Zuniga and Acuna' Development of Paralichthys spp larvae 



609 



Morphometric measurements follow the definitions of 

 Gutherz (1970) and were made with an ocular microm- 

 eter (to 0.01mm). Notochordal length (NL) was used 

 for yolksac larvae through flexion: from then on, stan- 

 dard length (SL) was utilized. In preflexion and flex- 

 ion larvae, body depth (BD) is defined as the vertical 

 distance across the body at the anus including the 

 dorsal-fin pterygiophores. After flexion, it is defined 

 as the vertical distance across the body at the pelvic 

 fin, from its base to the base of dorsal-fin rays. Head 

 length (HL) is defined as the distance from the snout 

 to the cleithrum, until and through flexion, and there- 



after from snout to the opercle edge. The total number 

 of myomeres and vertebrae does not include the uro- 

 style. Drawings were made from a compound micro- 

 scope equipped with a camera lucida. 



Linear regression models were fitted to six morpho- 

 metric relationships of the larvae, comparing the pre- 

 flexion stages with flexion, postflexion, and metamor- 

 phosis, to separate larvae of both species. An F test 

 (Neter and Wasserman 1974) was used to compare the 

 morphometric relationships of these two groups of lar- 

 vae within and between species. 



Determination of Paralichthys adults was based on 



