章节大纲


    • Individual sturgeon are identified by embedding electronic tags in them. Catching a large sturgeon is a difficult task.


    • Sturgeon are placed in nets or held by humans for measurement. A weighing scale or scale is used. After measurement, the weight of the sturgeon is calculated by subtracting the tare weight (weight of the net and human).


    • In order to test sturgeon egg maturation and ovulation ability, a large needle (egg examination equipment) is inserted into the body of the fish and the ovarian fragments are removed. The advantage of this method is that the sturgeon recover more quickly because the incision is smaller.


    • To examine the egg maturation and ovulation potential of sturgeon, a tube is inserted through an incision in the body of the fish and the egg follicle is removed. After the incision is made, the wound is sutured.


    • Eggs are cultured in petri dishes to test the maturation and ovulation potential of sturgeon eggs.


    • Hormones are administered to female sturgeon two days prior to egg retrieval to induce egg maturation and ovulation. After confirming that spontaneous ovulation has occurred, the eggs are removed by pushing on the abdomen.


    • Hormones are administered to male sturgeon one day prior to sperm collection to induce sperm production. Sperm are collected with a syringe with a tube and stored cold.


    • After egg retrieval, the eggs are washed one-third with seawater and replaced with freshwater. The condition of the sperm is observed prior to artificial insemination.


      Sperm that are judged to be in good condition are placed over the eggs and left to settle for one minute before artificial insemination is performed. Since the eggs are very sticky, they are de-stickified using 1% urea and 0.1% tannin.


      The fertilized eggs are then housed in a hatching jar, and fresh water is poured over them while waiting for hatching.


    • Pre-hatched individuals spin around inside the eggs. Sometimes they emerge from the tail first and begin swimming with the eggshell still on. The video was filmed in an incubator at 12°C.

  • Research Introduction Aquaculture Life Science