Data from: Full compensation of parental care after partner loss in an annelid
Data files
Oct 13, 2025 version files 384.52 KB
-
individual_clutch_attendance.csv
380.80 KB
-
README.md
3.72 KB
Oct 13, 2025 version files 385.06 KB
-
individual_clutch_attendance.csv
380.80 KB
-
README.md
4.26 KB
Abstract
In species with biparental care, each parent would benefit by exploiting its partner and reduce its investment over offspring care. The conflict is especially apparent when one parent deserts or reduces its investment, forcing the remaining parent to either abandon the brood or compensate for the loss of partner-care effort; however, compensation is expected to be partial for the evolutionary stability of biparental care. We investigated the level of parental care compensation in the simultaneously hermaphroditic annelid worm, Ophryotrocha diadema, where both parents care for egg clutches. We removed one parent and found that widowed parents fully compensated for the loss of their partner; the number of scan observations widows spent in clutch attendance was statistically equivalent to that of paired parents. Consistently, individually, widowed parents attended their clutch significantly more often than focal worms among paired parents. We discuss how full compensation can be compatible with evolutionary stability of biparental care in a rare species with sparse population and whose adaptations suggest that mate encounter might be rare. In this condition, nest attendance might be valuable as it promotes clutch protection from predators as well as mate encounters thus mitigating the conflict of interests over parental care.
Marie Kauffmann, Lula Insel, Maria-Cristina Lorenzi*
Laboratoire d'Ethologie Expérimentale et Comparée (LEEC), Université Sorbonne Paris Nord, Villetaneuse, France
*Corresponding author: mariacristinalorenzi@gmail.com
Dataset DOI: 10.5061/dryad.bg79cnppm
Description of the data and file structure
Files and variables
File: individual_clutch_attendance.csv
Description: The file contains the data collected during the lab experiment on compensation for partner loss in parental care in the annelid Ophryotrocha diadema, a marine worm with biparental care. As the number of behavioral observation scans varied among paired and widow worms, the data sheet contains empty cells (indicated with "NA").
Variables
-
ID: code of identification of the 213 pairs
-
developmental.environment: factor with two levels (Competitive environment/Non competitive environment).
This variable describes the two developmental regimes the experimental worms experienced before entering the experiment: 1) lab mass cultures (200-300 worms in 200 mL water), where worms experience high mating opportunities and high reproductive competition, thereafter: competitive developmental regime; or 2) separate bowls containing siblings, i.e., the offspring of 30 pairs of worms isolated from the lab mass cultures and kept in separate bowls (10-40 offspring in 60 mL water; n = 280 individuals) until they were newly sexually mature, thereafter: non-competitive developmental regime.
-
condition: factor with two levels (paired/widow). In the condition “widow”, we removed one of the two worms from the bowl; either the mother or the father, resulting in n = 54 bowls where the clutch was only cared for by the father, and n = 53 bowls where the clutch was cared for by the mother. In the condition “paired”, the pair was kept intact, and either the mother (n = 51) or the father (n = 55) was considered as the focal worm in the subsequent behavioral observations.
-
parental_role: factor with two levels (mother/father), which describes whether the simultaneously hermaphroditic worm was the mother or the father of the offspring which it cared for.
-
focal_size: body size of the focal worm at the start of the experiment (number of body segments).
-
partner_size: body size of the partner of the focal worm at the start of the experiment (number of body segments).
-
clutch_size: number of eggs in the clutch. The eggs are sealed into a jelly envelop.
-
time: day of the behavioral observation (the eggs were laid on day 0, behavioral observation performed on day 1 or 2). This variable was entered as a factor in the statistical analysis.
-
n_obs: number of observation scans.
-
focal_care: factor with two levels 1/0: the focal worm performed/did not perform parental care at the observation scan.
-
partner_care: factor with two levels 1/0: the partner of the focal worm performed/did not perform parental care at the observation scan.
-
total_care: total number of times the clutch was attended by any parent.
-
removal_2nd _clutch: factor with two levels 1/0: whether a second clutch was present/absent. In case it was present, we removed it before behavioral observations.
Dates and Location of data collection (incl. time zone)
April-May 2024, Laboratoire d'Ethologie Expérimentale et Comparée (LEEC), Université Sorbonne Paris Nord, Villetaneuse, France (UTC+01:00).
Code/software
SOFTWARE VERSIONS
Statistical analyses were done in R version 4.4.1 (R Core Team 2024).
We ran the GLMM using the package lme4 (Bates et al. 2015). The equivalence test was performed using the packages onewaytests and TOSTER (Caldwell, 2022).
REFERENCES
Bates, D., Mächler, M., Bolker, B., & Walker, S. (2015). Fitting Linear Mixed-Effects Models Using lme4. Journal of Statistical Software, 67, 1–48.
Caldwell A.C. (2022). Exploring Equivalence Testing with the Updated TOSTER R Package. PsyArXiv, https://doi.org/10.31234/osf.io/ty8de.