Dietary partitioning among three cryptobentic reef fish mesopredators revealed by visual analysis, metabarcoding of gut content, and stable isotope analysis

Understanding how mesopredators partition their diet and the identity of consumed prey can assist in understanding the ecological role predators and prey play in ecosystem trophodynamics. Here, we assessed the diet of three common coral reef mesopredators; Pseudochromis flavivertex, Pseudochromis fridmani, and Pseudochromis olivaceus from the family Pseudochromidae, commonly known as dottybacks, using a combination of i) visual stomach content analysis, ii) stomach content DNA metabarcoding (18S, COI), and iii) stable isotope analysis (δ15N, δ13C). In addition, P. flavivertex is found in two distinct color morphs in the Red Sea, providing an opportunity to analyze intra-morph differences. These techniques revealed partitioning in the dietary composition and resource use among species. Arthropods comprised the main dietary component of P. flavivertex (18S > 60%; COI > 10%), and P. olivaceus (18S = 57.2%) while P. fridmani ingested predominantly mollusks (18S = 51.3%, COI = 24.6%). ..., Fish and tissue collection 
A total of 125 adult individuals from three species and two color morphs of dottybacks (Pseudochromis flavivertex M1 = 48; P. flavivertex M2 = 28; P. olivaceus = 24, and P. fridmani = 25) were collected (Figure 1) in the central Red Sea off the coast of Thuwal, Saudi Arabia (22.2833° N, 39.1000° E) between 09:00 and 12:00 h of August and September 2021. Fish collections took place in different reefs along a cross-shelf gradient (coastal, mid shore, offshore) to broadly cover all available shallow reef habitats for these species in the central Red Sea, and to maximize the diversity of dietary items detected for each dottybacks species rather than compare habitats. Not all dottybacks species were collected across the different shelves because not all species were found in the same location during the sampling period (see ESM Table 1 for individual sample details). Fishes were collected under KAUST IACUC Protocol 19IACUC03.
Fish were caught using a hand net and ..., , ## Data from: Dietary partitioning among three cryptobentic reef fish mesopredators revealed by visual analysis, metabarcoding of gut content, and stable isotope analysis

[https://doi.org/10.5061/dryad.fqz612k12](https://doi.org/10.5061/dryad.fqz612k12)

Here we provide the 18S and COI zOTUs tables obtained with DNA metabarcoding of gut content of *Pseudochromis flavivertex* (morph 1: M1, and morph 2: M2), *P. fridmani*, and *P. olivaceus* (in .xlsx format). Tables show zOTUs and taxonomic assignments obtained after removing all the “self-hits” and endoparasitic protozoa from the dataset.

The corresponding species code for the zOTUs tables is presented below:

PFM1: Pseudochromis flavivertex M1

PFM2: Pseudochromis flavivertex M2

PFRI: Pseudochromis fridmani

POLI: Pseudochromis olivaceus

GutTrial_1: Pseudochromis flavivertex M1

GutTrial_2: Pseudochromis flavivertex M1

GutTrial_3: Pseudochromis flavivertex M1

Variables comprising the taxonomic assignments tables:

**OTUID**: Zero...