Dietary vitamin A requirement of juvenile greasy grouper (Epinephelus tauvina)

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“…In the present study, the necessity of dietary VA for normal growth of juvenile grass carp was confirmed, which was similar with the results reported in greasy grouper (Mohamed et al 2003), Atlantic halibut (Moren et al 2004), hybrid tilapia (Hu et al 2006), Japanese flounder (Hernandez et al 2007), European sea bass larvae (Mazurais et al 2009) and sea bass (Georga et al 2011). There were many VA deficiency symptoms reported in fish, such as depressed feed consumption (Saleh et al 1995), hemorrhages in eyes, fins and skin (Moren et al 2004), cataract (Moren et al 2004, Hemre et al 2004, photophobia (Hu et al 2006), bone deformities (Yang et al 2008) and lack of pelvic fins (Mazurais et al 2009).…”

“…This result was similar with the results reported by Hernandez (2005). However, Mohamed et al (2003), Hemre et al (2004) and Yang et al (2008) draw the opposite results that VA deficiency in the diet increased mortality. The different results may be involved in the size of the experimental fish and the feeding period of the diet (Moren et al 2004).…”

“…Similar results were reported by Thompson et al (1995). However, contradictory results were reported in greasy grouper (Mohamed et al 2003), which indicated a significant decrease of body fat as the dietary VA level increased. Biometric indices of particular organs or tissues relative to total body mass (such as HSI) were considered as indices of change in nutritional and energy status.…”

“…Because of differences of fish species, development stage, initial body weight, dietary composition and experimental conditions and other interacting nutrients, the dietary optimal supplementation dose could be different. And based on the SGR data, the supplementation dose in this study should be no less than 4769 IU/kg, which is similar to the requirement values reported for hybrid tilapia (Hu et al 2006), and greasy grouper (Mohamed et al 2003), which have requirements between 2000 and 5000 IU/kg. In our study, different VA levels showed no significant effect on the FCR and FR, as reported in Atlantic salmon by Thompson et al (1994).…”

“…Vitamin A (VA) shares a variety of biochemical functions, including maintaining normal vision, controlling the differentiation and proliferation of cells (Moren et al, 2004;Hemre et al, 2004), participating in mucus production and bone growth (Saleh et al, 1995), regulation of glucose concentrations and lipid metabolism of the whole body (Mohamed et al, 2003;Hernandez et al, 2005), affecting fish immune responses (Rhee et al, 2012;Furuita et al,2001; Thompson et al, 1995). Stunted growth and development of fish have been reported when insufficient or excessive VA intake occured, especially in juvenile fish (Rønnestad et al, 1998).…”