Ever wonder why male clownfish are smaller?

[peachyreef]

Today in my animal behavior class, my professor talked about a case study that was worked on by a grad student at Cornell. The case study was about cooperation in clown fish.

Initially large individuals (clown fish) who find an anemone, guard it. If an individual of similar size comes the intial clownfish will fight it off. Because it doesnt want to live with an individual who constantly tries to gain dominance. But if a smaller individual comes into the anemone. The female will fight with it and eventually allow it to stay.

Then if another SMALLER individual comes into the anemone, the female wont challenge it but the new alpha male will, and then they fight. If the new beta male can hold his own but not overly challenge the alpha male he can stay too. This continues depending on the size and size of the anemone.

But the males cannot grow or the female will feel challenged. SO how do they stay the same size?!?

The female essentially stresses the male out so that he doesn't grow. The average clown fish has 40 fights a day. This induces the males who fight amongst each other and the male who is being beat on buy the female, to have elevated stress hormone. That stunts growth.

Then when the female dies..... the alpha male clownfish is no longer being stressed so he grows and changes sex to be the new female. Then all the other males increase in size slightly. Males will not grow unless the others in the group grow so that they are not with out a home. So its forced cooperation gives them a place to live.

I thought it was really neat and that I would share

 

[stacy22]

Sounds like "HouseHusbands of Anemone Hills"

 

[hammcd]

that is very cool...i wonder if im so short caused i was too stressed when i was a kid lol

 

[haninja]

Good thing this doesn't happen to humans or I couldn't even reach the keyboard to write this.

 

[peachyreef]

Hahaha men.

 

[rdnelson]

I think the study is flawed. If "The female essentially stresses the male out so that he doesn't grow." how is it that my gut has continually grown since the day I got married????? I am just saying........

 

[dakota9]

I got two Onyx Mis-bar Clowns from Keen Reef 2.5 years ago. Granted, they were tiny when I got them, they have both grown, but they are still the exact same size as each other. How long does it take for a clown to turn female?

Anyone know?

 

[stacy22]

Dakota9;702807 wrote: I got two Onyx Mis-bar Clowns from Keen Reef 2.5 years ago. Granted, they were tiny when I got them, they have both grown, but they are still the exact same size as each other. How long does it take for a clown to turn female?

Anyone know?

I remember when you got those from Tim the day of the tour of tanks! I would have thought they would start to differentiate in size by now??????

 

[dakota9]

Yea...... Those are the ones.....

They are real b*tchy toward each other, but otherwise very healthy, and to date, the only fish I've had since I got back in the hobby (about the time I met you Stacy!).

Usually when males cohabitant, one becomes the girl in very short order. At least that's the way it works with humans anyway.........

 

[peachyreef]

Haha like in every study I'm sure its not 100% true, but its way cool. Glad ya'll liked it.

 

[ralph atl]

my female is more than twice the size of my male....

 

[rdnelson]

Yes but what about your fish??? Oh, come on now, that was a joke.