DOI: 10.5061/dryad.zpc866tfv
title: Behavioural ecology meets oncology: quantifying the recovery of animal behaviour to a transient exposure to a cancer risk factor

description: Wildlife is increasingly exposed to sublethal transient cancer risk
 factors, including mutagenic substances, which activate their anti-cancer
 defences, promote tumourigenesis, and may negatively impact populations.
 Little is known about how exposure to cancer risk factors impacts the
 behaviour of wildlife. Here, we investigated the effects of a sublethal,
 short-term exposure to a carcinogen at environmentally relevant
 concentrations on the activity patterns of wild Girardia tigrina planaria
 during a two-phase experiment, consisting of a 7-day exposure to cadmium
 period followed by a 7-day recovery period. To comprehensively explore the
 effects of the exposure on activity patterns, we employed the double
 hierarchical generalized linear model framework which explicitly models
 residual intraindividual variability in addition to the mean and variance
 of the population. We found that exposed planaria were less active
 compared to unexposed individuals and were able to recover to pre-exposure
 activity levels albeit with a reduced variance in activity at the start of
 the recovery phase. Planaria showing high activity levels were less
 predictable with larger daily activity variations and higher residual
 variance. Thus, the shift in behavioural variability induced by an
 exposure to a cancer risk factor can be quantified using advanced tools
 from the field of behavioural ecology. This is required to understand how
 tumourous processes affect the ecology of species.
description: Description of the experiment We used wild
 planaria (<em>Girardia tigrina</em>), a common freshwater
 invertebrate, as a study species to study how exposure to cancer risk
 factors may impact on animal behaviour, and individual behavioural
 variation at various hierarchical levels. For this purpose, we designed a
 14-day-long two-phase experiment using planaria collected in the Saint
 Augustine Lagoon in September 2022 (Highton, Victoria, Australia,
 38°11'30"S, 144°18'48"N). To
 investigate the effects of cadmium exposure on behaviour, 60 planaria per
 treatment group were transferred into ten 6-well plates, with one
 individual per well, filled with either 10 mL of 0.5 ppm
 Cd<sup>2+</sup> spring water water (Coles Natural Water
 Spring) solution (treatment group) or 10mL of spring water only (control
 group) and then placed in the dark in a 20°C incubator (Infors HT Ecotron)
 for seven days. On day eight of the experiment, the cadmium solution was
 replaced in both the control and the treatment group with 10 mL of clean
 spring water after gently rinsing each well with water after which the
 plate was replaced in the incubator for an additional seven days. In this
 experiment, we refer to the first seven days of the experiment as the
 exposure phase, and the subsequent seven days as the recovery
 phase. Once per day, each 6-well plate was removed from
 the incubator and placed on a filtered light pad (Born LED Light Pad,
 model BOLEDLPA4, 279 lumens, white light) housed within a dark box that
 blocked out external light sources. Planaria activity was filmed using a
 tripod-mounted Canon camera for 11 minutes before being replaced in the
 incubator. Individual planaria trajectories were reconstructed from video
 recordings by applying a background subtraction method provided by the
 OpenCV python library (that we optimised for planaria activity),
 calculating the average coordinates of the pixels identified as being part
 of an animal. The first minute of the trajectory was discarded to allow
 the algorithm to accurately detect and track individuals. The trajectories
 were then standardised by interpolating them to one location per second
 and the activity of each planaria was calculated as the total distance (in
 mm) travelled by an individual during a trial. The video footage was also
 used to measure planaria body length (mm). Since the
 video recordings were performed outside the incubator in the same room, we
 recorded the ambient air temperature (°C) to control for the potential
 confounding effects on the movement of the planaria.
 The whole experiment was repeated three times (i.e. three
 batches) with 40 animals (20 in the control group and 20 in the
 cadmium-exposed group) for a total of 120 individuals.
 In total, we obtained a total of 1,610 activity measurements,
 arising from 115 unique planaria. Over the course of the experiment, three
 planaria died in the control group and two in the treatment group and were
 excluded from the dataset.
description: # Quantifying the recovery of animal behaviour (planaria) to a transient
 exposure to a cancer risk factor (cadmium).
 To access comprehensive
 details about the protocol and the thorough rationale employed in
 gathering this dataset, kindly consult the publication referenced below:
 Klaassen H et al. 2024 Behavioural ecology meets oncology: quantifying the
 recovery of animal behaviour to a transient exposure to a cancer risk
 factor. Proc. R. Soc. B 20232666.
 ## Description of the data
 and file structure The "planaria_raw_dataset.csv" dataset is a
 .csv file of 8 columns and 1611 rows with variables as columns and
 measurements as rows. The first row of the dataset contains the name of
 each variables. The variables are defined as followed: **ID:** The
 individual ID code given to the planaria on which the activity measurement
 was collected (categorical variable) **Day:** The day of the experiment
 ranging between 1 and 14 during which the activity measurement was
 collected (interval variable). **Phase:** Categorical variable coded as
 "Exposure" or "Recovery" indicating if the activity
 measurement was collected during the Exposure or Recovery phase of the
 experiment. **Treatment:** Categorical variable coded as
 "Control" or "Treatment" indicating if the activity
 measurement was collected on a planaria allocated to the control or
 treatment (cadmium exposed) group. **Distance_mm:** The distance in
 millimetres (mm, i.e. the activity measured), travelled by a planaria
 during a behavioural trial (continuous variable). **Length_mm:** The
 length in millimetres (mm) of the planaria on which the activity
 measurement was collected (continuous variable). **Temperature**: The air
 temperature in degree Celsius (°C) of the laboratory at the time the
 behavioural trial was conducted (continuous variable). **Batch:** The
 batch number (coded as 1, 2 or 3) of the activity measurement (categorical
 variable).