Can you identify this fish?

[Kit]

Hi fishermen and fisherwomen,
I have a very unusual request. I am in the midst of trying to solve a treasure hunt, and I think that it will help me to identify the fish in this picture. It's blue and purple, with a homoceral tail, and only pectoral or pelvic fins. Does anyone know what the illustrator was going for? Thank you in advance.

[SKULL & BONES]

Double Post... drat.

[SKULL & BONES]

From The Crypt:

Manatee???? Just a quick guess

[Kit]

I think it's a bit smaller...

[joeksr]

Key west rainbow fish.

[nautiduck]

Key west rainbow fish.

The homo-ceral tail gave it away.

[Big Fish Billy]

The homo-ceral tail gave it away.

I hear some black blobs are showing up on Key West beaches....BP is calling them oil fish....I think.....

[gottaflylee]

Do you have a bigger picture?

[Captain Michael Buffington]

thats my guess and I'm sticking to it!

Mike

[Capt. Terry]

NEETER