Ichthyoplankton metabarcoding as a tool for studying fish reproductive dynamics

The study of ichthyoplankton composition, abundance and distribution is paramount to understand the reproductive dynamics local fish assemblages. analysis these parameters allows identification spawning sites, nursery areas migration routes. However, due lack characters in early life stages, morphological often impractical many studies identify only larvae. Additionally, its accuracy shows great variation between taxonomists laboratories according their experience specialty. DNA barcoding emerged as an alternative provide assertive eggs larvae, but it becomes too expensive laborious when demands processing huge amounts organisms. metabarcoding can overcome limitations a rapid, cost-effective, broad accurate taxonomy tool, allowing multiple individuals simultaneously. Here, we present sample containing 68 another 293 larvae from single site São Francisco River Basin, Eastern Brazil, through metabarcoding. We used low-cost saline extraction followed by PCR amplification with three primer sets targeting 12S rRNA gene: MiFish (~170bp), Teleo_1 (~60bp), NeoFish (~190bp). latter was recently developed our research group specifically for Neotropical fishes. All amplified samples were sequenced multiplexed Illumina MiniSeq run. performed filtering steps assigned Amplicon Sequence Variants (ASVs) using DADA2/Phyloseq based pipeline custom reference sequence database including 101 species 70 genera Jequitinhonha basins. Cyphocharax gilbert , Leporinus taeniatus Megaleporinus elongatus Prochilodus argenteus P. costatus Psalidodon fasciatus detected all larva pool, while Pterygoplichthys etentaculatus solely (Fig. 1). Within egg markers Characidium zebra, Curimatella lepidura, M. elongatus, Pimelodus fur Brycon orthotaenia NeoFish, maculatus Teleo, pohli Teleo consistency detection among underpins credibility this method accurately describe composition. Considering that most exclusive or experiment highlights importance reproduction studies, additional information about which are area. Furthermore, application help decision makers create more informed guidelines conservation economically ecologically important species.