; (B) polygons circumscribing areas bounded 

 by specimens in Stages 1-5. 



as the ability to settle (Jackson and Strathmann 1981), 

 a conceptual improvement that removes predefined 

 connections to metamorphosis. We identify precompe- 

 tent, competent, and postcompetent stages during 

 metamorphosis of Dover sole. 



Time-series analysis 



Two approaches were used to construct a time-line of 

 early development: modal progression analysis (MPA, 

 Bhattacharya 1967) and an analysis of seasonality of 

 stages. MPA was facilitated using the computer pro- 



gram ELEFAN (Pauly 1987), but its utility was limited 

 by sample sizes. Analysis of seasonality of stages was 

 corroborated partly by monitoring growth of a single 

 metamorphosing individual held in the laboratory at 

 13°C. The Stage-3 specimen was 57.7 mm SL when cap- 

 tured on 20 March 1989. It was measured regularly and 

 progressed completely through Stage 4 to an early 

 Stage 5, when it was sacrificed on 15 June 1989. 



Results 



Morphology and development 



Stage 1 jpremetamorphic larvae), 6. 1-58.5 mm SL 



For convenience and because of our emphasis on meta- 

 morphosis, all premetamorphic planktonic specimens 

 are referred to as Stage 1 . However, the premetamor- 

 phic phase of the larval period could be usefully divided 

 into two intervals, the first approximating Stage I of 

 Pearcy et al. (1977a). A transition from the first inter- 

 val to the second occurs around 10-15mmSL, during 

 which eye migration begins, body depth increases (Fig. 

 2), the first dorsal and anal fin rays form, and caudal 

 fin flexion begins. During the second interval, speci- 

 mens acquire the adult numbers of vertebrae, and 

 dorsal, anal, caudal, and pelvic fin rays; the stomach 

 and intestine coil; 3-4 pyloric cecae develop; and a 

 pigmentation pattern of dashes develops into a solid 



