Stable carbon and nitrogen isotopes in Panulirus argus phyllosomas in the Mexican Caribbean

The spiny lobster Panulirus argus (Latreille, 1804) is a commercially important fishery resource in the Caribbean Sea. The complex life cycle of P. argus, particularly during its pelagic life (phyllosoma larvae) is influenced by various oceanographic factors and makes it difficult to develop basic studies about its trophic ecology. The δ¹³C and δ¹⁵N values of the phyllosoma larvae sampled off the SE coast of Quintana Roo, Mexico contributes to assess the migration, feeding and trophic level of the early and intermediate stages of the P. argus life cycle. The δ¹³C values of the phyllosomas (−18‰ to −22‰) are characteristic of pelagic food resources in oligotrophic oceanic regions, also rich in lipids (ratio C:N 5 to 6). From stage I to IV, the observed δ¹⁵N value was enriched by 2.8‰ and remain without change between stages IV and VI, this isotopic equilibrium with the diet was reached between 60 and 70 days of life. The observed enrichment of ¹⁵N in P. argus phyllosoma larvae of the Mexican Caribbean suggests a change in trophic level from the early (I–III) to the intermediate stages (IV–VI), during which P. argus larvae remain feeding at the same trophic level.