I am only 11, and I have had a 7 cm red tailed shark for about 2.5 months in a 200 L community tank with 3 platies, 2 dalmation mollies, 2 blue swordtails, 5 neon and 4 serpae tetras, 1 pleco, and two gouramis. But he is not having any problems except occasionally chasing my serpaes. But it's more like herding them out of his territory, and he has never killed. He is beautiful!
I have a tank with two Red Tails, a male and a female, as well as two Tiger Barbs, two Electric Yellow Cichlids, and two catfish. At first the male Red Tail earned the name Hitler chasing the others around, making them play dead - until the little albino catfish was introduced. Hitler tried his best aggressive posturing, but the little catfish simply swept over his body as if looking for food and continued on. That tamed him. I find Red Tails can be very goofy at times, the male always floats upside down in his cave, and has been seen hanging on to a plant branch tip with his mouth and letting the current from the filter stream over him for hours. I've seen him swim complete upside down loops over and over again too. The female Red Tail is much smaller, but they get along just fine.
I just purchased my second red tailed shark, maybe about 5 cm in size. So far he is peacefully sharing his new 147 L home with 4 very small tiger barbs, one gold barb and a common pleco. My first one lived to be over 4 years old and over 12 cm in size and became one of my favorites. He was not aggressive at all, and I hope that I get as lucky this time as I did last time. That red tailed shark shared the tank with bluefin and zebra danios, tiger barbs and a bristlenose pleco. I know that they eat, as my last one grew and lived for over 4 years, but I have not seen him eat and have no idea what his diet is.
I bought my red talied shark (8 cm) around a year ago and the shop advised me it would be fine in my 400 liter comunity tank. I heard it was very territorial towards certain types of fish, but the shop pursuaded me that none of mine would be bothered. This was the truth, as it was bullied by my eel (25 cm) and never made an attempt to attack others. But when Erik (my eel) made a jump for freedom and sadly died, it all changed. The shark claimed Erik's home in the rocks and then started to bully the others. One by one the tiger barbs depleted in number from 6 to 0 in a few months. The annoying thing was that they never ever went near his reclaimed home. The shark was the one that went out of its own way to hunt and torture the poor things hiding at the other side of the tank. Now it seems that it's got a taste for killing and a taste for the macrel barbs that also live in the tank. I am seriously reconsidering if I should keep it or just turn my tank into a semi-agressive community, where it would live happilly without being bothered or bothering others.
I've kept RTBS's on-and-off for the past 15 years. I've now devoted myself to aquatic gardening, and this fish is an excellent addition to planted aquaria. They do eat a little algae and forage for scraps of food from the bottom, so they do contribute some janitorial work to the aquarium. Do not keep them with other RTBS or rainbow sharks; they will usually fight quite a bit. When they are kept properly, i.e. not fighting all the time, they will usually be a solid jet black body with a brilliant red tail, and are a graceful and elegant swimmer. My little guy in my planted tank is fairly sociable, brilliantly coloured, and likes to shoal with my bala sharks for a while in the afternoon. They get along fine, in my experience, with non-sharks, and add a lot of colour and beauty to a healthy planted aquarium.
Last year I purchased my first red tailed shark at nearly full size. On the drive home I named him Don. Like many others of his species, he is aggressive and is now the last fish in the tank, he never murded any other fish, but harrased my Flying Fox consistantly. Just last week I returned my Flying Fox to the pet store and they said he was a good size and put him in the display tank (he was about 12 cm). Don is my favorite fish, he is now around 14 cm. He often hides, floating upside down in an ornamental cave I bought for him. I now plan to buy more appropriate fish which won't quarrel with my red tail shark. Great fish to have, I adore mine a lot.
My RTBS has been a great addition to my community tank. With 6 active tiger barbs plus a shoal of neons, I was anxious about how its addition would impact upon the community. I had read all the warnings! My anxieties were heightened when I watched around 25 RTBS's engage in open warfare in the shop's tank! Choosing one was a tricky balancing act. I wanted to get one that had not had its dorsal fin ripped to shreds (like some in the tank) but I did not want one so dominant he would terrorise the tank. In the end I need not have worried. The first five minutes after his release were anxious. The alpha male of the barbs went for him and damaged the very tip of his dorsal fin. The other barbs followed suit and it was chaos for about five minutes. Then the red tail retreated to the shelter of a plant which he has made his home since. This juvenile red tail has grown in confidence and when the tank is more dimly lit he happily swims around, never troubling others and being left in peace by the barbs. Getting feeding right is important. I tend to let the greedy barbs get distracted by flake food on the surface then quickly flick a sprinkle of sinking pellets over the area of his plant. When they sink down, he loves to roll on his side and feed off the plant. He also has helped get rid of an algae problem, feeding off a bit of artificial coral after lights out. I have no hesitation in recommending this beautiful fish but choose carefully at the shop and make sure they bag the one you want!
In my case I have found that aggression is linked to feeding. After feeding my Labeo becomes super territorial and chases my bristlenoses and female guppies with a passion if they come into his territory. This subsides after a while and he becomes the friendliest gardener, gently tending to plants in the tank and not phased by other fish. If there are problems with your shark try keeping feeds to a minimum and don't use pellets or tablets unless the lights are out.
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