Newly recruited juvenile gray snapper Lutjanus griseus were collected each fall for two consecutive years (2000 and 2001) from sites in Florida and North Carolina. Spawning, settlement, and growth patterns were compared across sites based on otolith microstructure. Larval otolith growth trajectories were generally similar for larvae from different sites and years; however, the mean pelagic larval duration (PLD) was 1 d longer for fish from North Carolina than for fish from the more southern sites. As a result, fish were larger at settlement to North Carolina. Estimated juvenile growth rates ranged between 0.62 and 0.88 mm/d and differed across sites and years, growth being generally faster at the southern sites. Water temperature accounts for some of this variability; however, site‐specific differences in other factors probably contributed to some of the observed differences in growth. Back‐calculated spawning patterns showed a lunar association with the new and first‐quarter moons at all sites except for North Carolina. Settlement patterns were lunar cyclic as well: settlement pulsed during the third‐quarter and new moons at all sites, and in North Carolina an additional pulse associated with the full moon was present. Patterns of larval and juvenile growth coupled with recruitment dynamics across the latitudinal gradient are consistent with northward Gulf Stream transport of larvae from southern spawning sites.

The Atlantic blue marlin Makaira nigricans larvae were collected from Exuma Sound, Bahamas and the Straits of Florida over three summers (2000)(2001)(2002). Sagittal otoliths were extracted and read under light microscopy to determine relationships between standard length (L S ) and age for larvae from each year and location. Otolith growth trajectories were significantly different between locations: after the first 5-6 days of life, larvae from Exuma Sound grew significantly faster than larvae from the Straits of Florida. Exponential regression coefficients were similar among years for Exuma Sound larvae (mean instantaneous growth rate, G L ¼ 0Á125), but differed between years for larvae from the Straits of Florida (G L ¼ 0Á086-0Á089). Differences in larval growth rates between locations resulted in a 4-6 mm difference in L S by day 15 of larval life. These differences in growth appeared to be unrelated to mean ambient water temperatures, and may have been caused by location-specific differences in prey composition or availability. Alternatively, population-specific differences in maternal condition may have contributed to these differences in early larval growth. # 2005 The Fisheries Society of the British Isles

No abstract

Of the Atlantic istiophorid billfishes, larval age–size relationships and growth rates have been examined only for blue marlin (Makaira nigricans). Using otolith microincrement analysis, we describe age–length and age–weight relationships for larval sailfish (Istiophorus platypterus) collected from the Straits of Florida. Sagittae and lapilli were dissected from 70 larvae ranging from 2.8 to 15.2 mm in (notochord or standard) length. Comparisons between otolith images obtained by light microscopy and scanning electron microscopy indicated that increment widths were well within the resolving power of light microscopy. Indirect evidence and published descriptions of larval blue marlin otoliths suggest daily increment deposition. Estimated ages of specimens ranged from 3 to 18 days. Length data were fitted to age estimates with an exponential model (R2 = 0.85). The estimated size-at-hatch for sailfish was 1.96 mm notochord length, and the daily instantaneous growth coefficient was 0.14. A power curve with exponent 3.05 described the length–dry weight relationship for sailfish. The instantaneous growth coefficient for an exponential regression of dry weight, converted from length, versus estimated age was 0.41. Growth in the length of sailfish larvae from the Straits of Florida was very similar to that described for blue marlin larvae from Exuma Sound, Bahamas.