Résumé
Tropical rainforests harbor extraordinary biodiversity. The Amazon basin
is thought to hold 30% of all river fish species in the world. Information
about the ecology, reproduction, and recruitment of most species is still
lacking, thus hampering fisheries management and successful conservation
strategies. One of the key understudied issues in the study of population
dynamics is recruitment. Fish larval ecology in tropical biomes is still
in its infancy owing to identification difficulties. Molecular techniques
are very promising tools for the identification of larvae at the species
level. However, one of their limits is obtaining individual sequences with
large samples of larvae. To facilitate this task, we developed a new
method based on the massive parallel sequencing capability of next
generation sequencing (NGS) coupled with hybridization capture. We focused
on the mitochondrial marker cytochrome oxidase I (COI). The results
obtained using the new method were compared with individual larval
sequencing. We validated the ability of the method to identify Amazonian
catfish larvae at the species level and to estimate the relative abundance
of species in batches of larvae. Finally, we applied the method and
provided evidence for strong temporal variation in reproductive activity
of catfish species in the Ucayalí River in the Peruvian Amazon. This new
time and cost effective method enables the acquisition of large datasets,
paving the way for a finer understanding of reproductive dynamics and
recruitment patterns of tropical fish species, with major implications for
fisheries management and conservation.