scholarly journals Revisiting the Spawning Pattern of Nyale Worms (Eunicidae) Using the Metonic Cycle

2021 ◽  
Vol 26 (2) ◽  
pp. 87-94
Author(s):  
Imam Bachtiar ◽  
Shingo Odani
Keyword(s):  
Full Moon ◽  
Prediction Method ◽  
Mass Spawning ◽  
Lunar Calendar

Mass spawning dates of nyale worms (Eunicidae) have been scientifically predictable since 2019. The month of spawning is consistently following the pattern of the February full moon, while the date of spawning is consistently on the 20th of the lunar calendar. There are particular years with February only spawning, March only spawning, and split spawning in both February and March. The existing prediction of the split spawning, however, was constructed with very little available data. The present study aimed to revisit the split spawning prediction using the Metonic cycle, a 19-year lunisolar cycle. The results show that the spawning prediction very much follows the Metonic Cycle. There are minor dates on split spawning to be revised, when February full moon rises on 14th February. The revised hypothesis is that split spawning is very likely to occur when the full moon rises between the 7th to 13th of February. When February full moon appears before the 7th of February, single spawning will take place on the fifth day after the March full moon.  When February full moon befalls after the 13th of February, single spawning will occur on the fifth day after the February full moon. The revised prediction method has only 2 (two) deviances in 114 years of simulation dates. The present study is the first to suggest the link between Polychaete spawning patterns and the Metonic Cycle.

scholarly journals PEMIJAHAN INDUK, PROFIL KOLESTEROL, DAN ASAM LEMAK TELUR LOBSTER PASIR (Panulirus homarus) HASIL BUDIDAYA

2018 ◽  
Vol 13 (3) ◽  
pp. 219
Author(s):  
Yudha Trinoegraha Adiputra ◽  
Muhammad Zairin Jr. ◽  
Muhammad Agus Suprayudi ◽  
Wasmen Manalu ◽  
Widanarni Widanarni
Keyword(s):  
Fatty Acids ◽  
Full Moon ◽  
Spiny Lobster ◽  
Eyestalk Ablation ◽  
Early Indicator ◽  
Mass Spawning ◽  
New Moon ◽  
Low Incidence

Pembenihan lobster pasir (Panulirus homarus) belum berkembang di Indonesia karena terbatasnya teknik pemijahan induk dan belum diketahuinya tingkat keberhasilan induk betina membawa telur dan profil telur hasil pemeliharaan. Penelitian bertujuan untuk mempelajari pengaruh ablasi satu tangkai mata, metode pemijahan massal dan individual pada bulan gelap dan terang pada induk berganti kulit dan membawa telur, serta konsentrasi kolesterol dan asam-asam lemak telur pada lama pengeraman berbeda. Induk betina dan jantan dipakai secara terus-menerus saat percobaan pemijahan. Pemijahan pertama menggunakan pemijahan dengan rasio 2:1 pada bulan gelap. Percobaan kedua dan ketiga menggunakan pemijahan massal selama bulan terang dan gelap. Profil telur dibandingkan konsentrasi kolesterol dan asam lemaknya pada 1, 2, dan 3-4 minggu pengeraman. Hasil penelitian menunjukkan ablasi tangkai mata dapat menstimulasi pemijahan individual dan massal yang didahului dengan ganti kulit pada induk betina sebagai indikator pemijahan. Pemijahan massal pada bulan gelap menghasilkan induk betina membawa telur terbanyak dibandingkan pemijahan individual pada bulan gelap dan pemijahan massal pada bulan terang. Konsentrasi kolesterol dan asam-asam lemak telur mengalami perubahan mengikuti lama pengeraman oleh induk yang menunjukkan terjadinya peningkatan kematangan telur (P<0,05).Spiny lobster (Panulirus homarus) hatchery has not been developed in Indonesia. Major constraints were limited broodstock spawning techniques, low incidence of eggs-berried broodstock, and unknown eggs profile. This study aimed to evaluate the effects of eyestalk ablation, spawning methods and moon circulation to molted, the number of eggs berried of females, and eggs-berried cholesterol and fatty acids profiles. Individual and mass spawning during full and new moon were used in this studies. Female and male broodstocks were used for consecutive spawning with ratio 2:1. The first study was used individual spawning during new moon. The second and third studies were used mass spawning during full moon and new moon, respectively. Eggs-berried profile compared concentration of cholesterol and fatty acids during 1, 2, and 3-4 weeks. Results showed eyestalk ablation stimulated individual or mass spawned and molted of female as early indicator of spawning. Full moon and mass spawning supported more eggs-berried female broodstock than that of other methods. Cholesterol and fatty acids showed different concentration within 1, 2, and 3-4 weeks of eggs-berried that supported eggs maturity (P<0.05).

scholarly journals Moonrise timing is key for synchronized spawning in coral Dipsastraea speciosa

2021 ◽  
Vol 118 (34) ◽  
pp. e2101985118
Author(s):  
Che-Hung Lin ◽  
Shunichi Takahashi ◽  
Aziz J. Mulla ◽  
Yoko Nozawa
Keyword(s):  
Environmental Change ◽  
Laboratory Experiments ◽  
Full Moon ◽  
Regulatory Mechanism ◽  
Dark Period ◽  
Lunar Cycle ◽  
Suppressive Effect ◽  
Light Conditions ◽  
Mass Spawning ◽  
Coral Spawning

Synchronized mass coral spawning typically occurs several days after a full moon once a year. It is expected that spawning day is determined by corals sensing environmental change regulated by the lunar cycle (i.e., tide or moonlight); however, the exact regulatory mechanism remains unknown. Here, we demonstrate how moonlight influences the spawning process of coral, Dipsastraea speciosa. When corals in the field were shaded 1 and 3 d before the full moon or 1 d after the full moon, spawning always occurred 5 d after shading commenced. These results suggest moonlight suppresses spawning: a hypothesis supported by laboratory experiments in which we monitored the effects of experimental moonlight (night-light) on spawning day. Different night-light treatments in the laboratory showed that the presence of a dark period between day-light and night-light conditions eliminates the suppressive effect of night-light on spawning. In nature, moonrise gets progressively later during the course of the lunar cycle, shifting to after sunset following the day of the full moon. Our results indicate that this period of darkness between sunset and moonrise triggers synchronized mass spawning of D. speciosa in nature.

scholarly journals Predicting spawning date of nyale worms (Eunicidae, Polychaeta) in the southern coast of Lombok Island, Indonesia

2019 ◽  
Vol 20 (4) ◽  
pp. 971-977
Author(s):  
IMAM BACHTIAR ◽  
NAILA TASLIMAH BACHTIAR
Keyword(s):  
Traditional Method ◽  
Prediction Method ◽  
Southern Coast ◽  
The Past ◽  
Lunar Calendar ◽  
Invertebrate Reproduction ◽  
Available Information ◽  
International Visitors ◽  
Scientific Prediction ◽  
Lombok Island

Abstract. Bachtiar I, Bachtiar NT. 2019. Predicting spawning date of nyale worms (Eunicidae, Polychaeta) in the southern coast of Lombok Island, Indonesia. Biodiversitas 20: 971-977. Spawning of marine nyale worms has been an important component of Sasak tradition of Bau Nyale (fishing nyale) for centuries and a tourism icon of the District of Lombok Tengah since the 1990s. Nyale is a mixture of epitokies of 3-5 species of Polychaeta worms (mostly Palola spp.) for reproduction. At present, prediction of spawning date of the nyale worms is carried out traditionally that might not satisfy demand of tourism market. The present study is to develop a scientific-based method for predicting date of nyale worms spawning or nyale swarming. Since available data are scarce, development of the method of data collection mainly uses analogy from polychaetes and other invertebrate reproduction patterns and any available information from traditional customs. Three hypotheses were developed to generate prediction for 100 years, from 2000 to 2100, and then these prediction dates were verified using available data before 2018. In the past 9 years, there are two mismatches between scientific and traditional predictions, i.e., 2015 and 2017 spawnings, in favor of the new prediction method. The new scientific prediction method provides more objective and accurate date of nyale worm spawning than the traditional method. The present prediction also shows that split spawning dates, February and March, do not come to pass every year, as traditional nyale fishers generally believe them. It is also found that nyale worms are consistently using international lunar calendar for its spawning date, instead of local and national lunar calendars. This study provided the first scientific nyale swarming prediction in Lombok to complement existing traditional prediction. The prediction is very useful to promote the biggest annual traditional festival in Lombok for international visitors.  

Selection of a leading edge noise prediction method for PNoise

2018 ◽  
pp. 214-223
Author(s):  
AM Faria ◽  
MM Pimenta ◽  
JY Saab Jr. ◽  
S Rodriguez
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Prediction Method ◽  
Leading Edge ◽  
Wind Farms ◽  
Broadband Noise ◽  
Turbulence Energy ◽  
Noise Prediction ◽  
Migration Routes ◽  
Turbulent Inflow

Wind energy expansion is worldwide followed by various limitations, i.e. land availability, the NIMBY (not in my backyard) attitude, interference on birds migration routes and so on. This undeniable expansion is pushing wind farms near populated areas throughout the years, where noise regulation is more stringent. That demands solutions for the wind turbine (WT) industry, in order to produce quieter WT units. Focusing in the subject of airfoil noise prediction, it can help the assessment and design of quieter wind turbine blades. Considering the airfoil noise as a composition of many sound sources, and in light of the fact that the main noise production mechanisms are the airfoil self-noise and the turbulent inflow (TI) noise, this work is concentrated on the latter. TI noise is classified as an interaction noise, produced by the turbulent inflow, incident on the airfoil leading edge (LE). Theoretical and semi-empirical methods for the TI noise prediction are already available, based on Amiet’s broadband noise theory. Analysis of many TI noise prediction methods is provided by this work in the literature review, as well as the turbulence energy spectrum modeling. This is then followed by comparison of the most reliable TI noise methodologies, qualitatively and quantitatively, with the error estimation, compared to the Ffowcs Williams-Hawkings solution for computational aeroacoustics. Basis for integration of airfoil inflow noise prediction into a wind turbine noise prediction code is the final goal of this work.

Prediction Method of a System with Continuous Change Parameters Considering SNR Fluctuation

2018 ◽  
Vol 138 (9) ◽  
pp. 1075-1081
Author(s):  
Yasuhide Kobayashi ◽  
Mitsuyuki Saito ◽  
Yuki Amimoto ◽  
Wataru Wakita
Keyword(s):  
Prediction Method ◽  
Continuous Change
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