Observation of Dollar Sunfish Nest building

First off this is going to be a little long because of the multiple nests in one tank. As some of you know I have been using my Dollar Sunfish as surrogates for spawning Bluenose Shiners (Pt. welaka). Had some luck last summer with that project and brought all of the fish in to over winter. I put all of the Dollar Sunfish into my community 125 gallon just ot hold them over till next spring. Well apparently they couldn't wait because I have 3 dollar sunfish nests in the tank and each nest is slightly different. I am sure they have spawned once because I came home from work one day and all of the Spotfin shiners were picking something out of the nest of one of the Sunfishes. I will try to describe the nests for you. I have some pictures, but they need some work done to them.
Nest #1. This nest is made by the only wild caught that I have left. These were collected on the NANFA Convention in South Carolina. You can figure out what year. The nest is about 4-6 inches across and shallow dug. It is located right next to the stump I have in the tank. He tends to hide near the stump all the time. What was interesting about his nest is, once it was dug, the male carried in rocks a little bit bigger than pea gravel and filled the nest in with them.
Nest #2. This was built by one of my first offspring from spawning the Dollar Sunfish outside. The male is actually the larger male and seems to be the dominate male now. This nest is built in the middle of the tank and and extends from front to back and is every bit 12"+ . It is also the deepest nest in the tank. It is the one we watched the shiners eat something out of. What is interesting about this nest is for weeks it was just a depression in the gravel/sand with nothing in it. I came home today and he has started to stack rocks in his nest also.
What I find funny is where are they getting the rocks? I didn't know I had that many in there. I will add some more later for them to use.
Nest #3. This nest is built by one of the runts of the first spawn of the Dollar Sunfish. The 2 males are actually brothers, but you couldn't tell by size. The dominate one is at least twice the size of the runt. The runt has built a 4 - 6" nest that is deep. It is at the opposite end from the other nests. Lately tho he has started to build another nest in a pot I have for plants.
Some other observations on the activity in my 125. When the Spotfins were eating the eggs(I am assuming this) from the nest, no other fish were touching the nest. I had Golden shiners and Common shiners in the tank and they didn't even go near the nest. I will probably move the runt male plus a couple of other males, leaving the two largest males with the two females. The bad thing now is I wish I had some adult Welakas right now, because I would like to throw them in to see if they would spawn. If anyone knows where I can get some welakas, let me know? I have eight fry from last summers spawn, but i don't think they are quite ready.

Like i said I have some photos to massage and then post.

Thanks,
Bill Flowers

First off this is going to be a little long because of the multiple nests in one tank. As some of you know I have been using my Dollar Sunfish as surrogates for spawning Bluenose Shiners (Pt. welaka). Had some luck last summer with that project and brought all of the fish in to over winter. I put all of the Dollar Sunfish into my community 125 gallon just ot hold them over till next spring. Well apparently they couldn't wait because I have 3 dollar sunfish nests in the tank and each nest is slightly different. I am sure they have spawned once because I came home from work one day and all of the Spotfin shiners were picking something out of the nest of one of the Sunfishes. I will try to describe the nests for you. I have some pictures, but they need some work done to them.
Nest #1. This nest is made by the only wild caught that I have left. These were collected on the NANFA Convention in South Carolina. You can figure out what year. The nest is about 4-6 inches across and shallow dug. It is located right next to the stump I have in the tank. He tends to hide near the stump all the time. What was interesting about his nest is, once it was dug, the male carried in rocks a little bit bigger than pea gravel and filled the nest in with them.
Nest #2. This was built by one of my first offspring from spawning the Dollar Sunfish outside. The male is actually the larger male and seems to be the dominate male now. This nest is built in the middle of the tank and and extends from front to back and is every bit 12"+ . It is also the deepest nest in the tank. It is the one we watched the shiners eat something out of. What is interesting about this nest is for weeks it was just a depression in the gravel/sand with nothing in it. I came home today and he has started to stack rocks in his nest also.
What I find funny is where are they getting the rocks? I didn't know I had that many in there. I will add some more later for them to use.
Nest #3. This nest is built by one of the runts of the first spawn of the Dollar Sunfish. The 2 males are actually brothers, but you couldn't tell by size. The dominate one is at least twice the size of the runt. The runt has built a 4 - 6" nest that is deep. It is at the opposite end from the other nests. Lately tho he has started to build another nest in a pot I have for plants.
Some other observations on the activity in my 125. When the Spotfins were eating the eggs(I am assuming this) from the nest, no other fish were touching the nest. I had Golden shiners and Common shiners in the tank and they didn't even go near the nest. I will probably move the runt male plus a couple of other males, leaving the two largest males with the two females. The bad thing now is I wish I had some adult Welakas right now, because I would like to throw them in to see if they would spawn. If anyone knows where I can get some welakas, let me know? I have eight fry from last summers spawn, but i don't think they are quite ready.

Like i said I have some photos to massage and then post.

Thanks,
Bill Flowers

Bill,

Your observation of dollar sunfish putting coarser material into the nest is very interesting. Some of the coarse / large particle size material I expect to concentrated deeper in your aquarium gravel owing to interactions of particle size, gravity and bioturbation.

Did you actually see your fish move the rocks by mouth?

My redear and redspotted sunfishes, especially the latter, move rocks out by mouth sometimes swimming several feet from nest before ejecting and returning for more. Placing coarser material into nest might provide cover for prolarvae, especially from nest robbing sunfishes and minnows.

I have not seen my western dollar sunfish do what you describe but makes me want test since they are nesting on sand.

Jim

Bill,

Your observation of dollar sunfish putting coarser material into the nest is very interesting. Some of the coarse / large particle size material I expect to concentrated deeper in your aquarium gravel owing to interactions of particle size, gravity and bioturbation.

Did you actually see your fish move the rocks by mouth?

My redear and redspotted sunfishes, especially the latter, move rocks out by mouth sometimes swimming several feet from nest before ejecting and returning for more. Placing coarser material into nest might provide cover for prolarvae, especially from nest robbing sunfishes and minnows.

I have not seen my western dollar sunfish do what you describe but makes me want test since they are nesting on sand.

Jim

I have not actually seen them moving the rocks, but it seems they do most of their arranging/nest building after lights out. After the lights go out I can set across the room and watch more activity. During the day they seem to want to posture and protect the nests. What made me think they were moving the rocks around was the fact that the dominates males nest had no rocks in it last night and when i got home from work this morning, the nest had a few in it.

Bill

Bill,

My sunfish dig only with lights on or in daylight. When my presence disturbs them, they will stop digging but still defend nest site. Your reduced lighting might make harder for them to see you. Your dominate male may have had burst of digging while you were away, tail sweeping out the light stuff thus leaving behind coarser material. Have ever used a webcam? Might enable you to observe action in tank but be out of line-of-sight. The digging behavior might then be observed.

Bill, I too was thinking it is likely the males just have been digging out the nest more and the lighter smaller sand or gravel is more easily removed by the sweeping motion of their tail leaving behind only the larger stones that were buried before. I have seen this quite a few times in my tanks with various species of sunfish. This seems most visible in tanks with a more natural substrate that I collected myself out of a local stream because it has a large variety in the size of particles mixed in.

Bill, I too was thinking it is likely the males just have been digging out the nest more and the lighter smaller sand or gravel is more easily removed by the sweeping motion of their tail leaving behind only the larger stones that were buried before. I have seen this quite a few times in my tanks with various species of sunfish. This seems most visible in tanks with a more natural substrate that I collected myself out of a local stream because it has a large variety in the size of particles mixed in.

You may be right, but as an experiment, I am adding some small stones around the tank and see what happens. I had a trio of Longears several years back and when the male started building the nest, he would totally ignore anything outside of the tank. I could set next to the tank and watch him build the nest.


Bill F.

Bill,

Get any results yet?

Jim

You may be right, but as an experiment, I am adding some small stones around the tank and see what happens. I had a trio of Longears several years back and when the male started building the nest, he would totally ignore anything outside of the tank. I could set next to the tank and watch him build the nest.


Bill F.

You could also take the larger stones out of the nest see if he puts em back.

Surprised no one else mentioned it...
I wonder if the welakas use those nests because of the stones?
Or maybe the sunfish put the stones in there to attract the welakas?
Shiners spawn in chub nests made from stones, maybe there's a relationship?

Or maybe your captive fish are bored and moving stones unnaturally...

There are probably two things attracting shiners to constructed nests: the pheromones released by the host fish spawning, and the fact that the host fish is guarding the nest against most comers so all the eggs present have a better chance of surviving to hatching. And maybe something else, too?

There are probably two things attracting shiners to constructed nests: the pheromones released by the host fish spawning, and the fact that the host fish is guarding the nest against most comers so all the eggs present have a better chance of surviving to hatching. And maybe something else, too?

Well None of the stones I put in outside of the nest have moved. Either he is happy the way it is or you are right about their being rocks in the gravel when he dug the pit. I now have another male starting to dig and I think I am going to move a couple of the males out just to reduce some of the tension in the tank. Five males and two females may be a little much for the two females. Even tho my Welaka are about half grown, I think I will put them in the 125 with the Dollars. If nothing else they will grow out faster for the summer.

Bill F.

Bill,

You males may move rocks only during part of the nesting cycle. A fresh nesting bout may be required for behavior to be repeated.

Watch to see if your remaining male dollar starts to patrol / defend a larger territory since the others were removed. He may not allow females a refuge if he does not have to contend with rival males. That is a problem I have to deal with frequently.

Bill,

You males may move rocks only during part of the nesting cycle. A fresh nesting bout may be required for behavior to be repeated.

Watch to see if your remaining male dollar starts to patrol / defend a larger territory since the others were removed. He may not allow females a refuge if he does not have to contend with rival males. That is a problem I have to deal with frequently.

I wasn't going to remove all the males, because I feel they need to have something to take the aggression out on. I was going to remove 2 males and still leave 3 males and 2 females in the tank. Also going to add my Welakas, if nothing else to grow them out faster for the spring/summer outdoors. I am adding some pictures of the nests in the early stages.

Nest #1

 Nest1.jpg   76.85KB   3 downloads


Nest #2

 Nest2.jpg   86.81KB   0 downloads


Nest #3

 Nest3.jpg   90.83KB   0 downloads

Nest #2 is the dominate male and is the most aggressive builder and protector.

Well I am back with some more observations. The male is definitely moving things into the nest. I had taken the 2 pieces of PVC pipe out of the nest thinking he wouldn't like it anyway. I put the pieces of PVC at least 2" outside of the nest and this morning I found both of them back into the nest. Don't know how or when he did it, but he did. Thinking of taking a picture of the nest tonight and then in the morning and compare. Below is the nest of the dominate male.

Bill F.


 DSC_0003A.jpg   102.76KB   0 downloads

Is he doing it by mouth or tail-sweeping? We now use oil pans as more managable nest sights. Our longear and bluegill just tail sweep. On the other hand, redear are real bad about moving rocks by mouth all over the place. The habit makes it so that our efforts to keep tank bottom clear of debri must be repeated failry often. Movment (maybe just net like in economics) appears to always be away from nest but we never setup to distinguish direction of a given item as you are doing.

What is the nest diameter? Relative to the male's length? Are pro-larvae present? Custodial activities might vary as a function of brood developmental stage. I have suspicion that is case with my bluegill and what makes it hard to replicate observations.

Do you have white / pink or blue rocks? Red spots seem to move colored rocks from nest very quickly.

Edited by centrarchid, 09 March 2010 - 06:15 AM.

Is he doing it by mouth or tail-sweeping? We now use oil pans as more managable nest sights. Our longear and bluegill just tail sweep. On the other hand, redear are real bad about moving rocks by mouth all over the place. The habit makes it so that our efforts to keep tank bottom clear of debri must be repeated failry often. Movment (maybe just net like in economics) appears to always be away from nest but we never setup to distinguish direction of a given item as you are doing.

What is the nest diameter? Relative to the male's length? Are pro-larvae present? Custodial activities might vary as a function of brood developmental stage. I have suspicion that is case with my bluegill and what makes it hard to replicate observations.

Do you have white / pink or blue rocks? Red spots seem to move colored rocks from nest very quickly.

I am not sure how he moves the items. I work nights and when I come home the nest is different. Not sure if he is doing the moving at night or in the early morning before I get home. The lights are on a timer with 12 hours on and 12 off. The nest itself is roughly 15" in diameter. I would guess it is about twice the size of the male. I noticed this morning that two of the females are hanging with him now. Before he would chase them away. Guess I need to feed them more now hopefully to keep them full and lessen any egg eating. I don't see any larvae yet but am thinking of siphoning the nest(at least part of it) to see if i get any eggs. The females still look pretty round so I doubt they have spawned yet. As soon As they are thinner I will probably siphon out part of the nest.

Bill F.

Sounds like a good AC article!

Bill,

There is definantly periodicity with male digging behavior with ripe females causing an increase. When you say night, how low do your lights go. If you can see, then your male may be able to well enough to want to dig even with lights "out". The eggs require only about 36 hours to hatch. We often miss eggs if nest not checked daily, especially if the male continues to tail-sweep. Pro-larvae could easily be right under your nose. Yes, siphon a little to see if they are there. If they are old enough, then the little buggers can avoid your siphon giving a false negative.

Generally a male sunfish has little trouble keeping unwanted females away. His tolerance of their close proximity could indicate little or no brood in nest or they (females) are nearly ripe. Although ripe females should also keep him in a "dancing" mood.

Your dollar sunfish of the east coast variety?

Bill,

There is definantly periodicity with male digging behavior with ripe females causing an increase. When you say night, how low do your lights go. If you can see, then your male may be able to well enough to want to dig even with lights "out". The eggs require only about 36 hours to hatch. We often miss eggs if nest not checked daily, especially if the male continues to tail-sweep. Pro-larvae could easily be right under your nose. Yes, siphon a little to see if they are there. If they are old enough, then the little buggers can avoid your siphon giving a false negative.

Generally a male sunfish has little trouble keeping unwanted females away. His tolerance of their close proximity could indicate little or no brood in nest or they (females) are nearly ripe. Although ripe females should also keep him in a "dancing" mood.

Your dollar sunfish of the east coast variety?

The lights go off at 8 PM every night so there is some ambient room light that he might be able to work in. Also the lights come on at 8 AM, but their could be some day light coming in before the lights actually come on. Yes after the lights go off I can still see into the tank from across the room. I am trying not to get to close to the tank or mess with him much. Don't want to make him mad. I did notice that the females look a little smaller. Will probably do some siphoning in the morning.
These are the East Coast variety, specifically South Carolina.

Bil F.

Bill,

I am not that familiar with your eastern dollar sunfish. They may not be as aggressive in defense of the nest as western dollars.

Your lighting appears more than adequate for nocturnal digging behavior.

I do not like shy sunfish so getting them accustomed to the observers presence is almost a must.

Most of the sunfishes I have messed with while they were in breeding mode can be very quickly acclimatized to your being in close proximity. My best trick for habituating them to my presence when they are in a home aquarium is to sit nearby, face away and do something like read a book. Avoid rapid movements. After about 15 minutes or so of hiding the male is very likely to resume his defensive station over the nest. Giving him a small food item he likes after the fifteen minute exposure might also help him relax.

I have had problems with coppernose bluegill that would not settle down, so I constructed a blind (sheet with a hole in it) and sat so I could peek out at the male. Another trick is to sit in relative darkness beside tank but make sure the male is in a well lit location.

Jim