Advanced freshwater fish: O
All advanced freshwater fish whose common name starts with O, in alphabetical order. Each card links to its care guide.
14 species
Ocellate river stingray
Potamotrygon motoro
Freshwater19.7 in (50 cm) · 264 gal (1,000 L)75–82°F (24–28°C)
Ogilvie's lizard loach
Homaloptera ogilviei
Freshwater2.4 in (6 cm) · 20 gal (75 L)70–79°F (21–26°C)Omega betta
Betta omega
Freshwater3.2 in (8.1 cm) · 24 gal (90 L)73–81°F (23–27°C)
One-stripe spiny eel
Macrognathus aral
Freshwater23.6 in (60 cm) · 119 gal (450 L)73–82°F (23–28°C)
Opal licorice gourami
Parosphromenus opallios
Freshwater1.2 in (3 cm) · 5 gal (20 L)72–81°F (22–27°C)
Opossum pipefish
Microphis brachyurus
FreshwaterBrackish8.7 in (22 cm) · 32 gal (120 L)75–82°F (24–28°C)
Orange chromide
Etroplus maculatus
FreshwaterBrackish3.9 in (10 cm) · 55 gal (210 L)68–82°F (20–28°C)
Orange fin goby
Stiphodon maculidorsalis
Freshwater2.2 in (5.5 cm) · 14 gal (54 L)73–81°F (23–27°C)
Orangethroat darter
Etheostoma spectabile
Freshwater2.8 in (7 cm) · 25 gal (95 L)59–68°F (15–20°C)
Orinoco flagtail prochilodus
Semaprochilodus laticeps
Freshwater17.3 in (44 cm) · 264 gal (1,000 L)73–82°F (23–28°C)
Orinoco peacock bass
Cichla orinocensis
Freshwater24.4 in (62 cm) · 528 gal (2,000 L)77–86°F (25–30°C)
Ornate pimelodus
Pimelodus ornatus
Freshwater12.2 in (31 cm) · 65 gal (245 L)75–82°F (24–28°C)
Ornate-tail Borneo sucker
Gastromyzon ornaticauda
Freshwater3.3 in (8.4 cm) · 24 gal (90 L)68–77°F (20–25°C)
Ornate-tail licorice gourami
Parosphromenus ornaticauda
Freshwater0.9 in (2.4 cm) · 5 gal (20 L)72–81°F (22–27°C)
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