squirrelfish swims around the block or stands in the crevice. The smaller 

 triggerfish (B.l) arrives from the NW direction (algal- flats) and takes up 

 a dark livery; it tries to enter the crevice but is chased by the squirrel- 

 fish. 



17:35 The Lima are opened out, the Stenopus come out from their shelters. 

 The tilefish disappears, 



17:40 The damselfishes and Thalassoma activity begins to decrease, they 

 swim low before their night shelters. Some quarrels happen between these 

 two species in search of the best sleeping places. Blennies have disappear- 

 ed but gobies are still present. 



17:45 A very slight turgescence begins to appear on the corals, mainly on 

 Eusmilia . The Thalassoma and Pomacentrus swim more and more peacefully. The 

 jawfish is not often seen now and it does not come entirely out of its 

 burrow. The large sea-fan (Eunicea) begins to retract. This fact was 

 regularly noticed at dusk whereas at night it was found open; we noted that 

 during these night dives there was always a rather strong current perpendi- 

 cular to the sea-fan. 



17:50 Damselfishes are still swimming weakly very near the surface of 

 the block; Thalassoma have disappeared by now; the triggerfish B.l 

 enters the crevice and invites the moray to go out, this one leaves the 

 place and gets to the N tunnel. The squirrelfish starts to forage on 

 the neighboring sand. Nodulous tentacled sea-anemones are still visible 

 but the one with dichotomic tentacles has disappeared in a nook. 



17:55 to 18:00 Observations without artificial light become difficult. 

 The second triggerfish (B.2) arrives from NW. The first one comes quickly 

 to the east entrance of the crevice while B.2 comes to the W entrance. 

 Staccatos and very fast tail rustlings are emitted by B.l. They keep on 

 leaving the crevice and returning to it and when they are inside, B.l 

 always takes on an intimidating behavior. B.l has always been seen at the 

 E entrance and B.2 at the W one. The squirrelfish is more and more active, 

 it gets away and returns; some other Holocentrus pass near, the food quest 

 has started for this species. The corals begin to open out. 



19:00 Corals are now very turgescent. Sea-anemones sp. 1 and sp.2 are 

 retracted, the specimens of sp.4 are opened. The shrimps Periclimenes 

 have left the actinia sp.l and are found on the block. The triggerfishes 

 are sleeping; the moray is still in its second shelter, but its reactions 

 are much livelier than during day-time. The squirrelfish is still here. 

 It is pitch dark by now. 



DAWN: 6:00 There is very little light, much as at 18:00. The two trigger- 

 fishes stand outside the block, near their night shelters. The moray has 

 gone back to the main crevice. The squirrelfish swims actively around the 

 islet. The damselfishes wake up but don't go far from their night shelters. 

 The Thalassoma are still invisible, as are the blennies, the jawfish and 

 the tilefish. Some gobies stand near their hollows. The corals are still 

 a little opened, especially the Eusmilia . Stenopus are visible only by 

 their antennae, the Terebellids have retracted their tentacles. 



VI-288 



