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Bapary, M. A. J., Amin, M. N., Takeuchi, Y., & Takemura, A. (2011). The stimulatory effects of long wavelengths of light on the ovarian development in the tropical damselfish, Chrysiptera cyanea. Aquaculture, 314(1-4), 188–192.
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Camus, T., & Zeng, C. (2008). Effects of photoperiod on egg production and hatching success, naupliar and copepodite development, adult sex ratio and life expectancy of the tropical calanoid copepod Acartia sinjiensis. Aquaculture, 280(1-4), 220–226.
Abstract: The tropical calanoid copepod Acartia sinjiensis has good potential for mass culture as live feed for reef fish larvae. The present study was conducted to evaluate the effects of photoperiod on various parameters related to A. sinjiensis productivity in culture. Five photoperiods of Light:Dark = 0:24; 6:18; 12:12; 18:6 and 24:0h were setup. Daily egg production of individual females under each photoperiod was monitored for 8 consecutive days. The females were randomly selected daily from stock cultures kept under respective photoperiods and discarded after experiment. The results showed a clear trend of increasing egg production with longer illumination period. Under constant darkness, acclimatization was evident as egg output increased steadily over the 8??day period. Statistics showed that photoperiod significantly (p < 0.005) affected mean daily egg production, with the highest egg output recorded at 18L:6D and 24L:0D (17.6 ?? 1.7 and 17.6 ?? 1.8 eggs/female/day respectively), which were significantly higher than all other treatments. Photoperiod also significantly affected 48??h egg hatching success (p < 0.005), a trend of increased hatching success with longer light phase was demonstrated. The highest hatching rate (87.2 ?? 1.4%) was recorded at 24L:0D, which was significantly higher than the 0L:24D and 6L:18D treatments but not significantly different from the second highest (85.3 ?? 2.6%) hatching rate of 18L:6D treatment. Photoperiod was further confirmed to significantly (p < 0.005) affected naupliar and copepodite development with accelerated development observed with increased illumination period of photoperiods. Mean development time from egg to adult was the shortest at 6.00 ?? 0.33 days under constant light (24L:0D), followed by 6.24 ?? 0.24??days at 18L:6D, both were significantly shorter than that of 0L:24D and 6L:18D treatments although no significantly difference was detected between themselves. Adult life expectancy was also found significantly (p < 0.005) affected by photoperiod with the shortest adult life span recorded under constant light (24L:0D) (9.4 ?? 0.4??days), which was significantly shorter than all other photoperiods tested. Adult sex ratio was the only parameter tested that was not significantly affected by photoperiod, a skewed sex ratio in favor of female was found across all photoperiod treatments. Based on results of current study, it is recommended that a photoperiod of 18L:6D being adopted for A. sinjiensis culture to maximize its productivity for aquaculture hatcheries.
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Fukuda, H., Torisawa, S., Sawada, Y., & Takagi, T. (2010). Developmental changes in behavioral and retinomotor responses of Pacific bluefin tuna on exposure to sudden changes in illumination. Aquaculture, 305(1-4), 73–78.
Abstract: Schooling behavior traits during the process of retinomotor response from scotopic to photopic vision were examined in cultivated juvenile Pacific bluefin tuna (PBT) at 3 different ages. After a sudden change in illumination from darkness to 300 lx, retinal adaptations changed from scotopic to photopic vision. Retinomotor and schooling indices showed strong agreement, with juvenile PBTs forming polarized schools upon complete retinal adaptation to photopic vision. The behavioral and retinal adaptation to sudden illumination took 20, 15, and 10 min after illumination in PBT 25, 40, and 55 days after hatching (dah). At 40 dah, PBT took a longer time to adapt than fish aged 55 dah and showed the highest swimming speed, including momentary bursts of swimming immediately after illumination. This suggested that these fish were swimming at high speed under poor visibility conditions. In contrast, PBT at 55 dah showed a gradual increase in swimming speed that correlated with their retinal adaptation. Therefore, behavioral and retinal adaptation traits changed during growth, suggesting that the high mortality in PBT around 40 dah, due to collisions with the tank and net walls at dawn, may be because these adapt more slowly than fish at 55 dah and were swimming at a relatively high speed under conditions of poor visibility.
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Gao, X., Li, X., Zhang, M., Chi, L., Song, C., & Liu, Y. (2016). Effects of LED light quality on the growth, survival and metamorphosis ofHaliotis discus hannaiIno larvae. Aquac Res, 47(12), 3705–3717.
Abstract: Light is a key environmental factor influencing the growth, development and survival of aquatic organisms. We examined the effects of different light qualities (red, orange, white, blue, green or no light) and developmental stage at initial lighting [fertilized egg (FE), trochophore larva (TL), or eye-spot larva (EL)] on the growth, development, and survival of larvae of the Pacific abalone Haliotis discus hannai Ino. Larva-hatching success was significantly higher under blue, green, or no light compared with red, orange or white light (P < 0.05). Larval abnormalities were significantly increased under red, orange or white light compared with all other light qualities (P < 0.05). The incidence of metamorphosis in larvae illuminated from the TL stage was significantly higher under blue compared with other light qualities. Irrespective of the stage at initial illumination, the incidence of metamorphosis was lower in larvae cultured under red, orange or no light compared with other light qualities, but the differences were not significant (P > 0.05). Juvenile survival was significantly higher under blue or green compared with other light qualities (P < 0.05), with no significant effect of stage at initial illumination (P > 0.05). Larval size at completion of the shell was unaffected by stage at initial illumination, but was greater under blue or green light, while size at metamorphosis was greatest following illumination with blue or green light since the TL or EL stage (P < 0.05). Metamorphosis time was shortest with blue or green light and in cultures illuminated from the FE or TL stage (P < 0.05). Larval development from the FE to formation of the fourth tubule on the cephalic tentacles was fastest in larvae exposed since the FE or TL stage to blue or green light, compared with other light qualities (P < 0.05). However, there was no difference in terms of the rate of development from the FE to the TL stage between cultures lit or unlit since the FE egg stage (P > 0.05). These results suggest that a blue or green light source applied from the TL stage can increase the hatching and yield of H. discus hannai Ino, with important implications for the development of the aquaculture industry.
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Gao, X., Pang, G., Luo, X., You, W., & Ke, C. (2020). Effects of light cycle on motion behaviour and melatonin secretion in Haliotis discus hannai. Aquaculture, in press, 735981.
Abstract: The abalone Haliotis discus hannai is a typical nocturnal marine invertebrate. In this study, a quantitative analysis was performed on the motion behaviour characteristics of abalones exposed to different light cycles (0 L:24D, 12 L:12D, 24 L:0D) using infrared camera and behavioural analysis software. A preliminary analysis of the intrinsic correlations between melatonin secretion and abalone behaviour rhythms was also conducted. The results showed that the cumulative moving distance and duration of movement for abalone in the 0 L:24D group were significantly higher than those in the 12 L:12D and 24 L:0D groups (P < 0.05). The mean and maximum moving velocities of abalones in the 12 L:12D group were significantly higher than those in the 0 L:24D group (P < 0.05). The maximum cumulative moving distance and duration of movement for abalone in the 12 L:12D and 24 L:0D groups occurred between 00:00–03:00. In the 0 L:24D group, peak cumulative moving distance and duration movement were recorded between 00:00–03:00 and 15:00–18:00. According to the results of cosine analysis, melatonin content and expression levels of aralkylamine N-acetyl transferase (AANAT) and N-acetylserotonin O-methyltransferase (ASMT) in the 12 L:12D and 24 L:0D groups showed significant circadian cosine rhythms (P < 0.05) and tended to be higher during the day and lower at night. Compared with the variation trend of melatonin, the expression levels of melatonin receptor (MTR) in each group showed significant circadian cosine rhythms (P < 0.05). Especially in the 0 L:24D group, the expression levels of MTR also tended to be higher during the day and lower at night, indicating that MTR may mediate other factors which participate in the regulation of abalone circadian rhythms. The results of this study provide a quantitative description of the motion behaviour characteristics of abalone exposed to different light cycles. The intrinsic correlation between melatonin secretion and abalone motion behaviour rhythms was also examined in this study, which in turn provides a reference for light regulation and feeding strategies in aquaculture production.
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