Temperature effects on
larval development and occurrence of metamorphosis-related morphological
abnormalities in hatchery-reared spotted halibut Verasper variegatus
juveniles
M. Aritaki, K. Ohta, Y. Hotta, M. Tagawa, M.
Tanaka-2004
Nippon Suisan Gakkaishi, 70(1): 8-15
Abstract:
The occurrence of metamorphosis-related abnormalities
under different rearing water temperatures (9-21 °C) was examined in
hatchery-reared juveniles of spotted halibut Verasper variegatus. The
growth and development of the larvae were accelerated at higher
temperatures. After completing metamorphosis, juveniles were categorized
into three morphological types (normal, pseudoalbino and ambicolored fish)
based on eye location and body color (pigmentation). The temperature
spectrum of the occurrence of these three morphological types was consistent
among three experiments carried out in different years, and the normal fish
occurred most frequently at 18°C, pseudoalbino fish at 12°C and
ambicolored fish at 21°C. The morphological characteristics of both body
sides (left and right) in pseudoalbino and ambicolored fish were similar to
the blind side and ocular side, respectively, of normal fish, suggesting the
occurrence of abnormal asymmetrical development in either body side.
These results suggest the possible involvement of rearing temperature,
possibly through the timing of metamorphosis and/or the speed of larval
growth/development, in the asymmetrical differentiation of left and right
body sides during metamorphosis.
(Miyako Station, National Center for Stock
Enhancement, Miyako, Iwate 027-0097, Japan)