Aprahamian, M.W. and Lester, S.M. (2001) Variation in the age at first spawning of female twaite shad (Alosa fallax fallax) from the river severn, England. Bulletin francais de la peche et de la pisciculture [Bull. Fr. Peche Piscic.]., pp. 941-951
| Species | Development state | Trait | Primary Data | Secondary Data |
| Alosa fallax | Male | Age at sexual maturity | The average age of female at sexual maturity range between 4.86 to 5.26 years, with a mean of 4.80 ± 0.021 years [Female mature at beween 3 and 8 years old with the majority at age 4 and 5 years at the northern limit of their distribution and at age 4 years for more southernly populations; in different sutdies mean age at maturity range from : 4/55 ± 0.9 [Wye, Whales]; 4.80 ± 0.02 [severn, England];, 4.38 ± 0.31 [Barrow, England]; 3.94 ± 0.13 [holland]; 4.27 ± 0.2 and 3.55 ± 0.2 [Loire, France], 3.93 ± 0.21 [Charente, France]; 4.27 ± 0.2 and 3.74 ± 0.14 [dordogne, France], 4.35 ± 0.21 [Adour, France], 4.66 ± 0.14 [sebou, France] | 4.8 years |
| Alosa fallax | Male | Length at sexual maturity | For female from the Severn, the critical size appears to be approximatively 330 to 340 mm | 330.0 cm |