Chromides fall-out

[New Boy]

My two orange chromides who have been best of friends since I got them three weeks ago seem to not like each other anymore and one chases the other every couple of minutes - to the point where it's got ripped tail and fins. Does anyone know what could have happened? I presumed they were male and female as they seemed to have followed each other round everywhere - is there any way to tell? My theorys are that either - they're two males who have now settled in the tank and have had a fight for dominance OR they're male and female and the female won't breed so the male has beaten her up.....any of those sound right?

Thanks for any advice
Andy

 

[mbhw]

add more chromides to diffuse the aggression if your tank is big enough. I don't know how to tell them apart , try a google search and see what comes up

 

[GeoFuen]

The behavior of your chromides is not unusual. The advice you got to add more chromides is good, if your tank will accomodate more fish. (I've used a 75 gallon tank for a group of 12 chromides.) I've bred this fish, and more than once if I've tried to isolate the pair in order to insure the survival of the fry, one fish will turn on the other--usually when I remove the fry, and I will lose one of the pair. From my observation, it is usually the female under these circumstances which becomes aggressive. (Apparently she "feels" that the male didn't do his "job", which was to patrol and defend the territory and fry.) Which type of chromide do you have--the domesticated "red" type, or the "wild" (normal color) fish? In either case, if you observe carefully you'll see that the tips of the tail fin of the female (who is usually the larger fish) has some white highlights. If you do keep a large enough group of chromides they will school together, and if they pair off they'll claim some vertical surface in the tank for their territory in order to lay their eggs, and defend it. I tried to isolate pairs in order to observe parental care (at least in the wild type it has been observed that the fry feed off the parental slime like discus fry do, though I've not observed this in the red type).