Micro-elemental nutrition in the early life stage of fish

Abstract

Successful rearing of marine larval fish has long become the bottleneck of marine fish aquaculture. In spite of considerable progresses in recent years, many questions still remain for larval fish nutritional requirements. My study aimed to provid a full picture of essential micro-elemental nutrition in the early life stage of marine fish. Fish at the early life stage tend to have high micro-elemental requirements, and the requirement changed dynamically with their growth. By using a modified fractional model, we successfully quantified Zn and Fe requirement in the model organism marine medaka. However, responses to different micro-elemental supplementary levels were elemental dependent, with both fragile (low Zn) and resistant (low Fe) responses observed. Combined with elemental stoichiometry, sufficiency of each micro-element in typical live feeds (rotifer, artemia and copepod) to marine fish larvae was evaluated, with rotifer potentially deficient in Zn and Se. This can be solved by short-time or longtime Zn and Se enrichment in rotifer. However, the residue time of rotifer during real application should be minimized due to the rapid loss of these enriched micro-elements. Furthermore, zinc oxide nanoparticle can serve as a potential novel micro-element source due to their high bioavailability and low toxicity to stomach-less fish, which can be adopted in future micro-feed production. Further studies on standardization of micro-element enrichment in live feeds, anti-oxidative responses in larval fish and nanomaterial application in aquaculture are required for the advancement of larval aquaculture. Keywords: larval aquaculture, rotifer, nutrition, micro-elements, fractional model, nanoparticle

Date of Award	2017
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology