南海鱼类寄生粘孢子虫的研究——Ⅰ.角形虫属五新种

A STUDY ON MYXOSPORIDIA OF FISHES FROM SOUTH CHINA SEA——Ⅰ.FIVE NEW SPECIES OF Ceratomyxa

在南海鱼类胆囊中发现寄生粘孢子虫(Myxosporidia)角形虫属Ceratomyxa五新种。其中的肾形角形虫C.reniforma和石斑角形虫C.epinephela寄生于赤点石斑鱼Epinephelus akaara,桂山角形虫C.guishanensis寄生于青石斑鱼E.awoara,陈氏角形虫C.cheni寄生于黄鳍鲷Sparus lalus,(鱼祭)角形虫C.clupanoda寄生于斑(鱼祭)Clupanodon punctatus。

Since 1987, we have investigated the parasitic myxospora of the fish from South China Sea, and five new species of Ceratomyxa are found from Epinephelus akaara, E. awoara 籗pams latus and Clupanodon punctatus, respectively. The specimens are deposited in South China Sea Institute of Oceanology, Academia Sinica, Guangzhou. The diagnosis of the new species are briefly as follows:1. Ceratomyxa reniforma sp. nov. (fig. 1) Host Epinephelus akaara (Tern, et Sch. ). Habitat Gall bladder.Location of the host Daya Bay, Shenzhen.Vegetative form Trophozoite nearly rounded. Ectoplasm transparent. Endo-plasm fine granular. Younger sporont rounded,developed sporont elliptical. Each sporont produces two spores.Spore Mature spore reniform in sutural view. Shell valve curved backward less. The terminal of shell valve blunt. Two shell valves are similar in size and form. Sutural ridge slender distinct. Polar capsules rounded and equal-sized. The space of spore is full of sporoplasm in most cases. Dimension:sutural breadth of spore 22. 4(19. 0.7- 0)μm, sutural diameter 5- 9 (5. 0-70. 0)μm, diameter of polar capsules 2. 8 (2. 5-3. 0) μm.This new species closely resembles Ceratomyxa spari Awerinzew and C. platichthys (Fujita) , but the size of this new species is much smaller than that of two latter species, which are from different hosts.2. Ceratomyxa epinephela sp. nov. (fig. 2) Host Epinephelus akaara (Tern, et Sch. ). Habitat Gall bladder.Location of the host Daya Bay, Shenzhen.Vegetative form Younger trophozoit rounded. Ectoplasm transparent, endo-plasm granular. After growth, multiplication by binary fission occurs. In the early stage of sporogony, four polar capsules form in the center of sporont. Subsequently, polar cap- sules occur at the next cell membrane, sporont elongated. In later stage of sporogony, each sporont produces two spores, which are enveloped by cell membrane.Spore Anterior end of mature spore is in the shape of a smooth arch, not forming cone progress. Shell valve is longer. The terminal of shell valve is sharper and less curved. Sutural ridge distinct. Spore is spinclle-shapedin end view. Polar capsules rounded and equal-sized. Dimensions: sutural breadth 35 (30-44) μm, sutural diameter 5-3 (4.2-6.0) μm, diameter of polar capsules 2. 6 (2.4-3.0) μm.The new species resembles C. aggregata Davis and C. mesospora Davis, but, the shell valve of C. epinephela is smooth at anterior end. The size of new species is smaller than that of C. aggregata and C. mesospora.3- Ceratomyxa guishanensis sp. nov. (fig. 3) Host Epinephelus azvoara (Tern, et Sch. ). Habitat Gall bladder.Location of the host Guishan, Zhuhai.Vegetative form Trophozoite rounded or amoeba-shaped with short or longpseudopodial, cytoplasm fine granular, in which there are food vacuoles. In early stage of sporogony, sporont rounded with 4 polar capsules. Subsequently, sporont elongate, develops into oval-shapes. Each sporont produces two spores.Spore Spore near arch-shaped in sutural view. Shell valve slender, the terminal 昽f shell valve sharper. Sutural ridge fine, straight and distinct. Polar capsule rounded, small and equal-sized. Dimension : Sutural breadth 29. 4(20. 0?3- 0)fxm, sutural diameter 5. 6 (4.0?.0) jum, diameter of polar capsules 2. 0 (1-8?.2) /urn.This new species is similar to C. arcuata Thelohan, but differs from the latter in having rounded polar capsule and smaller measurements of sutural diameter and diameter of polar capsule.4- Ceratomyxa cheni sp. nov. (fig. 4) Host Spams lutus Honttayn. Habitat Gall bladder.Location of the host Guishan, Zhuhai.Vegetative form Younger trophozoite rounded, ectoplasm hyaline, endoplasm fine granular with 8?4 nuclei. In the early stage of sporogony,spore oval-shaped. After growth, it develops into crescentic form. Each sporont produces 2 spores.Spore Matural spore is crescentic form in sutural view, rhombus in end view. Shell valve short and strong, the terminal of shell valve sharp. Sutural ridge straight and distinct. Polar capsules rounded and equal-sized. Dimension; sutural breadth of spore 13. 2(1