# Cladoceran density and age structure is highly variable through time in three ponds in Northwest Indiana

## TL;DR

This study examines how zooplankton populations, specifically Daphnia, Ceriodaphnia, and Simocephalus, change over time in three small ponds in Northwest Indiana.

## Contribution

The study reveals high variability in zooplankton density and age structure, influenced by environmental factors like rainfall.

## Key findings

- Daphnia, Ceriodaphnia, and Simocephalus were the most common zooplankton genera found in all three ponds.
- Zooplankton density and age structure varied significantly over time, especially in ephemeral ponds during high rainfall years.
- The study highlights the importance of environmental conditions in shaping zooplankton population dynamics in small ponds.

## Abstract

Zooplankton are important primary consumers in freshwater food webs. We aimed to identify common zooplankton genera and describe population dynamics through time in three ponds. We measured the presence, density, and age structure of zooplankton over three years (2016-2018) from spring to fall. We found three common genera in all ponds:
Daphnia
,
Ceriodaphnia
, and
Simocephalus
. The presence, density, and age structure of all three genera was highly variable through time. Ephemeral ponds had higher densities in 2017 when rainfall was higher than other sampled years. This work adds to the understanding of zooplankton population dynamics in small ponds.