During the nights of September 8th, 9th, 10th and October 8th, 9th, 10th 2001 the annual ''Coral Spawning'' will take place in Curacao. ''Coral Spawning'' is a natural phenomenon where multiple coral species together with other invertebrates release their gametes into the water column at the same moment because of simultaneous triggering from certain environmental conditions including high water-temperatures and the lunar phase. Below you'll find an overview of what to expect during the spawning nights: 1. The Stony Corals (Scleractinia) 1.1 Acropora palmata (Elkhorn coral)This species (found in shallow water @ 15 feet) spawns on the 4th and the 5th night after the full moon, probably only during the first spawning in September. Spawning usually takes place between 9:15 and 9:45pm when little pink coloured balls consisting of both sperm and eggs held together by mucus detach from the corals. 1.2 Acropora cervicornis (Staghorn coral)This species is also found in the shallows like elkhorn and it's spawning occurs between 9 and 10pm on the 5th and 6th night after the full moon in September. This species also produces sperm/egg packages which come out of the coral's tissue and float to the surface where they fall apart because of the water movement. When the sperm and eggs are released from the packages they meet with either sperm or eggs from other colonies and fertilization takes place. The fertilized eggs then transform into free-swimming larvae, called ''planulae''. 1.3 Diploria strigosa (Symmetrical brain coral )This brain coral spawns during the first spawning as well releasing sperm and egg packages a little earlier in the night than the staghorn and elkhorn, generally around 8:45pm on day 7 after the full moon. 1.4 Montastrea cavernosa (Great star coral)This species, easily recognised by its large polyps, spawns during both spawning rounds in September and October on the 5th and 6th day after the full moon generally between 9:30 and 10:30pm. Since Great Star Coral colonies are either male or female the release be either sperm or eggs. The release of sperm looks like a cloud which is expelled by the coral. This may last up to 15 minutes. The eggs released by the female colonies look like the sperm/ egg packages of the previous species, but a little bit smaller. 1.5 Montastrea annularis complex (Boulder star coral) This is the most abundant coral in the reefs around Curaçao and because of its large colony size it will be one of the most spectacular species that can be seen during the spawning on day 6 and 7 after the full moon between 9:30 and 10:30pm (and sometimes later) during both spawning rounds in September and October. Just before the spawning takes place one will see the sperm/egg packages occur under the mouth-opening in the coral's tissue (''setting stage''), after which they're expelled (''birth stage'). The packages will stay near the colony for a while (''gliding stage'') and will gradually start floating towards the surface (''upward stage''), where they fall apart (''bursting stage''). If one colony starts spawning, this often triggers other colonies to do the same and soon after the entire water column will be full of sperm and egg packages. Normally the spawning of this species starts with the colonies growing in deeper water (60 feet) after which the colonies on the reef flat will follow. 1.6 Eusmilia fastigiata (Smooth flower coral)This species can be distinguished from all previous species because of its reproductive mode. The colonies of this species release full grown larvae instead of sperm, eggs or a combination of both. This means that fertilization took place earlier by the intake of sperm from other colonies. After the fertilization larvae develop themselves within the mother colony and gather in the tentacles. Most of the larval release can be seen from day 6 till day 9 after the full moon between 9:15 and 10:30pm, but before that the larvae can be seen as little white balls (1/32'') in the transparent tentacles of the mother colony. 1.7 Madracis senaria (6-Ray star coral)This relatively small encrusting species releases larvae like the previous species that swim immediately using small hairs on their body surface. Release takes place during day 8 and 9 after the full moon of both spawning rounds in September and October yet the time of the release is presently unknown. 1.8 Agaricia humilis en Agaricia agaricites (Lettuce corals)These two species are from the same family and both spawn several months a year including the month of October, which means they may be seen spawning during the mass spawning. Both species produce larvae that are released during the entire night although they are small (1/64'' and 1/16'' respectively) and therefore difficult to spot. 1.9 Stephanoecoenia michelini (Blushing Star Coral)Like Great Star Coral this species occurs either as male or female colonies. However, sometimes both sexes are found within one colony. This means that a cloud of sperm can come from the same colony releasing eggs a little bit later or earlier. The time difference between the release of male and female gametes prevents self-fertilization, which would result in inbreeding. Spawning is expected between 9 and 10pm and the species can be found along the entire reef-slope. 2. Echinodermata (Echinoderms)Several species of echinoderms will release their gametes together with the spawning coral. This process is often seen as a little cloud of very small balls (eggs or larvae) that are released into the water. Some species start spawning already during the day. Long Spined Urchin and Donkey Dung Sea Cucumbers spawn around noon and dusk respectively. Brittlestars spawn in the early evening between 7:30 and 8:30 when they leave the recesses where they hide during the day, gather on top of the reef (sometimes 10 to 15 individuals on top of each other), and release their gametes into the water, 3. Gorgonacea (Gorgonians)Although little is known about the spawning behaviour of this species, spawning occurs in the early evening around about 7:00pm when large clouds of small larvae are released resulting in a murky appearance of the water surrounding the colonies. 4. Annelida (Segmented worms) Contact Ocean Encounters at [email protected]