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Reproductive biology of species from the family Scorpaenidae and transition from oviparity to viviparity in the southern and northern Percomorphaстатья
- Авторы: Pavlov D.A., Emel’yanova N.G.
- Сборник: Viviparous Fishes II. New Life Publications
- Глава в коллективной монографии
- Год издания: 2010
- Место издания: Homestead Florida. USA
- Первая страница: 89
- Последняя страница: 105
- Аннотация: Among marine fishes of the order Perciformes and related taxa, two groups are of particular interest from the view of evolution of vi- viparity since they represent intermediate stages between oviparity and viviparity. They are representatives of the suborder Scorpaenoidei with a mostly southern distribution and the so-called “northern blenniids” belonging to the suborder Zoarcoidei. To find possible preadaptations to viviparity, the features of reproductive biology, including anatomical structure of gonads, sperm morphology and motility, oocyte composi- tion and morphology, and embryonic development, are examined in three tropical coral reef species from the family Scorpaenidae, Scor- paenopsis possi, Sebastapistes cyanostigma, and Dendrochirus zebra. The following adaptations, which are absent in the majority of teleost fishes, are registered: a hypertrophied urinary bladder in males that is used for sperm storage, morphology of ovaries with stroma and germinative tissue separated from the ovarian wall, peduncular structure of oocytes, specialized secretory epithelium of the inner ovarian wall for produc- ing floating gelatinous matrix surrounding ovulated eggs, extremely narrow egg envelope, differentiation of cytoplasm and yolk in ovulated oocytes before their activation, and very small perivitelline space in developing eggs. The species are oviparous with apparently external fertilization. However, release of eggs embedded in floating gelatinous matrix represents a step towards viviparity, and some features (e.g., the secretory epithelium, peduncles of oocytes and narrow egg enve- lope) can be regarded as preadaptations to viviparity. A parallelism in the steps of transition from oviparity to viviparity is observed in the suborders Scorpaenoidei and Zoarcoidei. This transition occurred without special adaptations in the structures of intromittent organs, gametes, or ovaries. A strategy directed at producing a large number of offspring at embryonic and larval developmental stages are usual in oviparous representatives of the suborder Scorpaenoidei, and it is retained in the viviparous species of this taxon. General strategy for fishes of the suborder Zoarcoidei is the production of a small number of offspring at advanced developmental stages reaching the juvenile state in some representatives of both oviparous and viviparous species.
- Добавил в систему: Емельянова Наталья Григорьевна