johnsear 的鑑定

Perhaps the Catshark (posted earlier but present in this image, as is the tail of a senator wrasse not yet posted) was out in the open in the middle of the day in this relatively exposed position because it sought cleaning by unseen hosts? This somewhat elevated 'nook' would make a suitable station, because it overlooked a fairly wide section of slightly lower terrain (eg I easily noticed it when swimming past because I followed the path most demersal reef fish would take, thus avoiding the bother of altered buoyancy for divers swimming over the top of that accumulation of jetty junk just to keep going straight ahead, while reef fish would reduce predation risk by following the same lower contour). So when these wrasses showed particular and persistent interest in the locus, they were probably prospective clients of a cleaning host or hosts.Whether the Catshark was also in client mode or its presence was merely coincidence (eg inquisitive about passing divers: Gulf Catsharks are usually nocturnally active and harder to find diurnally) I don't know.

Plenty seen on this dive. (And FWIW I saw quite a few Bluetail Leatherjackets as adults and older juveniles but they were all very wary and I don't think I got any worthy photos. Conversely I saw only a few Gunn's Leatherjackets (adults),and managed one useful shot but they were also wary. I saw no large potential predators eg kingfish, and the only Harlequin Fish I saw was a juvenile. But even the old wife, moonlighters and zebrafish (etc) were warier than usual for the location on outgoing tide in quite good visibility, so something must have spooked the main reef fish genera on the day (I don't mean to suggest large sharks, and cormorants were scarce while I was there, but I have niggling concerns about shark fishing from the jetty overnight. Relevant or not? Who can say? This is leading nowhere...hmm.