Studying the movement behavior of benthic macroinvertebrates with automated video tracking

Abstract

Quantifying and understanding movement is critical for a wide range of questions in basic and applied ecology. Movement ecology is also fostered by technological advances that allow automated tracking for a wide range of animal species. However, for aquatic macroinvertebrates, such detailed methods do not yet exist. We developed a video tracking method for two different species of benthic macroinvertebrates, the crawling isopod Asellus aquaticus and the swimming fresh water amphipod Gammarus pulex. We tested the effects of different light sources and marking techniques on their movement behavior to establish the possibilities and limitations of the experimental protocol and to ensure that the basic handling of test specimens would not bias conclusions drawn from movement path analyses. To demonstrate the versatility of our method, we studied the influence of varying population densities on different movement parameters related to resting behavior, directionality, and step lengths. We found that our method allows studying species with different modes of dispersal and under different conditions. For example, we found that gammarids spend more time moving at higher population densities, while asellids rest more under similar conditions. At the same time, in response to higher densities, gammarids mostly decreased average step lengths, whereas asellids did not. Gammarids, however, were also more sensitive to general handling and marking than asellids. Our protocol for marking and video tracking can be easily adopted for other species of aquatic macroinvertebrates or testing conditions, for example, presence or absence of food sources, shelter, or predator cues. Nevertheless, limitations with regard to the marking protocol, material, and a species’ physical build need to be considered and tested before a wider application, particularly for swimming species. Data obtained with this approach can deepen the understanding of population dynamics on larger spatial scales and of the effects of different management strategies on a species’ dispersal potential.

The influence of insecticide exposure and environmental stimuli on the movement behaviour and dispersal of a freshwater isopod

“…Locomotor behaviour is particularly vital to animal life as it facilitates feeding, predator avoidance, reproduction, or migration, and thus may link the effects of individual stress to the population level (Bayley et al 1997 ). This type of behaviour can be studied easily via video tracking (Augusiak and Van den Brink 2015 ; Rodrigues et al 2016 ).…”

“…Recovery, hence, depends mostly on the intrinsic reproduction potential and dispersal of individuals within a water body from uncontaminated patches towards exposed ones. This species also appeared to be easily studied using automated video tracking (Augusiak and Van den Brink 2015 ).…”

Movement-mediated community assembly and coexistence

“…To date, movement data of small vertebrates or insects are mostly obtained through mark-recapture (e.g., Perry et al, 2017) or by direct observation of marked moving individuals (Kay et al, 2016;Brown et al, 2017), which limits the scope and quantity of such data. Promising new approaches are automated radio-telemetry systems (Taylor et al, 2017), image-based tracking (Dell et al, 2014), and radar monitoring (Shamoun-Baranes et al, 2014), the latter two methods not requiring any animal-borne tags and thus being suitable for small invertebrates (Augusiak & Van den Brink, 2015). However, radar-and image-based methods still have to solve the problem of distinguishing species and individuals (Dell et al, 2014;Shamoun-Baranes et al, 2014).…”

Accuracy and reliability of a videogrammetry system in the analysis of displacement of Wistar rats

“…Classified as spontaneous physical activity, locomotor behavior is a key element in the daily lives of animals, required for survival and homeostasis 8 . In recent decades, the development of analytical methods to analyze displacement by videogrammetry has been used in studies with different objectives: to understand the effects of psychostimulants 9 , different environments 10 , food restriction 11 , different conditions of housing 12 , and drugs 13 .…”