Fermented water of Thai herbs effectively enhanced amputated fin regeneration in Siamese fighting fish (Betta splendens)

Abstract

The aggression of Siamese fighting fish (Betta splendens) during courtship and reproductive behaviors can result in torn fins. However, the natural regeneration of torn fins has been significantly improved by treating fish with fermented water of plants. We amputated half of the caudal fin of male Siamese fighting fish (1.29 ± 0.01 g body weight) in the vertical plane. The amputated fish were individually reared in fermented water containing eight combinations of herbs that included dried Indian almond (Terminalia catappa) leaf (IAL, 0.25 g L−1), dried banana (Musa sapientum) leaf (BL, 1.5 g L−1), and dried papaya (Carica papaya) leaf (PL, 2.5 g L−1) as major ingredients. Other ingredients included dried lemongrass (Cymbopogon citratus) leaf (LL, 1 g L−1), dried clay (50 g L−1), and salt (5 g L−1). For comparison, other fish were reared in non-fermented water. The experiment was conducted in a completely randomized design for five weeks, comprising fifteen fish per treatment. Individual fish served as experimental units. Fin regeneration was monitored weekly while growth performance was recorded at the end of the trial. The herbal treatments had no effects on growth, body morphometrics, and feed utilization (P > 0.05). However, fin regeneration was statistically improved for the fish reared in combinations of IAL, BL, and PL (P < 0.05). Among these alternative treatments, red color intensity was fully redeveloped in fish reared in three herbal treatments (P < 0.05) that all contained dried papaya leaf (BL + PL, IAL + PL, and IAL + BL + PL). Therefore, those three treatments effectively enhanced fin regeneration.