Composition, abundance and chaetognath species distribution in the north littoral of the Mexican Caribbean Sea

Abstract

Species composition and variations in abundance of chaetognaths from the north of Quintana Roo were carried out from January to December 2004. Sampling was made near surface with a conical net (0.40 m, diameter; 330 µm mesh) at 12 stations from Puerto Morelos to Cancun. Temperature and salinity were measured in situ. Weather conditions were atypical with previous reports (dry, rains, nortes). Instead, a better correlation was observed with the environmental conditions of the lagoon, reef and oceanic zones. A total of 16,966 chaetognaths were captured with an annual mean abundance of 575 org./100 m3 . Eleven species of chaetognaths were recorded, with Ferosagitta hispida as the most abundant (499.6 org./100 m3 = 77%) and unique species in the lagoon zone. Flaccisagitta enflata (80.2 org./100 m3 = 14.6%), was second in abundance and collected mainly in the oceanic zone. Krohnitta pacifica (17.8 org./100 m3 = 3%) and Serratosagitta serratodentata (13.2 org./100 m3 = 2.5%), both were abundant in the reef zone. Other species were: Sagitta tenuis, Pterosagitta draco, F. hexaptera, S. friderici, S. helenae, Mesosagitta minima and S. bipunctata contributing 12.8 org./100 m3 = 2.3% altogether.