Clown loaches growth rate difference - Why?

[Coryloach]

I am sure this question has been asked a lot...but I still don't know...

I have 10 clown loaches but this concerns my older 7 loaches as the last guys are only newbies...

I bought my first first group of 5 around 5.5 years ago.
For that period of time, the biggest has grown roughly to 7-8 inches, the smallest is as small as a clown loach of age of roughly no more than 2 years which I bought later and ended up growing faster. I also bought one older clown loach about 2 years after initially purchasing the 5, deserted in a shop by his previous owner. He was around 5-6 inches at purchase 3 years ago or thereabouts. For 3 years he got to 9 inches which is roughly an inch per year. Why haven't all loaches grown at the same rate?

I've heard about growth inhibiting hormones and stuff but buying the larger loach 3 years ago did not stop the growth of my largest loach from the previous group. And he/she keeps growing as fast as the 9 incher. who I reckon is at least 7 years old in ideal scenario, probably older though...The growth of these two is sort of going at the same rate and way faster than the rest.. They are currently about a tail length in difference and quite chunky but not fat.

I am not a bad fishkeeper. I haven't missed the large weekly water change in years. I filter well, I keep the tank clean and feed high quality food. Those loaches grew in a 100G tank initially, they weren't crammed with other fish, etc...though I did have tank troubles in the last year an a half with their tank breaking and overstocking the other but it hasn't stopped the big two from growing whatsoever...Now they are all in an indoor pond, pretty much having it to themselves.

What is your experience and why do you think that is? Is there anything we can do besides large water changes which don't seem to make much of an effect, even if the issue is hormonal....

Is there a definite way to also distinguish between males and females..Some are certainly slender than the others from a younger age and the "fatter" ones get fatter, the slimmer seem to stay slim...and shorter..

 

[tlindsey]

Its doesn't have anything to do with your care, but other variables such as who is hogging the food and male and female size.

 

[Alistair]

The smaller ones are probably Danny devitos and the larger ones that grow fast like the big show. Genes, sex, personality that may affect feeding behavior, etc etc. I have observed such variations too.

 

[Chub_by]

The smaller ones are probably Danny devitos and the larger ones that grow fast like the big show. Genes, sex, personality that may affect feeding behavior, etc etc. I have observed such variations too.

Exactly. This is especially true when it comes to fish like clown loathes that have a relatively complex social behaviour.

 

[Hoplo]

Yea, I have also experienced different growth rates in my clown loaches. I have put it down to the more dominant ones eating more food, and genetically being faster growers.

 

[RD.]

Sex, genetics, social hierarchy, etc, determine growth rates among clown loaches, with every group typically having those that are smaller, and/or larger than the rest of the group - even if all raised from the same size, under the same conditions, eating the same quantity of food. I have kept CL's for many years, including in species only tanks, and this appears to be quite common.

 

[Mr Pleco]

Sex, genetics, social hierarchy, etc, determine growth rates among clown loaches, with every group typically having those that are smaller, and/or larger than the rest of the group - even if all raised from the same size, under the same conditions, eating the same quantity of food. I have kept CL's for many years, including in species only tanks, and this appears to be quite common.

Same experiences here have raised some 12"+fatties.. only thing I do different is remove the larger ones to different tanks and rotate so the hierarchy was always shaken up..wormed my loache's once a year . also they ate lots of fresh foods, mussels , clams , crushed snails , zucchini....GL

 

[Coryloach]

Thanks for all your replies everyone, very informative.

I was staring today at my loaches and I noticed that my 2 year old clown loach has surpassed in growth the smallest of my 5 year old loaches. He is faster growing than this older loach, growing several inches in the same length of time the 5 year old probably didn't, or grew so little I haven't noticed. This is despite all subjected to the same exact living conditions and the 2 year old loach starting as a 2 incher where the other one was already a 4 inches or thereabouts.

What I noticed years ago was that this same 5 year old loach was definately at the bottom of the pecking order and I sometimes felt sorry for him because when the clowns did the "dance" up on the glass, this loach was used as a "cushion" by them. They just bounced of him when going up and down the glass and he heroically persevered with it landing each time at the bottom. I hoped that in getting younger loaches, the pecking order at the bottom will change but perhaps it didn't.

I once watched a documentary about wolves and the one at the bottom of the pack was used as an object of "abuse"...if I can call it that when it comes to animals. They said in the video it is normally the least aggressive and docile wolf, something that is normally most desired in dogs but in nature those animals don't live the best of lives. They are hardly allowed to even eat enough...

 

[RD.]

I have never seen the smallest loach in a group getting punked by the others. I have also never seen them not allowed to eat. Larger loaches are stronger, faster, and therefore do get more food when it hits the tank water, but that makes sense regardless of species. Without understanding more about how sex, social hierarchy, genetics etc. play out with regards to growth in this species it's really hard to say exactly what takes pace in each individual tank.

 

[smjack]

Hi Cory. Since my clowns are still with severums, I have noticed that the small ones have to eat more often. The bigger ones don't. I feed shrimp. The small ones have to pick the smaller bits to chew. The bigger ones might have the teeth to chew shrimp. They eat and leave in 5 minutes. I leave the pump off for 30 minutes. For the smaller ones.