An aquatic animal measuring device is disclosed, which is used for deriving the precise moment for dividing a fish farm. The device includes a video recording system, a buoy, a pole, a gliding member, a base, and a control unit. The video recording system includes a housing and a video camera, where the video camera is mounted in the housing, and the housing is made of waterproof materials. The buoy is connected to the housing. The pole has an end abutted against the bottom of a pond. The gliding member is mounted on the pole and able to slide along the pole. Such gliding member includes a first connecting part and a second connecting part, where the first connecting part is connected to the buoy. The base is connected to the second connecting part while including a reflective surface facing the housing. The control unit is coupled to the video camera for receiving and processing the image shoot by the video camera.一種水生物檢測裝置,係用於判定一養殖魚塭之分池時機點,包含:一攝影裝置,包含一殼體及一攝影機,該殼體為防水材質,而該攝影機設置於該殼體中;一浮筒,結合於該殼體;一桿體,具有一頂端及一底端,該底端供固定於一容槽之底部,該容槽供容納一水體;一連動件,係設置於該桿體上,且能夠沿該桿體之軸向自由滑移,該連動件具有一第一結合部及一第二結合部,該第一結合部連接該浮筒;一底座,連接該第二結合部,且該底座具有一反光面朝向該殼體;及一控制單元,係耦接該攝影機,供接收該攝影機所拍攝之影像,據以進行影像辨識處理。1‧‧‧攝影裝置11‧‧‧殼體111‧‧‧底面112‧‧‧外周面113‧‧‧頂面12‧‧‧攝影機121‧‧‧鏡頭13‧‧‧隔板2‧‧‧支撐裝置21‧‧‧桿體22‧‧‧連動件221‧‧‧第一結合部222‧‧‧第二結合部223‧‧‧連桿23‧‧‧浮筒24‧‧‧底座3‧‧‧控制單元31‧‧‧警告單元W‧‧‧水體S‧‧‧取樣空間F‧‧‧魚
