ID: Goby or Blenny??

[drdiver1952]

Just found the thread. Archman is right, the first fish pictured is a Diamond Blenny. I've never heard of or seen yellow headed secretary blennies.

The REEF advanced workshops are great as are all the REEF staff and REEF itself. All divers should join--it's free!

Dennis
REEF Sustaining Member

What I've been keenly awaiting from you and Dee is information about the head colours on these "secretary blennies" you're seeing in Utila. I don't *think* you're using the humann guide to make that sort of I.D.. I'd like to know what reference you are using. It would be quite neat if a "Utila-variant" of the secretary blenny existed... one with a yellow coloured head of course.

The best resource would be the web nowadays. Punch up GOOGLE searches for your taxon and see what comes up.
Bookwise, Snyderman & Wiseman have a very easy to read book on Caribbean fauna... Guide to Marine Life Caribbean Bahamas Florida is the name of the tome. Plenty of wonderful photos, with photography tips. Not expensive, either.

For general information on fish taxonomy, anatomy, and physiology, you still can't beat a generic ichthyology text.

And I've heard great things about the more advanced REEF I.D. workshops. REEF is based out of Key Largo, and some of their folks are the best Caribbean fishwatchers in the business. They blow the pants off me six ways to Tuesday.

 

[KrustyTheClownFish]

Good discussion, thanks!!

 

[diver567]

Okay, it is my understanding of blennies that seretary blennies usually live in tubes formed by worms. This photo is of a tube blenny.

Diamond blennies have a very distinct black spot on there dorsal fin - the photo shows no such thing. Also Diamond blennies which I often see here on Utila also do not in my experience usually live in tubes or worm holes.

I have also been consulting photos from the Marine life of the Bay Islands of Honduras CD-ROM, available from Joyce and Frank Burek. Their photos seem to back up my theory.

 

[archman]

Okay, it is my understanding of blennies that seretary blennies usually live in tubes formed by worms. This photo is of a tube blenny

Ok, this is something that certain texts can often mislead people on. I had to look up "tube blenny", as it's not an established grouping at all. By natural habit, the majority of gobies, blennies, and their related ilk will occupy "tubes" if they're so inclined. Hidey-hole preference in many species isn't even taxa specific, but up to the "personality" of the individual animal. With the exception of cleaner-species, all blennies like to hide most of the time. Heck, I've even seen SKILLETFISH sitting in barnacle holes. I have a baby PIGFISH in my lab that hides out in a hole dug out by a snapping shrimp.

To simplify, some blenny species prefer snug holes a LOT (emblemaria taxa), and most others will use them if the mood and habitat suits. So will a great deal of non-blenny cryptic taxa. I'd stay away from hole preference as a diagnostic indicator.

Diamond blennies have a very distinct black spot on there dorsal fin - the photo shows no such thing. Also Diamond blennies which I often see here on Utila also do not in my experience usually live in tubes or worm holes.

From the photo Krusty posted, the dorsal is not angled well to discern any detail. I could even interpret the lack of one altogether from this photo. As for not seeing diamond blennies in tubes, that's perfectly valid. Most divers never notice blennies, period... and the ones jammed in holes are particularly elusive. Therefore the lack of noticing something in coral reef communities does not imply its absence. The bright coloring of the diamond blenny makes it stand out more so than most other blennies, and this can lead to it being reported with far more frequency.

I have also been consulting photos from the Marine life of the Bay Islands of Honduras CD-ROM, available from Joyce and Frank Burek. Their photos seem to back up my theory.

Hmm... I don't have this reference available. What does this CD-ROM state about the head coloring of secretary blennies, and the shape of the head? Also, what does it state regarding diamond blennies?

What this thread all boils down to is, what Caribbean blenny species have bright yellow heads? Does Utila harbor a species/subspecies unique to its area?