Ultrastructural aspects of spermatogonesis in Metamicrocotyla macracantha (Alexander, 1954) Koratha, 1955 (Monogenea; Microcotylidae) Leia mais sobre Ultrastructural aspects of spermatogonesis in Metamicrocotyla macracantha (Alexander, 1954) Koratha, 1955 (Monogenea; Microcotylidae)