Abstract

CASTILLO-RIVERA, Manuel  and  MORGADO-DUENAS, Guadalupe. Seasonal and diel variation in the distribution of Beloniformes at the inlet of a tropical coastal lagoon. Rev. Mex. Biodiv. [online]. 2022, vol.93, e934047.  Epub Dec 12, 2022. ISSN 2007-8706.  https://doi.org/10.22201/ib.20078706e.2022.93.4047.

The objective of the study was to analyze the temporal patterns in the distribution of Beloniformes in an intermittent tropical estuary. During 19 months, a 24-hour sampling cycle was performed each month, taking samples every 2 hours (442 samples in total). Simultaneously, abiotic and biotic variables were recorded in situ, as well as variables with historical-regional records. Six species were caught, of which Strongylura notata notata showed a significant peak from May to August, while S. timucu, Hyporhamphus unifasciatus and H. meeki showed significant pulses during February-April and December (PERMANOVA, p < 0.04). According to the inter-set correlations of a canonical correspondence analysis, the seasonal occurrence of S. notata notata was mainly determined by longer days, and high values of atmospheric temperature and rainfall, while S. timucu and H. unifasciatus were mainly related to phytoplankton and zooplankton densities. Only S. notata notata showed significant diel differences (PERMANOVA, p < 0.0005). The historical-regional variables showed a greater influence on the distribution patterns of the species than the in situ variables. An intensive fieldwork allowed to know in a more complete way, the conditions that determine the migration patterns, which contributes to the conservation and management of these species.

Keywords : Gulf of Mexico; Ramsar site; Semi-parametric ANOVA; Photoperiod; Needlefishes; Halfbeaks.