My figure 8's aren't the fierce predators I expected!

[bencymru]

Hi all

I just bought 3 figure 8's for my 180 litre tank. It was cycled with platys(now in my 10g) and it also has a sailfin pleco. The latter was a mistake and will be going back soon!

I researched and researched before buying and decided a species only tank with 5 figure 8's or 3 and some bbg's would be good. I put the f8's in the tank with the platys and pleco and there were no signs of aggression at first. Later in the day, the 3 platys started harrasing the f8's so I took them out.

They have totally ignored the pleco and have been chased around by tiny platy fry I didn't know I had! I'll be honest, I'm pretty sure I saw a snail harrasing then today! Are these actually decent community fish or is this because they are juveniles?

Would 5 or a max of 6 be too many if kept alone?



Thanks

[Pufferpunk]

Give em time... Mine picked off their molly tank mates one at a time.
Sailfin plecos grow to over 2'! They also are not BW fish at all.

[bencymru]

I figured they might get aggressive once older. The tank is still FW as this is how they were kept in the shop. I'll be losing the pleco over the weekend and starting the brackish process. I'll struggle to catch the fry though!

[G S P Freak]

My f8 puffer coexisted with 2 bumblebee gobies and a Molly (who actually bullied and harrased the puffer frequently) for several months. Needless to say I thought my puffer would have tankmates forever... But notice its all past tense, he decided one day to kill a goby, and in less the a week the other goby and even the Molly that harassed him were killed and partially eaten. I'm not saying not to try tankmates, but be aware the puffer decides if you can have them or not, not you lol... And they can change their minds anytime.

[RTR]

bencymru wrote, in part: "I just bought 3 figure 8's..." and "I put the f8's in the tank with the platys and pleco and there were no signs of aggression at first. Later in the day, the 3 platys started harrasing the f8's so I took them out."

First off, adding newly purchased fish to a tank with an already established population of fish and expecting them to show full normal adult behavior is a pipe dream. Only an inexperienced hobbyist would expect that. Unless they were trade-ins and not newly captured wild fish. (All F-8s ate wild caught, none are captive bred to date). As they mature, you can expect to see more adult behavior, as the other replies above state. Newly captured fish have been through multiple shipments and water/tank/changes and handlings and are far from settled in, much less than having matured and established their territories. That process will take at least week to months, and may require more than a year before they are full adults with an established pecking order and established territories.

IME, a 180L tank may be too small for more than 3 F-8s, and there may be incompatibilities between those if there are 2-3 likely males involved. The set-up need to be visually complex and invoilve adequate currents and shelter areas for resting and sleeping.

The pleco needs to go ASAP, as already stated by Pufferpunk.

[RTR]

Sorry, I forgot to qualify aggression/predation. F-8s are active hunter-predators, which means roughly that in the wild the actively seek out their prey, and defend their own hunting territory from conspecifics (other fish of the same species, or similar predators. In the wild that strong territoriality may be seasonal, but in captivity it is more likely to be year-round. That is likely to be due to our tanks being generally smaller than the area occupied in the wild. Females of these fish seem less territorial than the males, but we have do have reliable means of sexing these fist ay present. Predation is constant, but territoriality is an adult characteristic. Young fish tend to school move (there is safety in numbers). Aggression is highest among mature males, but is also shown among mature females ready to spawn. Territoriality is basically defense of the hunting territory, which may also serve as the spawning site for some species.

We do not know the spawning behavior of F-8s as yet, either in the wild or in captivity. We do know that immatures tend to tolerate conspecifics, while post-puberty fish are less tolerant to intolerant of conspecifics and of unrelated fish.

HTH

[Pufferpunk]

I'll struggle to catch the fry though!

Not to worry, the puffers will.