Circumglobal distribution of fish environmental DNA in coral reefs

Coral reefs host the highest fish diversity on Earth despite covering less than 0.1% of ocean’s seafloor. At same time they are also extremely threatened. Data syntheses over decades surveys estimate total number coral reef fishes to vary from 2,400 8,000 species distributed among roughly 100 families. But this remains largely unknown. Here, we investigated how environmental DNA (eDNA) could describe distribution in reefs. We generated 504,457,267 raw 12S ribosomal (rDNA) sequence reads 251 samples (2,693 PCR replicates) collected at 25 sites 145 stations five regions across Indian, Pacific and Atlantic Oceans. Bioinformatic analysis clustered these sequences into 2,160 molecular operational taxonomic units (MOTUs) corresponding distinct (Marques 2020) compared our results, with visual census Reef Life Survey, 2,813 transects tropical regions. Our outcomes demonstrate capacity eDNA metabarcoding water reconstruct well-known biogeographic patterns reefs, such as richness gradients towards triangle, family proportion stability (Bellwood Hughes 2001). Additionally, survey data documented a higher (16%) (50%) estimates obtained underwater carried out 20 times more sites. MOTU per retrieved closely matched within families recorded data. However, revealed reef-associated adjacent habitats, cryptobenthic or nocturnal species, but pelagic wide-ranging species. showed that is characterized by spatially heterogeneous assemblages regions, dissimilarity detected Unlike surveys, prevalence rarity expected under neutral theory biodiversity, suggesting predominance random processes ecological equivalence trophic groups large scale explain biodiversity study demonstrates sequencing provides rapid effective approach characterize assess spatial scales, thereby uncovering hidden patterns.