Bullhead (Cottus Gobio)

[sezra]

Yesterday, My son and I went to a friends farm, which has a large lake, stocked with lots of native fish. He allowed us to catch a few minows for us to put in my sons aquarium, and upon getting home, I noticed a fish that I didnt know was in the bucket. after doing some research, it turns out the mystery fish is a bullhead (Cottus gobio).
 
He is only small, no bigger than 1cm. I understand they eat small crustaceans and snails. There are some native snails in my tank, so will he be fine eating the smaller ones, or should I buy some blood worm etc?

 

[fluttermoth]

He should do okay on any meaty food. Bloodworm isn't really very nutritious, so shouldn't be used as a staple diet.
 
Your biggest problem will probably be keeping the temperature down; they do need cool, highly oxygenated water; it practical terms that means filtration with a very high turnover rate.
 
The same applies to native minnows (I'm assuming you're in the UK!).
 
How big is the tank and is it properly cycled? These fish are very sensitive to any trace of ammonia or nitrite.
 
Oh, and don't forget, once they've been in captivity, they can never be returned to the wild. They could pick up an infection or virus from the aquarium environment (from food, plants, décor) that might devastate the native population through lack of resistance to it.

 

[sezra]

thanks for the reply. they (2 minows, and the baby bull head) are currently in a 100l tank decorated with hornwort as i understand this is a good oxygenator. I know bull heads can grow to around 18cm, and reach maturity after 2 years, but by this time i would have upgraded my main tank so he can go in there.
 
The tank and filters are cycled properly. It used to house my fire eel and has been running for over a year now with no outbreak of disease at all.
 
The water is at 20c at the moment. Will this be cold enough? There is no heater in there. I'll buy some blood worm as my fish love them as well, but like you said, shouldnt be used as a staple diet.
 
I will try to get a picture of him. Like I said, I had no idea he was in the bucket, we were only supposed to catch a few minnows, but now he's here, I want to make sure my son knows how to care for him.