Abstract
Coral reefs are experiencing a catastrophic global decline. Caribbean reefs, in particular, are deteriorating due to various threats. To combat this, it is important to understand the early life stages of coral. However, the small size of the embryos and the difficulty of distinguishing between different species at this point in their life makes tracking these stages difficult. A recent study by Doropoulos and Roff (2023) found that using vital stains is a possible solution to (1) understanding early coral life stages, (2) locating preferential settlement locations, and (3) tracking different species. The purpose of this study was to assess if larvae of Caribbean corals could be stained and how long the stains were retained. I achieved this by 1) assessing larval survival, 2) examining how effective vital stains were in coloring the larvae of Caribbean corals, 3) assessing how long specific vital stains remained in coral tissue, 4) whether stains affected settlement rates of larvae, and 5) if stains affected post-settlement survivorship of newly settled corals. The experiment used coral larvae of the following Caribbean species: Colpophyllia natans, Pseudodiploria clivosa, P. strigosa, and Acropora cervicornis. Coral larvae were obtained from an ex-situ coral nursery.Larvae were stained with Nile blue and neutral red, evaluated individually, and separated by species. The larvae were placed in mason jars on an orbital shaker for twenty-four hours to prevent settlement. Coral larvae were then placed in a six-well plate with a tile conditioned in a III raceway encrusted with crustose coralline algae (CCA). I took images of the larvae and newly settled corals weekly to assess vital stain retention, settlement, and pre-and post-settlement survivorship. Vital stain color and retention were quantified following a revised protocol from Winters et al. (2009), by assessing images in GIMP via color balance and histogram procedures. This experiment found that the vital stains were effective in staining the coral tissue, that stains were retained for eight days, and that stains had no significant effects upon coral settlement or post-settlement survivorship. Further studies should include larger samples, more Caribbean coral species, and other vital stains to determine if the vital stains have any significant impact on additional species.