Cozumel oddities

Hi all,

We spend two weeks at Scuba Club Cozumel (Feb 4-20) with several other wetpixelers and made some new friends during Bonnie Pelnar's UW photography workshop. After 31 dives and a lot of images there are as usual a couple I can't ID for sure and others that are clear but don't look like the images in the ID books or any individuals I have seen before. Here are a few of the latter category. I'd like to hear how normal or odd they are, and if applicable if these patterns are associated with behavior, geographic region, or something else.

Thanks Bart

My wife found this sergeant major on the shore dive site of SCC. We only saw one and it seems to a genetic aberration to me

This one was at Villa Blanca. I think it is an ocean surgeonfish that dressed up for carnival a bit too soon

This yellowfin grouper is trying to fool fish ID newbies with its bright yellow mouth

With the gold price as high as it is, this goldentail moray at SCC has opted for a cheaper coating

Most dusky damselfish on the SCC shore site where this light almost silvery color, rather than the black/dark brown I am used to (see image below)

More typical dusky damselfish

More later ...

Hi Bart. It's Ellen!! Nice to meet you and your wife in Coz. I love your descriptions. hee hee. You sure are the king at identifying critters.

I just checked the Reef Fish Behavior book and the top of page 183 shows a similar pale "dusky damselfish" except that they ID it as a threespot damselfish. So now I'm confused, can it be a threespot without the dark spots at the pectoral and caudal fin base?

Bart

With the exception of the eel, all the fish you've shown change colors at will - from silver to dark and back again. Sgt Major's are pale with stripes while feeding, but dark black when angry - defending their nests. The first one is interesting, it looks like it got stuck halfway! The eel is a color variation - I'm glad to see that he/she's still in front of SCC.

Hi Jim,

Fish are certainly very variable in their coloration which ensures there are always surprises on every dive. I just read your "3-weeks in Cozumel" web page and wished I had known about it prior to my trip. Beautiful images and great finds. There is now a batfish (shortnose) on the SCC shore site (just south of their lot). Not sure if it is a permanent resident as well.

Oh, man! We looked all over for that little guy and never found him. I hope he's still there when we return in August.

The surgeonfish is not an ocean surgeon, it is a doctorfish (Acanthurus chirurgus) and the odd color is probably a bacterial skin infection.

Thanks Rocha, very interesting to know. Any tips on how to tell doctorfish and ocean surgeonfish apart if you can't simply use vertical banding on the former.

Bart