MOTU detection and taxonomic
identification
The number of MOTUs detected differed between molecular markers: 398
using COI and 351 using 16S. After comparing the sequences against the
reference databases, we could assign Linnean species names to 40% of
the MOTUs in the COI dataset and 37% in the 16S dataset. Identification
rates increased at higher taxonomic levels: more than 97% of the MOTUs
could be assigned to an Order with either marker. The proportion was
also very high at the Family level, but here the success rate was
considerably higher using COI: 89% with this marker versus 76% using
16S (Table 1).
The use of two markers increased detection success, but only at lower
taxonomic levels. There were 22 different orders in total, all of them
detected by COI, but only 14 picked up by 16S. The orders missed by the
16S marker were: Mantodea, Opiliones, Plecoptera, Poduromorpha,
Sarcoptiformes, Symphypleona, Thysanoptera and Trombidiformes. At lower
taxonomic levels, many families were detected by the two markers (N =
81), but some of them were only found by one: 36 for COI and 8 for 16S
(Table 1). Table S14 shows all families recovered and marker
identification, as well as the number of MOTUs classified into each
family. Regarding determinations to the Genus level, roughly 50% of the
MOTUs were identified per marker and differed between markers: from a
total of 266 genera, 117 were exclusively identified by COI and 91 by
16S (Table 1). That is, only 58 genera were identified by both markers.