Home / Care Guides / Rainbowfish, Killifish and Medaka Care

Rainbowfish, Killifish and Medaka Care

By Pet Zone SD Team · Updated October 7, 2026 · 4 guides

These fish sit in different families but share needs a store customer should know: they like open top-level swimming space, many are jumpers, and each group has a preferred water type. Rainbowfish want hard, alkaline water and long tanks, killifish are often short-lived and prefer live or frozen foods, and medaka tolerate cool, unheated tanks.

Quick rules of thumb

• Use a lid; most of these fish jump.
• Rainbowfish do best in groups in harder water.
• Check the exact killifish species before buying; needs vary.

Rainbowfish, Killifish and Medaka guides

• Boesemani RainbowfishMelanotaenia boesemani4.5 in · 40+ gal
• KillifishAphyosemion, Aplocheilus and related species2-4 in · 10+ gal
• Medaka (Ricefish)Oryzias latipes1.5 in · 5+ gal
• RainbowfishMelanotaenia and related species4 in · 30+ gal

Find it at Pet Zone

Pet Zone Tropical Fish is a San Diego aquarium store with two locations. Stock changes daily, so call ahead if you are after a specific species or plant. Shop online at petzonesd.com.

Pet Zone Convoy

4160 Convoy St, San Diego, CA 92111
(858) 987-0309
Open daily, 10am-6pm

Aquascaping, planted tanks

Pet Zone Mid-City

4266 University Ave, San Diego, CA 92105
(619) 283-1812
Closed Monday; Tue-Fri 10:30am-6pm, Sat 11am-6pm, Sun 11am-4pm

Monster fish, koi