I was looking at getting some YP eggs. I was wondering if it's worth it and what if anything special I would have to do and if anyone has done this before? I have weeds and cattails in pond and got a tree waiting to fall in when ice goes away and I have red ears, LMB, gills, 12YP, 4WE in my pond so far if that helps! I no LMB and YP don't get along but the bass were in there when I got this house! I have fished them heavy through the summer!

Are you anywhere near Bill Cody? He might give you some.

Bill?

I would be leery of adding wild eggs as the water could contain veliger larvae (zebra mussels).

Why not just add the fish themselves?

I wish I had lots of positive information to stock YP eggs that resulted in harvestable YP. The YP eggs when hatched as fry will provide forage for all the small fish and later food primarily for the LMB. Using YP successfully in a pond with LMB and BG is a real challenge.

To get YP to recruit and produce adult YP with LMB, one needs a heavy harvest of LMB so the predation pressure is low for the fingerling, yearling, and small adult perch - a period of about 3 yrs. However when one removes lots of bass the BG begin to quickly overpopulate. Now you are caught in a dilemma of two choices, each causing a resulting problem.

IMO the best path for growing YP as a bonus fish when LMB are present is to have a heavy harvest of the larger bass (12"+) and stock only large YP 8"+. Bass 15"-16" will easily eat 8" long YP because YP are slender bodied and live near the bottom where bass frequently hunt. YP also become sedentary or "couch potatoes" at dusk and LMB hunt well in low light conditions.

You don't have to buy the large expensive sized YP. You can buy the lower cost 4"-6" size, grow them in a cage all summer and release them as 7"-9" sizes before winter. Although if one considers their time involved in growing cage raised fish all summer, it is often cheaper to just buy the 10-20/ac large YP each year to serve as bonus fish.

Great post Bill! I read that comment above and thought a smilar statement might hold true for RES, but it would read like this:

RES 8"-9" will easily eat 2-1/2" long YP because YP are slender bodied and live near the bottom where RES frequently hunt. YP also become sedentary or "couch potatoes" at dusk and RES hunt well in low light conditions.

Shorty - Let us look a little closer at this topic. I question how many 2"+ fish that RES will eat per year in the wild setting. Size of the RES could also play a role here. Small fish are better at escaping predation in the natural environment compared to being confined in the aquarium or tank habitat. I think this becomes much more important when the predator (RES) is at best a marginal predator of predator wary or 'conditioned' small fish larger than 1" that have previously experienced being chased - threatened. RES have the reputation and have evolved the adaptation of 'cherry picking' their food items and not having to chase or actively attack the food.

To shed some light on this topic, have you tried to drop snails into the aquarium with the RES to see how they respond when presented a choice of food items? We also have to consider that your current several RES in the fish tank have not had to forage in the wild for food. They have spent much of their life in a tank and being hand fed - conditioned to a life style. This also may affect how your RES forage and select their food.

When making conclusions or assumptions about animal behavior, the total picture should be evaluated and the results compared to previous food habit studies for that species. Maybe a member (Eric?) can reference a good RES food habit study involving various sizes of RES sampled from the natural environment?? My literature library is pretty limited when it comes to RES. Yes adult sized RES can eat 2" slender fish but do RES have the ability to capture those same fish in the natural setting? Another thing to consider is, will really slow naïve fish (FHM, YP resting) even be available as food when other much more efficient and more adapted predators are also present in the same habitat and likely consume the small fish very early "in the predator-prey game"? With other predators (juvenile bass etc) present with RES I wonder if small "dumb" fish will even wander into areas where the RES spend their forage (hunt) time. Are not RES more inclined to be found in the deeper water vs the shallow water 'haunts' of small fish?

As a test it would be very interesting and educational to put a LMB (same length or weight as RES) in the aquarium with the RES. After a day or two, add the minnows and watch the results. I would like to know how many minnows the bass eats before the 1st RES eats a minnow.

Understood Bill, my observations are that RES are very likely better adapted to low light level conditions than LMB. From what I have researched LMB eyesight is roughly five times more sensitive to light than human beings. Not having eyelids or the ability to adjust their pupils very much means RES likely do not see well enough to chase fast moving prey items during normal daylight. RES do behave very differently when the lights go out v. when the lights are on. When the lights are on they consistently stay as far away from my aquarium light as possible and they mostly stay in the bottom half of the tank. They also very seldom chase FHM when the tank light is on. Once the light goes out they spread out and move up to the top half of the tank and start chasing minnows. The vast majority of FHM eaten by my RES are in very dark conditions in my basement.

So far I have not dropped any snails in the aquarium to see how they react but I can tell you that snails were noticeably absent from my pond last year. Adding snails to the aquarium is not likely to help with foraging when I turn them loose. I can also tell you that despite my best efforts fishing nightcrawlers deep and slow last year I was only able to catch a single 4" RES from my pond in 2013. The bulk of my forage base last year was YOY GSH and I am confident that my larger RES are utilizing them with the absence of snails in my pond.

I have read the study on RES utilizing different sizes of snails and size preference, I found it fascinating. I have observed a similar size preference with them eating FHM. Gape wise an 8" RES can easily inhale a 3" FHM but the tail always protrudes out of their mouth and they usually spit it out. When eating smaller and shorter FHM that they can completely fit in their mouth they will pop their jaw hard three times as they "crush" the FHM down their throat, I see lots' of small FHM scales come out of their gill plates as they are popping their jaw and crushing a FHM. IMO it is not just the gape size that limits RES predation on small fish, but overall length also plays an very important role, a small fish needs to fit completely in their mouth.

Back in college I did senior level term paper on “Perception and Predation in LMB” for one of my Psychology classes. In that paper I hypothesized that the near sighted visual system in LMB is what triggers a fixed action pattern (FAP) of opening the mouth and inhaling a prey item. My thoughts are that this is the reason my RES do not chase FHM when my aquarium lights are on, bright lights impair their abilty to judge depth and distance. LMB do have a very short and small area several inches in front of their mouth where they are quite capable of binocular vision and depth perception when both eyes are turned forward. IMO it is this small area of binocular depth perception that serves as the trigger of a FAP in capturing prey.

A few commnets Bill:



Size of RES definatley plays a role, when they were smaller a few months ago they prefered FHM under 1-3/4" long. Within five days of introducing smaller pet shop minnows they were eating 20-30 RRFHM a day and almost exclusively in the dark.



I have a significant amount of stucture and current moving in my tank making predation more difficult. FHM do have places they can hide where my RES cannot get to them. Between the two powerheads and two filters I am moving ~ 840 GPH in a 75 gallon tank, this makes eating a FHM head first quite a challenge in my tank. It also make feeding and removing uneaten pellets very difficult.



They were on their own in the pond for 11 to 12 months before I put them in my pellet training program last May/June. I have had them for 10 months now.



Aint that the truth, very little research has been done with RES. I know it defies conventional wisdom but I truly believe that someday RES will be viewed as a "dark adapted nocturnal sunfish" and that they move in shallow once the sun goes down. This probable dark adaptation is a niche that is not exploited by most other sunfish. A dark adapted predator should have an advantage over prey that does not see as well once the sun goes down.



If I am right about RES being dark adapted then the answer could very well be yes.



Very valid point Bill, FHM are not known for their predator smarts and there are very few left in my pond, mostly large adults, but I do have an over abundance of small GSH. Last spring/summer I walked my pond after dark with a flashlight several times and observed RES in less than a foot of water along the edge of the pond but mostly what I saw were small GSH.



The bass would win hands down given the larger gape and presuambly less light sensitive eyes. A more interesting test would be to match gape size for gape size, then turn out the lights and then examine stomach contents ocnce the lights are turned on.

I can quit posting about about my indoor RES if I am ruffling too many feather here but I am definatley hungry for more RES researh to done based on what I have observed.

Shorty, I always look forward to reading your RES posts, indoor or otherwise. Oftentimes they cause me to rethink certain aspects that I had previously took for granted, or had failed to assign the proper significance to....and that's a good thing.

I think all research on RES has merit. I believe there is tremendous potential there, and the more we understand, the better position we will be in utilize that potential in our own ponds.

Just a couple of comments from someone that knows little about fish.

When I dropped snails into a 10 gallon aquarium with 4 3" RES they would immediately attack them on the way down. If the snail was small enough, it would be consumed immediately. You could see the RES crunching up the shell. This was fairly early on when the RES were still becoming accustomed to pellets (at the time they would attack the pellets and spit them back out). The RES seem to be attracted to movement. They would strike anything that moved, but once it was stationary on the bottom, loose interest. For the snails that made it to the bottom (I would dump in quite a few at once) the snail movement would get the RES attention, then the RES would "stare" at the snail with the body of the fish being completely motionless except for fin movement to keep it in place. It would stare at its prey till it saw the snail move, then strike. No movement, no strike. I even saw one once before being pellet trained strike at a pellet sitting on the bottom because another fish fin movement had caused the pellet to move.

As far as FHM going into deeper water (5-6' at least) they do. As I was scuba diving I would lay motionless on the bottom above the thermocline. Not wearing a wet suit in the summer I could tell when a FHM school found me. Usually took about 30 seconds to one minute. No matter where I laid on the pond bottom, as long as it was above the thermocline, the FHM's would find me in short order. I could tell because I would have 25-50 fish nibbling all over whatever body parts were exposed (arms and legs mostly, it was summer) including my head (I keep short hair). They would be pecking all over me. Don't know if they thought they could get a chunk off of me or if salt on my skin attracted them or what, but they would be all over me, from shallow depth to the thermocline anywhere in the pond. This was with only BG, a few RES, and FHM in the pond. So I would have to assume FHM do range deeper in the pond than some might expect. I rarely see adult FHM's in the shallow in my pond unless I am feeding. Then the adults will come up for the feed. Mostly along the shore line I see the Juvenal FHM's in the very shallow water.

When I put crushed limestone rock around the bank down to a couple feet deep, it almost immediately grew a layer of algae. This attracted snails by the tens of thousands. In some areas, snails on the order of being an inch apart in the very shallow where the fresh growth is (one reason I got some more RES and stocked them last fall). These snails are in very shallow water. If the RES are going to eat them, they are going to have to come up from the depth. Just today I pulled a little fresh filamentous algae out around the edge of the pond where the ice had receded. Snails in the FA.

So I have to wonder, is there maybe a time of day or night that RES frequent the shallows to feed on snails?

My observations. Don't know that much about fish.

All information about all aspects of fish and fish behavior are useful and informative on this Pond Management Forum. Observations are learning experiences. Discussion causes us to think and hopefully improve our knowledge.