Journal Article
Geographical and taxonomic variation in the pattern of natural sex reversal in the teleost fish order Synbranchiformes
Liem, K.F.
Record Number:
5287
Year:
1968
Journal:
Journal of Zoology London
Pages:
225-238
Volume:
156
Abstract:
Two types of males have been found in all members of the Synbranchidae. The primary
males are born as males and possess single, but bilobular, testes with two gonadal sinuses.
Secondary males evolve by sex reversal of functional females and possess a lamellar organization
of the testes with three gonadal sinuses and often ovarian residua. Undifferentiated
races lack primary males and are recorded only from certain geographical areas. Rudimentary
hermaphroditism is classified as a derived evolutionary stage and gonochorism, which
is represented in the Amphipnoidae, a primitive evolutionary condition. The alternative of
primary versus secondary male is decided by a genetic shift mechanism instead of by environmental
conditions. The precarious poise of sexual identity in the Synbranchidae is defined
as a switch mechanism to compensate for the vicissitudes of the natural habitat, allowing
reproduction in spite of severe population depletions. Based on an examination of its
gonadal structure, Alabes is considered to have no phylogenetic affinities with the Synbranchiformes.
The occurrence of natural hermaphroditism in phylogenetically unrelated
groups of fishes in radically different environments is regarded as the results of chance
evolution, rather than convergence.
Times Cited:
1
Relevent Species:
Related Records:
Pellegrin, J. (1922)
Sur un nouveau poisson aveugle des eaux douces de l'Afrique occidental
Liem, K.F. (1968)Geographical and taxonomic variation in the pattern of natural sex reversal in the teleost fish order Synbranchiformes
Rosen, D. E. and Greenwood, P. H. (1976)A fourth neotropical species of synbranchid eel and the phylogeny and systematics of synbranchiform fishes
Sadovy de Mitcheson, Y. and Liu, M. (2008)Functional hermaphroditism in teleosts
Britz, R., Lalremsanga, H.T., Lalrotluanga and Lalramliana (2011)Monopterus ichthyophoides, a new species of scaled swamp eel (Teleostei: Synbranchiformes: Synbranchidae) from Mizoram, India
Britz, R., Doherty-Bone, T.M., Kouete, M.T., Sykes, D. and Gower, D.J. (2016)Monopterus luticolus, a new species of swamp eel from Cameroon (Teleostei: Synbranchidae)
Britz, R., Sykes, D., Gower, D.J. & Kamei, R.G. (2018)Monopterus rongsaw, a new species of hypogean swamp eel from the Khasi Hills in Northeast India (Teleostei: Synbranchiformes: Synbranchidae).
Britz, R., Sudasinghe, H., Sykes, D. and Tharindu Ranasinghe, R.H. (2020)Ophichthys desilvai, a poorly known synbranchid eel from Sri Lanka (Teleostei: Synbranchidae)
Britz, R., Dahanukar, N., Standing, A., Philip, S., Kumar, B. amd Raghavan, R. (2020)Osteology of ‘Monopterus’ roseni with the description of Rakthamichthys, new genus, and comments on the generic assignment of the Amphipnous Group species (Teleostei: Synbranchiformes).