Question about stunted fish

I know that L. cyanellus are known for overpopulating small ponds which leads to a stunted population.

Is the stunting usually permanent in fish if theyre moved to a better environment (less crowded, cleaner etc.)

Is it in anyway heritable?

I have had three of these fish for around a year or so and they haven't grown very much. By comparison a red breast in the tank almost doubled in size in the same amount of time and they were all added together at around the same size. The male green and one of the two females recently spawned and I'm wondering what to do with the fry if they survive. I'd keep some but I don't want stunted fish that stop growing at 3 inches. That's what the female did.

Thanks

I'm sure there would be people interested in min-greens assuming it is heritable.

I think micro-sunfish would be akin to fish like flowerhorns and blood parrots though no? Does the stunting have an effect on the health of the fish?

Edited by mikeb210, 03 September 2011 - 10:20 AM.

I honestly don't know. But it probably would if it does for other kinds of fish.

If fry from stunted parents have clean, uncrowded conditions, they will not stunt and will grow normally. The ability and propensity to stunt is heritable, but fry from stunted parents will not be stunted just because their parents were stunted.

I know that L. cyanellus are known for overpopulating small ponds which leads to a stunted population.

Is the stunting usually permanent in fish if theyre moved to a better environment (less crowded, cleaner etc.)

Is it in anyway heritable?

I have had three of these fish for around a year or so and they haven't grown very much. By comparison a red breast in the tank almost doubled in size in the same amount of time and they were all added together at around the same size. The male green and one of the two females recently spawned and I'm wondering what to do with the fry if they survive. I'd keep some but I don't want stunted fish that stop growing at 3 inches. That's what the female did.

Thanks

I can't explain this as well as a biologist can, but I'll do my best to explain it the way I understand it. If the green sunfish is stunted from poor environmental conditions, then it will not pass on "small genes" to it's offspring. As far as I know, environmental conditions that an organism is exposed to will not change the DNA in such a way as to affect the offspring in the same way as the parent. Examples might be a farmer who loses a hand in a farming accident will not have children without hands, but someone exposed to certain levels of some types of radiation may have children that are more likely to have birth defects, but these particular defects will not be present in the parent who is exposed to the radiation. I'm not at all insinuating that the offspring of your sunfish will have birth defects, I'm just using this as an example. If the small size of your green sunfish is from environmental factors, then I believe the offspring would still have the genetic make-up of a normal sized green sunfish assuming the pond was stocked with normal sized green sunfish when they were healthy. If these offspring are allowed to grow where they have the space and nutrition they need then I believe they would obtain full size.

I do believe that the stunting can be permanent for the individual that is stunted, as with most animals, there is a time to grow and a time not to grow. Most physiological growth takes place early in life, and when certain stages of that growth are not allowed to happen due to environmental factors, it is difficult for this growth to continue properly at a later date even once the negative factors are reversed. In short, the animal has already went through these growth stages, but couldn't use them to it's full potential, and will not likely be able to go back and get what it missed out on in terms of developmental growth opportunities.

If I'm off track here on my explanation someone please correct me. This is just the way I understand it.

Steve.

The term that was on the tip of my tongue is "Lamarckian evolution," and it's what Steve and I both alluded to. In short, it doesn't happen.

The term that was on the tip of my tongue is "Lamarckian evolution," and it's what Steve and I both alluded to. In short, it doesn't happen.

exactly. Lamarkian evolution is not real. Some sunfish stunt more than others (shellcrackers seem less likely to, but they may refrain from spawning in overcrowded conditions, whereas bluegill do not, but this is conjecture). A stunted fish will most likely respond to tank life with one heck of a growth spurt. They may retain the overly large head/big eyes, but perhaps not.

I think you guys are right on track but there may or may not be exceptions. Case in point: I was visiting a friend of a friend today that has also set up a recirculating system in his basement. He claimed that one of the bluegills in the tank that is now in the 10 to 11 inch range (yes it's really that big) was caught out of a pond that had stunted bluegills. If this indeed is the case then this is an exception to the rule. On the other hand perhaps he assumed the bluegills were stunted and he was simply observing a large age class of small fish?