The effects of dietary HUFA level on flame angelfish (Centropyge loriculus) spawning, egg quality and early larval characteristics

Abstract

This study was conducted to determine the effects of dietary highly unsaturated fatty acids (HUFA) on flame angelfish (Centropyge loriculus) reproduction, and egg and larval quality. In the experiment, formulated diets containing 1.8, 2.9 or 3.6% n-3 HUFA were fed to flame angelfish broodstock (n = 4) for 5 months. Mean fecundity (daily egg production), egg fertilization rates and embryo viability were used as indicators of egg quality. In addition, mean egg diameter, oil globule diameter, per cent hatch, larval size at hatch, per cent survival to yolk exhaustion and larval size at yolk exhaustion were recorded for each treatment. Flame angelfish fed the diet containing 3.6% n-3 HUFA exhibited significantly increased fecundity, fertilization rates and embryo viability than fish that were fed the other two formulated diets. Egg diameter, egg oil globule diameter, larval size at hatch, larval survival to yolk exhaustion and larval size at yolk exhaustion from the 3.6% n-3 HUFA broodstock treatment group were not significantly different from those derived from the Control broodstock treatment. These data revealed that flame angelfish egg quality could respond rapidly (within weeks) to maternal dietary changes. Results from this study further support that dietary HUFA composition can significantly affect broodstock reproductive performance as well as subsequent performance of eggs and larvae.

Reproductive performance of gilthead seabream (Sparus aurata) broodstock showing different expression of fatty acyl desaturase 2 and fed two dietary fatty acid profiles

“…In turn, DHA increase in females would lead to an increased production of docosanoids, which play an important role in the induction of oocyte maturation 61 , improving fecundity in terms of eggs produced. Our observation of a direct positive correlation between n-3 LC-PUFA contents in the egg and egg viability and larval survival confirms that these fatty acids are determinant of embryo and larval development 14,43,46,47 . That the dietary fatty acid profile is reflected in tissue fatty acid profile is well established and our data show that broodstock fed with a diet rich in rapeseed oil led to increased levels of 18C fatty acids and relatively reduced levels of LC-PUFAs in egg lipids.…”

“…Indeed, treatments with 17β-estradiol have shown to increase fads2 expression in female rats 45 . This higher fads2 expression in females seems to be a response to the higher level of requirement of n-3 LC-PUFA fatty acid for the normal gonadal, oocyte and larval development through vitellogenetic processes in different teleosts 9,14,33,43,46,47 . Interestingly, in females showing a very high expression of fads2 such a strong correlation was not found, despite a general trend to increased fads2 expression in females with higher oestrogen levels.…”

“…However, total replacement of FO in the diets of marine fish is difficult due to the scarcity of other sources of long chain polyunsaturated fatty acids (LC-PUFA) of the n-3 family, which are essential for purely marine teleosts 9,10 . Vegetable oils (VO) have been frequently used to partially replace FO, alone 11,12 or in combination with FM replacement [13][14][15][16] . Replacement of FO by VO is constrained by the lack of n-3 LC-PUFA in VO, despite their high concentrations in 18 carbon (18C) fatty acid precursors, because marine teleost has a limited capacity of bioconversion of 18C fatty acids into LC-PUFA.…”

Examination of broodstock diet effects on egg production and egg quality in flame angelfish (Centropyge loriculus)

“…Flame angelfish ( Centropyge loriculus ) were obtained from a commercial aquarium fish wholesaler as individuals and paired according to external characteristics (Callan 2007). The mean size for female individuals under this observation period was 6.5 ± 0.5 cm, 7.6 ± 1.6 g. The mean size for male individuals under this observation period was 7.8 ± 0.6 cm, 11.4 ± 2.6 g. Upon arrival, fish were placed into 20 L containers and acclimated for 1 h to the water conditions on site.…”

The effects of water source and secondary water treatment on flame angelfish Centropyge loriculus (Günther) reproduction

“…Flame angelfish ( C. loriculus ) were obtained from a commercial supplier (Hawaiian SeaLife, Honolulu, HI, USA) as individuals and paired according to external characteristics (males being larger and having more vertical stripes than females) as described by Callan (2007). Upon arrival at OI, fish were placed into 20 L buckets and acclimated to the water conditions on site.…”