Pattern of gonad maturation and the question of semelparity in the paedomorphic goby Aphia minuta

At variance with previous reports, the paedomorphic goby Aphia minuta does not show semelparity, but abbreviate iteroparity like other small Mediterranean gobiid species. In spring, the mature ovary contains several batches of eggs at different stages of vitellogenesis. This indicates that the breeding season of A. minuta is quite long and that spawning takes place at least twice during its short lifespan, involving in each ovulatory wave different batches of oocytes which undergo vitellogenesis at different times. These observations agree with the testicular cycle data. In males, which in spring exhibit active spermiation coinciding with deposition of the first batch of oocytes, spermatogonial mitosis also resumes, eventually resulting in the production of new sperm in summer.