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Moon Period (moon + period)

Distribution by Scientific Domains
Earth and Environmental Science40%

Kinds of Moon Period

  • new moon period
    		•

    Selected Abstracts

    Yield, growth and mortality rate of the Thai river sprat, Clupeichthys aesarnensis, in Sirinthorn Reservoir, Thailand

    FISHERIES MANAGEMENT & ECOLOGY, Issue 4 2003
    T. Jutagate
    Abstract The Thai river sprat, Clupeichthys aesarnensis Wongratana, is a clupeid with a short life span, and supports artisanal fisheries in a number of reservoirs in the Mekong Basin. The growth parameters, mortality rates and the status of the Thai river sprat in Sirinthorn Reservoir (28 800 ha), NE Thailand (15°N; 105°E), are presented. The fishery is based on lured lift-nets, operated 7,14 days in the new moon period, September to April each year. It was shown that the von Bertalanffy growth function (VBGF) model was Lt (mm) = 78.43[1 , exp{,0.211[t , (,0.7996)]}] and its growth conformed to an isometric pattern. Natural mortality rate (month,1) was 0.13 month,1. Total mortality rates ranged from 0.69 to 1.53 month,1 depending on the weather and the fishing season. Recruitment was continuous throughout the year but peaked in June and July. The yield per recruit model indicated that the exploitation rate of this fishery is probably too high. [source]

    Moonlight affects nocturnal Period2 transcript levels in the pineal gland of the reef fish Siganus guttatus

    JOURNAL OF PINEAL RESEARCH, Issue 2 2008
    Nozomi Sugama
    Abstract:, The golden rabbitfish Siganus guttatus is a reef fish with a restricted lunar-synchronized spawning cycle. It is not known how the fish recognizes cues from the moon and exerts moon-related activities. In order to evaluate the perception and utilization of moonlight by the fish, the present study aimed to clone and characterize Period2 (Per2), a light-inducible clock gene in lower vertebrates, and to examine daily variations in rabbitfish Per2 (rfPer2) expression as well as the effect of light and moonlight on its expression in the pineal gland. The partially-cloned rfPer2 cDNA (2933 bp) was highly homologous (72%) to zebrafish Per2. The rfPer2 levels increased at ZT6 and decreased at ZT18 in the whole brain and several peripheral organs. The rfPer2 expression in the pineal gland exhibited a daily variation with an increase during daytime. Exposing the fish to light during nighttime resulted in a rapid increase of its expression in the pineal gland, while the level was decreased by intercepting light during daytime. Two hours after exposing the fish to moonlight at the full moon period, the rfPer2 expression was upregulated. These results suggest that rfPer2 is a light-inducible clock gene and that its expression is affected not only by daylight but also by moonlight. Since the rfPer2 expression level during the full moon period was higher than that during the new moon period, the monthly variation in the rfPer2 expression is likely to occur with the change in amplitude between the full and new moon periods. [source]

    The influence of the full moon on the number of accessions to an animal emergency centre

    AUSTRALIAN VETERINARY JOURNAL, Issue 10 2007
    TJ McALEES
    Objective To test the hypothesis that the number of animal emergency centre accessions is associated with the time of the full moon. Design and procedure Retrospective study. A comparison was made of the number of accessions to the University of Melbourne Animal Emergency Centre in the period February 2003 to January 2006 on full moon and non,full moon days, adjusted for day of the week and public holiday. A three day period with the day of the full moon as the middle day was taken to be a full moon period. Results A total of 12,102 animals were presented to the Centre in this time. An adjusted count ratio of 1.048 (95% CI 0.97 to 1.14; P = 0.26) for accessions on full moon days compared with those on non,full moon days indicated that there was no significant association between the full moon and the number of accessions per day. Conclusion There was no significant difference between the number of animals presented to the University of Melbourne Animal Emergency Centre on full moon days and non,full moon days. [source]

    Oceanic migration and spawning of anguillid eels

    JOURNAL OF FISH BIOLOGY, Issue 9 2009
    K. Tsukamoto
    Many aspects of the life histories of anguillid eels have been revealed in recent decades, but the spawning migrations of their silver eels in the open ocean still remains poorly understood. This paper overviews what is known about the migration and spawning of anguillid species in the ocean. The factors that determine exactly when anguillid eels will begin their migrations are not known, although environmental influences such as lunar cycle, rainfall and river discharge seem to affect their patterns of movement as they migrate towards the ocean. Once in the ocean on their way to the spawning area, silver eels probably migrate in the upper few hundred metres, while reproductive maturation continues. Although involvement of a magnetic sense or olfactory cues seems probable, how they navigate or what routes they take are still a matter of speculation. There are few landmarks in the open ocean to define their spawning areas, other than oceanographic or geological features such as oceanic fronts or seamounts in some cases. Spawning of silver eels in the ocean has never been observed, but artificially matured eels of several species have exhibited similar spawning behaviours in the laboratory. Recent collections of mature adults and newly spawned preleptocephali in the spawning area of the Japanese eel Anguilla japonica have shown that spawning occurs during new moon periods in the North Equatorial Current region near the West Mariana Ridge. These data, however, show that the latitude of the spawning events can change among months and years depending on oceanographic conditions. Changes in spawning location of this and other anguillid species may affect their larval transport and survival, and appear to have the potential to influence recruitment success. A greater understanding of the spawning migration and the choice of spawning locations by silver eels is needed to help conserve declining anguillid species. [source]

    Moonlight affects nocturnal Period2 transcript levels in the pineal gland of the reef fish Siganus guttatus

    JOURNAL OF PINEAL RESEARCH, Issue 2 2008
    Nozomi Sugama
    Abstract:, The golden rabbitfish Siganus guttatus is a reef fish with a restricted lunar-synchronized spawning cycle. It is not known how the fish recognizes cues from the moon and exerts moon-related activities. In order to evaluate the perception and utilization of moonlight by the fish, the present study aimed to clone and characterize Period2 (Per2), a light-inducible clock gene in lower vertebrates, and to examine daily variations in rabbitfish Per2 (rfPer2) expression as well as the effect of light and moonlight on its expression in the pineal gland. The partially-cloned rfPer2 cDNA (2933 bp) was highly homologous (72%) to zebrafish Per2. The rfPer2 levels increased at ZT6 and decreased at ZT18 in the whole brain and several peripheral organs. The rfPer2 expression in the pineal gland exhibited a daily variation with an increase during daytime. Exposing the fish to light during nighttime resulted in a rapid increase of its expression in the pineal gland, while the level was decreased by intercepting light during daytime. Two hours after exposing the fish to moonlight at the full moon period, the rfPer2 expression was upregulated. These results suggest that rfPer2 is a light-inducible clock gene and that its expression is affected not only by daylight but also by moonlight. Since the rfPer2 expression level during the full moon period was higher than that during the new moon period, the monthly variation in the rfPer2 expression is likely to occur with the change in amplitude between the full and new moon periods. [source]