Fish generally respire through gills. most bony fish es have a swim bladder a gas-filled organ used to adjust swimming depth.

一般是经由鳃呼吸。大部分硬骨鱼有鳔，这是源于消化管的憩室，司控制浮力或为辅助呼吸器官。

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Fish generally respire through gills. most bony fish es have a swim bladder a gas-filled organ used to adjust swimming depth.

一般是经由鳃呼吸。大部分硬骨鱼有鳔，这是源于消化管的憩室，司控制浮力或为辅助呼吸器官。

youdao