Bluegill behavior

Every so often I see one or two of my Bluegills "sweeping" a hole in the gravel with its tail.

I read another post about how another member's Sunfish may in breeding mood but as this one is the biggest and most aggressive in the tank, I'm not sure.

Has anyone seen their fish doing this?

Yep. He's building a nest. He is likely to remain near the nest and become maybe even more territorial.

We have the same behavior going on now with a good number of our males. It is very likley a female or two is nearly ripe and spawning will occur very soon. Any of the others showing a plump belly and occasionally getting dark eyes. When she does this the digging male may do a dance for her.

Just about all my male sunfishes do it, perfectly normal and typical behavior. Watch out though, with their increased desire to breed they'll get more aggressive. Most of my males need to be kept alone and once they start wanting to breed it never seems to stop.

Just about all my male sunfishes do it, perfectly normal and typical behavior. Watch out though, with their increased desire to breed they'll get more aggressive. Most of my males need to be kept alone and once they start wanting to breed it never seems to stop.

Breeding behavior can be suppressed by lowering temperature or the amount of time lights are on.

Breeding behavior can be suppressed by lowering temperature or the amount of time lights are on.

Yeah, I know that but seeing as how they all live in my livingroom and kitchen it really is not practical to decrease the photoperiod and make the house colder for the sake of the fish. Maybe when I get a fishroom...

Edited by sandtiger, 28 May 2009 - 06:32 AM.

Yeah, I know that but seeing as how they all live in my livingroom and kitchen it really is not practical to decrease the photoperiod and make the house colder for the sake of the fish. Maybe when I get a fishroom...

You can could use a timer on lights. Photoperiod can include variables such as intensity and spectrum. Dim lights / block direct sunlight.

Try following to bypass need for photoperiod manipulation.

Purchase melatonin pills, pulverize into powder and add to a live feed item just before offering to fish. Will need to be repeated daily.
I would attempt to supply a dosage about 10 times recommended for human use.

This not USDA/ FDA approved.

You can could use a timer on lights. Photoperiod can include variables such as intensity and spectrum. Dim lights / block direct sunlight.

Try following to bypass need for photoperiod manipulation.

Purchase melatonin pills, pulverize into powder and add to a live feed item just before offering to fish. Will need to be repeated daily.
I would attempt to supply a dosage about 10 times recommended for human use.

This not USDA/ FDA approved.

Well it truthfully doesn't bother me all that much, its just preventing me from keeping them together. I may try light dimming, I wasn't aware that that could have an affect, figured it would have to be lights off to work. Admittedly the lights are on up until I go to sleep, generally around midnight.

Lights with less blue / ultraviolet in spectrum might have same result.

Hi Folks:

Interesting topic for me, as I was given a well marked male Longear Sunfish this spring to replace a male Bluegill I had raised for roughly 3 years and died of Ich.

The Longear shares a 35 gallon tank with a much larger 3 year old Bluegill female and are separated by a plastic tank divider with a substrate mixture of gravel and fine sand.

Within a couple of days of being introduced to the tank, the two of them were always at the divider gazing at each other like two 14 year olds at a high school dance. The Longear was a real treat to watch when he displayed nest building behaviour.

You might have seen a picture of a drag racer taken right at the moment the light turns green and the rear half of the dragster is obscured by smoke form the tires ..... well, thats how he looked as he was fanning up loose sand in a large cloud with only his front half visible in the cloud of sand ..... it was really, really neat to watch. Sort of like this picture. http://www.hugewallp...gster-68845.htm


I tried to get pictures but this activity only lasted a few seconds at a time and by the time I got the camera powered up and focused, he would stop and I never got any pictures. I thought it was pretty slick that he could use his tail to fan up such a large volume of water and sand without forward motion ... how the heck do they do that?

Thinking they were ready to spawn, I removed the divider and left them together for a couple of days. At first it was OK, with both of them displaying breeding behaviour, but one morning I came down stairs and noticed the male had the female cornered in the tank and her fins were ragged and scales were missing.

That was enough for me, so I placed the divider back where it was and they've been apart for the last few months but spend hours each day at the divider behaving like star-crossed lovers separated by the Berlin Wall.

All in all, it has been a very interesting experience and I hope they do indeed have "young uns" eventually.

Regards to all,
Radioguy

Hi Folks:

Interesting topic for me, as I was given a well marked male Longear Sunfish this spring to replace a male Bluegill I had raised for roughly 3 years and died of Ich.

The Longear shares a 35 gallon tank with a much larger 3 year old Bluegill female and are separated by a plastic tank divider with a substrate mixture of gravel and fine sand.

Within a couple of days of being introduced to the tank, the two of them were always at the divider gazing at each other like two 14 year olds at a high school dance. The Longear was a real treat to watch when he displayed nest building behaviour.

You might have seen a picture of a drag racer taken right at the moment the light turns green and the rear half of the dragster is obscured by smoke form the tires ..... well, thats how he looked as he was fanning up loose sand in a large cloud with only his front half visible in the cloud of sand ..... it was really, really neat to watch. Sort of like this picture. http://www.hugewallp...gster-68845.htm


I tried to get pictures but this activity only lasted a few seconds at a time and by the time I got the camera powered up and focused, he would stop and I never got any pictures. I thought it was pretty slick that he could use his tail to fan up such a large volume of water and sand without forward motion ... how the heck do they do that?


Thinking they were ready to spawn, I removed the divider and left them together for a couple of days. At first it was OK, with both of them displaying breeding behaviour, but one morning I came down stairs and noticed the male had the female cornered in the tank and her fins were ragged and scales were missing.

That was enough for me, so I placed the divider back where it was and they've been apart for the last few months but spend hours each day at the divider behaving like star-crossed lovers separated by the Berlin Wall.

All in all, it has been a very interesting experience and I hope they do indeed have "young uns" eventually.

Regards to all,
Radioguy

The tail-sweeping male clamps his tail fin, and simply flexes his body back and forth which is different form flexing associated with forward swimming where the flexing begins in the body front and propogates to the back. The pectoral fins also fight forward motion through exagerated movements pushing backwards.

Longear sunfishes not always the easiest to spawn in such small tanks (35-gallon is small). Male will regard entire tank as his when courting and female will have no refuge from his advances. With northern longear I use two or three nest building males in a 75-gallon tank and provide lots of plastic plants for females to use as cover. Males direct much of their aggression at each other.

The female may not be so much in love as in needing to get her eggs off and she is desperate enough to have a longear help out even though under normal conditions she would normally avoid him in favor of a male bluegill.

Just about all my male sunfishes do it, perfectly normal and typical behavior. Watch out though, with their increased desire to breed they'll get more aggressive. Most of my males need to be kept alone and once they start wanting to breed it never seems to stop.

I may look into a tank divider. The dominant Bluegill is extremely aggressive and many times keeps the other three at one end of the 100 gallon tank.

I have what I think is a Green Sunfish that is quite docile (except when I feed crickets) that I keep in the 40 with another very calm, good sized Bluegill along with two small ones.

Interesting responses here. I will keep an eye on them. Thanks for the replies.

As a general rule with bluegill (except the coppernose variety) housed in tanks larger than 55-gal, the negative effects of breeding male aggression can be suppressed by having more than one territorial male in the tank. A male redear can be the same as a second male bluegill. Males fight, usually more as a display, with each other and not so much with females.