Overview
The Pajama Cardinalfish (Sphaeramia nematoptera) is a beginner saltwater species known for its green-yellow, black bar, polka dot rear coloration. Polka-dot pattern. Mid.
Origin & Appearance
Origin: Western Pacific.
Colors: Green-Yellow, Black bar, Polka dot rear.
Body Shape: Deep Fusiform (oval/robust). Typical adult dimensions: 8.5 x 1.7 x 3.4.
Sexual Dimorphism: Minimal; males have wider jaw (holding eggs).
Tank & Water Requirements
| Min Tank Size | 20 gallons |
| Temperature | 75–79°F |
| pH Range | 8.1–8.4 |
| Water Hardness (GH) | dKH 8-12 |
| Bioload | low |
| Oxygen Demand | low |
| Plant Safe | yes |
| Aquarium Position | Mid |
Behavior & Activity
Slow hoverer near reef structures; nocturnal feeder; lazy during day; hides among coral branches
Speed: 28/100Aggression: 2/10nocturnalSchooling (6+)
Breeding
Moderate; paternal mouthbrooder
Common Diseases
💊 Ich
Expert Notes
Polka-dot pattern; nocturnal