BACKGROUND: Microalgae Dunaliella salina is a national source of carotenoids which
can be used in aquaculture, meanwhile synthetic Astaxanthin is very expensive for use in
aquaculture and several attempts have been made to find alternatives for Astaxanthin.
OBJECTIVES: The purpose of this study is to investigate the effect of oral administration of
Astaxanthin and D.salina on skin carotenoid level, skin and fins coloration as well as lipid
peroxidation of muscles in H.severus. METHODS: One hundred and thirty five H.severus
weighing 27±0.5g were randomly divided to three groups in triplicate: Groups 1 (G1) was fed
with basal diet, group 2 (G2) and group 3 (G3) were fed with basal diet supplemented with
200 mg kg-1 D.salina or Astaxanthin respectively. After 6 weeks, digital photo were taken
from 15 fishes of each group and skin and muscles samples were taken after euthanasia. Skin
beta carotene rate, lipid peroxidation of muscle (based on Malondialdehyde activity) as well
as skin and fins coloration pattern (a*, b*, Hue, L* and Chroma) were compared among
groups. RESULTS: Skin beta-carotene rate significantly increased in G2 and G3 compare to
G1 but, Lipid peroxidation rate were decreased in G2 and G3 compare to control (p<0.05).
Although some improvement in color quality were observed in trunk area, there was no
significant difference in color indicators among the groups (p>0.05). In the fin areas a* value
significantly increased in G2 and G3 compare to control also Hue and b* value significantly
decreased in G2 and G3 compare to control (p<0.05). Chroma significantly increased in G3
compared with other (p<0.05). No significant difference were observed in L* between the
groups (p>0.05). CONCLUSIONS:Although the effect of Astaxanthin on skin carotenoid level
and skin and fins coloration was better compared with D. salina. However, because of
reasonable price, wide availability and the production of Dunaliella salina, it can be used as
an alternative for Astaxanthin.