[darthodo]

It is difficult for me to eyeball any of my fish for a good measurement. I read about fish sizes and all a good bit on the forums and some are hard to believe, some not. I thought my male istlanum was 5 inches until I moved him recently. I broke out the tape and he was 6.5 inches! So I tend to underestimate. I don't take fish out of the tank just to measure them but if I'm taking one out anyway I'll put a tape up to him in a minute! I've heard of rulers up against tanks and such and I have even put gradations on the side of my tank with a marker to see how big the fish is when he lines up with it. Can't really see the gradations that well unless you know what you are looking for and they can be placed anywhere on the tank. Wipe off pretty easily too. Anyone else have any methods they use to measure fish?

 

[bernie comeau]

Yeah, to know exactly how long a fish is, you really need to put a tape measure right up to the fish, out of the water. And of course sometimes you have to wait untill the fish settles down, but usually doesn't take too long. Sometimes its a little deceiving: smaller fish are little longer then you think and larger fish are sometimes a little shorter then you expect. I have a Tilapia zilli, for example, that has grown considerably in the last year, putting on some serious weight, but he has not grown length wise one iota in 15 months! Much to my suprise he measured exactly the same, 13 3/4", even though he is a larger fish now, and I really expected he would measure a little over 14", maybe even 15".

If you want to take a picture to document, I think a ruler underneath the fish would work better in most cases, unless your photography skills are good. All my pictures I took make it look like I can't read a tape, and look like I'm exaggerating 1/8" to 3/4" on just about every fish:lol: http://cichlid-forum.com/phpBB/viewtopic.php?t=168278&highlight=
Also, the belly on my auratus is SEVERELY exagerrated by the photo :lol: I think the belly got turned upwards because of the body shape of the auratus and because it is slightly closer to the camera it got exaggerrated. A similar thing, I think, happenned at times to the tape, either because it was a little closer, up in the air, or because of the angle of the picture taken. Just a thought. At least I will have learned and should be able to make better pictures next time, either with a ruler underneath or the tape directly on and over the fish for a picture.

 

[dwarfpike]

Yes, a tape measure is the really only exact way ... but as a guess I've found a dollar bill works well. It's exactly 6 inches long. So it makes a good comparision for up to 8" fish or so ... it's a lot easier to visualize two inches versus eight for example. Used to use dollar bills in the pet store when worked there when customers asked how big a certain fish was.

 

[Frameshift]

I always plan on measuring when I pull fish out, but it's too stressful on me and the fish so I just get them in the tank asap. I guess it would be easier with a partner to take the photos while I held the fish, but people look at me weird when I ask them to take photos of my pet fish.

I usually just use my clay pots for reference. They all have a certain diameter opening that I can use to get a good estimate of the total fish length when they swim by it.