Speare, E.P., 1965. Fecundity and egg survival of the central johnny darter (Etheostoma nigrum nigrum) in southern Michigan. Copeia, pp.308-314.
| Species | Development state | Trait | Primary Data | Secondary Data |
| Etheostoma nigrum | Egg | Egg size after water-hardening | 1.00 | 1.0 mm |