Male mandarin attacking female mandarin

[CoolGuy77]

So as the title says, I have a male and a female green mandarin. I have had the male for close to 3 years now, and he eats pellets. About six months ago I got a female mandarin and trained her to eat pellets as well. I had them in two separate tanks and just recently combined them when I set up my new reef tank. Besides the clean up crew, they are the only fish in the system.

 

The first day I combined them the male stayed close to the female and displayed his fin. Over time, I started to notice the male not only display it's fin, but also chase the female around whenever he saw her. This went on for a week or two. I never saw him clamp down on her, like I've seen two males do before, but he would chase her aggressively relentlessly until she got away. I happened to have an acrylic piece that was the exact width of the tank so I separated the two of them. They have been separated for probably close to a month now, but can see each other through the acrylic and some slits. The male still displays his fin when he sees her, and I'm not sure if I should remove the acrylic and let them together for longer.

 

I'm not sure what happened and I'm wondering if anyone has any experience introducing two mandarins and if that kind of aggression is normal for a little while. I've heard of females attacking males if they are similar in size, but this is the male attacking the female. Before anyone asks, I'm positive I have a male and female. The female is much smaller, has no dorsal spine or remnants of a broken one, and her stomach is much wider than the males. I've also had her for 6 months so at this point, I also would have known for sure if it was a younger male. The aquarium is a 20 long with lots of rock work. Before anyone jumps and says they need a bigger tank for pods, I'm not worried about them starving in a 20 long because they are both pellet trained, and had been living in smaller aquariums than that until recently.

 

Any helpful advice or past experiences are appreciated!

[Cencalfishguy56]

So as the title says, I have a male and a female green mandarin. I have had the male for close to 3 years now, and he eats pellets. About six months ago I got a female mandarin and trained her to eat pellets as well. I had them in two separate tanks and just recently combined them when I set up my new reef tank. Besides the clean up crew, they are the only fish in the system.

 

The first day I combined them the male stayed close to the female and displayed his fin. Over time, I started to notice the male not only display it's fin, but also chase the female around whenever he saw her. This went on for a week or two. I never saw him clamp down on her, like I've seen two males do before, but he would chase her aggressively relentlessly until she got away. I happened to have an acrylic piece that was the exact width of the tank so I separated the two of them. They have been separated for probably close to a month now, but can see each other through the acrylic and some slits. The male still displays his fin when he sees her, and I'm not sure if I should remove the acrylic and let them together for longer.

 

I'm not sure what happened and I'm wondering if anyone has any experience introducing two mandarins and if that kind of aggression is normal for a little while. I've heard of females attacking males if they are similar in size, but this is the male attacking the female. Before anyone asks, I'm positive I have a male and female. The female is much smaller, has no dorsal spine or remnants of a broken one, and her stomach is much wider than the males. I've also had her for 6 months so at this point, I also would have known for sure if it was a younger male. The aquarium is a 20 long with lots of rock work. Before anyone jumps and says they need a bigger tank for pods, I'm not worried about them starving in a 20 long because they are both pellet trained, and had been living in smaller aquariums than that until recently.

 

Any helpful advice or past experiences are appreciated!

screw whoever jumps the gun, let me know how you trained them on pellets!

[CoolGuy77]

screw whoever jumps the gun, let me know how you trained them on pellets!

 

Hahaha

 

I actually wrote an article about how I trained the female mandarin. It took about a month of training, but she eats pellets

 

http://www.fishstoresnearme.com/articles/mandarin-fish-pellet-training-new-method/

 

My male ended up doing it on his own after a year.

[Tamberav]

This isn't that uncommon for males and females to fight. Sometimes its a food issue, sometimes that particular male and female just don't get along.

 

It is best to have the biggest size difference possible.

 

I had 6 dragonetts in a 20g successfully for a long while but it was heavily planted and had a stupid amount of pods. They were all trained on frozen, some pellets but there was also constant pods, perhaps having so many pods to pick at kept them distracted. Hard to say. I copied Matt Peterson's type of set up when he had a few breeding pairs in one tank. I can say that setup was successful for me also for happy spawning mandarins.

 

If you haven't read the mandarin issue of coral magazine, it is very informative. Marine Breeder website is also a good resource. I know you may not be trying to breed, but you may still find some information on the insight of pairing them.

[CoolGuy77]

Thanks for the reply, I'll definitely have to read the mandarin issue of coral magazine. I know they have enough food, but it's possible they don't realize it and are thinking they'll need to compete. Also, to your point, my end goal is to have them spawn, so I really want them to get along.

[metrokat]

What is their size difference? Any pictures?

[CoolGuy77]

They're sleeping right now, but I'll get some pictures posted tomorrow. The male is larger than the female, but he's still on the smaller size.

[CoolGuy77]

Here are some pictures of the mandarins I took this morning.

[metrokat]

They're so cute.

Hard to tell which one is which but it is possible that if the male is a small guy, the other one may be a juvi and could also be male. Juvenile males do not have a pronounced dorsal fin, and so can be mistaken for a female.

 

This picture shows you the size difference that works well for a pair.

Basically he has to be the size of Dwayne Johnson, and she needs to be like Ariana Grande

 

[CoolGuy77]

Hahaha nice pictures!

 

The first picture I posted is the female that's getting attacked and the second picture is the male who does the attacking. I've only heard of females attacking males that are close in size, not the other way. I've had the female for about 6 months or more so I figured if it was a juvi male it's dorsal spine would have started to show by now. I wonder if because I put them both in at the same time that caused the issue. I'm hoping when I release the male from his portion of the tank, he feels like he has his territory already or something.

[sheen]

Here's what I would do. If possible, remove the male, put him in isolation (or even in a breeder net) for a few days. You want the male to feel like he is entering a totally new environment. Let the female settle in to the whole tank, maybe rearrange some rock, then reintroduce the male in the evening when lights are dim. Keep a close eye on them. If both are in good physical condition you should see little aggression. Maybe some flaring at first but nothing that won't die down. Pretty soon they will just ignore each other. With mandarins there is this theory that maybe they "just don't like each other" but I don't subscribe to that theory. They do not form pair bonds in the wild and are lek-type in breeding structure, so as long as they are both healthy, they should leave each other alone except in the twilight hours.

[CoolGuy77]

Just wanted to provide an update for anyone interested or for anyone who stumbles across this later. A few days after the last post I tried to introduce them again. Within hours the male was chasing the female aggressively and actually broke his own dorsal spine off on a rock in the tank while chasing her. I separated them again by dividing the tank. About 2-3 weeks after that his spine had started to regrow, and he actually jumped the barrier into the other side, my wife accidentally left the lid off. I decided I would let them stay together and hope the aggression would lessen over time. After about a month of this, he is still chasing her aggressively anytime he sees her. She now hangs out in the corner of the tank hiding from him. So I decided to separate them again today. I'll be setting up a separate tank I can put him in for a while and let her have the whole tank. I'll try to reintroduce them again after 2 or more months maybe and if that doesn't work he'll be banished from my main tank.

 

One thing I wanted to point out is I now have no doubt I definitely have a male and a female. When the male broke off his spine, I could tell his top fin was still shaped differently than the females. Also, it only took him about a month to grow it completely back, so if the other was indeed a male, it would of had it's spine grow back by now considering I've had it for a little under 8 months now.

 

I know I shouldn't get mad at a fish for just being a fish, but he pisses me off when he chases her for no reason. It's very frustrating.

[sheen]

How's the body condition and food availability? Before setting up my breeding pair of S. picturatus I had some serious aggression. I removed the male and fattened him up more, since he had just come out of QT. After another 4 weeks of QT, he was fatter and reintroduced with brief aggression, which subsided after the first few days. Same deal with the pair of S. splendidus I just setup. I bought them at the same time and attempted to QT together. That didn't work- the male attacked the female so I separated them and finished QT. After 5 weeks of QT for the female I introduced her to the DT, then the male followed after another week. Both were in great physical condition and the aggression subsided after 2 days. Now I am getting spawning behavior nightly (after 1st week of introduction).

 

So.... I think you can succeed. Maybe feed the heck out of the male and get him super well nourished. Body condition is the number one reason opposite sex dragonet pairs do not get along.

[CoolGuy77]

Just saw this post now, I'm glad to know someone who went through the same thing as me. I have them separated from each other for now. I put together a Mandarin diner which I'm hoping will help. He's in good condition, had him for about 3 years now. I could see food being the cause though. I'm hoping that by giving him access to unlimited for throughout the day in the diner his aggression with go down. We'll see!

[CoolGuy77]

Just wanted provide an update. I removed the divider about a month ago. There is still some aggression from the male at times, but other times they are peaceful and ignore each other. Sometimes it looks like the male reacts to the female being skittish and swimming away fast. There are times when they are on the rocks right next to each other eating and completely ignoring each other. What's more strange is a couple times I've actually seen some spawning behavior when the lights go out, even though the male aggressively chased the female earlier during the day. Also, I've noticed there is somehow less aggression on days after I miss a feeding, which makes me wonder if the aggression is at all related to food. I would think he'd be more aggressive on days where I missed a feeding if it was food related. My fish are definitely strange.

[tango]

Very interesting reading.. just noticed the date of the post ..lol  i have what i thought was a male with his spike broken off.. but 6 months later no growth so thinking i was wrong and it is a female. i introduced  a male.  straight away they were swimming together and i thought it was lovely, but over course of a couple of days the male i introduced started to not leave the other one alone and i saw what i think was aggression pecking at the other one and chasing, then they would be ok for a while .. but only about 5 mins then would carry on..  so i have separated the newest one (which is 100% male) still in the tank but in a large fish trap...  so wondering if my original one IS actually a male but still no spike  after 8 mths.  the size difference is quite noticeable you can see there is definitely a larger one but not a massive difference.  my original mandarin  keeps hanging around the fish trap which the male is in. you think that it would be pleased to get rid of him. lol.. so do they want to be together? I don't know ,  not sure wether to introduce them together again. I just didn't like the idea of the male harassing my other one. weather it be male of female.. other than the spike are there any other noticeable differences  between the  male and female.