DNA BARCODING OF IBERIAN TRICHOPTERA: DOCUMENTING BIODIVERSITY FOR FRESHWATER BIOMONITORING IN A MEDITERRANEAN HOTSPOT
Joana Paupério (CIBIO-InBIO, Portugal) | June 17, 2019 | 8th International Barcode of Life Conference, Trondheim, Norway
Background: Trichoptera is a moderately diverse order of aquatic insects, with aquatic larvae and small moth-like adults. This group is closely related to the order Lepidoptera, and comprises over 14 500 described species. Trichoptera larvae are found in a wide range of freshwater habitats and show differential sensitivity to pollution, and thus their diversity and abundance are widely used in biological freshwater monitoring. However, these monitoring studies rely on larval morphological identification, which is much more difficult than adult determination and in fact impossible in the many species whose larvae have not yet even been described. The applicability of DNA metabarcoding for molecular identification of taxa in biodiversity monitoring is expected to be high, but dependent upon the availability of DNA reference collections. In this context, and within the framework of the InBIO Barcoding Initiative (IBI), we are developing a DNA barcoding database focusing on Iberian Trichoptera. Results: We have collected more than 700 specimens covering 22 families of Trichoptera, of which over 500 were already barcoded. Genomic DNA was extracted, and the 5=-region of the mitochondrial COI gene (658 bp) was amplified in two overlapping fragments. DNA barcodes were generated using high-throughput sequencing techniques (Illumina). From the over 150 Iberian species barcoded, most could be easily distinguished using the targeted DNA fragment, although in some cases low divergence was detected between species of the same genus (e.g., Ceraclea). Also, cryptic diversity was observed in some genera (e.g., Rhyacophila). Significance: The DNA reference database of Iberian Trichoptera being generated is directly supporting the development of freshwater biomonitoring methods based on DNA metabarcoding. With over 60% of Portuguese species and 40% of Spanish taxa already barcoded, and the current effort to increase its coverage, the IBI database of Trichoptera is expected to become a fundamental tool in freshwater biomonitoring in the Iberian Peninsula.