No detailed citation.
| Species | Development state | Trait | Primary Data | Secondary Data |
| Gasterosteus aculeatus | Spawning conditions | Spawning period duration | This indicates that in 1975, the breeding season in the Rheidol lasted for thrre to four months, but in Frongoch it lasted only about one month | 1975.0 weeks |
| Gasterosteus aculeatus | Female | Maximum GSI value | Peak in May: Mean of 19%, up to 21 in 1974 and mean of 12.5, up to 15.5 in 1975 | 19.0 percent |
| Gasterosteus aculeatus | Female | Onset of oogenesis | September-October: A period of slow increase over the autumn and the winter | ['March', 'January', 'September', 'December', 'February', 'October', 'November'] |
| Gasterosteus aculeatus | Female | Intensifying oogenesis activity | Very rapid increase in the GSI in March and April | ['April', 'March'] |
| Gasterosteus aculeatus | Female | Weight at sexual maturity | Weights of female caught in May anf June: 0.557 ± 0.0835 g and 0.626 g, respectively in Frongoch and 1.098 ±0.1553 and 0.823 ±0.0525 g in Rheidol | 0.557 kg |
| Gasterosteus aculeatus | Female | Length at sexual maturity | Lengths of female caught in May anf June: 38.5 ± 1.55 mm and 41.7 mm, respectively in Frongoch and 46.0 ±2.01 mm and 44 ±1.01 mm in Rheidol | 38.5 cm |