Wisniewolski, W. (1988) Fecundity of catfish (Silurus glanis L.) from the rivers Vistula and Bug. Acta Ichthyologica et Piscatoria [ACTA ICHTHYOL. PISC.], pp. 25-34
| Species | Development state | Trait | Primary Data | Secondary Data |
| Carassius auratus | Female | Absolute fecundity | 48-60 [in April] and 38-54 [In June] | 54.0 thousand eggs |
| Carassius carassius | Female | Absolute fecundity | 22-24 | 23.0 thousand eggs |
| Silurus glanis | Egg | Oocyte diameter | Oocytes attain final size of 2-3 | 2.5 mm |
| Silurus glanis | Female | Absolute fecundity | Number of the yellow oocytes in particular females amounted to from 34.7 thousand in a female weghting 5.3 kg to 788.0 thousand in a female weighting 36.0 kg [Described in other study : 38592-306240; 11810-1380000; 27400-384500; 42822-391411; 356400; 14600-285000; 61400-249300] | 172416.0 thousand eggs |
| Silurus glanis | Female | Oocyte development | Two groups of the oocytes were present in all samples [Also described as: asynchronic development of the oocytes was observed in catfish as late as 10 days before spawning] | Asynchronous |
| Silurus glanis | Female | Onset of oogenesis | The peak of vitellogenesis was observed in summer (July-August), and females passed winter with the ovaries in the IV th stage of development | ['January', 'February', 'March', 'July', 'August', 'September'] |
| Silurus glanis | Female | Intensifying oogenesis activity | Supplementary vitellogenesis took place in spring | ['April', 'May', 'June'] |
| Silurus glanis | Spawning conditions | Spawning season | In Dagestan (USSR) catfish spawn at the end of May, but in Polish conditions in mid-june | ['May'] |