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.
Last edited by Jim Wetzel; 08/20/1712:16 PM.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Last edited by Jim Wetzel; 08/21/1705:37 AM.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
I'm always at work at least an hour before starting time. Been a habit of mine for decades.
"Forget pounds and ounces, I'm figuring displacement!"
If we accept that: MBG(+)FGSF(=)HBG(F1) And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1) Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT? PB answer: It depends.
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.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Typically males do not feed while tending brood.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Last edited by Jim Wetzel; 08/22/1711:16 PM.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.
Close up showing limitations of my camera.
Aquaculture Cooperative Research / Extension Lincoln University of Missouri
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.