[Rin]

I'm pretty sure it's a tang, I just don't know which one. Can anyone help? This one is 2.5 in long.

[scubadude]

looks like a Kole Tang to me

[Rin]

Thanks for the response Scuba.

Are there different types of Kole Tangs? The only one I can compare it to is the Yellow eye. This doesn't have the yellow eye, the face isn't spotted like the Kole Tangs that I've seen.

[Teleost]

Rin / Scubadude

It is a juvenile "Acanthurus nigroris" or Grey-head Tang / Surgeonfish. Easily identified by the overall dusky coloration & blue lines. Common in the pacific, i.e. Hawaiian islands and grows to about 9.5 inches in the wild - so an 8 inch adult in most tanks.

There are different "Color Morphs" of Kole / Yellow Eye tangs.

Another picture of the tang, especially the tail / caudal fin can also help in solidifying the identification.

[scubadude]

You cant judge by the spots or lines....those can change with age of the fish. Im gonna give you some links Rin which would help you better. Heres 2 pages of pictures of different kinds of Kole Tangs
Kole tangs page 1
Kole tangs page 2
and here is a page of the Greyhead tangs Teleost mentioned
Greyhead tangs page

[Ninong]

Rin,

I don't think it is a juvenile Kole Tang (Ctenochaetus strigosus) and it is certainly not a juvenile Chevron Tang (C. hawaiiensis). I am not really sure about the identification because the juveniles, especially in the genus Ctenochaetus, are often a quite different coloration than the adults.

I couldn't seem to find any good juvenile pictures of Acanthurus nigroris to compare to your picture. The pictures of adult specimens that I found online all showed a distinctive white band at the base of the caudal fin which may not be present in the juveniles. We will have to ask Teleost if this is true or not. Perhaps Teleost could link us to some pictures of A. nigroris that resemble your picture. (P.S. -- Fishbase has pics of A. nigroris that do not show a white band at the base of the caudal fin.)

Your picture does resemble some pictures of Ctenochaetus striatus (Striped Bristletooth) that are available on Fishbase and WetWebMedia.

One point I would like to make about using any of the popular online image search engines to find fish pictures is that they seem to combine different fish of the same genus. You do not have that problem with websites like Fishbase, but you do have it with Google Images for instance. A good example of this is the fact that of the 20 pictures that Scubadude posted for the Kole Tang, only the first 6 pictures are actually of Ctenochaetus strigosus, which is the only one that has the common name of Kole Tang or Yellow Eyed Tang. One picture was of C. binotatus (Blue Eyed or Two-Spot Bristletooth), four pictures were of C. hawaiiensis (Chevron Tang) and nine pictures were of C. striatus (Striped Bristletooth).

[Ninong]

Ctenochaetus striatus www.wetwebmedia.com




Acanthurus nigroris

Here is a link to some pics on Fishbase for A. nigroris that do not show a white band at the base of the caudal fin: http://www.fishbase.org/Photos/Thumb...ry.cfm?ID=4738

[Teleost]

Ninong

You are definitely correct in your assumption that it is not C. Hawaiiensis, or even any of the "Bristle tooth / Combmouth" tangs / surgeons of the "Ctenochaetus" genus. This can easily be seen in the mouth structure of "Rin's" picture.

It shares a few characteristics with C. striatus, which generally doesn't have colored pectoral fins & shows orange dots on the head region (this was my second guess). The picture does show the white / whitish band just following the caudal peduncle. Remember this is a picture of a frightened tang - not showing true coloration.

Only 1 to 2 species of Ctenochaetus have a different color morph as a juvenile, i.e. C. hawaiiensis

Again without a photo of the tang in "normal coloration" & showing the caudal fin, its hard to be definite / complete identification, but that is my experienced guess.

Scubadude

You can use the juvenile coloration for identification. Granted certain species are more difficult then others, but an experience eye can easily differentiate btw most species. The main problem with Identification of these "Acanthurus" types is both the juveniles & even more the sub-adults coloration changes dependent upon location, evironmental stimuli, etc., i.e. A. blochii, xanthopterus, etc.

[Teleost]

Ninong

I didn't notice your link to Fishbase below the posted pictures of adult tangs.

As you can see they have a "Clown" / "Blue-line", A. lineatus listed under the A. nigroris heading. Granted the European / Japanese hobbyests consider A. nigroris as the "Blue-Line" tang.

[Ninong]

Teleost,

Fishbase shows three pictures by Dr. Randall that are almost certainly A. nigroris, based on his expertise in fish identification. I have no idea why they chose to tack on that picture of a 50-cent Australian stamp unless it is, as you suspect, confusion with the common names.

I have taken another look at Rin's picture and I now notice the points you mentioned about the shape of the mouth and the possible coloration on the caudal peduncle.

[Teleost]

Not questioning Dr. Randall at all! Just mentioning / showing that certain available pictures don't match w/ described species. All were nice photos of grey-heads.

[Elmo18]

Ok here's my verdict:

It's an ADULT Chevron Tang. In the juvenile stages the Chevron Tang is one of the most colorful and striking fish, but later on it darkens to a gray, almost black coloration with blue strikings going horizontal.

- Elmo

[Ninong]

Elmo,

Did you miss this in Rin's description: "This one is 2.5 in long."

[Teleost]

Elmo

An adult Chevorn Tang [Ctenochaetus hawaiiensis] is quite a bueatiful fish! They are a blue-greenish to black overall background color & horizontal white to bluish lines.

They also have a very distinctive mouth structure - almost protruding / etended snout near its terminantion [upper / lower lips / mandibles].

There really isn't any way to confuse an adult or juvenile C. hawaiiensis / Chevron Tang with others.

Hope this helps...................

[Rin]

Thanks for all the wonderful responses. I'm glad I've been able to spark a good discussion with this fish.

Note the two dark spots near the tail of the fish in my pic. These match perfectly with Fishbase's pic of the Acanthurus nigroris. My fish also has the blue edge shown in fishbase's picture. He looks nothing like the Chevrons or the Koles--the stripes and coloration just aren't right, juveniles not withstanding.

I'm glad to be able to pin down the exact species. He's a replacement for the purple tang which got too big (5") and aggressive for the 75--he's been moved to a much larger tank. Hopefully my 180 will be ready before this one gets too big. It was sold to me as a Assort. Hawaiian Tang--which only told me that the collector didn't know what it was, either. I had only asked for one that isn't as territorial as a PT. So far, he/she is proving to be every bit as aggressive as the purple. No other fish can get near it without being thrashed—including a 6 inch Maroon Clown. Hopefully, it won't grow too fast.

Teleost, is this really your first post since joining Reefland last March? You seem really knowledgeable for a simple lurker.

Ninong, as usual your attention to detail is nothing short of phenomenal.

Elmo, Scuba, it's been a while. How are y'all doing?

[Elmo18]

Ninong, I didn't see that length info

Todd I'm glad you finally found the name of your nice specimen. I'm doing well, busy with university school stuff, etc etc, graduating next year with Bachelors in ME and minor in Math.

BUt then again....it never stops...

- Elmo :-P