Microcystins bioaccumulate but do not biomagnify in an experimental aquatic food chain

Microcystins-common hepatotoxins produced by cyanobacteria—have been detected in a wide range of organisms, though research examining the trophic transfer of microcystins and whether microcystins bioaccumulate or biomagnify in food webs has generated contradictory results. Here, we explored the trophic transfer of microcystins from the herbivorous water flea, Daphnia pulex, to the predatory larvae of a damselfly, Enallagma sp. We tested the hypotheses that microcystins transfer from the tissue of herbivorus zooplankton to that of predatory invertebrates and that these toxins biomagnify across trophic levels. We also assessed the relative contribution of toxin transfer from the gut and tissue of Daphnia pulex to Enallagma sp. We found that microcystins are effectively sequestered in the tissue of Daphnia pulex, and that these sequestered toxins are then transferred to the tissue of Enallagma sp. The contribution of gut contents to toxin transfer was negligible. Contrary to the pattern pr..., This dataset includes measurements of microcystin in three trophic levels in an experimental aquatic foodweb. Data were collected as described in associated manuscript. Microcystins were measured using the MMPB technique. Final concentration of microcystin per dry weight (mg) for each sample is reported in column labeled ngMC/mgTL. As described in the associated manuscript, in one of the five trials, microcystins were detected in Microcystis but not in the grazing Daphnia. Data from this trial have been omitted from the dataset, as they were not used in the reported analysis.
This R script includes all steps for reproducing figures and statistical tests using the associated dataset., , # Data from: Microcystins bioaccumulate but do not biomagnify in an experimental aquatic food chain

[https://doi.org/10.5061/dryad.280gb5n0n](https://doi.org/10.5061/dryad.280gb5n0n)

## Description of the data and file structure

This dataset includes measurements of microcystin in three trophic levels in an experimental aquatic food web including *Microcystis*, *Daphnia*, and *Enallagma*. The data were used to test for biomagnification, toxin transfer route, and trophic transfer efficiency across trophic levels. Data were collected as described in associated manuscript. Microcystins were measured using the MMPB technique. Final concentration of microcystin per dry weight (mg) for each sample is reported.

### Files and variables

#### File: Data\_29Oct24.csv

**Description:** 

##### Variables

* Algae: One of two values:* Microcystis* (toxic algae) or* Scenedesmus* (non-toxic algae)
* Daphnia gut: Describes whether gut of *Daphnia *was full (including algae) or clear
* Enallagma gut...