Open AccessDegeneration of the olfactory epithelium in the Anguilid eels by hormone treatment
Author(s) -
Fui Fui Ching,
Gunzo Kawamura,
Kazuhiko Anraku,
Bensan Ali,
Nabilah Zieha Sikh Mohamad,
Shigeharu Senoo
Publication year - 2019
Publication title -
borneo journal of marine science and aquaculture
Language(s) - English
Resource type - Journals
eISSN - 2600-8882
pISSN - 2600-8637
DOI - 10.51200/bjomsa.v3i2.1426
Subject(s) - biology , degeneration (medical) , rosette (schizont appearance) , hormone , sexual maturity , olfactory epithelium , olfactory system , endocrinology , medicine , anatomy , pathology , immunology , neuroscience
While the olfactory cue hypothesis has been proposed for spawning migration of silver eels, it has been shown that olfactory cells and associated mucus cells degenerate in male and female eels after hormonally induced sexual maturation. However, the degeneration of the olfactory organ could be a real event in the sequence of maturation, or may be an unnatural side effect of the hormone treatment itself. We morphologically and histologically examined the olfactory rosettes of hormone-untreated and hormone-treated (mixture of hCG and PG) giant mottled eel (Anguilla marmorata) and Japanese eel (A. japonica). The olfactory rosette from all the hormone-treated specimens significantly degenerated at various degeneration levels even in sexually immature specimens, indicating the side effect of the hormone-treatment. However, a sexually immature non-hormone treated female A. marmorata (87.4 cm TL, 199.4 g BW, at less advanced maturity) had slightly degenerated olfactory rosette. Further studies should focus on conducting natural degeneration of the olfactory rosette during the sexual maturation in tropical eels.