scholarly journals Morfometri Portunus pelagicus Linnaeus, 1758 (Malacostraca : Portunidae) Pada Fase Bulan Yang Berbeda Di Perairan Betahwalang, Demak

2019 ◽  
Vol 8 (2) ◽  
pp. 204-210
Author(s):  
Errizal Machmud Putra ◽  
Rini Pramesti ◽  
Gunawan Widi Santosa

Rajungan (Portunus pelagicus) merupakan komoditas unggulan Indonesia. Perairan Betahwalang, Kabupaten Demak memiliki sumberdaya rajungan yang  potensial dengan tingkat eksploitasi yang tinggi. Rajungan ini ditangkap setiap hari tanpa memperhatikan faktor alam berupa fase bulan yang menyebabkan menurunnya populasi. Informasi penangkapan berdasarkan fase bulan diperlukan agar populasi rajungan dapat terjaga. Tujuan Penelitian ini adalah mengkaji jumlah dan sebaran morfometri rajungan yang tertangkap pada fase bulan purnama dan bulan baru di perairan Betahwalang. Penelitian ini dilakukan dari November 2017 sampai Februari 2018 di perairan Betahwalang. Metode penelitian yang digunakan yaitu metode deskriptif. Penentuan lokasi penelitian berdasarkan area penangkapan rajungan di perairan Betahwalang. Pengambilan data dilakukan 8 kali dari tanggal 5 November 2017 sampai 18 Februari 2018. Pengambilan data berupa jumlah, lebar karapas, berat, jenis kelamin rajungan, dan parameter lingkungan. Hasil penelitian menunjukkan total rajungan tertangkap yaitu 448 ekor, 296 ekor pada Bulan Purnama dan 152 ekor pada Bulan Baru. Morfometri rajungan ukuran ≤ 10 cm pada Bulan Purnama 190 ekor lebih banyak dari Bulan Baru 90 ekor. Rajungan ukuran > 10 cm pada Bulan Baru 106 ekor lebih banyak dari Bulan Baru 62 ekor. Blue Swimming Crab (Portunus pelagicus) is Indonesia's flagship commodity. The waters of Betahwalang, Demak Regancy have potential Blue Swimming Crab resources with high levels of exploitation.  The crabs are catched every day regardless of natural factors, such as the moon phase that causes the population to decline. Blue Swimming Crab catch’s information based on the moon phase is required for the population to sustaine. The purpose of this research is to study the amount and distribution of Blue Swimming Crab morphometry catched on the full and new moon phase in Betahwalang waters. The study was conducted from November  2017 till February 2018 in the waters of Betahwalang. The research method used was descriptive method. Determination of research location based on Blue Swimming Crab catching area in Betahwalang waters. The data were collected 8 times from November 5, 2017 till February 18, 2018. Data were collected in number, width of carapace, weight, sex, and environmental parameters. The results showed total of catched crabs, were 296 crabs on Full Moon, and 152 crabs on New Moon. Blue Swimming Crab morphometry size ≤ 10 cm on Full Moon was 190 crabs more than New Moon was 90 crabs. Then, in Size> 10 cm on New Moon was 106 crabs more than New Moon was 62 crabs.

1969 ◽  
Vol 47 (6) ◽  
pp. 1183-1186 ◽  
Author(s):  
G. J. Doucet ◽  
J. R. Bider

Activity of Microtus pennsylvanicus was recorded as the number of crossings per day over a sand transect during four consecutive summers. Appropriate samples were selected to test the effects of both moon phases and moonlight on activity. Initially the results of tests comparing new moon to full moon phases showed that the voles were more active during new moon in only 3 of 10 discreet paired samples tested. However, when the effects of sampling sequence, phenology of population growth, date at which moon phases occurred, and, finally, the effect of climate were all considered as factors which could have affected the above results, it seemed reasonable to conclude that the new moon phase tended to be associated with higher activity. To establish if moonlight by itself, independent of phases, was a factor affecting the activity, tests were made during brightest and darkest nights of the lunar month and results indicated that moonlight did not affect the differences in activity found in the moon phase tests.


2021 ◽  
Vol 10 (1) ◽  
pp. 109-116
Author(s):  
Wukir Berliana Pratiwi ◽  
Ria Azizah Tri Nuraini ◽  
Widianingsih Widianingsih

Fase bulan secara periodik mengalami perubahan dan menjadi faktor yang mempengaruhi perairan secara fisika, kimia, maupun biologi. Kondisi tersebut di wilayah perairan laut menimbulkan fenomena pasang surut yang memiliki pengaruh besar terhadap kehidupan biota laut seperti rajungan (Portunus pelagicus). Strategi penangkapan yang tepat dapat dilakukan dengan menentukan target satu spesies atau dengan cara melihat fase bulan. Penelitian ini bertujuan untuk melakukan kajian morfometri, nisbah kelamin, hubungan lebar berat, dan tingkat kematangan gonad rajungan (Portunus pelagicus) yang tertangkap nelayan pada fase bulan purnama dan bulan mati dari Perairan Desa Tunggulsari, Rembang. Pengambilan data dilakukan terhadap rajungan (Portunus pelagicus) yang tertangkap oleh nelayan dari perairan Desa Tunggulsari. Kegiatan penelitian dilakukan pada tanggal 9 Januari 2020, 28 Januari 2020, 10 Februari 2020, 25 Februari 2020, 10 Maret 2020, dan 24 Maret 2020. Hasil penelitian berdasarkan uji T statistik menunjukkan bahwa ada perbedaan komposisi rajungan dari fase bulan purnama dan bulan mati dengan selisih yang tidak signifikan. Rajungan yang tertangkap pada fase bulan purnama memiliki rata-rata ukuran berat dan lebar yang lebih kecil dibandingkan pada fase bulan mati. Analisis power curve hubungan lebar dan berat rajungan yang ada di perairan Desa Tunggulsari bersifat allometrik negatif yang berarti pertumbuhan lebar karapas lebih cepat dibandingkan beratnya.  The lunar phase periodically changes and becomes a factor that affects the waters physically, chemically, and biologically. These conditions in the marine waters cause tidal phenomena which have a major influence on marine life such as blue swimming crab (Portunus pelagicus). The right fishing strategy can be done by determining the target of one species or by looking at the phases of the moon. This study aims to study the morphometry, sex ratio, weight-width relationship, and maturity level of the crab gonads (Portunus pelagicus) caught by fishermen in the full moon and new moon phases of the Tunggulsari Waters, Rembang. The method used in this research is descriptive exploratory. Research activities were carried out on January 9, 2020, January 28, 2020, February 10, 2020, February 25, 2020, March 10, 2020, and March 24, 2020. The results of the study based on the statistical T test showed that there was an insignificant difference in the catch of the full moon and new moon phases. The crabs that are caught in the full moon phase have an average size of weight and width that is smaller than in the new moon phase. Analysis of the relationship between the width and weight of small crabs in the waters of Tunggulsari Waters is negative allometric, which means that the carapace width grows faster than its weight.


2018 ◽  
Vol 33 (1) ◽  
Author(s):  
Morad Sabdullah Umpa

Muslim communities are known to be united, but every year, towards the start of Ramadhān, some of them argue which started to be divided over the issue on the determination of the start of the blessed month. This study aimed to investigate the different options proposed for the determination of the month of Ramadhān including local and global sighting; Number of witnesses required; Size of Matla'; and Saudī Sighting Process and its implications. Data were gathered through an in-depth study using the descriptive method. The objectives were to determine the universally accepted legal opinion on sighting the New Moon in connection with the elimination of differences that frequently surface and for ensuring the celebration of 'Eid on a single day in one lunar unit. Based on the findings, it is revealed that sighting the new moon must be conducted in each locality because there are Multiple Horizons (the time at which the moon rises, varies from place to place). Muslims must show unity during the month of Ramadhān and at the occasions of 'Eid at least locally if not nationally or internationally. This would be of great value and importance to the whole Muslim nation by fostering the initial steps towards united observance of Ramadhān.


2000 ◽  
Vol 57 (3) ◽  
pp. 581-590 ◽  
Author(s):  
Nathalie Gaudreau ◽  
Daniel Boisclair

We tested the influence of the moon phase on the relative number of fish performing daily horizontal migrations and we used this information to develop a sampling strategy that accounted for expected effects of the moon phase on fish behavior. Hydroacoustic surveys were performed over 3 days at each moon phase for the months of July and August (from the day before to the day after the new moon, the first and last quarter moon, and the full moon). Dace (Phoxinus eos × Phoxinus neogaeus) migrated from the littoral towards the pelagic zone at dusk and returned to the littoral zone at dawn. Their relative abundance (FRA) in the pelagic zone averaged 0.1 fish echo·m-3 during midday and 17.0 fish echoes·m-3 at night. The number of dace performing horizontal movements was eightfold larger during new-moon than full-moon nights. Simulations indicated that sampling fish populations six times during a 2-month period (once at full, new, and quarter moon; once during the day and once during the night) provided the most accurate estimates of FRA.


2019 ◽  
Vol 8 (3) ◽  
pp. 223-228
Author(s):  
Ulfah Nur Hidayah ◽  
Ibnu Partikto ◽  
Irwani Irwani

Rajungan (Portunus pelagicus) merupakan salah satu komoditi perikanan yang memiliki nilai ekonomis tinggi yaitu Rp. 70.000 – 90.000 /kg dan banyak diminati oleh masyarakat baik di dalam maupun luar negeri. Penurunan potensi sumberdaya rajungan (Portunus pelagicus) di beberapa perairan Indonesia mulai memprihatinkan. Hal tersebut dapat dihindari dengan memahami faktor-faktor internal dan eksternal yang berpengaruh pada sumberdaya rajungan. Penelitian ini bertujuan untuk mengetahui distribusi ukuran, nisbah kelamin dan tingkat kematangan gonad, hubungan panjang berat dan faktor kondisi, serta tingkat pertumbuhan rajungan berdasarkan fase bulan baru dan bulan purnama di Perairan Teluk Awur Jepara. Hasil penelitian distribusi ukuran lebar rajungan rata-rata 12,65 ± 1,335 pada bulan purnama dan 12,64 ± 1,259 cm pada bulan baru. Distribusi berat rata-rata 147,28 ±53,85 gram pada bulan purnama dan 146,65 ± 53,31 gram pada bulan baru. Distribusi tingkat kematangan gonad rajungan betina yaitu TKG 1 sebanyak 126 ekor, TKG 2 sebanyak 77 ekor, dan TKG 3 sebanyak 112 ekor sedangkan rajungan betina yang belum matang gonad 225 ekor. Nisbah kelamin rajungan jantan dan betina di Teluk Awur yaitu 0,9 : 1. Pola pertumbuhan rajungan di Teluk Awur yaitu bersifat allometrik negatif dimana pertumbuhan panjang karapas lebih dominan daripada pertumbuhan bobot tubuhnya. Sedangkan tingkat pertumbuhan rajungan untuk mencapai panjang maksimal yaitu 8,16 cm dengan koefisien pertumbuhan 0,6 per tahun. Blue Swimming Crab (Portunus pelagicus) is one of the fisheries commodity which has high economic value Rp. 70.000 – 90.000 /kg and is much in demand by the both domestic and foreign societies. The decrease of blue swimming crab (Portunus pelagicus) resource potential in some Indonesian waters is starting to apprehensive, that can be avoided by understanding the internal and external factors that influence the blue swimming crab resources. This research aimed to determine the size distribution, sex ratio and gonad maturity level, the relationship of length of weight and condition factor, and blue swimming crab growth rates according to the phase of the new moon and full moon in the Jepara Teluk Awur Waters. The results of the research of the width distribution of most crab in the full moon 12,65 ± 1,335  cm and 12,64 ± 1,259 in the new moon. The distribution of weight are 147,28 ±53,85 grams in the full moon and 146,65 ± 53,31 in the new moon phases. The distribution of maturity levels of female blue swimming crab gonads that is TKG 1 amounted 126 crabs, TKG 2 amounted 77 crabs, and TKG 3 amounted 112 crabs. While the female immature blue swimming crab were gonads 225. The sex ratio of male and female blue swimming crab in Teluk Awur is 0,9 : 1. The blue swimming crab growth pattern in Teluk Awur is negative allometric where the growth of carapace length is more dominant than the growth of its body weight. While the blue swimming crab growth rate to reach the maximum length is 8.16 cm with a growth coefficient of 0.6 per year. 


Author(s):  
Margarida Saavedra ◽  
Pedro Pousão-Ferreira

Environmental cues such as photoperiod and water temperature are often used by fish as a sign to begin reproduction. However, even after the reproductive cycle has started there are other signs, such as the moon phase that may affect the number of eggs laid by some fish species. The existence of a moon effect has never been investigated in any fish of the sparid family.In the present study, the effect of moon phase was observed on eggs laid by two Sparus aurata in indoor tanks over a four month period, from January to May, 2003. During this period a peak in eggs laid was observed around the Full Moon. A total of 8644 g and 5653 g of eggs were collected, 4535 g corresponding to the Full Moon and 2882 g to the New Moon.


2021 ◽  
pp. 074873042098363
Author(s):  
Alejandro A. Aguirre ◽  
Roberto A. Palomares ◽  
Aitor D. De Ondiz ◽  
Eleazar R. Soto ◽  
Mariana S. Perea ◽  
...  

Evidence has accumulated over the years indicating that the moon influences some aspects of the reproductive activity in animals and humans. However, little is known about the influence of the lunar cycle on the reproductive performance of cows under tropical conditions, where the environment strongly affects reproduction. This retrospective study was conducted with the aim of assessing the influence of the lunar cycle on some reproductive traits of tropical crossbred cows managed in a pasture-based system. Data from 5869 reproductive records from two commercial farms localized in the Maracaibo Lake Basin of Zulia State, Venezuela, were analyzed. Variables studied were first service conception rate, calving frequency, first postpartum estrous frequency, and pregnancy frequency. In addition to the lunar cycle, the effects of farm, season, and predominant breed were also considered. Data were analyzed using logistic regression and general linear model from SAS. First service conception was affected by lunar phases and predominant breed, but not by farm or season. For frequencies of calving, first postpartum estrus, and pregnancy, there was no main effect of farm, season, and predominant breed, whereas the effect of lunar phases was highly significant. First service conception was significantly greater in waning than in crescent phase of the lunar cycle. Frequencies of calving, first estrus, and pregnancy were highly correlated and showed greater figures around full moon and new moon. In conclusion, lunar cycle influenced first service conception, attaining greater values in the waning phase of the moon cycle. Frequencies of calving, first postpartum estrus, and pregnancy in crossbred cows showed a clear bimodal rhythm, whose greatest values coincided with new moon and full moon.


2009 ◽  
Vol 5 (S260) ◽  
pp. 514-521
Author(s):  
Ilias M. Fernini

AbstractThe Islamic society has great ties to astronomy. Its main religious customs (start of the Islamic month, direction of prayer, and the five daily prayers) are all related to two main celestial objects: the Sun and the Moon. First, the start of any Islamic month is related to the actual seeing of the young crescent after the new Moon. Second, the direction of prayer, i.e., praying towards Mecca, is related to the determination of the zenith point in Mecca. Third, the proper time for the five daily prayers is related to the motion of the Sun. Everyone in the society is directly concerned by these customs. This is to say that the major impetus for the growth of Islamic astronomy came from these three main religious observances which presented an assortment of problems in mathematical astronomy. To observe these three customs, a new set of astronomical observations were needed and this helped the development of the Islamic observatory. There is a claim that it was first in Islam that the astronomical observatory came into real existence. The Islamic observatory was a product of needs and values interwoven into the Islamic society and culture. It is also considered as a true representative and an integral par of the Islamic civilisation. Since astronomy interested not only men of science, but also the rulers of the Islamic empire, several observatories have flourished. The observatories of Baghdad, Cairo, Córdoba, Toledo, Maragha, Samarqand and Istanbul acquired a worldwide reputation throughout the centuries. This paper will discuss the two most important observatories (Maragha and Samarqand) in terms of their instruments and discoveries that contributed to the establishment of these scientific institutions.


1997 ◽  
Vol 8 (2) ◽  
pp. 185-206 ◽  
Author(s):  
Susan Milbrath

AbstractAztec images of decapitated goddesses link the symbolism of astronomy with politics and the seasonal cycle. Rituals reenacting decapitation may refer to lunar events in the context of a solar calendar, providing evidence of a luni-solar calendar. Decapitation imagery also involves metaphors expressing the rivalry between the cults of the sun and the moon. Huitzilopochtli's decapitation of Coyolxauhqui can be interpreted as a symbol of political conquest linked to the triumph of the sun over the moon. Analysis of Coyolxauhqui's imagery and mythology indicates that she represents the full moon eclipsed by the sun. Details of the decapitation myth indicate specific links with seasonal transition and events taking place at dawn and at midnight. Other decapitated goddesses, often referred to as earth goddesses with “lunar connections,” belong to a complex of lunar deities representing the moon within the earth (the new moon). Cihuacoatl, a goddess of the new moon, takes on threatening quality when she assumes the form of a tzitzimime attacking the sun during a solar eclipse. The demonic new moon was greatly feared, for it could cause an eternal solar eclipse bringing the Aztec world to an end.


1967 ◽  
Vol 1 (1) ◽  
pp. 11-11 ◽  
Author(s):  
J. H. Carver ◽  
B. H. Horton

We have used rocket-borne photometers to determine the ultra-violet flux of the full moon in the wavelength range 2400-2900A where atmospheric ozone prevents ground-based observations. The lunar fluxes determined in two rocket firings from Woomera on 9th December, 1965, and 30th August, 1966, are summarized in the Table. The results for the two firings have been corrected to full moon values on the assumption that the lunar phase law is the same at these ultra-violet wavelengths as it is in the visible.


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