Longhorn cowfish growth?

longhorncowiedude · Mar 23, 2026

Calling anyone who has owned longhorn cowfish. I’ve had my dude for a month and a bit and he’s doing great health-wise, but I’m wanting to know how quick they grow?

He’s about 2 months old and in a 220L tank right now, but I’m saving to upgrade him to a new 550L setup soon, which I know still might be on the small side.

He hasn’t grown much at all in the last month so people who have owned them, how long did it take for your longhorn to grow?

I’ve also attached a photo of dude

Gumbies R Us · Mar 23, 2026

Never personally had one. From what I have read, they can grow up to 16 inches, and 5-6 inches just in the first year alone.

Rob A · Mar 23, 2026

Mine went from tater tot 1.5 inches to 6 inches in less than 6 months. They are eating machines and grow fast. I think that a lot of people don't realize how fast they grow or how big they get. I got mine in 300gal stock tank lagoon and he needs every bit of it they are active and curious and need lots of room.

longhorncowiedude · Mar 23, 2026

Rob A said:
Mine went from tater tot 1.5 inches to 6 inches in less than 6 months. They are eating machines and grow fast. I think that a lot of people don't realize how fast they grow or how big they get. I got mine in 300gal stock tank lagoon and he needs every bit of it they are active and curious and need lots of room.

Yeahhh I know they get really big I just don’t have the space for a big 300gal until I move in a year or two, but he’ll be getting the 550L in a couple of months so he’ll have plenty of room while he grows fast.

I think I’m just worried because he hasn’t grown since I’ve had him

FishRN · Mar 23, 2026

Mine went from the size of a quarter to about 6 inches in a year.

longhorncowiedude · Mar 23, 2026

FishRN said:
Mine went from the size of a quarter to about 6 inches in a year.

FishRN said:
dang! what were you feeding him? I give mine brine with the rest of the fish daily and also give clam meat, cucumber slices sometimes and red nori.