To understand the physiological and ecological responses of marine fishes to the change of water temperature,
newly-hatched larvae of Yellowtail clownfish Amphiprion clarkii were reared in captivity at water
temperatures of 23, 26 and 29 C till they completed the metamorphosis to juvenile phase, and larval
survival, development, growth and feeding were evaluated during the experimental period. The results
showed that water temperature influenced the physiological performance of larvae of A. clarkii significantly.
The survival and growth rates of larvae of A. clarkii increased significantly with the increase of
water temperature from 23 to 29 C (P < 0.05). Water temperature also influenced larval development
of A. clarkii significantly and larvae reared at 23 C took longer time for post-larval development and metamorphosis
compared to 26 and 29 C (P < 0.05). Total length and body weight for post-larval development
and metamorphosis decreased with the increase of water temperature from 23 to 29 C (P < 0.05). Q10 in
developmental rate was higher than in daily growth rate at the same rearing temperature, indicating that
at water temperature had greater influence on larval development than on growth. Water temperature
also influenced larval feeding of A. clarkii significantly with feed ration (FR) and feed conversion efficiency
(FCE) increased with the increase of water temperature from 23 to 29 C (P < 0.05). There was a positive
correlation between FR and specific growth rate (SGR) (P < 0.05) but not between FCE and SGR
(P > 0.05), indicating that FR influenced growth rate significantly in larvae of A. clarkii. This study demonstrated
that the physiological responses of larvae of A. clarkii to the change of water temperature and confirmed
that water temperature influenced larval survival, development, growth and feeding significantly.
This study suggests that the decline of larval survival and growth rates, extension of pelagic larval duration
and reduction of larval feeding at lower temperature have ecological impacts on larval dispersal and metamorphosis,
juvenile settlement and population replenishment in A. clarkii in the wild