The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of...The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of the swimming crab(Portunus trituberculatus).We found that dark pigmentation as a result of boiling has an influence on the observation of the eyestalk microstructure.Choosing an unboiled eyestalk,this study compared the cross section and longitudinal section,and concluded that the cross section is suitable for the observation of growth increments with 6.1%CV(coefficient of variation),and growth bands are suitable for the observation of the longitudinal section with 5.4%CV.The width of growth increments near the edge of the endocuticle is small,and the width of growth increments of the middle part of the endocuticle is large.Relationship of number of growth bands to molting time was fitted to a linear function with the slope not significantly different from 1,indicating that growth bands are formed associated with molting.Periodicity of growth increment formation was calculated as 3.7 d,however was not verified.Our results provide a new improved technique for identification of crustacean molting and growth.展开更多
Eyestalk ablation is the most common procedure to induce gonadic maturation of Eriocheir sinensis. In addition to reproduction, other physiological and metabolic processes are also affected by the removal of X-organ s...Eyestalk ablation is the most common procedure to induce gonadic maturation of Eriocheir sinensis. In addition to reproduction, other physiological and metabolic processes are also affected by the removal of X-organ sinus complex located in the eyestalk. In this study, we studied physiological and biochemical effects of eyestalk ablation of E. sinensis, and the results were as follows. The amylase activity of male crabs with unilateral or bilateral eyestalk ablaion was increased with the days increasing, and the maximal value was on the 20th day (P展开更多
Eyestalk ablation has been widely used in artificial breeding of crustaceans due to its significant promotion effect on gonadal development, which plays a certain role by directly affecting neuroendocrine function of ...Eyestalk ablation has been widely used in artificial breeding of crustaceans due to its significant promotion effect on gonadal development, which plays a certain role by directly affecting neuroendocrine function of X-organ sinus gland （XO-SG） complex in eyestalks. As an important endocrine organ, XO-SG complex of the eyestalk has become a hot issue in crustacean endocrinology. This paper introduced the biological structure and physiological functions of XO-SG complex and summarized the molecular mechanism of eyestalk neuroendocrine, which provided theoretical references for further revealing the regulatory mechanism of eyestalk neuroendocrine system.展开更多
We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanism...We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanisms of these two highly energy-demanding processes. Bilateral eyestalk ablation resulted in precocious acceleration of both molting and reproduction, irrespective of the season at which each experiment was conducted. The rate of accelerated ovarian growth, however, was maximum if the eyestalk ablation was conducted during August–January, the breeding season in the wild, or in February–May(molting-reproductive season), wherein a section of the wild population would be engaged in molting and another section in breeding. The highest degree of precocious molt acceleration, on the other hand, was obtained during June–July when the population was primarily engaged in molting, but with no reproductive activity. The precocious oocyte maturation(due to de-eyestalking) was minimal in June–July. Significantly, the eyestalk ablation also resulted in a dramatic increase in the hemolymph ecdysteroid titer, revealing that a high ecdysteroid titer would have no restraining influence on vitellogenesis. No spawning was, however, observed among de-eyestalked females, even though their final oocyte size surpassed the size of the normal mature oocytes, implying that spawning is not exclusively under the control of eyestalk hormones. A comparative study performed on the vitelline components of the experimentals and the controls revealed that the precociously incorporated yolk under eyestalk ablation was biochemically impoverished. These results indicate that throughout the annual cycle, both the somatic and the reproductive growth of U. triangularis are under the influence of inhibitory principles from the eyestalks. It is also revealing that mere deprival of the inhibitory principles does not culminate into successful vitellogenesis. Arguably, the inhibitory influence from the eyestalks could be a prerequisite for normal healthy maturation of the oocytes and spawning.展开更多
基金The National Key R&D Program of China under contract No.2019YFD0901404the National Natural Science Foundation of China under contract No.41876141+3 种基金the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning under contract No.0810000243the Shanghai Pujiang Program under contract No.18PJ1404100the Shanghai Science and Technology Innovation Action Plan under contract No.19DZ1207502Programs Foundation of Ministry of Education of China under contract No.20133104120001。
文摘The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of the swimming crab(Portunus trituberculatus).We found that dark pigmentation as a result of boiling has an influence on the observation of the eyestalk microstructure.Choosing an unboiled eyestalk,this study compared the cross section and longitudinal section,and concluded that the cross section is suitable for the observation of growth increments with 6.1%CV(coefficient of variation),and growth bands are suitable for the observation of the longitudinal section with 5.4%CV.The width of growth increments near the edge of the endocuticle is small,and the width of growth increments of the middle part of the endocuticle is large.Relationship of number of growth bands to molting time was fitted to a linear function with the slope not significantly different from 1,indicating that growth bands are formed associated with molting.Periodicity of growth increment formation was calculated as 3.7 d,however was not verified.Our results provide a new improved technique for identification of crustacean molting and growth.
文摘Eyestalk ablation is the most common procedure to induce gonadic maturation of Eriocheir sinensis. In addition to reproduction, other physiological and metabolic processes are also affected by the removal of X-organ sinus complex located in the eyestalk. In this study, we studied physiological and biochemical effects of eyestalk ablation of E. sinensis, and the results were as follows. The amylase activity of male crabs with unilateral or bilateral eyestalk ablaion was increased with the days increasing, and the maximal value was on the 20th day (P
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201003070)Youth Fund from Natural Science Foundation of Jiangsu Province(BK2012090)Central Public-interest Scientific Institution Basal Research Fund(2013JBFM09)
文摘Eyestalk ablation has been widely used in artificial breeding of crustaceans due to its significant promotion effect on gonadal development, which plays a certain role by directly affecting neuroendocrine function of X-organ sinus gland （XO-SG） complex in eyestalks. As an important endocrine organ, XO-SG complex of the eyestalk has become a hot issue in crustacean endocrinology. This paper introduced the biological structure and physiological functions of XO-SG complex and summarized the molecular mechanism of eyestalk neuroendocrine, which provided theoretical references for further revealing the regulatory mechanism of eyestalk neuroendocrine system.
基金Supported by the International Foundation for Science(Stockholm,Sweden)(RGA:A/3520-1)the Junior Research Fellowship,Kannur University
文摘We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanisms of these two highly energy-demanding processes. Bilateral eyestalk ablation resulted in precocious acceleration of both molting and reproduction, irrespective of the season at which each experiment was conducted. The rate of accelerated ovarian growth, however, was maximum if the eyestalk ablation was conducted during August–January, the breeding season in the wild, or in February–May(molting-reproductive season), wherein a section of the wild population would be engaged in molting and another section in breeding. The highest degree of precocious molt acceleration, on the other hand, was obtained during June–July when the population was primarily engaged in molting, but with no reproductive activity. The precocious oocyte maturation(due to de-eyestalking) was minimal in June–July. Significantly, the eyestalk ablation also resulted in a dramatic increase in the hemolymph ecdysteroid titer, revealing that a high ecdysteroid titer would have no restraining influence on vitellogenesis. No spawning was, however, observed among de-eyestalked females, even though their final oocyte size surpassed the size of the normal mature oocytes, implying that spawning is not exclusively under the control of eyestalk hormones. A comparative study performed on the vitelline components of the experimentals and the controls revealed that the precociously incorporated yolk under eyestalk ablation was biochemically impoverished. These results indicate that throughout the annual cycle, both the somatic and the reproductive growth of U. triangularis are under the influence of inhibitory principles from the eyestalks. It is also revealing that mere deprival of the inhibitory principles does not culminate into successful vitellogenesis. Arguably, the inhibitory influence from the eyestalks could be a prerequisite for normal healthy maturation of the oocytes and spawning.
