scholarly journals Gliocyte and synapse analyses in cerebral ganglia of the Chinese mitten crab, Eriocheir sinensis: ultrastructural study

2016 ◽  
Author(s):  
H. Zhang ◽  
P. Yu ◽  
S. Zhong ◽  
T. Ge ◽  
S. Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Eriocheir Sinensis ◽  
Type I ◽  
Aquatic Species ◽  
Histological Findings ◽  
Chinese Mitten Crab ◽  
Cerebral Ganglia ◽  
Transmission Electron ◽  
Mitten Crab ◽  
Nerve System

The Chinese mitten crab Eriocheir sinensis is an economically important aquatic species in China. Many studies on gene structure, breeding, and diseases of the crab have been reported. However, knowledge about the organization of the nerve system of the crab remains largely unknown. To study the ultrastructure of the cerebral ganglia of E. sinensis and to compare the histological findings regarding the nerve systems of crustaceans, the cerebral ganglia were observed by transmission electron microscopy. The results showed that four types of gliocytes, including type I, II, III, and IV gliocytes were located in the cerebral ganglia. In addition, three types of synapses were present in the cerebral ganglia, including unidirectional synapses, bidirectional synapses, and combined type synapses. 

The epithelial cytotypes of hepatopancreas in the Chinese mitten crab Eriocheir sinensis (Decapoda, Varunidae)

Crustaceana ◽  
2017 ◽  
Vol 90 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Hui Zhang ◽  
Shengwei Zhong ◽  
Qinyong Fan ◽  
Pengcheng Yu ◽  
Tingting Ge ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Eriocheir Sinensis ◽  
Embryonic Cells ◽  
Chinese Mitten Crab ◽  
Septate Junctions ◽  
Large Vacuole ◽  
Transmission Electron ◽  
Mitten Crab ◽  
F Cells

The Chinese mitten crab,Eriocheir sinensis, is an economically important crustacean. However, the hepatopancreas structure of the crab has not been fully disclosed. Here, we employed light microscopy and transmission electron microscopy to identify the epithelial cytotypes of the hepatopancreas. The hepatopancreas consisted of four epithelial cytotypes, which were B (blister-like), R (resorptive), F (fibrillar), and E (embryonic) cells. B cells had club-shaped nuclei, scant cytoplasm, and contained some small vacuoles and one extremely large vacuole. Both R and F cells were columnar, and F cells were separated by two to three serial R cells. R cells contained small vacuoles, but had no extremely large vacuole in the cytoplasm. Two neighbouring R cells established contact by septate junctions. Many microvilli were present on the surface of the plasmalemma of R cells. Endocytotic vesicles were frequently observed in apical regions of the R cells. F cells were hyperbasophilic and argyrophilic, and contained abundant rough endoplasmic reticulum. E cells were small and contained scant cytoplasm and we rarely observed organelles in these cells. In addition, many vesicae were present in the lumen of the hepatopancreatic tubules.

A spiroplasma associated with tremor disease in the Chinese mitten crab (Eriocheir sinensis)

Microbiology ◽  
2004 ◽  
Vol 150 (9) ◽  
pp. 3035-3040 ◽  
Author(s):  
Wen Wang ◽  
Bohai Wen ◽  
Gail E. Gasparich ◽  
Ningning Zhu ◽  
Liwen Rong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Light And Electron Microscopy ◽  
Eriocheir Sinensis ◽  
Rrna Gene ◽  
Chinese Mitten Crab ◽  
Mitten Crab ◽  
The 16S Rrna Gene

An epidemic of tremor disease has been a serious problem in Chinese mitten crabs, Eriocheir sinensis, in China in recent years. The disease-causing agent was previously considered to be a rickettsia-like organism. Here, analysis of the 16S rRNA gene sequence, light and electron microscopy and cultivation in vitro were used to identify the agent. Sequence analysis of the 16S rRNA gene found it to have 98 % identity with that of Spiroplasma mirum. The agent was able to be passed through membrane filters with pores 220 nm in diameter and could be cultivated by inoculating the yolk sac of embryonated chicken eggs and M1D medium. Rotary motion and flexional movement were seen by light microscopy, and electron microscopy showed that the organism had a helical morphology and lacked a cell wall. The organism produced small colonies with a diameter of 40–50 μm after 17–25 days of incubation on solid M1D medium. The agent was found in blood cells, muscles, nerves and connective tissues of crabs inoculated with a filtrate of yolk sacs or with cultures grown in M1D medium, and it was similar in structure to those grown in eggs and cultivation broth. Disease was reproduced by experimental infection with the cultivated organisms. This study has demonstrated that the causative agent of tremor disease in the Chinese mitten crab is a member of the genus Spiroplasma. This is believed to be the first time a spiroplasma has been found in a crustacean. These findings are not only significant for studies on pathogenic spiroplasmas, but also have implications for studies of freshwater ecology.

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