Feeding ecology of the critically endangered Gobio Insuyanus (Gobionidae)

Despite the critical conservation status of the endemic gudgeon Gobio insuyanus, its feeding ecology remained unstudied. This research addresses this gap by investigating the diet of G. insuyanus in the Insuyu spring-stream system of Central Anatolia (Turkey) analyzing spatial, temporal, and intraspecific variations. We compared two distinct habitats: a stable spring and its continuum, a fluctuating stream. Results indicate that G. insuyanus is an omnivore, consuming primarily detritus, Gammarids, and Diptera larvae. Feeding activity was higher in the spring habitat, particularly in summer, possibly related to its stable temperature and lower turbidity. Dietary diversity was higher in the stream, potentially reflecting its greater habitat complexity, but decreased in both habitats in autumn, suggesting a seasonal decline in prey availability. A significant ontogenetic shift in diet was observed; mature individuals exhibited a narrower niche and preferred larger prey, probably due to inc..., , , # Feeding Ecology of the Critically Endangered Gobio insuyanus (Gobionidae)

[https://doi.org/10.5061/dryad.cz8w9gjft](https://doi.org/10.5061/dryad.cz8w9gjft)

## Description of the data and file structure

The data consist of the contents of the stomach of *Gobio insuyanus*, collected for the analysis of the feeding ecology of the species.

### Files and variables

#### File: EcoEvo\_Gobio.7z

**Description:** The folder contains two .xlsx and one .csv files through which the stomach content of the individuals analysed.

*Habitat_FVN*: this file contains 9 sheets of percent Frequency of occurrence (%FO), percent Volume of preys (VO%), percent number of preyd (N%) and calculated index of relative importance (IRI). All these are provided for Spring and Stream habitats separately. The first 5 columns in each sheet include the prey taxon from phylum to the lowest possible taxon. The rows represent individual fish, and their prey values starting from the F column. The other *Volumetrics Se...,