Lunar Cycle Influences Production of Tilapia (Oreochromis spp) Eggs in an Intensive Outdoor Production System in the Tropics

2022 ◽  
pp. 074873042110694
Author(s):  
Miguel F. Perea ◽  
Daniel A. Perdomo ◽  
Zenaida A. Corredor ◽  
Mario González ◽  
Hugo Hernandez-Fonseca ◽  
...  

A robust body of evidence has demonstrated that the lunar cycle plays an important role in the reproduction of fish living in natural environments. However, little is known about the influence of the moon on tilapia reproductive activity in intensive fish farming systems. This study aims to evaluate the influence of the lunar cycle on the reproductive performance of tilapias in an intensive outdoor tropical production system in Latin America. Records of two tilapia strains (Nile tilapia [ Oreochromis niloticus; n = 75] and Red tilapia [ Oreochromis spp.; n = 1335]) reared in concrete tanks in a commercial fish farm were analyzed. Over a 3-year period, 60,136 captures were made in intervals of 12 to 14 days and 6,600 females were manually spawned. The number of females spawned and the volume of eggs collected from each tank ( n = 9) were recorded. Data was analyzed by the general linear model and means were compared by least squares means method. A very slight or no variation was observed when the lunar cycle was split into two halves (crescent and waning). The proportions of females spawned and the volume of eggs per spawned female and per female in the tank varied considerably across the eight periods of the lunar cycle, with greater values in the waning than in the crescent phase. A significantly greater proportion of tilapia spawned and yielded more eggs around the full moon than around the new moon and remaining days of the lunar cycle. The moon cycle affected the reproductive activity of tilapia, which were more reproductively active around the full moon and most of the waning phase.

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.


1998 ◽  
Vol 20 (1) ◽  
pp. 21
Author(s):  
B.S. Law

Observations of radio-tagged Common Blossom Bats Syconycteris australis on the Atherton Tablelands, Queensland indicate that the time of departure from roost areas is related to the lunar cycle. During the dark phase of the moon, bats leave their roost between 5-20 mins after dark. Departure times are delayed up to 4 hrs between the period of the first quarter and full moon when the moon is bright after dusk. The predatory role of owls at night is suggested as the probable cause of this behavioural change.


The table given in this paper contains the results of calculations relating to the objects specified in the title; cast into periods of six, seven, or eight days, so as to bring the day of the lunar phase belonging to it in the middle of the time. The observations were all made in the neighbourhood of London. It appears from them that in the period of the last quarter of the moon the barometer is highest, the temperature a little above the mean, and the depth of rain the smallest. In the period of the new moon, both the barometer and temperature are considerably depressed, and the rain increased in quantity. The influence of the first quarter shows itself by the further depression of the barometer; but the temperature rises almost to the point from which it had fallen, and the rain still increases, but not in an equal ratio. Lastly, the full moon again reduces the temperature; while the barometer attains its maximum mean height, and the quantity of rain is the greatest. Thus it appears, that during this lunar cycle, the approach of the last quarter is the signal for the clearing up of the air, and the return of sunshine.


1972 ◽  
Vol 61 (3) ◽  
pp. 565-576 ◽  
Author(s):  
D. S. Kettle

The biting rates of Culicoides furens (Poey) and C. barbosai Wirth & Blanton on Florida Beach, Jamaica, were observed in 50 trials conducted 40–115 min after dawn from 5 February 1960 to 10 February 1961. The data were logarithmically transformed and non-zero biting rates standardised. Biting rates of both species varied markedly from week to week but monthly mean rates were significantly higher and lower for C. furens in September (111·4) and March (13·7), respectively. Monthly mean rates for C. barbosai fell into three groups, (i) March-June (15·3); (ii) November–December (9·1); (iii) January–February and July–October (3·1). These changes were negatively correlated with mean sea level. Biting rates of C. barbosai were highest at new moon (10·3) and lower but similar (4·3–5·2) for the other three phases of the moon. Those of C. furens were maximal at new moon (62·8), minimal at full moon (20·4) and intermediate (35·9, 39·5) at the quarters. The lunar effect is assumed to act through the tides. There were no significant differences between the standardised biting rates at different times after dawn. In a comparison of the quantitative effects of ten factors on the biting rates of C. furens, C. barbosai and Leptoconops becquaerti (Kieff.), most important were month of year and wind speed; of less importance were lunar cycle, temperature, collector and limb exposed; while site position, intensity of illumination, time after dawn, saturation deficit were of minor or no importance. It is concluded that the biting rate of L. becquaerti should be the least affected by changes in these factors, C. barbosai more affected and C. furens most affected.


1980 ◽  
Vol 31 (1) ◽  
pp. 13-26 ◽  
Author(s):  
J. H. B. Roy ◽  
Catherine M. Gillies ◽  
M. W. Perfitt ◽  
I. J. F. Stobo

ABSTRACTA study of the factors that influence the age at first oestrus has been made with 57 Friesian heifers reared on high planes of nutrition in a partially-controlled environment. Although animals born during the period of increasing daylength reached puberty approximately 2 months earlier than those born during decreasing daylength, there was also a marked influence of live weight at 182 days of age and of the phase of the moon at the time of oestrus.Frequency of occurrence of first oestrus and of conception showed four distinct peaks at approximately 7-day intervals within the lunar cycle; this association between conception and lunar phase appeared to decline with increasing parity. Frequency of occurrence of artificial insemination, which reflected all suspected instances of oestrus, was also related to lunar phase. This effect of the lunar phase appears to be associated in the young heifer with 7-day cycles of oestrous activity positioned in time by the occurrence of the full moon.


2019 ◽  
Vol 8 (2) ◽  
pp. 71-74
Author(s):  
Niall McCrae

For millennia, people have associated the Moon with human behaviour. The concept of lunacy is derived from a presumed destabilising effect on the mind, although there is limited evidence of such causation. Recent sleep research has renewed interest in lunar influence, showing qualitative and quantitative changes in sleep at full moon. This brief review of studies measuring sleep in relation to the lunar cycle discusses possible impact on mental health and presents implications for further study.


1946 ◽  
Vol 36 (4) ◽  
pp. 395-417 ◽  
Author(s):  
C. R. Ribbands

1. 97 per cent, of the ♀ A. gambiae, A. funestus and A. melas remained until after dawn in the huts in which they had fed.2. ♀ A. melas seldom left suitable huts in the daytime.3. There was a high positive correlation between the time at which ♀ A. funestus entered huts and the time of moonlight. The maximum correlation coefficient was between the size of the catch at 8 p.m. and the duration of moonlight after this period, and its value was –0·783±0·068.4. During moonless periods, the flighting of ♀ A. funestus was partially inhibited, and when the moon came out, the waiting mosquitos entered the huts in greatest numbers. The average proportion caught when the moon rose during catching periods ending 10 p.m., midnight and 7 a.m. was approximately 50 per cent., 100 per cent. and 400 per cent. greater, respectively, than the proportion caught during these periods on moonless nights. On moonless nights many mosquitos waited until twilight of the following evening before entering the huts, and in consequence the average proportion caught in the period ending 8 p.m. was six times greater on moonless nights than on the nights after full moon.5. The records for ♀ A. melas are less complete, and the correlation coefficient for the relation between time of entry and time of moonlight has the value 0·421±0·184, a result which is barely significant. In view of the highly significant correlations found in the case of A. funestus it is unlikely that this correlation is fortuitous.6. The average rate of entry of ♀ A. funestus throughout one complete lunar cycle at Krabonekrom, Gold Coast, was 27 per cent. before 8 p.m., 22 between 8 p.m. and 10 p.m., 21 between 10 p.m. and midnight and 30 after midnight. The similar rates for A. gambiae (based on very few records), were 10, 20, 30 and 40 per cent. respectively. Comparable rates for A. melas in Sierra Leone are not available, but at least 45 per cent. entered before 10 p.m. (= 11 p.m. Gold Coast time).7. The essential difference between the behaviour of ♀ A. funestus and that of A. gambiae is that the former flight earlier than the latter. A. funestus also seem to be more active at dawn, so that they are more crepuscular in their habits than A. gambiae.8. 58 per cent, of the Anophelines caught at 8 p.m. were unfed. This indicates that early entrants usually rest after entry and before feeding, and average time of biting is later than average time of entry. Gravid or half-gravid mosquitos and those containing partly-digested blood, did not enter the huts; there was evidence that Anophelines usually became fully gorged at one feed. Of the Anophelines caught in huts after dawn 95 per cent, were fully fed.


BMJ Open ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. e022759 ◽  
Author(s):  
Simo Näyhä

ObjectiveTo test whether homicides in Finland vary according to moon phases.DesignA time series study.SettingFinland.Participants6808 homicides committed in 1961–2014.OutcomeDaily numbers of homicides.MethodThe daily numbers of homicides were related to eight moon phases and the illuminated percentage of the moon disc using negative binomial regression. To identify lunar patterns, piecewise linear terms of lunar days were used, together with changes from one moon phase to another. Homicides were similarly regressed on quintiles of the illuminated percentage of the moon disc. A periodic term of length 29.53 days was included to detect cyclic patterns. The results were adjusted for sex, age, secular trend, distance from the moon, seasons, weekday, major holidays and temperature.ResultsDuring the full moon, 15% less homicides were committed than during the new moon (RR 0.85; 95% CI 0.77 to 0.94) and 86% less during the lightest quintile of illumination compared with the darkest quintile (RR 0.14; 95% CI 0.04 to 0.50). Adjustments did not change the results. Piecewise linear regressions showed a significant decline in homicides at the full moon and a rise thereafter. The full moon drop in homicides was directionally similar for seasons, weekdays, sex, age and time periods, and it was particularly pronounced in the early part of period studied (1961–1974). Periodic regression showed a regular cyclic pattern of length 29.53 days (p~0.035).ConclusionsContrary to current scientific opinion, an association exists between moon phases and homicides, and contrary to what has been previously assumed, homicides declined during the full moon, especially in earlier decades. However, the causality of the association remains elusive.


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