Szedlmayer and Conti: Nursery habitat, growths rates, and seasonality of age-0 Lut/anus campechanus 



631 



120 n 



100 



80 



60 



40 



i ^° 



C 



•o 



s 



•D 



C 



o5 120 



100 H 



80 

 60 

 40 

 20 



1994 

 n = 1803 

 /•-square = 62 

 b = 0.52 mm/d 



1995 

 n = 5704 

 r-square = 52 

 b = 0.43 mm perd 



I I I 1 1 1 1 1 



Jun Jul Aug Sep Oct Nov Dec Jan 



t^onth 



Figure 5 



Linear regression of age-0 red snapper, Lutjanus campechanus. 

 SL on date for 1994 and 1995, for all fish collected from the north- 

 east Gulf of Mexico. Data points are individual fish. Growth rates 

 were significantly different between years (Mest; P<0.05). 



many fish species this transition occurs simulta- 

 neously with habitat change, i.e, from pelagic larvae 

 to benthic juveniles. On the basis of smallest fish 

 collected during this study, larval red snapper meta- 

 morphose near 26 d and at 18 mm in length. Collins 

 et al. (1980) suggested similar settlement sizes (12.4 

 to 22.4 mm SL) from plankton net samples. 



Age-0 red snapper otoliths had daily microin- 

 crements when growth rates were >0.3 mm/d (Szedl- 

 mayer, 1998). In the present study, the nursery pe- 

 riod was in the warmer summer months, when food 

 should be abundant; and by all indications, growth 

 rate far exceeded the 0.3 mm/d threshold rate. Thus, 

 back calculation of first increment formation accu- 

 rately estimated hatching date for age-0 red snap- 

 per. One difficulty with the otolith ageing methods 

 was the low (579'^) percentage of otoliths that met 

 the required predetermined precision. However, this 

 low percentage was due to personnel skill in otolith 



preparation. For example, an inexperienced techni- 

 cian would typically over polish several otoliths, that 

 were subsequently rejected when counting. This 

 same technician, after gaining experience and in- 



