Decreasing fish resources in estuaries is a subject of anthropogenic activities. Studies of the spatiotemporal distribution of fish eggs and larvae can help identify the status and processes underlying recruitment in ...Decreasing fish resources in estuaries is a subject of anthropogenic activities. Studies of the spatiotemporal distribution of fish eggs and larvae can help identify the status and processes underlying recruitment in a fishery. As the fifth largest river estuary in the world, the Huanghe (Yellow) River estuary (HRE) is a typical estuary that has been seriously aff ected by human activities. Annual surveys on ichthyoplankton and environmental factors were conducted in the months of May of 2005 and 2009-2016 in the HRE to investigate the spatiotemporal distribution of fish eggs and larvae and the associated infl uencing factors. A total of 23 and 20 species of eggs and larvae, respectively, were collected. The dominant orders were Perciformes (51.2%) and Clupeiformes (25.6%). The average number of fish species eggs and larvae were 6.0 and 4.1 in average abundance of 0.91 and 0.13 ind./m^3 , respectively. The dominant species were mainly low-commercial-value small-sized fishes, such as Clupanodon punctatus , Harengula zunasi, and Acanthogobius, whereas certain traditional commercial fishes, such as Trichiurus lepturus , and Clupea pallasii, were not seen. Analysis of the fish egg and larval community revealed four temporal assemblages and two spatial assemblages. Salinity was the main factor on the spatial distribution of ichthyoplankton communities, the species number and Shannon-Weiner diversity index (H′) of the fish egg and larval community near the river mouth with lower salinity were signifi cantly lower than the community far away from the river mouth with higher salinity. In addition, increases of water temperature promoted the number and abundance of fish species eggs, and the areas of abundant prey tended to have a more diversified and abundant of ichthyoplankton species. In overall, overfishing, dam construction, and other human activities were the main drivers that led to the substantial decline in fishery resources in the HRE.展开更多
[Objective] The paper was to explore the species composition, number distribution and seasonal dynamics of fish eggs and larvae in Liaodong Bay in 2008. The protection and exploitation status of spawning ground in Lia...[Objective] The paper was to explore the species composition, number distribution and seasonal dynamics of fish eggs and larvae in Liaodong Bay in 2008. The protection and exploitation status of spawning ground in Liaodong Bay was analyzed, and the corresponding protection measures were put forward. [Methods] The species composition of fish eggs and larvae in spawning ground of Liaodong Bay was investigated by horizontal trawling associated with vertical trawling with zooplankton net in May, July, September and October in 2008. [Result] It was found that 7 724 eggs and 229 larvae of fishes belonging to 32 taxa were collected, in which 29 taxa were identified as species, belonging to 9 genera, 21 families and 28 orders, 2 taxa were identified to only family level, and one failed to be identified. The main spawning groups were Cynoglossus joyneri, Engraulis japonicus, Johnius belengerii, Larimichthys polyactis, Konosirus punctatus, Sardinella zunasi, and Scomberomorus niphonius, and the main spawning ground was found in northern waters and Changxing Island waters in Liaodao Bay. There was slightly less spawning species in 2008 compared with 1998, especially the number of fish eggs and larvae decreased greatly. [Conclusion] The effective measures for protection of spawning grounds in Liaodong Bay are suggested, including control of fishing intensity, development of artificial reefs, establishment of germplasm resources reserves, and standardization of compensation standards for marine ecological damage.展开更多
In this study a visual machine technology-based intelligent system was developed and evaluated for separation and recognizing the alive and dead eggs of rainbow trout fish.The features derived from imagery processing ...In this study a visual machine technology-based intelligent system was developed and evaluated for separation and recognizing the alive and dead eggs of rainbow trout fish.The features derived from imagery processing of alive and dead eggs were used as the decision-making variables in the classifier.Multi-layer Perceptron neural network(MLP)and Support Vector Machine(SVM)models were used as the classifiers.With paired t-test,10 effective features were selected from 15 features for classification.The k-fold cross validation method was used for better evaluation the classifiers.By changing the size of the training data set from 80%to 20%,the classifier ability and stabilitywere evaluated.The results showed that in the training phase,all the mean values of the statistical indices forMLP and SVMclassificationswere complete for all categories(100%of the classification was predicted correctly).Also,in the test phase,the performance indicators of both classifiers were very satisfactory(the average accuracywas 99.45%).Therefore,it is possible to use both classifierswith certainty for separation the rainbow trout fish eggs.展开更多
The effects of ultrasound on the hatching of the goldfish (Carassius auratus auratus) and loach (Paramisgurnus dabryanus (sauvage)) cytulas were studied. The ultrasound with certain frequencies can accelerate the deve...The effects of ultrasound on the hatching of the goldfish (Carassius auratus auratus) and loach (Paramisgurnus dabryanus (sauvage)) cytulas were studied. The ultrasound with certain frequencies can accelerate the development of cytulas, induce the embryos to break membrane earlier, increase the survival rate of larvas, and increase 50% hatching rate of loach cytulas at lower temperature.展开更多
基金Supported by the National Natural Science Foundation of China—Shandong Provincial Joint Fund for Marine Science Research Centers(No.U1606404)the National Key Basic Research Program of China(973 Program)(No.2015CB453301)the National Marine Public Welfare Research Project of China(No.201405007)
文摘Decreasing fish resources in estuaries is a subject of anthropogenic activities. Studies of the spatiotemporal distribution of fish eggs and larvae can help identify the status and processes underlying recruitment in a fishery. As the fifth largest river estuary in the world, the Huanghe (Yellow) River estuary (HRE) is a typical estuary that has been seriously aff ected by human activities. Annual surveys on ichthyoplankton and environmental factors were conducted in the months of May of 2005 and 2009-2016 in the HRE to investigate the spatiotemporal distribution of fish eggs and larvae and the associated infl uencing factors. A total of 23 and 20 species of eggs and larvae, respectively, were collected. The dominant orders were Perciformes (51.2%) and Clupeiformes (25.6%). The average number of fish species eggs and larvae were 6.0 and 4.1 in average abundance of 0.91 and 0.13 ind./m^3 , respectively. The dominant species were mainly low-commercial-value small-sized fishes, such as Clupanodon punctatus , Harengula zunasi, and Acanthogobius, whereas certain traditional commercial fishes, such as Trichiurus lepturus , and Clupea pallasii, were not seen. Analysis of the fish egg and larval community revealed four temporal assemblages and two spatial assemblages. Salinity was the main factor on the spatial distribution of ichthyoplankton communities, the species number and Shannon-Weiner diversity index (H′) of the fish egg and larval community near the river mouth with lower salinity were signifi cantly lower than the community far away from the river mouth with higher salinity. In addition, increases of water temperature promoted the number and abundance of fish species eggs, and the areas of abundant prey tended to have a more diversified and abundant of ichthyoplankton species. In overall, overfishing, dam construction, and other human activities were the main drivers that led to the substantial decline in fishery resources in the HRE.
基金Supported by Special Fund for Scientific Research(Marine)in the Public Interest(201405010)
文摘[Objective] The paper was to explore the species composition, number distribution and seasonal dynamics of fish eggs and larvae in Liaodong Bay in 2008. The protection and exploitation status of spawning ground in Liaodong Bay was analyzed, and the corresponding protection measures were put forward. [Methods] The species composition of fish eggs and larvae in spawning ground of Liaodong Bay was investigated by horizontal trawling associated with vertical trawling with zooplankton net in May, July, September and October in 2008. [Result] It was found that 7 724 eggs and 229 larvae of fishes belonging to 32 taxa were collected, in which 29 taxa were identified as species, belonging to 9 genera, 21 families and 28 orders, 2 taxa were identified to only family level, and one failed to be identified. The main spawning groups were Cynoglossus joyneri, Engraulis japonicus, Johnius belengerii, Larimichthys polyactis, Konosirus punctatus, Sardinella zunasi, and Scomberomorus niphonius, and the main spawning ground was found in northern waters and Changxing Island waters in Liaodao Bay. There was slightly less spawning species in 2008 compared with 1998, especially the number of fish eggs and larvae decreased greatly. [Conclusion] The effective measures for protection of spawning grounds in Liaodong Bay are suggested, including control of fishing intensity, development of artificial reefs, establishment of germplasm resources reserves, and standardization of compensation standards for marine ecological damage.
基金Financial supports fromthe Ferdowsi University of Mashhad and Agricultural Sciences and Natural Resources University of Khuzestan,are highly appreciated.
文摘In this study a visual machine technology-based intelligent system was developed and evaluated for separation and recognizing the alive and dead eggs of rainbow trout fish.The features derived from imagery processing of alive and dead eggs were used as the decision-making variables in the classifier.Multi-layer Perceptron neural network(MLP)and Support Vector Machine(SVM)models were used as the classifiers.With paired t-test,10 effective features were selected from 15 features for classification.The k-fold cross validation method was used for better evaluation the classifiers.By changing the size of the training data set from 80%to 20%,the classifier ability and stabilitywere evaluated.The results showed that in the training phase,all the mean values of the statistical indices forMLP and SVMclassificationswere complete for all categories(100%of the classification was predicted correctly).Also,in the test phase,the performance indicators of both classifiers were very satisfactory(the average accuracywas 99.45%).Therefore,it is possible to use both classifierswith certainty for separation the rainbow trout fish eggs.
基金This work is supported by National Natural Science Foundation of China
文摘The effects of ultrasound on the hatching of the goldfish (Carassius auratus auratus) and loach (Paramisgurnus dabryanus (sauvage)) cytulas were studied. The ultrasound with certain frequencies can accelerate the development of cytulas, induce the embryos to break membrane earlier, increase the survival rate of larvas, and increase 50% hatching rate of loach cytulas at lower temperature.
