This dataset contains four tabs with the information used to analyse the role of developmental plasticity in adult male size in a spider. The first tab contains the overall developmental data per individual. The second tab contains the data for the animal model, the third tab the pedigree, and the fourth tab contains the summary of mortality data per family. 

The spiders for this study were taken from a laboratory population that was established in 2015. The seed population (females = 40, males = 22) was collected in South Africa in January of 2015. For this study, a total of 16 females were mated with 16 different males in a full-sib breeding design. When the spiderlings were around 14 – 16 days old, they were separated individually in upside down plastic cups (200 ml). In a split-brood design, they were assigned to two different feeding regimes: low feeding regime (2 fruit flies a week) (n = 21 per egg-sac) and ad libitum (more fruit flies than they can eat) (n = 21 per egg-sac). Subadult males were further exposed to two sex-biased environments, either to environment with female silk cues (presence of females) (n = 123) or to environment with male silk cues (presence of males) (n = 134), while maintaining the feeding regime and split-brood design. We checked spiderlings five times a week and recorded the duration of the subadult stage and the size (i.e. carapace width) and mass of the males at maturation.

Body size was obtained by measuring carapace width. For measuring carapace width at both the sub-adult and the adult stages, we photographed each spider using a Canon Eos 7D camera equipped with a Canon 50 mm macro lens. For all photography of spiders, we used a standardized fixed focal length and calculated carapace width by converting the pixel distance. Growth at the sub-adult stage was obtained by subtracting the size at the sub-adult stage from the size at maturation. Mass of adult individuals was measured a day or two after moulting using an electronic laboratory scale (KERN GI, 220-3NM; min = 0.02, d = 0.001 mg). Body condition was calculated as standardized residuals from regression with carapace width and body mass as independent and dependent variable, respectively. Developmental time was estimated by counting the days from the hatching date until the day of the last moult to maturation. The duration of the sub-adult stage was obtained by subtracting the dates between ultimate and penultimate moults.

The file contains the raw data and there are missing values. Complete cases of the variables are needed to analyse the data.