Summary This paper reports length–weight relationships and summarizes data for Lutjanus argentiventris from Río Caté, a tropical estuary on the Gulf of Montijo, Pacific coast of Panama. The length–weight relationship obtained was W = 0.012Lt3.07. The L. argentiventris mature throughout the year, although in fewer numbers from September to November. The sex ratio was 1 male to 0.9 female. Occurrence in stomachs showed that they feed mainly on crustaceans (75.4%), fishes (18.5%), polychaetes (4.6%), and molluscs (1.5%). Portunid crabs (Portunus asper) were the most frequent prey group.

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Growth patterns and biochemical analy!'>is al laboratory condilions (temperatUre 28°c' saJinily 22) were analyzed in juveniles wiJd pink shrimp, Farjr/!/tepenaeus duorarum (Burkenroad, 1939), eaught in tlle Gulf of Mexica compared with cultivated (F2) organisms. Shrimp were maintained for 55 days to monitor lhe molt frequency and weight gain over lime. We detennined the frequency of molting and wel ~'ejght gain per day over the experiment lime. Wild shrimp had an average molting frequency of 10 ± 2.03 days with an increase in wet weight af 0.024 ± 0.00 I g day-J; whereas cullivated shrinlp had an average frequency of 11 ± 2.15 days and a growth rate of 0.084 ± 0.002 g day-l. Osmolic capacity was delermined in wild shrimp al 154.85 ± 7.3.47 mOsm kg-1 and for eultivated al 128.67 ± 42.24 mOsm kg-l. Total protein concentration wus 35.15 mg mI-1 for wild shrimp, while values for culrinted shrimp werc significanlly differen\ at 112.22 mg nll-l (ANOVA; p < 0.05). Also, an e"periment was conducted to determine the amounl affood consumed befare and after ecdysis in wild and eultivated shrimp. No significan! differences were faund in the food consumption (F = 0.220, P = 0.641) between groups befare and after ecdysis. We detennined fhat foad consumption ntle fel! by 30% during moll and that fceding did not cease when ecdysis oceurs.

This study reports growth parameters and mortality for Sphoeroides testudineus from La Carbonera, a karstic tropical coastal lagoon on the northwestern coast of the Yucatán Peninsula, Mexico. A total of 461 specimens were collected between April 2009 and March 2010. We obtained the length-weight relationship and the growth parameters of von Bertalanffy growth model (VBGM) by length frequency analysis. Additionally, mortality was estimated and analyzed. Exponent b indicated an isometric growth pattern. The growth parameters of VBGM were: L ∞ = 29.50 cm, k= 0.77 year-1 and t 0 =-0.168 years. The instantaneous natural mortality was 1.53 year-1 .

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