Diet of Flatheads in the Susquehanna

[jifigz]

sometimes as an angler I think I am guilty of forgetting the relative proportion of non-sport fish components of the aquatic ecosystem. The study indicated the native stone cats were one of the main prey items so it would make sense if they did not evolve with invasive flatheads it would make sense they might be more vulnerable than the allegheny introduced transplants you mentioned. Same may go for native fall fish, white suckers, northern hog suckers, log perch ect. This is why growth plasticity can peak because when the native forage get unsustainably burned though eventually the food source diminishes as you lose density or presence of native species. Then you get blue cats in the James river, 75% of the biomass all 20 inches long. Flatheads likely will experience the same phenomena at some point if they are burning through stone cat’s unsustainably. Then the question is what else depends on stone cats for anything from food, symbiosis, or taking partial forage pressure off another species.

We all imitate stonecats for nonnative smallmouth so for stone cats you can see the nonnative fish introductions start to compound from a predator standpoint. Question is for me who else depends on these stone cats and what happens to the food web if we lose em.

Well, we'll find out what the ramifications are when the madtom disappears. This is a crazy world we live in.

I'm very interested to see how the python situation shakes out.

 

[sandflyx]

they found blue cats are decimating the upper chessy blue crabs. one blue cat had 45 crabs in it

 

[bringthepain]

Well, we'll find out what the ramifications are when the madtom disappears. This is a crazy world we live in.

I'm very interested to see how the python situation shakes out.

Shakes out or snakes out, haha

 

[Kgregor12]

Lol just wait till some brilliant bucket biologist dumps in 100 wells catfish and establishes a guide bussiness, and a “conservation” non-profit devoted to “let them go and let them grow” overnight. Will have 8 foot catfish farting out remains of 20 inch smallies and everyother fish that lives in that river. Wonder how long entire susky food web go kablooey in that scenario?

 

[jifigz]

Wonder how long entire susky food web go kablooey in that scenario?

3 years, 49 days, 8 hours, and 23 seconds......

 

[jifigz]

On a separate note, those Wels Catfish in Spain really are something, aren't they? Catfish are pretty much top dog predators, or damn near the top, in every ecosystem they inhabit. Usually, somewhere, there is a badass catfish near the top of the food chain.

 

[Kgregor12]

3 years, 49 days, 8 hours, and 23 seconds......

Solid guess my estimate is coming in inside that ballpark

 

[Kgregor12]

On a separate note, those Wells Catfish in Spain really are something, aren't they? Catfish are pretty much top dog predators, or damn near the top, in every ecosystem they inhabit. Usually, somewhere, there is a badass catfish near the top of the food chain.

Yea don’t forget the Goonch of the ganjes

 

[Kgregor12]

On a separate note, those Wells Catfish in Spain really are something, aren't they? Catfish are pretty much top dog predators, or damn near the top, in every ecosystem they inhabit. Usually, somewhere, there is a badass catfish near the top of the food chain.

 

[jifigz]

The Wels, flathead, blue, redtail, etc. Fish with whiskers are serious critters. Even though the Mekong eats mostly vegetable matter, it, too, is a serious fish.

I used to be a pretty avid catfish angler. I liked it a lot. A chair, some beer, some weight, and just chuck it out there wait for the goods. Catfish are incredibly good fighters, too, at least in my opinion.

 

[jifigz]

 

[Kgregor12]

Ive seen that its nuts

 

[jifigz]

Ive seen that its nuts

I can't blame them. I like eating pigeons, too.

 

[Kgregor12]

I can't blame them. I like eating pigeons, too.

I wonder how many lap dogs fetching a ball in the water those things have claimed over there

 

[5footfenwick]

Pigeon fly pattern?

 

[Kgregor12]

Pigeon fly pattern?

In the film

 

[5footfenwick]

You are gonna wanna downsize to a dove dry fly if they are picky. Maybe a Merganser submerger fly. Might even have to get out the parachute ducklings if they get on that midge bite.

 

[Mike]

There is a good reason for that actually. Its called “growth plasticity.” When you drop an invasive species in a new environment none of the native species that evolved there ever got a chance to genetically adapt to it. So this means no evolved chemical warning cues, avoidance strategies or defense mechanisms against the invader thus there is a much higher success rate when that invasive species forages. Many invasive species grow largest outside their native range for this reason.

One can go with ecological principles and/or use the simpler explanation for the “lower Susquehanna.” It is true that introduced species typically have high individual growth rates as well as high population growth rates, both of which diminish as the populations mature and settle into the long term carrying capacity for the species in their respective environments. The simpler explanation for the lower Susquehanna, however, is that while newly introduced invasives typically grow rapidly, the lower Susquehanna has such an excellent forage base, long growing season, and high productivity that rapid growth would be expected anyway, especially for an opportunistic predator. The forage base is so good that this individual fish rapid growth period may continue longer than would normally be expected. I can’t say that this would be true throughout the river because the forage base diminishes in quality and quantity to some extent in an upstream direction. Gizzard shad YOY, for example, are annually quite abundant in the lower Susquehanna.

As for Blue Catfish, they’ve been confirmed in the Delaware Estuary in the Chester, Pa area. So add those to other recent and longer term, but relatively recent, invasives in the Delaware…northern snakeheads, flatheads, and freshwater drum.