Rainbow Shark. Really cool freshwater fish, but I suggest only putting it in 20+ gallon tanks with semi-aggressive tank mates. Fishometer: 8
Dwarf gourami can do fine in a small tank, but their bigger cousins should be avoided unless you have the space to care for them properly. Gourami are large, aggressive fish with complex behaviors, and a pair should be kept in no tank smaller than 55 gallons. They may be colorful and attractive, but if you add them to your small tank you'll get more than you bargained for.
Give your tank a makeover. Dominant cichlids stake out certain territories. If a fish dares enter that area, he's quickly chased out and sometimes physically disciplined. Switching around the placement of your decorations and larger plants changes up the territories, and the dominant cichlid will usually no longer aggressively patrol the same area. He will, of course, find different areas in time, but the makeover reduces aggression temporarily. Don't change up your tank any more than every two months or you may stress out your fish.
[HD] Epic Aggressive Fish Tank! - YouTube
My new aggressive fish tank with predatory fish! - YouTube
It is very important to know which fish species are aggressive and how to avoid disastrous combinations of keeping fish in the same tank resulting in the death of multiple fish.Yes Chinese algae eaters are very aggressive and can live with oscars, convicts, frontosa, red devil Cichlids, Texas Cichlids, you name it. When they get big they are very tough and mean fish that will kill non aggressive tank mates and eat them. They are catfish.Aggressive freshwater fish may receive a poor reputation by some people due to a bad experience, prejudice, or not enough knowledge about fish behavior, requirements, and suitable tank mates.A step up from community species are semi-aggressive species of fish. These fish are typically a little larger and they have a higher tendency toward fin-nipping or general aggression. Semi-aggressive fish can be kept in community tanks as long as you only keep one male of each species and as long as you provide plenty of hiding places for your fish in case the semi-aggressive fish starts to bully them.I agree that these are excellent fish but they are very fast growers and a 10 gallon tank is not suitable for the common pleco. They can reach up to 18 inches in size. If you want to get one and you have a smaller tank just be prepared to get them into a larger tank when the time comes. Or try to get a bristlenose pleco which should only grow to about 5 inches or so. Also, although we've experienced it, we've heard reports of them becoming aggressive towards their tank mates. All that we have kept have always been very peaceful.If you plan to add any semi-aggressive or aggressive species of fish to your tank, do not start with them. If you add your aggressive fish to the tank first, they may come to view the entire tank as their territory and any fish added later may be regarded as invaders. Start with the most peaceful species of fish and give them time to get used to the tank before you add the next species. This ensures that each species will be able to establish its own territory.