This thread will document efforts to breed bluegill using resources some of the people I work with have. Goal is to produce a whopping 50 fingerlings with a total length of 1". Likely just going through motions because so late in season so will repeat effort next year.
Tank is roughly 4' x 4' x 8'. Location is on north side of barn where is collects rain water. Nest site added so I can monitor breeding activity and collect prolarvae to manage stocking density. Some prolarvae may be transferred to additional culture units in the form of 30-gallon protein tubs like used for supplementing forage / hay fed cattle.
Broodstock started as four Hand-paint Bluegill ranging in length from 2" to 3.5". Slight problem, only male died. Will be replaced today with similar sized male Northern Bluegill. Females will be removed once prolarvae confirmed present. Male may be left with brood which might of interest to some why that could allowed.
Photoperiod may need to be manipulated. Plankton will need some coaxing. Feed will be started once fish are about 0.75".
Thread will also provide me with opportunity to manage images.
I have done such before with other sunfishes that have larger larvae. Larvae size and sometime behavior is more important that you might think. Larval spotted bass are super easy as are members of the rockbass clan.
All life-stages. Pond and tank. Breeding just like with Bluegill. I use Redear males as teasers for male Bluegill.
A lot of combinations too.
Pure Diploid Triploid
Hybrid with Redear as female parent Allodiploid (w/Green, Warmouth, Pumpkinseed, Bluegill and Redspotted) Allotriploid (W/Green, Warmouth (both ways), and Pumpkinseed)
Larval rearing easy and all feed train at least as easily as Bluegill when fry.
Redear very easy in tanks. In ponds they eat feed better than most people give them credit, for but they do not feed at surface very well which I think is common knowledge. They do get big easy but crowd that bends my ear is not as enthusiastic about eating them as they are Bluegill or the crappies.
All the crosses above where from when we doing snail control experiments and trying to make tetraploids. Students, some high school, did a lot to the hybridization and pressure shocking as pretty low tech. The hard part was keeping the little ones from drying out in pretty dishes until old enough to feed plankton or stock into ponds. Some of the hybrids also done as part of a hatchery class so I just watched to make so no one got hurt operating jack ingested spoo.
My experience is that Redears will feed well on the surface during low light levels such as right before sunset. I have a working hypothesis that RES are more light sensitive and also better dark adapted than other sunfish, it has worked well with feed training a batch of RES in a 300 gallon tank this summer.
That is pretty much what I see. Redear in natural habitats (streams) seem to be in deeper part of runs and pools. Maybe light level is what helps them stay in those micro-habitats.
I added male NBG (Northern Bluegill) to stock tank. He is about 1/2" longer than the larger HpBG (Hand-paint Bluegill) females. Dominant female went from brat to submissive with just a few seconds. Other displays occurred but may not be of interest here. When male leaves her immediate vicinity (~18") she goes brat again.
RES eat pellets well just not at the surface. I have many eating as the pellets sink down about 6-8 inches. They eat sinking pellets well especially in tanks. You can make a RE feeding platform with the shelf submerged about a foot off the bottom in 4 feet of water. A few floats some rope or wire(plastic coated) and a piece of tin or rigid plastic.
With RES, have you ever tried using a belt feeder or some other type of automated feeder? Sinking pellets likely still best approach and I suggest using larger pellet size that you would for similar sized BG. RES have a larger gap size but are not as good at processing a lot of mouth fulls.
Fish is this setting are not being fed a practical diet despite being feed trained. The is endeavor is to provide my kids a little fun so we are providing insects in the form of meal worms and grass hoppers. Fish are fed to apparent satiation near end of day. I have popped them with a feed formulated for aquarium use. Feeding rate is modest to reduce turbidity. Some insects are clearly falling in although not at rates needed to promote conditioning for breeding. A night light of some sort my be used for that at some point.
You could get a roll of 12/2 G or 10/2 G UF copper cable and run that. Better conductance than extension cords.
There are problems with that arrangement. It would deny the opportunity to put up and put down cords every time I mow. It would make fencing less vulnerable to overloading outlet during storms. It would be smart. Some things simply are not to be on my little farm.
I will be on that likely next year. Really pondering photovoltaic charger to run barn ventilation and lighting. The micro-scale aquaculture could be powered off that. Night flying insects have some serious potential almost 8 months of the year. During half that, temperature too low for fish consumption to keep up.
Insect drift I have really been aware as very significant protein source for my free-range juvenile chickens.
I too would love to see pics and video! The girls are always looking over my shoulder asking what I'm reading. Great to involve the kids!
Out of curiosity, about how many amps does your micro-scale aquaculture tank consume?
Solar panels seem to be getting cheaper and cheaper...might be something to that.
What is an amp?lol. We are in milliamp-land with this venture. Currently the only power required involves a D-cell powered aerator that runs only a couple hours each evening to destratify tank. Next year I may want continuous service to ventilate a sunfish nest or to and keep keep plankton cultures rolling gently.
The lighting to attract night flying insects is what I am trying to wrap my head around. What bulbs are effective that I can operate in a high humidity setting? The black lights like used on light-traps are at top of list but a fixture supporting lamp needs to be worked out. Light-trap I use for teaching is not made for continuous / frequent use although it can be powered by 12-volt power point of an automobile. If that could be worked out then it might be scaled up for use on an organic reservoir I am trying to work for aquaculture.
Ultimately continuous aeration is to be used but very little but is not so much for aeration as simply water flow. Dissolved oxygen not expected to be a problem as typically at or above saturation. The above I do not like. I do not see how the small fish keep from getting bends. In aquariums placed in sun bends is an issue.
You could get a roll of 12/2 G or 10/2 G UF copper cable and run that. Better conductance than extension cords.
There are problems with that arrangement. It would deny the opportunity to put up and put down cords every time I mow. It would make fencing less vulnerable to overloading outlet during storms. It would be smart. Some things simply are not to be on my little farm.
Jim, That type of conductor (UF) is made for permanent direct burial, so no mowing issues there.
What about a small solar powered fence charger? I don't know if this would work, just thinking off the top of my head. I was just thinking that you could have two metal screens very close to each other in front of the light. Using the cheap silver clamp on light fixtures from walmart. mount the two screens on the end of the fixture, maybe with some of the rubber bolt on wire holders...they are insulated with rubber to keep wire from chaffing. Put the hot on one screen and the ground on the other, have the screens offset and as close together as possible. That way the possibility of the insect touching both screens will be high. The screen i am talking about is the kind like is used on the floor of chicken or rabbit coops. You can get it smaller. Like 1/4" holes. Maybe using a flouresent (sp?) light or even an led to save power. The little fence chargers can be had pretty cheaply. You are charging a very small area, so anything that would charge a 1/4 acre would probably knock the snot out of a bug. Don't know if it would work, but would be cheap and off the grid if you could do it. The fence charger would be self contained.
The permanent connection to grid will be buried. A hook up was built into house with 20-amp breaker in anticipation of connecting barn later. Barn just built.
The light, whether it is LED, flourescent or incandescent must produce the proper spectrum and intensity to work. I am very partial to LED's but have not found a local supplier of UV bulbs.
I use a solar charged fence charger now that is not well suited for running a right. A bigger unit would be needed to run ventilation fans and charge battery enough to keep light on at least half the night. It will be pricey I am sure.
That is cool as all get out! I always wanted to try something similar in our greenhouse when I was still teaching agriculture. Never could get the funds together. With the temps being controlled I thought it would be neat. There is even an aquaculture class I could have taught. It wasn't in our program though so it just kind of faded. What is the milk crate for?
Milk crates provide cover. When only one male he sometimes tries harry females even when they are several feet away from nest. Multiple males in that same setup nest tighter and do not pursue females nearly as much. Females generally only need to block the males line of sight in a tank of that size. In tighter confines partition is usually better.
Male working on nest quite a bit. Bare black spot evidence for tail-sweeping. Bowl well formed. Female I think going to spawn is all barred up. She is not the brat which periodically challenges the male.
A game cam is setup with 15-second interval between shots. Hopefully at least some of what goes on will be recorded.
Jim, I know this would take some time, and I could probably look it up. But your attention to detail and your observations that you have seen make me want to ask.
Would you start a thread detailing the general mating habits of the sunfish. Who starts what, when and in what order do the things happen, what details do we as pond owners look for to see what stage they are in and what is actually happening when our kids ask. I know a male makes the nest and protects it until the fry hatch and the female lays eggs in that nest at some point. Thats about the extent of it. And you can catch fish in the spring when they are on beds I know that one..lol. I know that may be asking a lot. But I would love to hear the observed from the field and true to sunfish details instead of the textbook for most freshwater fish ones.
Thanks for all the time and expertise you are willing to share and have brought along with.
Peachgrower a good idea. There is extensive info on that. I suggest to anyone interested in BG that they start with a book on BG biology called Bluegills Biology and Behavior by Spotte . It is the best single source on the subject. There are also some great studies written by Bryan D Neff with thousands of hours of underwater viewing. Both of them are based on applied in the field Fisheries Science (like that PB has encouraged through SDSU).
I would like to provide an alternative to that where discussion would not be limited to Northern Bluegill. Some would be based on extensive experience observing species remotely.
I am going to try cobbling together video clips depicting key behaviors of the male Northern Bluegill and possibly some of the females. I think spawning will occur in the AM tomorrow.
Tail sweeping. Male orients over nest sites, clamps tail then undulates while pushing back with pectoral fins as tail dips down into substrate where substrate is displaced.
Duration of recordings two short. Will fix tomorrow.
Camera will be deployed all day. Male should start "spinning up" this morning once sun hits tank.
We have a lot of sunfish farmer terms that I will be using. Staging breeding cycles for us critical so we settled on terms to stream line communications. The day of the males introduction involved a spate of "ventral present" and "dorsal present". Be watching for "dark eyes" )(not in literature in any form), "look down", "rock biting", "turning", "vent rubbing", "egg deposition", and "fanning". The behaviors all occur on ponds and in the wild for all species I have observed so these are common components of sunfish breeding efforts. When I say sunfish is includes the black basses, crappies, rock basses, and Fliers. May try to repeat this with Fliers nest spring before conditions suitable for Bluegill.
Just to entertain, as kids Fliers we called Black Crappie and all crappie we called White Crappie. Spotted Bass we called Redeye Bass . Bumpkin Indiana kids were not well schooled in fish taxonomy.
I do remember stealing bass eggs to attempt rearing in the cattle trough.
10-4 on the Hoosier bumpkin kids. I was a teenager before I figured out that Green Sunfish were called, well, Green Sunfish. Everyone I fished with referred to them as "old fashioned bluegills". True Story.
Jim, were you catching those fliers in Indiana? I know their range is limited here in the state, was curious if you knew a good location to try and catch a few.
As a kid we caught most in the Little Pigeon Creek drainage around Lincoln City and Dale. As an adult also caught them in the Patoka River Drainage north of Oakland City. You have to fish through a lot of Longear before the Fliers and Yellow Bullheads can get their shot at the bait. We also had two ponds with Fliers. They have a hard time getting to 8" in where sunfish are only fish forage. They might be different with lots of minnows. They are tasty.
Locations varied year to year because of how the streams wiggled. Same locations often yielded Pirate Perch and rather nice Grass Pickerel. The Patoka River drainage also has nice Redspotted Sunfish.
Most you will catch in the streams will have a hard time beating 2 oz. I like metric system better.
I have pet Fliers that can approach if not exceed the record but they are pellet fed in a tank.
If legal, would be fun to setup a pond with fliers and fatheads to see how big the Fliers could get. They are not as prone to over populate as crappie but I do not know how that would work in a pond lacking bass.
Front just came through. Kids ran about almost naked in yard and hens with chicks came up on to porch. If weather does not improve fast then breeding will not occur today.
Use of term spawning does not fit right with sunfishes since they are like many fishes that separate fertilization from dispersing gametes.
Spawning in the classical sense has gametes abandoned upon time of release like many marine species do when letting it go into current. Egg scatterers in freshwater do the same. Term get iffy as soon as brood care involved but still used a lot.
Sun is coming out. We may get some brood yet. Male NBG showing spots on nape typical of nesting males of the subspecies. The female HpBG I think most likely to spawn is constantly barred which differs from NBG and all CNBG I have seen. The HpBG's also a red tint that sets them apart from the other subspecies. Final difference is vertical fin color, NBG is aquamarine while HpBG is gray. If CNBG's were present, then they would be yellowish to red with white trim.
Digging by tail sweeping really picking up. The male NBG is not keeping the bratty HpBG clear of nest site. They are "vent presenting" at each other. Something is up.
Hand-paint Bluegill I have limited experience with where complex social interactions possible. Most mating I have done with them were pair wise. It is likely something new is going to be seen with this. Based on what Coppernose Bluegill from the St. Johns River basin do, we can extrapolate from Northern Bluegill too much.
My hope is I got the sex wrong on one of the HpBG.
To bad there isn't a live feed of this! Loving this thread. Thanks Jim for taking the time and describing everything.
Are fish similar to farm animals? I'm way more familiar with those, education wise. The bratty female...is this similar to a heifer or cow that is bulling, fighting , riding one another, and the like?
Which one initiates this or is it completely temperature? Like in animals we are talking heat cycle, pheromones, daylight periods and such, but the female starts the process by coming into heat.
Here we see the male doing stuff first. How does he know when to start?? Does he know there are females around that are ready?
I know these are probably silly questions, but just trying to relate it to what I know.
To bad there isn't a live feed of this! Loving this thread. Thanks Jim for taking the time and describing everything.
Are fish similar to farm animals? I'm way more familiar with those, education wise. The bratty female...is this similar to a heifer or cow that is bulling, fighting , riding one another, and the like?
Which one initiates this or is it completely temperature? Like in animals we are talking heat cycle, pheromones, daylight periods and such, but the female starts the process by coming into heat.
Here we see the male doing stuff first. How does he know when to start?? Does he know there are females around that are ready?
I know these are probably silly questions, but just trying to relate it to what I know.
Thanks and awsome thread!
Female actually initiates. Males simply give signs you can see.
We know pheromones are involved and they are not species specific. Our aquaculture setups make us uniquely qualified to have figured that out. We do not know the chemical(s) involved. Both sexes primed by environmental cues such as photoperiod and temperature. Social status is important as well which is particularly evident in LMB.
When everything correct and females conditioned, females generally cycle together. The pheromones they produce promote males to move into nesting areas, workout rank and territories, then construct nest.
Bratty is distinct from breeding behavior. Both sexes do it. Fish well below what even I can spawn size-wise can be brats. I have been able to spawn BG less than 2.5" when about 90 days post-hatch which means they are not stunted. Brattiness not part of that either.
I am betting spawn will be today. $1.
Some people do not sleep here. I have an excuse because in path of totality and doing some science with it.
Change in barred up female HpBG. She is starting to vent present to male(s). Very good sign! The brat HpBG might be a female mimic. If so I will let it father some brood and sort them out later as that should not be too hard even when small. All that is needed is a little back lighting in a jar and the pure HpBG stand out like sore thumbs.
I have a male CNBG Manatee River Drainage F2 doing just that in an indoor RAS. Eggs / embryos where evident in nest early this morning. Will be rearing the and a couple more broods just like it using more intensive methods.
I will do my best to up load video clips depicting what is going on. It may require burrowing from other species, but where such is done, the behaviors are conserved.
No reference with respect to size but gives idea of general appearance of eggs (actually embryos once fertilized). These eggs from CNBG of the Manatee River Drainage. The parents of the eggs have never been outside the lab.
Below is a video showing the father of the brood above fanning. Fanning is energetically demanding. You tell a male is fanning because pushes forward with tail as pushing back with the pectoral fins. The male will often turn on the nest moving water over different points in turn.
He will tolerate other large males in vicinity of nest but will not tolerate smaller fish or females. Both are prone to be predators on embryos and prolarvae.
Far from done. Will generate images clear enough to see eggs extruded. Images of prolarval and larval development also in the works. I already have lots of those for other species but never took time to do the BG's because they were too common.
Jim, very dumb question here, but how do males allow other males around but not smaller males or any females? We can't tell the difference reliably, especially with 'sneaker' or 'mimic' fish, how do they do it? lack of pheromones? I'm sure they don't inspect the size of the ear tab or other visible characteristics like we attempt to do?
Jim, very dumb question here, but how do males allow other males around but not smaller males or any females? We can't tell the difference reliably, especially with 'sneaker' or 'mimic' fish, how do they do it? lack of pheromones? I'm sure they don't inspect the size of the ear tab or other visible characteristics like we attempt to do?
Olfaction probably does not play a role in threat assessments made by parental males. Rather, it is likely the male keys in on what the target fish is looking at. Keep a bluegill an aquarium and you will see the BG eyes readily betray what a given fish is interested in. The parental male does not want someone that is interested in his brood.
Olfaction paper ewest refers to is evidence for the BG's ability to use scent but not likely in the context of assessing who is a threat. To my eyes scent is what maintains the male's broodiness.
We have hatch in the Coppernose nest. Tomorrow I will photograph prolarvae. The pop is getting cranky too. All I need is a couple hundred fry so culls will be used for purpose of this thread to show some things the literature does not.
Looks like this year will be a botch. Night time temperature now dropping too low taking water temperature into low 70's. That coupled with shorter photoperiod is dropping the need to breed.
The fish will be transferred to tank indoors where spawn should be realized quickly with elevated temperature and longer daylight. The resulting brood will be reared indoors.
Vacated stock tank will be stocked with about 50 larvae from brood currently being reared by Coppernose BG above. I have already started pushing for a stronger plankton bloom by adding some alfalfa.
It is very likely what is produced in the coming weeks will be large enough to spawn late next spring when conditions are more realistic.
Larvae left nest Sunday night, presumably just after sun down. They were a full 24 hours behind siblings kept in the warmer lab. Larvae easy to see by placing white piece of plastic behind them.
Zooplankton still a little lean. Midge larvae on tank sides grazing much of that down. Starting tomorrow I will supplement with baby brine shrimp.
For those that have not stuck their nose into a panfish or black bass nest under good seeing conditions.
Images from another brood produced indoors. Based on how indoor group is blowing doors off those in the stock tank, these guys will pace the stock tank guys up as well.
This brood (~72 h post-hatch) by another female has close to 40,000, possibly more based on coverage. The prolarvae are the gray patch around the bare black center. Prolarvae also stacked up among the rocks.
The dad is getting more active. It may be a method for keeping brood in nest. Somehow the brood aggregates.
Prolarval brood swarming behavior on September 2, 2017.
Prolarval brood swarming behavior on September 3, 2017. Note golden eyes becoming evident. Exodus may occur tonight although it is more more likely to occur tomorrow night.
Prolarvae in AM of September 4, 2017 getting really active now. Look closely and you should be able to see eyes as golden flecks. What I can see here much better than what you see filtered by camera and internet. Few people, even biologist, see this stuff.
Male Bluegill in adjacent compartment of same system jumped out. Most likely because he was going after flying insect attracted to light above tank. When he moved out the female Hand-paint Bluegill went bratty again. The Hand-paints are really prone to defending feeding territories.
Prolarval Coppernose in nest as they appear morning prior to exodus. Physiologically they are already larvae as would like eat if I put brine shrimp in nest with them. Tonight as lights dim they will swim out in mass such that is looks like smoke. Fathers of other sunfish species I have watched get really aggressive at that time. The black basses have to switch over to tending a mobile brood that somehow stays together in his territory.
The larva is from previous brood that is ~9 days post exodus. You can clearly see color coming from food in its gut. In terms of weight it is about 6 times what it weighed at exodus. They still look nothing like adults. Over the next few days the fin rays and spines will come in very fast.
Thanks so much again for sharing this with us! Its really amazing to see. Makes me want to go out this winter late and try to make a nice spot for spawning.
Worth while effort to that end is very much a function of your ponds topography. Do you have pics of where the fish currently spawn?
I might be able to talk you through process to make spawning site for a colony that is good enough to pull them up where you can see them and be comfortable. Will require some carpentry, sand and a small boat.
Excellent! Thanks, Jim, for sharing this great information people would otherwise not see. Let's work together to produce a story, or series, for Pond Boss. Interested?
No exodus yet. All still in nest. Apparently still a little yolk remained yesterday evening. Some of the prolarvae/larvae are neutrally buoyant so the occasionally bounce up into water column.
Bob, I am giving it some thought on how to proceed. We do some pretty cool stuff here that is likely very well aligned with the interest of Pond Boss.
Interest seems to be dropping off on this. If more interesting, we could start sampling fry and taking higher quality images so you can see what they look like as if you were not old enough to need glasses.
The young fish in the stock tank are proceeding slowly, largely due to low water temperature. Their siblings being reared indoors are now metamorphosing to the fry stage so are at the point they could be transitioned to a feed that will in another week or so completely replace the zooplankton they are currently being fed. The feed training is done at a size which is a lot smaller than typically realized in a pond setting.
Jim it's still interesting, I think it may be a case of the membership trying to figure out what components are immediately applicable to ponds. I know that's true in my case anyway. I enjoy learning the science behind my interests, but on the other hand when It's time to change the oil on my pickup I don't research to learn what species of dinosaur it came from, my immediate need is to identify what weight and type of oil, and where can I buy it?
I see our membership as diverse, and there is absolutely a faction that delves into the details. But I also think there is probably a larger segment that is looking for more pond how-to, rather than how it happens?
It's only one guy's opinion, and worth what you paid for it, but maybe integrating some of the info into a real world pond setting will help illustrate the repercussions and possibilities of what your discovering?
It's very interesting. I have been following it. Could the same technique be used to raise a batch of albino channel catfish? I have the adults in my pond.
"How to" can be improved by understanding "how it" happens. Understanding biology of systems / ponds you are interested in can help make informed decisions in how to manage. I have managed ponds quite a bit and many are for recreational fishing purposes, like more here. The process is a lot more rewarding when you can conceptualize what is going on at the level of individual animals and how it interacts with their life cycle.
Petroleum products I use are not derived from dinosaurs, at least not on any appreciable level.
"How to" can be improved by understanding "how it" happens. Petroleum products I use are not derived from dinosaurs, at least not on any appreciable level.
Absolutely agree. My trouble seems to be in finding an audience willing to expand upon their awareness in the manner I envision.
"How to" can be improved by understanding "how it" happens. Understanding biology of systems / ponds you are interested in can help make informed decisions in how to manage.
Jim I have been preaching this for years. The more you know/understand the better choices you can make.
Good. That will justify effort to get photographing system for small stuff back online this week. Images so far are using a little scope I purchased for about $150.
I would call these guys mesolarvae. Rays coming yet tail still heterocercal. I can get fish at this size (not saying age on purpose) to take feed. About 15 days post-exodus (after leaving the nest).
I too am very interested. I just do not have anything to add so I do not post. I just check it everyday for updated pictures on the little guys, and a description of where they are at in their lives. I agree on knowing where it came from will change your decisions later on.
This is a very simplified case, but when I was teaching ag (FFA), when I was about to fit a show calf for a show, knowing how the calves hair was taken care of directly effected what I was going to try to do with it. When you had 20 or 30 calves at a fair, time is VERY important, if a calf had not been taken care of correctly the months before the show, I wasn't about to try to spend an hour or so fitting it, when it would not effect the end result any. Now one that had been taken care of correctly and had its hair trained, well I would spend the time. If I spent that amount of time on every calf...well, I would have still been fitting after the fair was over. lol
Watching this has really prompted me to want to try to fix up a better area for spawning before next spring. Love the pics and info Jim...most over my head, but I'm really enjoying it. Thanks for taking the time!
Fry still alive and growing albeit slowly. They are on the cusp of being fry now, nearly a week behind full siblings of same brood being kept indoors.
I couple dragonfly nymphs also present and likely getting a couple of the fish. Midges likely dominated the dragonfly's fare. Still too many fish as they will over run forage base soon. Need to cull about three quarters of them as all I want is between 10 and 20. This late summer has been exceptional for the tank water temperature. Normally temperatures would consistently be in the lower 60's by now yet we are staying in the upper 60's to lower 70's. Still below optimal
Jim, Is the temperature the only factor effecting growth of the brood in inside compared to outside? What is optimal water temperature?? Mid 70's of what? Are both tanks getting the same forage?
Would love to see a video of the little guys. Do they stay in a ball or do they separate from one another at this stage?
Thanks for keeping us in the loop!! Was wondering yesterday how it was going.
Jim, Is the temperature the only factor effecting growth of the brood in inside compared to outside? What is optimal water temperature?? Mid 70's of what? Are both tanks getting the same forage?
Would love to see a video of the little guys. Do they stay in a ball or do they separate from one another at this stage?
Thanks for keeping us in the loop!! Was wondering yesterday how it was going.
Temperature, photoperiod, stocking density, water column characteristics and forage all differ between groups. Optimal temperature range for larval thru fry stages not worked out to my knowledge. Extrapolating from adult Northern BG may not be wise. We shot for mid to upper 70'S F when rearing fish for research purposes where rapid growth desired.
I have been having trouble making videos. Most of the fish were culled so as to reduce labor and needs for brine shrimp indoors. Camera does not focus on them well from above and underwater camera is on drugs when used for very small fish.
The larval through fry stages do form a large school although is not as tight as you would see with larval LMB. It is nothing like the schools you see with the larger catfish species that appear to roll as a ball while feeding. In cylindrical tanks when well fed, the small fish form a polarized torus (donut). When hungry they move about with a more random directions they face as looking for eats. After first feeding indoors, the torus is maintained for the balance of the work day. The fish in the outdoor tank are seldom so well fed to more constantly moving about. Distribution still not random.
Larval stages differ markedly between sunfish species and even between subspecies. Differences I think are critical to why some species are particular to some habitats and not others. A huge area of research possible with this.
The behavior discussion could go on for a very long time so will stop.
Something just happened with larger fry developing of the indoor system. Sometime since yesterday morning they started to clump up much tighter in small groups. I associate this with the transition from being highly mobile and pelagic to being more sedentary and associated with structure. With some sunfishes this can be associated with adoption of home ranges. No pecking order action yet but that is not far off. Fry about 2/3" total length and starting to get chunky when looking at them from above.
Not generally. The formation of the small shoals requires a mechanism to disperse surviving fry. Even with bass I have watched that go through same changes at much larger size, intrabrood cannibalism is not the rule. Age-1 bass and larger sunfish generally knock the age-0 brood back low enough that cannibalism does not kick in withing the age-0. The artificial thing you have with breeding bass in a pond without predators is where I see the intrabrood cannibalism.
In a tank setting where size disparity is extreme you can get cannibalism. Under those conditions you typically have additional loss in value due to more than cannibalism.
If you mean predation by taken on larger prey items, then yes, that is point where I expect the fish to take on bigger stuff as well. They still have diet dominated by zooplankton that is taken as it floats past cover patches the fry associate with. I think the more dominant fry in a given group can direct more attention to foraging while subordinates have to avoid getting displaced as they forage making foraging less efficient. Spotted Bass and SMB do much the same until they split into their exclusive little territories they advertise with their tricolored tails and parr marks.
I have seen LMB do similar but only the lateral stripe is obliterated that I can see easily. LMB more likely to keep moving about in little shoals.
I grade hard when confining black fingerlings. Additionally, you can suppress a lot of the outright aggression by increasing stocking density.
When a ponds are harvested for LMB fingerlings, the fingerlings are sorted immediately to uniform size classes where there can be as many as four classes. Fish that are abnormally large / suspected cannibals are tossed in with larger fish as forage. Once they are feed trained, interest in eating brethren is greatly reduced. My preference is to bring fry into confined when only 1" as they are still in schooling mode with dad. That also generally before zooplankton bloom crashes.
If all goes well, next spring we will be feed training about 10,000 each of LMB and Spotted Bass for use in experiments. Some can be set aside for photographs showing color changes related to what I do not like to see.
Water mites that were very abundant today appear to targeted now by the fry. Larger adult female appear to to be immune. I generally do not consider water mites a good forage for any type of fish. The brightly colored red mites and blueish mites I think taste bad to fish.
We are actively looking for Spotted Bass and may seek to be a supplier ourselves. We need to have lots of Spotted Bass for a food-fish trial where they will be compared to LMB used to supply the live-fish market. It is fun wading through the legal code trying to see how it can be done.
I want to culture native stock rather than import a strain from down south. Not 100 yards from our ponds we have a strong Spotted Bass population that is generally considered invasive at the expense of Smallmouth Bass. The Spotted Bass moved in only a couple decades ago, possibly through natural range expansion. Not all Smallmouth Bass stocks are handling that well. In one location, where I did crayfish work about 20 years ago, a lot of hybrids were evident that have now been largely replaced by Spotted Bass.
I just made visual estimate on the number of surviving fish. It appears to be at least 80 fish and they are catching up to indoor-reared siblings. Temperature outside over last week has been flirting with what I think is lower part of the optimal range for growth. I am also also supplementing forage with brine shrimp nauplii that are less than 24-h old. Very soon the fry will start going after insects at surface. This has not been a normal year as normally we would start looking for frost. We have not had normal years for at least a decade.
Fry are now about 40 days post-conception. Larger fish are pushing an inch. They are now getting chunky in width and depth. I am providing am supplementing forage with a combination of live and dried feeds. Indoor fish at least four times mass of those outside. Fish now move into structure rather than away when a shadow goes over them. Current size is now in range where typical small nets / seines will pick them up. Soon I will place them in tanks of an RAS where they will be fed exclusively on a salmon starter until they are about 2.5 inches long which for many will be realized in another 45 days. Then they will be tagged and combined into a larger tank where they will be pushed to breeder size by next spring.
Food quality and quantity I think are roughly similar. What likely sets indoor ahead is the warmer temperature. The tank does experience a range of temperatures that are likely on average below what is optimal for BG larvae and fry. The indoor setup holds a very steady 25 C where growth rates we see at least match best you can find in the literature. That said, we do not know optimal temperature for such early life-stage BG, regardless of subspecies.
Temperature in stock tank now down into middle 40's F, below what these guys would ever experience in the wild. The fish are only three generations from collection out of natural waters near Tampa. None appear to be interested even in live BS so likely not feeding. They are far too small and thin to go into winter, even if they were Northern Bluegill. Will harvest all that remain and acclimate them to a 75-gallon aquarium for winter.
Tank will then be drained till next March. Round two will involve breeding Fliers in same tank. I really want get pictures of a male Flier on the nest, then rear them up in the same tank.
CNBG even a few generations from their natural homeland don't do well in cold water. Probably at/near there minimum lethal temp at low 40s. Sounds like a good plan.
