Dataset: Phillips_et_al_2014 - Experiment 3 minutes

Ceraesignum maximum larvae were obtained from field- collected adults. Individual adult C. maximum were chiseled from the coral matrix intact in their tubes, transported to the laboratory in coolers of seawater, and their brooding status ascertained by gently poking each snail until it retracted deep into its shell. If late-stage capsules were observed attached to the inside of the shell, a mesh-sided cage (mesh = 150 µm) was secured around the tube with cable-ties, and the adult (with mesh enclosing the openings to their tubes) was then placed in a large tank with flowing seawater. Swimming larvae were released by females after 1–3 days.

Fragments (approximately 2x3 cm) of live coral were collected from the lagoon on the morning of each experiment and left for 2 h in flowing ambient seawater to recover. Fragments were examined under a microscope prior to each experiment to ensure that polyps were extended.

For this experiment:

Fragments of each coral species were placed into tubs with 500 ml filtered seawater (n = 4 replicate tubs for each treatment). 20-25 3-day posthatch larvae from a single female (number 4) were added to each tub. Larvae were pipetted out very slowly and released a few cm above the coral, ensuring the velum was extended and that larvae would exit the pipette swimming in a trajectory that would bring them slowly into contact with the coral polyps. A dissecting microscope was used to observe as many larvae as possible as they came into contact with coral polyps. After approximately 5 min, as many larvae as could be found were collected from each dish with a pipette and scored as live or dead. Live larvae were placed in a petri dish with filtered seawater for 2 h and then examined for recovery. Larvae were observed for several min before a determination was made about their recovery status. Larvae were considered ‘recovered’ if they were swimming, or if the velum was extended or was in the process of being extended, and the velar cilia were visibly beating. Larvae judged to be dead did not recovered after 2 h.