PROBLEM TO BE SOLVED: To make completely closed circulation type land breeding for abalones possible.SOLUTION: A completely closed circulation type land breeding system for abalones has: a foam separator 15 which removes suspension property organic matters contained in water in a breeding tank 2； an electrolytic chlorine generator 16 which converts persistent organic matters contained in the water in the breeding tank into easily decomposable organic matters； a biofilter apparatus 18 which nitrifies ammonia contained in the water in the breeding tank and converts it into nitrate； a denitrification apparatus 24 which denitrifies nitrate； and a sludge recovery tank 8 which collects sludge in the breeding tank. The breeding tank is provided with: a breeding tank body 3； a plurality of breeding baskets 4 which are arranged inside the breeding tank body while forming a water flow space 301 between a bottom of the breeding tank body and itself； a plurality of shelters 6 which are vertically arranged in the breeding basket respectively and are housed； air generating means 5 which are placed below the breeding baskets； and a plurality of sludge pockets 7 which are formed in parts on the bottom of the breeding tank. The denitrification apparatus is provided with: a denitrification area 25； and a circulation area 27 for circulating water that has passed the denitrification area 25 again in the denitrification area.【課題】アワビ類の完全閉鎖循環式の陸上養殖を可能にすること。【解決手段】飼育槽２内の水に含まれる懸濁性有機物を除去する泡沫分離装置１５と飼育槽内の水に含まれる難分解性有機物を易分解性有機物に変換する電気分解塩素発生手段１６と飼育槽内の水に含まれるアンモニアを硝化して硝酸に変換する生物濾過装置１８と硝酸を脱窒する脱窒装置２４と飼育槽内のスラッジを回収するスラッジ回収槽８を具備し、飼育槽は、飼育槽本体３と、飼育槽本体内に飼育槽本体の底との間に水流空間３０１を形成しながら配置した複数個の飼育籠４と、飼育籠のそれぞれに縦置きに並べて複数枚収容したシェルター６と、飼育籠の下方に配置したエア発生手段５と、飼育槽の底部複数個所に形成したスラッジポケット７を具備し、脱窒装置は、脱窒エリア２５と、脱窒エリア２５を通過した水を再び脱窒エリアに循環するための循環エリア２７を具備した。【選択図】図１
