1 kinds · tap one for a closer look
Peaceful but shy; keep with calm tankmates in a planted tank with plenty of hiding spots.
This one is best kept on its own, or with its own kind.
Peaceful but shy; keep with calm tankmates in a planted tank with plenty of hiding spots.
Algae, spirulina and flakes with small live foods; offer vegetable food often.
Tap a food to see what it is.
Hard to tell apart. Males have the notched anal fin (splitfin), a slightly bigger dorsal fin and a blue tail, the blue spreading over the body in breeding colour; females keep two dark horizontal lines and a clear tail.
Common problems. Tap one to see the signs. This is a guide, not a diagnosis.
Livebearer · Moderate
Livebearer; the only goodeid whose newborns lack functional trophotaeniae. Gestation about 60 days; fry are usually not eaten, so a colony breeds easily. Young mature in 6-7 months.
A group of 6 or more.
Large planted tank with hard alkaline water, rocks and plants.
Stable cool water and a well-fed group.
5-15 young per brood after about 60 days.
Feed baby brine shrimp and crushed flake.
A rare goodeid from the Río Verde valley, San Luis Potosí, Mexico, and the only splitfin whose newborns lack trophotaeniae (hence the genus name, "living without a ribbon"). Males show a blue tail; it is Endangered in the wild.
American ichthyologist Seth Meek described this fish in 1904. It is unusual among goodeids because its embryos lack the ribbon-like feeding structures found in its relatives.
First described by Seth E. Meek in 1904.
10 facts checked with sources
Valid. Usual common names are bluetail splitfin / bluetail goodea; 'hidden goodeid' is not used by FishBase or the GWG. The genus name means 'living without a ribbon' (no trophotaeniae in newborns), not 'hidden'.
FishBase: Ataeniobius toweri summaryLegacy has no family field.
FishBase: Ataeniobius toweri summaryNo Seriously Fish profile. FishBase 10 cm TL for females, 7 cm TL males; GWG maximum 7.6 cm SL. Matches legacy.
FishBase: Ataeniobius toweri summary · Goodeid Working Group: Ataeniobius toweriFishBase 22-30 °C (warm springs); GWG advises not keeping it constantly above 26 °C, with a 2-3 month winter rest below 22 °C. Legacy 20-26: the lower end is below FishBase.
FishBase: Ataeniobius toweri summary · Goodeid Working Group: Ataeniobius toweriLegacy 150 L.
Goodeid Working Group: Ataeniobius toweriLegacy has no range field. IUCN: Endangered (assessed 17 April 2018, per FishBase v2025-2; GWG also 'Endangered'). Not Extinct in the Wild.
FishBase: Ataeniobius toweri summaryLegacy 'notched anal fin and bluer sheen' agrees.
Goodeid Working Group: Ataeniobius toweriLegacy breeding is generic; the missing trophotaeniae are the notable fact.
FishBase: Ataeniobius toweri summary · Goodeid Working Group: Ataeniobius toweriMatches legacy (5-15 after 8-10 weeks).
FishBase: Ataeniobius toweri summaryLegacy says it is 'named hidden because it spends time in cover' and has a 'silvery body with a bluish sheen': the 'hidden' etymology is unsupported.
Goodeid Working Group: Ataeniobius toweri · FishBase: Ataeniobius toweri summary