PROBLEM TO BE SOLVED: To provide a spat sorting method or the like that can easily sort out spats delivered in an aquarium by grown shellfishes.SOLUTION: A spat sorting method concerning the present invention includes: a breeding preparation step of installing a net (bottom net 2a of a net box 2) of an area slightly smaller than the area of the bottom at the bottom of an aquarium 1 for breeding shellfishes serving as bait for firefly larvae, and pouring water W into the aquarium 1 and putting grown shellfishes 3 of the shellfishes serving as the bait for the firefly larvae on the net; a breeding step of breeding the grown shellfishes 3 in the aquarium 1; and a spat sorting step of vibrating the net after the grown shellfishes 3 deliver spats 4 and screening out the spats 4 through the mesh of the net on bottom face 1a of the aquarium 1, and thereby sorting out the grown shellfishes 3 and the spats 4.【課題】水槽内で親貝が産んだ稚貝を簡単に選り分けることができる稚貝選り分け方法等を提供する。【解決手段】本発明に係る稚貝選り分け方法は、蛍の幼虫の餌となる貝を飼育するための水槽1の底に当該底の面積よりも一回り小さな面積の網(網箱2の底網2a)を設置するとともに、水槽1内に水Wを入れて、網の上に蛍の幼虫の餌となる貝の親貝3を入れる飼育準備ステップと、水槽1内で親貝3を飼育する飼育ステップと、当該親貝3が稚貝4を産んだ後、網を振動させ、網の網目を通して稚貝4を水槽1の底面1aに篩い落とすことによって、親貝3と稚貝4とを選り分ける稚貝選り分けステップと、を備えたことを特徴とする。【選択図】図1