Bettas & guppies, variety by variety.
Two aquarium favourites that are really catalogs of lines with opposite trade-offs - a plakat betta is nearly bulletproof while a rosetail can barely swim, and guppy strains range from hardy old cobras to inbred show lines that need pampering. Here are 31 profiles with the genetics spelled out. New to bettas entirely? Start with the betta basics guide. For the species itself, see the guppy basics guide.
Betta varieties One species, wildly different fins - from bulletproof plakats to fragile rosetails. Open the full Betta varieties page
Guppy strains Pattern and tail-shape lines of the world's favorite livebearer - plus the wild-type Endler. Open the full Guppy strains page
The more extreme the finnage or the purer the line, the weaker the fish - rosetails and dumbo ears pay for their looks in torn fins and swimming effort, and heavily inbred show guppies tend to be less robust than scrappy mutts. If you want easy, pick the variety closest to the wild shape: plakat bettas and common-strain guppies.
Gear for bettas and guppies
Links go to Amazon or a partner brand's own store and may earn us a commission at no extra cost to you. As an Amazon Associate we earn from qualifying purchases. An Amazon link leads to a type of gear and you choose the exact product; a card that names a store leads to that partner's own shop.