Questions about the Undulated Trigger.?

Question

The first thing I would like to know, is how can you tell the male from female? Here is a picture of mine.
http://img.photobucket.com/albums/v147/Fredrick_NP/fish2.jpg

Also it seems like when mine gets fightened, the spot near its tail fin turns dark. Is there any reason / signifance to that? Here is a pic of what I'm talking about.
http://img.photobucket.com/albums/v147/Fredrick_NP/fish1.jpg

And the last thing that I'm most concerned about is I want to know if these fish are playful. Mine likes to do spins, rest against rocks, and flop around on the sand. It seems almost like its ill, but it always snaps out of it after noticing me, so its hard to tell. Also another thing is does it it likes to float around where the water from the filter pours in. But after it has been doing it for a while, the area around it's gills temporarily turns dark.

Is that a sign that somthing's wrong?

Answer 1

From the photos I'd say yours is a female. Males shouldn't get the facial striping yours shows. The color spot is probably how yout trigger is letting you know if it's happy or stressed. Many fish change color somewhat to express their moods to other fish around them. These do have personalities, but can be quite aggressive - it's equally like the spot means "back off!".

The sitting around the filter overflow may indicate a low oxygen content in your tank. Do you use a protein skimmer (adds O2 as well as remove organic compounds) and is your filtration a cannister (lower oxygenation, especially if the return is well underwater and doesn't cause surface movement), or do you use a wet/dry, or hang-on (higher oxygenation)? The gill coloration will change with the amount of oxygen in the bloodstream.

The spinning and resting are normal enough, but does the flopping look like it's trying to scrape its sides on the rock or substrate? This could be the early warning of a parasite infection. Look to see if you notice any white dots, thick mucus, or reddened areas, and if it only appears to be doing this on one side. If the area it's trying to scrape is the gill area, it may be having a problem with a gill parasite, which is also causing it to have problems maintaining adequate oxygen - another reason it might be sitting bu the filter outflow.

Some additional info on undulateds - the second has photos of male and female (although it doesn't identify them as such) to compare facial markings:

http://www.wetwebmedia.com/triggers2.htm
http://www.wetwebmedia.com/marine/fishes/triggers/balistapus/index.htm

Answer 2

I can't tell you the sex of your trigger, although, the colors seem to be very vibrant, which indicates a male...but, colors on the web can be deceitful. Triggers are very territorial, if he/she is distressed, they will display their fears...either with flayed fins, change in color, or body form (such as "blowing up"). Resting against rocks is normal since they need to rest, flopping around on the sand may indicate a parasite problem, gill color change may indicate a water/parasite issue, as well. Take a sample of your water to your local aquatic store, tell them your issues...you may have a parasite/bacterial problem. Take care, be aware.