This notebook entry details methods for larval rearing and settlement for Montipora capitata early life history in July 2020. Sampling of these life stages is described in additional notebook entries.

Activities

Larval Rearing

• Larvae were reared in conical conditions described in Mcapitata Spawning and Fertilization entry until 5 days post fertilization.
• Hourly cleaning throughout full 24 h of each day with no light exposure (ambient room lighting only).

Larval Settlement

• Larvae were settled with two methods: on aragonite plug surfaces and “free” floating (not attached to a substrate). The purpose of these methods was to allow for different sampling methods. Free floating recruits were required for sampling and for respirometry (described in additional entries). Juveniles attached to plugs are able to be used for molecular and physiological metrics.
• Larvae were pooled from all conicals at 5 days post fertilization. Larvae were then moved to outdoor, flow-through seawater tables and added to settlement chambers. Settlement chambers were constructed from plastic containers with mesh bottom set upon plastic crate mesh to allow for water flow into the settlement chamber. Chambers were covered with 1 layer of shade cloth (<100 PAR exposure, low light conditions). Approximately 50 aragonite plugs conditioned for 1 week in ambient seawater were added to the chamber such that the top surface of the plug was upside down and in contact with the mesh bottom. Temperature was approx. 27-29°C.
• After 48 h, larvae were settling. I separated a bin of “high density” and “low density” plugs from remaining swimming larvae so that they can be sampled each day and the time from settlement is known. Moved all larvae either into: empty small chamber to encourage water/free settlement or moved them into one large bin with alternate substrate (including waterproof paper squares, plain glass slides, white taped glass slides, and red taped glass slides).
• Settlement on all substrates was checked each day. Settlement substrates including paper, glass, and tape had low settlement. Aragonite plugs had high settlement.
• Plugs remained upside down throughout sampling and had the same light conditions (<100 PAR, low light).
• Each day, recruits were isolated so that time from settlement was known for free and plug recruits.