Down-Flowing Tank
In April 2008 we attempted to rear Pocillopora meandrinalarvae in the spiral-flowing tanks, but because of
the negatively buoyant nature of the larvae, this method
resulted in 100% mortality. Therefore, we developed a
down-flowing tank for rearing P. meandrinalarvae in May
2008 (see Figure 4). The tank was constructed of a 1.65 L
glass bowl with a plastic lid. The center of the lid was removed and replaced with 40 m mesh, leaving a 2 cm ring
around the outside in which a hole was made to insert a 2
mm plastic rigid air line attached with air-line tubing to a
manifold for controlling water flow. To maintain the water quality close to that which the larvae would experience
in the open water, the down-flowing tanks were attached
to a filtered (1 m) flow-through system with seawater
pumped from the reef. Flow to the tanks was maintained
at 120 mL/min.
The larvae were fertilized in 50 mL tubes, rinsed with
sterile filtered seawater, and placed into two bowls at
28°C to develop overnight at a density of approximately
80,000/L. After 24 h postfertilization, larvae were counted
and then cleaned using a 40 m mesh and 0.5 m-filtered