The Research Of Peculiar Sense Organs The Tongue Sole (Cynoglossus Semilaevis)

Cynoglossus semilaevis Günter, a flat fish which live in deep water, is an economic valued and high-nutrition species and currently cultured widely in Asia. However, the tongue sole has a characteristic lethargic browsing feeding habit, which makes it difficult to manage feeding in aquaculture systems and can lead to inefficient feeding, high death rates and low growth rates. This has become the main bottleneck of aquaculture and enhancement for this species. Oviously, the sensory mechanisms of the tongue sole in feeding are of special significance. This study further research peculiar sense organs on the abocular side of Cynoglossus semilaevis based on the researches of the feeding mechanism. The sensory physiology functions of peculiar sense organs including both mechanical and chemical stimulations were investigated by electrophysiological techniques; The positioning study of TRPV4 in the peculiar sense organs was studied by immunol histochemistry methods; And the development of the peculiar sense organs of the tongue sole Cynoglossus semilaevis was firstly investigated and compared by scanning electron microscope (SEM). To research the sensory physiology functions of peculiar sense organs on the abocular side of Cynoglossus semilaevis,both mechanical and chemical stimulations of the peculiar sense organs were investigated by using electrophysiological techniques.The mechanical stimulations can be demonstrated by evoking discharges from the nerves of peculiar sense organs after being touched with glass hooks lightly,which were recorded by Biomedical Mutichannels Data Acquisition System.The results of small and big mechanical stimulations showed that stimulatory effects were significantly affected by the strength of mechanical stimulations; While using six kinds of L-amino acids,dimethyl sulphoxide and clam worm as chemical subjects, chemical stimulations of the dermal surface structures were also checked by the evoking discharges recorded by Biomedical Mutichannels Data Acquisition System, and the frequencies and scopes of evoking discharges from the nerves of peculiar sense organs were raised as the concentrations of chemical subjects increasing.In comparison with the relations about natural responses and concentrations of chemical subjects,we knew that the orders of the strength of chemical subjects were: clam worm >L-Arg> L-Met> L-Lys> L-His> dimethyl sulphoxide> L-Gly> L-Ala. The results indicated that peculiar sense organs on the abocular side have dual sensory function to both mechanical and chemical sensitivity. Since C. semilaevis depend on sensory organs to find food, it is probable that the dermal surface structures may be relative to feeding activities, and have an active effect on feeding of tongue sole. This study develops a research about peculiar sense organs on the abocular side of C. semilaevis using electrophysiological techniques, which stands as a valuable resource of further ultrastructure and behavioral science research of C. semilaevis.The positioning study of TRPV4 in the peculiar sense organs on the abocular side of Cynoglossus semilaevis was investigated by immunol histochemistry methods. The skins on the abocular side was stripped, accompanying procedures of hydratization,dewaxing and thermal-remediation with microwave energy. A synthetic peptide of zebrafish trpv4 was chosen as parmingen. The positive result of SEM revealed that presence of antigen-antibody complex mostly at the periphery of mantle-cells, a few at the hair-cell. The negative result didn't show presence of antigen-antibody complex. We concluded that the expressions of TRPV4 were in the mantle-cells and hair-cell of the peculiar sense organs of the tongue sole Cynoglossus semilaevisThe peculiar sense organs of the tongue sole Cynoglossus semilaevis was firstly investigated and compared by scanning electron microscope (SEM). The qualitative research on the transient receptor potential (TRP) superfamily mediating mechanical and chemical sensory function in the peculiar sense organs by SABC(Strept Actividin-Biotin Complex). The results demonstrated that the development laws of the peculiar sense organs were: (1) the format of development was from independent existence to agminated existence of three to five; (2): the queuing discipline turned from absolutely linear array to disorder; (3): the shape of the shield-shaped cover with flanges that were wrapped through the top of each papilla developed from circle to the four-point star; (4):The development laws of the peculiar sense organs coincided with feeding rhythms of Cynoglossus semilaevis which the feeding intensity reached highest in the daytime before metamorphosis, and feeding behaviors began to occur at night after benthic life. The optesthesia of Cynoglossus semilaevis with high visual acuity played great roles in predation when the peculiar sense organs did not developed well at the stage of fish larval. After benthic life, the peculiar sense organs of Cynoglossus semilaevis developed well gradually and the visual sense with inferior visual acuity and light sensitivity started to lose its primary role in predation. Above all, we concluded that the peculiar sense organs of Cynoglossus semilaevis had an active effect on predation after metamorphosis.The ultrastructure of peculiar sense organs of the tongue sole Cynoglossus semilaevis was studied by scanning electron microscope (SEM). The result showed that the peculiar sense organs had three cells: hair cells,mantle cells and mental cell, which was similar to superficial neuromasts. Most of support cells were elongated, with nuclei occupying a large portion of the cytoplasm. In the margin of the neuromast, mantle cells were particularly narrow. The density of cytoplasm for mantle cells was larger than that of hair cells. A lot of mitochondria were localized on the head of hair cells. There were still rough surfaced endoplasmic reticular,Golgi apparatus,vesicle and ribosome in the cytoplasm.Above all, we concluded that peculiar sense organs of the tongue sole Cynoglossus semilaevis were superficial neuromasts which had both mechanical and chemical sense.