synodontis multi question

[KBush]

I started a tank about a year ago, 3 of its residents are synodontis multipunctatus. All were purchased at the same time and size, 2 have grown nicely and are significantly larger then the other. The small one has no problems getting food or anything, im just wondering why he is remaining smaller (about half the size) of the other two.

Thanks

 

[toddnbecka]

Are you certain the smaller one is a multi too? Petricola or lucipinnis take longer to grow than multi's.

 

[KBush]

Ya Im almost positive they are all multi's. The dorsal fins and bodies have the same coloration. I thought maybe the size difference was due to the sex?

 

[toddnbecka]

No apparent size difference between adult males and females IME. Most likely just a difference in growth rate. Has the smaller one grown at all? How big were they when you started, and how much have they grown in a year?
I've seen a huge difference in growth rate among cichlid fry, after a couple months some are 2-3x the sized of the smallest. S. multi's don't produce nearly as many fry at one time, but I would expect the same variation among individual fish. Particularly if they were farmed (eggs stripped from host cichlid and hatched in a tumbler) rather than allowing the larger fry to eat the smaller ones like they normally do.

 

[KBush]

I believe the small one has grown somewhat, it is difficult to say since the other two have doubled or maybe trippled in size in 1 year. But the small one seems completely healthy so hopefully like you said he just has a different growth rate then the other two. I am a little worried he will be bullied if the other two continue to put on size the way they have. Should I be concerned about this?

 

[toddnbecka]

You'd be better off with 2 more, they are social/schooling fish but still have a pecking order. The more there are to interact with each other the less any one fish gets bullied. I had a mixed group of 10 perticola/lucipinnis and had to move 2 of them out because their fins were ragged, but as long as the small one isn't taking damage don't worry. I've grown them out in the same tank they were spawned in w/out any issues due to size differences. The younger ones don't typically school with the adults until they're close to their size, but when they get to about 3/4 they all swim together. I've seen adult multi's with fair-size patches of hide chewed off, particularly around spawning time, but it grows back quickly enough and they're fine.