What length fish are you catching?
I fish a private pond and I am curious as to why the male bluegill are so thin, yet the females are thick. When I say thin I mean filleting them with an electric fillet knife is virtually impossible, so I keep the females and release the males. It's not just during the spawn either. They are thin all year long. I know certain things happen such as "stunting" when fish are over populated in a particular pond or lake, so is this sort of like that? Is there a scientific name for this?
What length fish are you catching?
More than likely they are just old and not long for this world. Depending on the population, it takes 8 years on average to reach 8" in length. Fast growing fish can do it in 5. IF there has been a significant decrease in the amount of vegetation in the pond, this can lead to a decrease in the aquatic insects that larger bluegill need.
There was a huge decrease in vegetation, the pond was overtaken with coontail so bad that u couldn't use a trolling motor. After 2-3 years, the bass were starving, the crappie and bluegill made a huge rebound bc they weren't being eaten, and then he stocked 40 grass carp and now every stitch is gone. With that being said, why would it only affect the males?
They expend the most energy building and defending nests
So you're saying that when they lose their size during the spawn, they don't gain it back throughout the rest of the year?
It can be hard if food is limited. Aquatic vegetation produces lots of insects, without the vegetation they could struggle to regain mass due to limited food base. It can also be a function of their age too. IF these are old fish, it makes it harder to regain size
I would say get rid of the grass carp
That makes sense now.
Would love to get rid of em, have to be extremely sneaky bout it though. I didn't mind the coontail