The results showed that the major immune organ in the carp was the head-kidney.The surface of the head-kidney was covered with a thin layer of fibroid connective tissue capsule.

• 结果表明，头肾是鲤鱼的主要免疫器官，表面覆盖有一薄层纤维结缔组织性被膜，未见明显的小梁。