Runty Tetras. Does this happen?
Tropical Fish

Tropical Fish Keeping - Aquarium fish care and resources » Freshwater Fish and Aquariums » Beginner Freshwater Aquarium » Runty Tetras. Does this happen?

Runty Tetras. Does this happen?

This is a discussion on Runty Tetras. Does this happen? within the Beginner Freshwater Aquarium forums, part of the Freshwater Fish and Aquariums category; --> So, as you can see from my signature, I have a largeish school of Pristella Tetras (Pristella maxillaris) in my 55g tank. I've had ...

Check out these freshwater fish profiles
Head & Tail Light Tetra
Head & Tail Light Tetra
Croaking Gourami
Croaking Gourami
Reply
LinkBack Thread Tools vBmenu Seperating Image Search this Thread vBmenu Seperating Image
Runty Tetras. Does this happen?
Old 02-02-2011, 10:00 AM   #1
 
burnsbabe's Avatar
 
Runty Tetras. Does this happen?

So, as you can see from my signature, I have a largeish school of Pristella Tetras (Pristella maxillaris) in my 55g tank. I've had these guys for the better part of a year now and they have grown up quite a bit. Most are very deep bodied now and I'd say approaching two inches. Nice fish. Anyway, two fish in the school have yet to develop this deep body and are somewhat shorter. Say 1.5 inches. I've been worried on and off about these two but after paying attention they seem to eat at least some when fed and are otherwise accepted by the group and normal.

Are there just runty fish? Or is it possible these two have some sort of parasite? I can't help feeling that they're fine, even though they differ in size pretty remarkably. Thoughts?
burnsbabe is offline   Reply With Quote
Old 02-02-2011, 10:45 AM   #2
 
I have the same with my pristellas (and also my glowlight tetras). Some are large and some don't seem to grow as big, despite being in the tank for 6 months and feeding fine. I found the smaller individuals could be more aggressive too. I started a thread about this ages ago and Byron said he had the same experience. I can only conclude that the fish are genetically different from one another - and therefore are different physicaly (unless it's a parasite, which seems unlikely as I'd expect it to spread to all individuals). A possible explanation for the genetic difference is that the wild stock might have been collected from different locations... who knows
sik80 is offline   Reply With Quote
Old 02-02-2011, 01:50 PM   #3
 
burnsbabe's Avatar
 
It makes enough sense I suppose. And you're right. I'd expect a parasite to spread to everyone.
burnsbabe is offline   Reply With Quote
Old 02-02-2011, 07:35 PM   #4
 
Byron's Avatar
 
As sik80 mentioned, I do have this with Pristella, actually several other fish species too. Some seem to grow fast, some grow much slower, very little at all. As long as they are normal I don't worry. If they develop black blotches or white patches or something, that's very different. But healthy fish...not to worry.
Byron is offline   Reply With Quote
Old 02-03-2011, 07:22 PM   #5
 
jeaninel's Avatar
 
I have not kept the Pristellas but could it be that the larger, deeper bodied ones are the females and the smaller, slimmer ones are the males?
jeaninel is offline   Reply With Quote
Old 02-03-2011, 07:33 PM   #6
 
Byron's Avatar
 
Quote:
Originally Posted by jeaninel View Post
I have not kept the Pristellas but could it be that the larger, deeper bodied ones are the females and the smaller, slimmer ones are the males?
I had initially thought much the same jeaninel, but as I observed this over time there seem to be males and females among the 10 "larger" fish judging by their girth and behaviours. The two smaller fish are about half the size of the rest.

Byron.
Byron is offline   Reply With Quote
Old 02-03-2011, 08:36 PM   #7
 
burnsbabe's Avatar
 
I had also thought of this, but the mathematical odds that in my school of fourteen I come out with a ratio of 12:2 is pretty low.

Incidentally, what sort of behavioral differences are there between fish of different sexes in the Pristellas?
burnsbabe is offline   Reply With Quote
Old 02-03-2011, 08:57 PM   #8
 
Byron's Avatar
 
Quote:
Originally Posted by burnsbabe View Post
I had also thought of this, but the mathematical odds that in my school of fourteen I come out with a ratio of 12:2 is pretty low.

Incidentally, what sort of behavioral differences are there between fish of different sexes in the Pristellas?
The males display, not a lot, but I find all characins do to some extent. Sort of sidling up side by side and turning a bit on one side, sometimes with a slight quiver. Then there is the male "nudging" of females, presumably trying to push her into a plant thicket.

I've observed rummynose doing the above, and my Pretty Tetra do too.
Byron is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
bucktoothed tetras, vampire tetras, pickerel, red evils need help an info mlhunsaker Characins 18 09-01-2010 02:37 AM
Do Neon Tetras school with any other fish (part. Gold Tetras or Harlequin Rasboras)? Akeath Freshwater and Tropical Fish 1 11-09-2009 08:15 PM
Ich, How did this happen? Jerryed Tropical Fish Diseases 2 10-14-2009 02:04 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search



All times are GMT -5. The time now is 01:06 AM.