Zelepien, J. (1997) Klen [Chub, Leuciscus cephalus (L.)]., pp. 120
| Species | Development state | Trait | Primary Data | Secondary Data |
| Leuciscus cephalus | Egg | Oocyte diameter | Diameter of mature eggs ranges from 1.5-2.0 mm | 1.75 mm |
| Leuciscus cephalus | Egg | Egg size after water-hardening | After swelling diameter increases by a factor of 1.3-1.6 | 1.45 mm |
| Leuciscus cephalus | Egg | Egg adhesiveness | Fertilised eggs stick to the substrate due to their sticky and thick egg envelopes | Adhesive |
| Leuciscus cephalus | Egg | Incubation time | At 16-20°C incubation period ranges from 150 to 75.4 hours | 18.0 days |
| Leuciscus cephalus | Larvae | Initial larval size | Newly hatched larvae is 5.3-6.5 mm long | 5.9 mm |
| Leuciscus cephalus | Female | Age at sexual maturity | In Poland, chub usually reach maturity at the age of 3-4 years. Females maturing at the age of 6 years in the river Stobnica. 28% of chub reached maturity at the age 3+, and 60% at the age 4+. In other countries 3-4 year period of maturation was reported. | 3.5 year |
| Leuciscus cephalus | Female | Length at sexual maturity | Length of females was 19.4 cm. Other described fish matured > 20 cm (sex not specified) | 19.4 cm |
| Leuciscus cephalus | Female | Weight at sexual maturity | < 150 g (Sex not specified) | 150.0 kg |
| Leuciscus cephalus | Female | Relative fecundity | 69239 [Size 17 cm], 81372 [Size 24.8 cm], 61449 [Size 35]. Maximum values of relative fecundity was observed in females 24-30 cm long | 27.0 thousand eggs/kg |
| Leuciscus cephalus | Female | Absolute fecundity | 6370 [Size 17 cm], 22947 [Size 24.8 cm], 51443 [Size 35] | 6370.0 thousand eggs |
| Leuciscus cephalus | Female | Oocyte development | Asynchronous process of oocyte maturation in ovaries was reported. Also observed oocytes of different size and maturity state in pre-spawning chub ovaries. The largest oocytes were released as the first batch of eggs (70-73% of ovary content) | Asynchronous |
| Leuciscus cephalus | Female | Onset of oogenesis | Weight of gonads increase after September | ['September'] |
| Leuciscus cephalus | Female | Maximum GSI value | Just before spawning ovaries may contribute to 1% body mass. Other authors said that at the brginning of spawning ovarian mass depends on female body size and contributes to 7.3-19.6% | 13.45 percent |
| Leuciscus cephalus | Female | Resting period | Gonads of chub females and males after spawning remain in a resting state until September. | 2.0 months |
| Leuciscus cephalus | Male | Age at sexual maturity | In Poland, chub usually reach maturity at the age of 3-4 years. Males maturing at the age of 4 years in the river Stobnica. 28% of chub reached maturity at the age 3+, and 60% at the age 4+. In other countries 3-4 year period of maturation was reported. Typically males mature 1-2 years earlier than females. | 3.5 years |
| Leuciscus cephalus | Male | Length at sexual maturity | Males maturing were 12.0 cm. | 12.0 cm |
| Leuciscus cephalus | Male | Weight at sexual maturity | > 150 g (sex not specified) | 150.0 kg |
| Leuciscus cephalus | Male | Male sexual dimorphism | Fin rays of some chub individuals are intensively coloured during spawning | Absent |
| Leuciscus cephalus | Male | Onset of spermatogenesis | Weight of gonads increase after September | ['September'] |
| Leuciscus cephalus | Male | Maximum GSI value | Up to 6% | 6.0 percent |
| Leuciscus cephalus | Male | Resting period | Gonads of females after spawning remain in spawning remain state until September | 2.0 months |
| Leuciscus cephalus | Spawning conditions | Spawning migration distance | Usually it displays no spawning migration | No data |
| Leuciscus cephalus | Spawning conditions | Spawning season | In European temperate waters chub spawn in spring, usually in May and June | ['April', 'May', 'June'] |
| Leuciscus cephalus | Spawning conditions | Spawning temperature | Usually > 18°C | 18.0 °C |
| Leuciscus cephalus | Spawning conditions | Spawning water type | Fast current speed | Flowing or turbulent water |
| Leuciscus cephalus | Spawning conditions | Spawning substrate | Belongs to a reproductive guilds of lithophils. They spawn on stones or gravel | Lithophils |
| Leuciscus cephalus | Spawning conditions | Spawning release | In natural conditions chub females release maximally two batches of eggs. Russian authors suggest that the number of released batches depends on the time of beginning of breeding season. Females spawning in May can repeat spawning in August, while those maturing in June release only one batch of eggs. | Multiple |