Dualistic feeding pattern of Nile tilapia (Oreochromis niloticus, L.) reared under different self-feeding system conditions

Abstract

Nile tilapia (Oreochromis niloticus) is one of the most important cultured species worldwide. The research aims to clarify the feeding characteristics, such as daily feeding pattern of Nile tilapia using a self-feeding technique. The feeding pattern was conducted under two rearing conditions, indoor treatments under a controlled light regime (LD 12:12) and constant water temperature (25°C), and outdoor treatments under natural conditions which consisted of duplicate trials with two periods each. The outdoor treatment was carried out from early summer through late autumn in Mie, Central Japan. Daily self-feeding activity of Nile tilapia in indoor treatments was nearly daytime feeding pattern, synchronizing with the given photoperiod (24 hr). However, the self-feeding activity in the outdoor experiments from early summer to early autumn was almost daytime feeding pattern, but it became less clear and shifted to a nighttime feeding profile in late autumn. The results revealed that Nile tilapia has a dualistic capacity for demand-feeding both in light and dark phases. These results might have been caused by the seasonal change in light intensity and/or water temperature. Information obtained from the self-feeding experiments enables us to identify the influence of environmental changes on the physiological condition of farmed fish through their expression of appetite. K E Y W O R D S diel feeding behaviour, Nile tilapia, Oreochromis niloticus, self-feeding 1 | INTRODUCTION The Nile tilapia (Oreochromis niloticus, L.) is one of the most important aquaculture species groups especially in South East Asia, Africa, South America and China. Several species of tilapia are cultured commercially, but Nile tilapia is the predominant cultured speciesand its global production has reached to nearly 3,670,000 tons in 2014 (FAO 2017). The gross production of Nile tilapia increases year by year because of the strong worldwide demands for this potential freshwater fish as a food resource of human being. Therefore, further research is necessary for the establishment of the culture technology for this species because knowledge about the physiology and ecology on this fish species is still lacking and there are many obscure points such as appropriate rearing conditions and feeding technology.The self-feeding system delivers food based on the learning ability of fish and it is considered to be a feeding technique for aquaculture that might be controlled by a biological clock (Alan€ ar€ a, 1992) with food demands depending on appetite (Amano et al., 2007). Therefore, the feeding method agrees with the physical state of the cultured fish. Indeed, self-feeding systems have been studied in several culture fish species such as rainbow trout Oncorhynchus mykiss (

Feeding behaviour, locomotion rhythms and blood biochemistry of the neotropical red‐tail catfish (Phractocephalus hemioliopterus)

“…alexandri ) (Kitagawa et al ., 2015) and tilapia ( O . niloticus ) (Pratiwy & Kohbara, 2018), which have food plasticity and can change their daily activity rhythms according to food availability. Thus, our results are similar to other studies that demonstrate that food greatly influences the synchronization of daily activity rhythms (Sánchez‐Vázquez et al ., 2001; Vera et al ., 2007).…”

“…tinca ) (Herrero et al ., 2005), pacamã ( L . alexandri ) (Kitagawa et al ., 2015), Atlantic salmon ( Salmo salar ) (Shi et al ., 2017), tilapia ( Oreochromis niloticus ) (Pratiwy et al ., 2017) and pirarucu ( A . gigas ) (Mattos et al ., 2016; Pedrosa et al ., 2019) showed excellent rates for the performance variables WG, consumption, SGR and FC.…”

“…The self-feeding system enabled the identification of the feeding preference of tambaqui (C. macropomum), where it presented 84.9% nocturnal feeding activity (Reis et al, 2019) and locomotor activity greater than 90% (Fortes-Silva et al, 2016. As for zebrafish (Danio rerio), this system demonstrated that the animals have nocturnal feeding activity et al, 2000), tench (T. tinca) (Herrero et al, 2005), pacamã (L. alexandri) (Kitagawa et al, 2015), Atlantic salmon (Salmo salar) (Shi et al, 2017), tilapia (Oreochromis niloticus) (Pratiwy et al, 2017) and pirarucu (A.…”

Digitization of aquaculture: A review

“…Several studies have been conducted to support this claim, such as the European Seabass (Dicentrarchus labrax) [28] , Yellowtail (Seriola quinqueradiata) [29] , and Tilapia (Oreochromis niloticus) [30] . Using robots to make human activities easier is the goal of the 3.0 industrial revolution.…”

Digitization in Detecting Fish Freshness Quality: Literature Review

“…Currently, in Indonesia, there have been many digitalization tools developed to help the cultivation process to get excellent and efficient results. One of the digitization developments is the assembly of self-feeding systems [9,10]. Using a feed dispenser (Food timer, Seiko Clock) and modified to be driven by the control unit according to the signal from the switch actuation.…”