Undulated flooring in the rearing tank decreases hypermelanosis in Japanese flounder Paralichthys olivaceus

作者：Nakata Kuniaki; Yamamoto Ikki; Miyama Yoshifumi; Nakamaru Toru; Masuda Reiji; Tagawa Masatomo^*

来源：Fisheries Science, 2017, 83(6): 1027-1035.

DOI：10.1007/s12562-017-1135-8

• Color anomaly
• Flatfish
• Japanese flounder
• Dimpled floor
• Floor contact area

In the aquaculture of the Japanese flounder Paralichthys olivaceus, hypermelanosis, a malpigmentation condition in which the scales of a significant area on the blind side express the characteristics of those on the ocular side, remains a major concern. Since introducing sand into the rearing tank effectively suppresses hypermelanosis, the inhibitory effects of various characteristics of the surface of the tank floor were investigated. Although an inhibitory effect was observed in both tanks with a sand-image floor and a sand-pasted floor, the strongest effect was found in tanks with a dimpled floor. In addition, covering the inner surface of the tank with net also inhibited hypermelanosis. Using a commercially available corrugated plate, the inhibition of hypermelanosis was confirmed with a noted increase in this effect when combined with light coloration. Juveniles tended to situate themselves in the valley portions of the corrugated plate, suggesting that floor contact with the blind side may contribute to hypermelanosis inhibition. Further observations on the floor contact area with various floor configurations suggested that hypermelanosis is locally suppressed in the areas with floor contact. Therefore, suppression by an undulated (both dimpled and corrugated) floor is likely due to an increase in floor contact area with the blind side.

• 出版日期2017-11