A lot of water reservoirs offer good natural conditions for crayfish breeding. Today there are four crayfish species present in Latvia--the European species noble crayfish （Astacus astacus）, narrow-clawed crayfish ...A lot of water reservoirs offer good natural conditions for crayfish breeding. Today there are four crayfish species present in Latvia--the European species noble crayfish （Astacus astacus）, narrow-clawed crayfish （Astacus leptodactylus）, the North American signal crayfish （Pacifastacus leniusculus） and spiny-cheek crayfish （Orconectes limosus）. In general, crayfish were found in 258 localities--lakes （175）, rivers and streams （66）, reservoirs, ponds and gravel-pits （17）. A. astacus in Latvia is the dominant crayfish species distributed in all regions. Narrow-clawed crayfish was registered since 1960s. North American signal crayfish was introduced due to its resistance to diseases, but spiny-cheek crayfish arrived from Lithuania waters spontaneously. The main threat for crayfish population is crayfish plague, initiated by mucus Aphanomyces astaci. Astacus astacus was more susceptible species in comparison with Pacifastacus leniusculus and Orconectes limosus. Though the North American signal crayfish and spiny-cheek crayfish were not only resistant, they were the carriers of this disease. The physical habitat alterations, pollution and overfishing are significant during the first year breeding period. Crayfish might serve as bacteria carriers and can cause substantial fish diseases （such as aeromonosis, flavobacteriosis）.展开更多
This study carried out detailed structural analyses of the plane structural deformation pattern and sectional structural deformation styles of the Fauqi Anticline by the 3D seismic section with full cover collection, ...This study carried out detailed structural analyses of the plane structural deformation pattern and sectional structural deformation styles of the Fauqi Anticline by the 3D seismic section with full cover collection, and carried out the kinematical simulation of the Fauqi anticlinal deep decollement coupling shallow growth folds and faults based on the fault decollement fold model and the forward balanced geological section technique. The study subsequently evaluated the differentiated petroleum enrichment mechanism of the Fauqi Anticline by utilizing the results of the structural analysis and combining the spatial-temporal relationship analysis of the source, the reservoir, and the caprock. The results showed that the differentiated plane structural deformation pattern and hierarchical sectional structural deformation style were developed by the superposed coupling of deep decollement, syntectonic sedimentation of shallow growth strata, and the compression of the south-west horizontal tectonic stress from the Zagros Mountains. It was found that the differentiated structural deformation caused the differentiated enrichment of petroleum in the Fauqi Anticline. It was also found that the horizontal slip distance of the Fauqi Anticlinal Folds reached around 3.5 km by the simulation of deep decollement coupling the movement of the shallow growth folds and the faults.展开更多
文摘A lot of water reservoirs offer good natural conditions for crayfish breeding. Today there are four crayfish species present in Latvia--the European species noble crayfish （Astacus astacus）, narrow-clawed crayfish （Astacus leptodactylus）, the North American signal crayfish （Pacifastacus leniusculus） and spiny-cheek crayfish （Orconectes limosus）. In general, crayfish were found in 258 localities--lakes （175）, rivers and streams （66）, reservoirs, ponds and gravel-pits （17）. A. astacus in Latvia is the dominant crayfish species distributed in all regions. Narrow-clawed crayfish was registered since 1960s. North American signal crayfish was introduced due to its resistance to diseases, but spiny-cheek crayfish arrived from Lithuania waters spontaneously. The main threat for crayfish population is crayfish plague, initiated by mucus Aphanomyces astaci. Astacus astacus was more susceptible species in comparison with Pacifastacus leniusculus and Orconectes limosus. Though the North American signal crayfish and spiny-cheek crayfish were not only resistant, they were the carriers of this disease. The physical habitat alterations, pollution and overfishing are significant during the first year breeding period. Crayfish might serve as bacteria carriers and can cause substantial fish diseases （such as aeromonosis, flavobacteriosis）.
基金supported by the National Basic Research Program of China (Grant No. 2014CB239201)the National Science and Technology Major Project (Grant No. 2011ZX05030-005-03)
文摘This study carried out detailed structural analyses of the plane structural deformation pattern and sectional structural deformation styles of the Fauqi Anticline by the 3D seismic section with full cover collection, and carried out the kinematical simulation of the Fauqi anticlinal deep decollement coupling shallow growth folds and faults based on the fault decollement fold model and the forward balanced geological section technique. The study subsequently evaluated the differentiated petroleum enrichment mechanism of the Fauqi Anticline by utilizing the results of the structural analysis and combining the spatial-temporal relationship analysis of the source, the reservoir, and the caprock. The results showed that the differentiated plane structural deformation pattern and hierarchical sectional structural deformation style were developed by the superposed coupling of deep decollement, syntectonic sedimentation of shallow growth strata, and the compression of the south-west horizontal tectonic stress from the Zagros Mountains. It was found that the differentiated structural deformation caused the differentiated enrichment of petroleum in the Fauqi Anticline. It was also found that the horizontal slip distance of the Fauqi Anticlinal Folds reached around 3.5 km by the simulation of deep decollement coupling the movement of the shallow growth folds and the faults.
