AboutRon Coleman Expertise I am an expert on cichlid fishes, particularly New World cichlids. My broader expertise includes the behavior, ecology and reproduction of fishes in general. (I am NOT an expert on Goldfish. Please do not ask me questions about why your goldfish are sick -- they are almost always sick due to the way that they are sold). Also, please do not use abbreviations, such as "my GT has a swollen
eye" because I don't know what a "GT" is. The more clearly you can explain your question, the better chance I have of understanding what it is that you seek. Thanks.
Experience I teach at the California State University, Sacramento in the Department of Biological Sciences, and I run a website, called the Cichlid Research Home Page . I also write for many popular aquarist magazines, and I am editor of Cichlid News magazine. I am a scientist and I spend my time teaching fish biology, ecology, behavior and evolution and doing research on the reproductive biology of fishes, particularly cichlids. I do research in the laboratory and in Costa Rica, Nicaragua and Mexico. My main interest is understanding the evolution of parental care in fishes. I am interested in encouraging greater public awareness, understanding and participation in science.
Organizations belong to American Cichlid Association, Pacific Coast Cichlid Association, American Society of Ichthyologists and Herpetologists, etc
Publications Cichlid News, Tropical Fish Hobbyist, Freshwater and Marine Aquarium, Science, Behavioural Ecology and Sociobiology, Copeia, Canadian Journal of Zoology, Trends in Ecology and Evolution, AUK, Environmental Biology of Fishes
Expert: Ron Coleman Date: 6/4/2008 Subject: aggresive oscars
Question QUESTION: We bought two Oscars back in October, they have always been very passive and hilarious, I have never seen fish with such a humorous nature. My question is that recently the one that we believe is a female as gotten bigger not much but still bigger than the other and they/she has started fighting. Also suddenly they don't appear to be intersted in the feeder fish they would rather have pellets. Is it normal for them to behave like this, or is there something else going on. I would hate to lose them, everyone including my daycare kids love to watch them. Thank you.
ANSWER: Hi Melany,
First, please stop feeding them feeder fish. Pellets are much better and safer for them. Feeder fish are notorious for carrying various diseases, such as ick, and it is just a matter of time before they get to your oscars and kill them.
-- Ron
rcoleman@cichlidresearch.com
Cichlid Research Home Page <http://cichlidresearch.com>
---------- FOLLOW-UP ----------
QUESTION: what about the aggressive behavior is that normal?? Also, the larger of the two (shes white and orange) has managed to pull the smaller of the twos (hes black and orange) top lip off. Will he heal up or should I start preparing my kids that they will not be seeing him after awhile? Remember we are only guessing at the sexes.
Answer Hi Melany,
There is no way to tell the sexes of oscars so your guess is as good as any.
Aggression is a very normal part of oscar life. They fight. It is hard to say whether the lip will heal perfectly or not -- that depends on the extent of the damage. Cichlids such as ocars can heal up some rather remarkable wounds. Face to face fighting is an important part of both combat and courting. In combat, they do that kind of fighting and then eventually one backs down and the other starts chasing it incessantly. At that point you need to do something because the aggressor could easily kill the other fish. In courting, which starts out exactly the same, and equally violent, they will fight, sometimes for days at a time, but then just stop and make a nest.
Basically, the courting fighting is how they test each other, to see if their potential partner is up to the challenge of raising a brood of kids, which is tough business in the wild. The parents are going to face all sorts of predators that want to eat the kids and each parent needs to know that its partner is up to the task.
-- Ron
rcoleman@cichlidresearch.com
Cichlid Research Home Page <http://cichlidresearch.com>
