Quantitative determination method for migration speed and course of Yangtze River Chinese mitten crab parent crabs

Abstract

The invention relates to a quantitative determination method for migration speed and a course of Yangtze River Chinese mitten crab parent crabs. The number of sifted parent crabs is 5000-10000. The quantitative determination method for the migration speed and the course of the Yangtze River Chinese mitten crab parent crabs is characterized in that marks are coated on the parent crabs and lantern ring symbols are tied to the parent crabs. On the same day, the parent crabs are released in the river in the region which is overlapped with a migration locus of natural population parent crabs, and the longitude and the latitude of the release point and the time of release are recorded. Three monitoring sections of fixation gill nets are set in the lower course, 4-8 monitoring points are arranged on each monitoring section, the caught marked parent crabs by each monitoring point are checked each day, and the time and the quantity of catching are recorded. From the time that the first marked parent crab is caught, seven times are counted continuously, the migration speed V=S (T1-T2), S is the distance between the release point and the monitoring points, T1 is the time of catching the parent crabs, and T2 is the time of release. The fastest migration speed and the average migration speed are calculated, the quantity of the caught parent crabs of each monitoring point on the three monitoring sections is counted, and the release locus is connected with the monitoring points of catching the parent crabs and the migration course of the parent crabs and the proportion of the parent crabs are obtained.

Description

technical field [0001] The invention belongs to the resource monitoring technology of Chinese mitten crab in the Yangtze River. Background technique [0002] Chinese mitten crab, also known as river crab and hairy crab. Belonging to Crustacea, Decapod order, Square crab family, Eriocheir genus. Eriocheir sinensis is widely distributed in my country, forming three major populations of Eriocheir sinensis mainly in the Yangtze River, Oujiang River and Liaohe River. Among them, the Yangtze River population is superior to the other two populations in terms of germplasm and yield. In recent years, with the changes in the habitat of aquatic organisms in the Yangtze River, the increase of hydraulic construction and the increase of fishing intensity, the quantity and distribution of Chinese mitten crab resources have also undergone tremendous changes. Historically, the Chinese mitten crab of the Yangtze River has been widely distributed in the middle and lower reaches of the Yangtz...

AI Technical Summary

Problems solved by technology

However, there are few studies on the migration speed and route of parent crabs at present, and they are basically in the stage of qualitative description and empirical evaluation, lacking accurate evaluation values. Grasp the eigenvalues ​​of the migration rules of brood crabs in order to provide theoretical basis and reference materials for the fishing of brood crabs in the Yangtze River Estuary, habitat protection, proliferation and release, ecological restoration and ecological risk assessment

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