Dataset: The effect of relatedness and density on survival and growth of Bugula neritina in the Gulf of Mexico, Florida from October to December 2021.

Experiment 1: the effect of relatedness and density on survival and growth.

The first experiment ran from October to December 2021. There were 10 density treatments (ranging from 2 to 20 individuals per dish in increments of 2) crossed with two relatedness treatments (related or unrelated). Overall, there were 25 maternal families. In the “related” treatment, 10 of these maternal families were used, where each of the 10 density treatments comprised offspring from a different maternal family (i.e., density = 2 is two offspring from family A, density = 4 is four offspring from family B, and so to where density = 20 is 20 offspring from family J). In the “unrelated” treatment, each of the 10 density treatments comprised one offspring randomly chosen from one of the 25 maternal families, such that the 10 maternal families in the related treatment were also used in the unrelated treatments, plus an additional 15 maternal families to achieve the desired density. Within each dish, individual colonies were randomly assigned to a position in a 3 × 4 cm grid on a Petri dish lid. The distance between grid points was 1 cm. Petri dishes were randomly assigned to PVC poles, spaced 1 m apart and arranged in a 4 × 5 grid. After 7 days in the field, individuals were collected and transported back to the lab, where survival (present or absent) and size (number of zooids) were measured under a dissecting scope. Individuals were returned to the field the following day. Individuals were left in the field for another 7 days, at which point they were collected, transported back to the lab, and measured for survival and size.