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Lunar periodicity of growth cycles in rainbow trout, Salmo gairdneri Richardson
Abstract
Rainbow trout (Salmo gairdneri Richardson) maintained in the laboratory under a fixed artificial 12 hrs light: 12 hrs dark photoperiod exhibited alternating periods of rapid and slow growth. The cycles of growth were rhythmic, and evident in ‘longitudinal’ and ‘transverse’ experimental series. The length of the cycle was approximately two weeks in duration. Peaks of growth rate predicted by least square cosine models describing the relative growth rate patterns were associated with new and full moon suggesting that the lunar calendar is a Zeitgeber used in the regulation of the growth cycles. Changes in growth rate cycles and activity of the fish were associated with the spring equinox, indicating that the fish are sensitive to the event, and that they may re‐adjust their growth rate cycle at that time of the year.
... In addition to these fluctuations due to external parameters, events dependent on fish physiology such as reproduction (Le Bail, 1988) or, in certain salmonids, smolting (Hoar, 1988) influence growth. Growth rate fluctuations have been observed over shorter periods also, under seemingly constant environmental conditions, but the few data that are available are not consistent: in smolt and parr of coho salmon Oncorhynchus kisutch (Walbaum) (Farbridge & Leatherland, 1987a) and in rainbow trout (Farbridge & Leatherland, 1987b), a 14-day periodicity of fluctuations has been observed, while periodicities of 4–6 weeks in common trout Salmo trutta L. (Brown, 1946) and 50 days for Arctic charr Salvelinus alpinus (L.) (Dabrowski et al., 1992) have been described. These discrepancies might be explained by the use of inappropriate experimental designs, in terms of sampling methods, like calculating growth rate from independent data recorded alternatively in three groups of fish (Farbridge & *Author to whom correspondence should be addressed. ...
... In addition to these fluctuations due to external parameters, events dependent on fish physiology such as reproduction ( Le Bail, 1988) or, in certain salmonids, smolting ( Hoar, 1988) influence growth. Growth rate fluctuations have been observed over shorter periods also, under seemingly constant environmental conditions, but the few data that are available are not consistent: in smolt and parr of coho salmon Oncorhynchus kisutch (Walbaum) ( Farbridge & Leatherland, 1987a) and in rainbow trout ( Farbridge & Leatherland, 1987b), a 14-day periodicity of fluctuations has been observed, while periodicities of 4-6 weeks in common trout Salmo trutta L. ( Brown, 1946) and 50 days for Arctic charr Salvelinus alpinus (L.) ( Dabrowski et al., 1992) have been described. These discrepancies might be explained by the use of inappropriate experimental designs, in terms of sampling methods, like calculating growth rate from independent data recorded alternatively in three groups of fish ( Farbridge & Leatherland, 1987a). ...
Ninety rainbow trout Oncorhynchus mykiss were reared in three tanks (n= 30), and their growth rate was monitored for 25 weeks. During the experiment, fish were fed ad libitum, and kept under simulated natural photoperiod and constant temperature (14 ± 1°C). Throughout the experiment, water quality (pH, O2, N-NH3, N-NH4, NO2) was considered optimum. Two growth rate periods were observed on the population: first an acclimation period (weeks 1–5), followed by a period of general decrease in growth rate (weeks 5–25). This trend was modelled with a third-order polynomial function. The autocorrelation analysis of the fluctuations revealed a cyclicity of the growth rate with a 4–5-week period. This cyclicity was independent of the tanks and of the growth rate trend type (long- v. short-term acclimation period). However, at the individual level, trends as well as short-term fluctuations were heterogeneous and no clear cyclicity could be detected. The biological relevance of the population growth rate cyclicity and the apparent absence of similar individual fluctuations are discussed.
... One may assume that once the daily ration is known, that merely weighing up the daily amount as a proportion of the biomass of the fish to be fed, will be a simple procedure. However, fish species, individual fish size, water temperature, time of year, and an array of behavioural, physiological, and environmental variables can affect the daily and seasonal requirements of the fish (Farbridge & Leatherland, 1987; Langhans & Scharrer, 1992; Heggenes et al., 1993; Jobling, 1994; De Silva & Anderson, 1995; Saether, Johnsen & Jobling, 1996; Tveiten, Johnsen & Jobling, 1996; Thetmeyer et al., 1999). Feeding fish on demand, either through fish feeding themselves (self-feeders) or by automatic cessation or reduction of feed delivery when feeding activity declines (interactive feedback system), has received much attention within the aquaculture industry (Alanärä, Kadri, & Paspatis, 2001). ...
... One may assume that once the daily ration is known, that merely weighing up the daily amount as a proportion of the biomass of the fish to be fed, will be a simple procedure. However, fish species, individual fish size, water temperature, time of year, and an array of behavioural, physiological, and environmental variables can affect the daily and seasonal requirements of the fish (Farbridge & Leatherland, 1987;Langhans & Scharrer, 1992;Heggenes et al., 1993;Jobling, 1994;De Silva & Anderson, 1995;Saether, Johnsen & Jobling, 1996;Tveiten, Johnsen & Jobling, 1996;Thetmeyer et al., 1999). ...
This thesis deals with the feeding management of salmonids, from the calculation of the daily feed requirement to the presentation and delivery of that ration taking into consideration the feeding behaviour. The digestible energy need (DEN) to grow 1 kg of wet body weight was calculated for different farmed fish species. In general, the DEN increased with increasing body weight. Using this information, a feed ration model was created and tested using rainbow trout (Oncorhynchus mykiss). Fish fed using this model showed a high rate of growth and a good feed conversion ratio (FCR). The model accurately predicted growth in trout and can be easily applied as a method of calculating the daily ration. For comparison, 3 groups were fed using self-feeders. These groups showed a pattern of fluctuating trigger-biting activity across days and this type of pattern was further studied using time series analysis for groups of rainbow trout. Peaks in activity occurred in the morning and evening at lights on and lights off. Across days, peaks in activity are significantly higher every second day. This pattern is probably a result of an “hourglass” mechanism such as the time required for gastric evacuation and the return of appetite.
Knowing how much feed to give each day, one must then present it in an optimal way. Rainbow trout were fed the daily ration using various portion sizes and at different temperatures. At 5 ºC, growth and FCR were best when small portion sizes were used. At higher temperatures, good growth rates and FCR were observed over a broader range, indicating a high level of plasticity in the trout’s ability to adjust to different portion sizes at higher temperatures. To further evaluate feed presentation, Atlantic salmon (Salmo salar L.) were raised in sea cages, and fed using different combinations of pellet sizes and delivery rates. Treatment groups were compared using growth rate. No significant linear effect on growth due to pellet size or delivery rate could be detected. For pellet size, however, indications point to a non-linear relationship with growth rate. Salmon grew equally well irrespective of treatment further indicating a high level of plasticity in the salmon’s ability to adjust to changes in feed presentation.
... Semilunar growth rate and feeding rhythm [107][108] --Abbreviations: ML = moonlight, TTu = tidal turbulence, TTe = tidal temperature first two criteria-free-running nature and entrainment-have been tested. The remarkable phenomenon of temperature compensation in these long-term developmental or reproductive cycles has only been demonstrated in the annelid Syllis prolifera (previously Typosyllis prolifera), [20] the midges Clunio tsushimensis [21] (see Figure 2) and Pontomyia oceana, [22] as well as the killifish Fundulus grandis. ...
Circalunar clocks, which allow organisms to time reproduction to lunar phase, have been experimentally proven but are still not understood at the molecular level. Currently, a new generation of researchers with new tools is setting out to fill this gap. Our essay provides an overview of classic experiments on circalunar clocks. From the unpublished work of the late D. Neumann we also present a novel phase response curve for a circalunar clock. These experiments highlight avenues for molecular work and call for rigor in setting up and analyzing the logistically complex experiments on circalunar clocks. Re-evaluating classic experiments, we propose that (1) circalunar clocks in different organisms will have divergent mechanisms and physiological bases, (2) they may have properties very different from the well-studied circadian clocks and (3) they may have close mechanistic and molecular relations to seasonal rhythms and diapause.
... However, water content tends to be more a factor of nutritional status with water content generally negatively correlated to lipid content [7,21,26]. Also, growth in salmonids is also not linear, and may occur in pulses according to environmental cues such as lunar cycles and annual seasons [27][28][29][30], which may differentially cause slight increases in body length, at a given body mass. All of these factors may contribute to producing a fish growth dynamic that results in a changing condition factor index for the same individual temporally. ...
Somatic growth is a complex process that involves the action and interaction of genes and environment. A number of quantitative trait loci (QTL) previously identified for body weight and condition factor in rainbow trout (Oncorhynchus mykiss), and two other salmonid species, were used to further investigate the genetic architecture of growth-influencing genes in this species. Relationships among previously mapped candidate genes for growth and their co-localization to identified QTL regions are reported. Furthermore, using a comparative genomic analysis of syntenic rainbow trout linkage group clusters to their homologous regions within model teleost species such as zebrafish, stickleback and medaka, inferences were made regarding additional possible candidate genes underlying identified QTL regions.
Body weight (BW) QTL were detected on the majority of rainbow trout linkage groups across 10 parents from 3 strains. However, only 10 linkage groups (i.e., RT-3, -6, -8, -9, -10, -12, -13, -22, -24, -27) possessed QTL regions with chromosome-wide or genome-wide effects across multiple parents. Fewer QTL for condition factor (K) were identified and only six instances of co-localization across families were detected (i.e. RT-9, -15, -16, -23, -27, -31 and RT-2/9 homeologs). Of note, both BW and K QTL co-localize on RT-9 and RT-27. The incidence of epistatic interaction across genomic regions within different female backgrounds was also examined, and although evidence for interaction effects within certain QTL regions were evident, these interactions were few in number and statistically weak. Of interest, however, was the fact that these predominantly occurred within K QTL regions. Currently mapped growth candidate genes are largely congruent with the identified QTL regions. More QTL were detected in male, compared to female parents, with the greatest number evident in an F1 male parent derived from an intercross between domesticated and wild strain of rainbow trout which differed strongly in growth rate.
Strain background influences the degree to which QTL effects are evident for growth-related genes. The process of domestication (which primarily selects faster growing fish) may largely reduce the genetic influences on growth-specific phenotypic variation. Although heritabilities have been reported to be relatively high for both BW and K growth traits, the genetic architecture of K phenotypic variation appears less defined (i.e., fewer major contributing QTL regions were identified compared with BW QTL regions).
Periodicities in daily food intake, growth, and ammonia concentration of water were estimated and compared for two size classes of brook trout (~ 5 g and > 30 g) held at two temperatures (10 and 15 °C) under laboratory conditions. Periodicities in ammonia concentration of water were also estimated for a basin containing 37,000 juvenile brook trout of 3-6 g at 8 °C under farming conditions and compared to those of the laboratory setting. A multi-frequential periodogram analysis identified short-to-intermediate periodicities in daily food intake, growth, and ammonia concentration under laboratory conditions. The predominant periods in daily food intake ranged from 7 to 12 d (R 2 = 82-95 %). Prevailing periodicities in the temporal trajectory of mean fish weight (7 and 10 d; R 2 = 82-93 %) coincided with those estimated for daily food intake. Ammonia concentration in the experimental tanks had predominant periods of 7-8, and 12 d (R 2 = 86-99 %), coinciding with both the daily food intake and the trajectory of mean fish weight. Periods were similar at both temperatures for both size classes, illustrating the absence of an effect of body size and temperature on periodicities in daily food intake, growth, and ammonia concentration. In the fish farm, periodic components of the ammonia concentration in basin jointly explained 96 % of the total variation of the data. The predominant period was 7-8 d, supporting the results obtained in laboratory.
The purpose of this study was to examine whether the previously identified biweekly patterns of change in the growth rate of rainbow trout, Oncorhynchus mykiss, are associated with similar patterns of change in aspects of thyroid hormone and growth hormone physiology, and to continue to test the hypothesis that the lunar cycle may be serving as a Zeitgeber for the synchronization of this phenomenon.
A significant biweekly pattern of change was observed for food consumption, plasma L‐thyroxine (T4), triiodo‐L‐thyronine (T3) and growth hormone (GH) levels, liver protein content, hepatosomatic index, hematocrit, and in vitro hepatic monodeiodination of T4. The correlation of high and/or low levels of these values with the occurrence of new and full moons is discussed.
A hypothesis about two physical fields that created organic life in Earth's ancient ocean 3–4 billion years ago, and still determine the biological clock phenomenon via changes in the structure of water.
Male and female gulf killifish, Fundulus grandis, were kept in large cages submerged in their natural habitat in the Gulf of Mexico. Gonadosomatic indices (GSI: 100 × gonad weight/body weight) and blood samples were obtained from male and female fish every 4 hours (beginning at 1600) throughout a day on 3 separate days of the semilunar cycle: at the GSI and spawning peak (July 27–28), at midcycle (August 2–3), and on a day prior to the probable spawning peak (August 9–10). Blood samples of females were assayed for cortisol, estradiol-17β (E2), progesterone, testosterone, thyroxine (T4), and triiodothyronine (T3). The daily rhythms of hormones at each of the three days during the cycle differed markedly from one another. At the spawning peak, E2 and T3 peaks occurred at 1200, testosterone and progesterone peaks were found at 2400 and the GSI and cortisol peaks were at 0400. The GSI decreased sharply at 0800 indicating a period of probable spawning. At midcycle, most hormone levels were low throughout the day and the amplitudes of the hormone rhythms were suppressed. One day prior to the spawning peak, testosterone and progesterone variations (peaks at 2400) were similiar to those found on the day of the first semilunar GSI and spawning peaks. Daily variations of other hormones, especially E2, were prominent on the day prior to peak spawning but different from those found on the day of peak GSI/spawning. In males, plasma concentrations of cortisol, testosterone, T3 and T4 also underwent daily variations that differed from one another on the 3 days of the cycle. The results clearly demonstrate that there are dramatic changes in the daily variations of plasma hormone concentrations during the semilunar spwning cycle.
We previously found short periodicities of 4–10 days in the relative growth rates in length and in mass of brook trout Salvelinus fontinalis that persisted under constant lab conditions as well as under different levels of stocking density, food ration and handling. In this experiment, we used the multifrequential periodogram analysis and ANOVA of finite Fourier transform to study growth rates and food intake under different levels of stocking density (1.52 kg m−3 versus 0.76 kg m−3) and ration (1.25% versus 2.5%). We found significant periodicities: 4–6 days in growth rate in length, and 5–10 days in mass respectively explaining 82 and 80% and of the total variation. We also found that daily food intake did not follow the same rhythmic patterns as growth rate with periodicities of 6 and 20 days explaining 91% of the total variation. Stocking density and ration level significantly affected daily food intake but not growth rate rhythms. We developed a system of trigonometric functions of time in days that incorporated significant frequencies estimated by the multifrequential periodogram. The models captured the short-term temporal variations of relative growth rates and daily food intake of young-of-the-year (YOY) brook trout and accounted for the effects of in food ration and stoking density. The models also predicted the relative growth rates and daily food intake with a Rpred2 varying from 73 to 93%. Our findings could improve our understanding of the dynamics in growth rates and food intake of fish populations in natural environments and could have practical consequences for the design of growth experiments and pisciculture.
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Rainbow trout were sprint-trained (30 s duration) once or twice on alternate days for a period of 6 weeks. Swim speed for the first 10 s of a training bout averaged 11.4 bls for group 2 (trained once) and 10.2 bl s −1 for group 3 (trained twice). Food consumption, growth rate and conversion efficiency were measured over 2-week periods. Food consumption was 31-38% less for the trained groups than for the control group (group 1). The growth rates of control and trained fish increased gradually over the training period. The growth rate of trained fish was always significantly less (48-81%) than that of control fish. Although conversion efficiency was significantly less for group 3 at the beginning of training, no other significant differences in conversion efficiency were recorded. Maintenance rations were high in the initial period for all groups, but were lower than the initial values in the second and third periods. While condition factor was significantly lower for the trained groups, there were no differences in percent tissue protein, lipid, or moisture.
Otoliths of five Hygophum species were examined by means of light and scanning electron microscopy. In otoliths of four species (H. benoiti, H. macrochir, H. reinhardtii and H. taaningi) a strong cyclic pattern of the incremental structure was observed. In the fifth species (H. hygomii) such a pattern did not exist. An analysis of archival data on mesopelagic collections suggested three types of Hygophum spp. migratory behavior in relation to the lunar cycle which corresponded with the otolith microstructure. In H. hygomii only limited influence of moon phase on the uppermost range of night-vertical migration toward the surface was observed. The abundant nighttime occurrence of this species moved from the 0 to 50 m into the 50 to 100 m depth strata at full moon. In H. benoiti, a great part of the population, mainly juveniles, showed a tendency toward cessation of the vertical migrations during the first and fourth quarters of the lunar cycle. H. macrochir and H. taaningi had the strongest correlation of behavior with the lunar cycle. Both species showed arrested vertical migrations at the new moon phase, staying at day depths during the night, i. e., below 400 m. Thus, sequences of clear growth increments in otoliths represented a fast-growth period associated with the night migration to the warm surface layers, while bands without easily distinguishable incremental structure were interpreted as a period of slow growth in deep, cold waters due to limitation of the upward migration range occurring approximately at new moon.
Increased aquaculture production has raised concerns about managing protocols to safeguard the welfare of farmed fish, as consumers demand responsible aquaculture practices to provide 'welfare friendly' products. Feeding is one of the largest production cost in a fish farm and can be one of the biggest stressors for fish. Under farming conditions, fish are challenged with artificial diets and feeding regimes, and inadequate feeding conditions cause stress, alteration of normal behavioural patterns, poor performance and eventually diseases and death, which are by no means acceptable neither economically nor ethically. This review aims to highlight the impact of feeding rhythms and feeding time upon physiological and behavioural welfare indicators, which show circadian rhythms as well. Therefore, all these variables should be considered when designing feeding strategies in farming conditions and assessing the welfare state of cultured fish.
Either handling or exercise cause an increase in body weight in fish acclimated to fresh water, and a decrease in body weight in fish acclimated to sea water.
The otolith microstructure of juvenile starry flounders (Platichthys stellatus) sampled from a monitored environment was examined for evidence of lunar periodicity. Three types of biweekly cycles were observed in all of the flounder otoliths; two of the cycles were correlated with a tidal modulation of the environment. Through a multiple regression model, much of the day-to-day variability in increment width could be related to daily variations in temperature, salinity and tidal mixing. My results suggest that a 15-d increment width cycle was entrained by the interaction of a 15-d tidal cycle with temperature and salinity. The same tidal cycle/temperature interaction probably produced a biweekly pattern of increment contrast. However, the presence of otolith checks formed at weekly and/or biweekly intervals could not be so explained, although checks were consistently formed on the new and full moons.
[14C]glycine uptake by scales in vitro was measured in coho salmon (Onco- rhynchus kisutch Walbaum) smolts at different times during several semi-lunar cycles. There was a clear cyclical pattern of glycine uptake during the semi-lunar period.
Evidence for semi-lunar cycles of liver and muscle RNA:DNA ratios, carcass water content, haematocrit, and plasma triglyceride, glucose and cholesterol levels was also found in coho salmon parrs.
Plasma L-thyroxine (T4) levels exhibited a cyclical pattern during the semi-lunar cycle in parrs sampled in March when plasma T4 levels tended to be low, but no such pattern was seen in parrs sampled in January when the plasma T4 levels were relatively high (l·39–l·88 μg dl−1 in January compared with 0·38–0·83 μg dl−1 in March).
There were no apparent semi-lunar cycles in liver mass:body mass ratios and plasma triiodo-L-thyronine (T3) levels.
Changes in growth parameters (nucleic acid levels and glycine uptake by scales) and the content of nutrient reserves are discussed in relation to the semi-lunar patterns of growth in length, growth in mass, and food intake in this species.
Coho salmon (Oncorhynchus kisutch Walbaum) parrs and smolts, maintained in a laboratory under a fixed artificial 12h light: 12h dark photoperiod from the time of hatching, exhibited a pattern of alternating periods of rapid and slow growth in body mass; the peaks and troughs in growth rate were significantly different from one another. The alternating growth rate changes were rhythmic in nature, of approximately 14 to 15 days in length.
Evidence for cyclic patterns of growth in relative length and in food consumption was also found in coho salmon parr. Peak food intake appeared to occur 2–4 days after each peak of growth in relative mass. Although the pattern of growth in relative length was less clear, there was evidence to suggest that growth in length might be out of phase with growth in mass.
There was no pattern of cycling growth rates in coho salmon parr subsampled from a common stock. The significance of this is discussed.
The data suggest that the lunar cycle acts as a Zeitgeber for synchronization of the growth rate rhythms.
1. The effectiveness of oxygen uptake by the blood of rainbow trout (Salmo gairdneri) approaches 100%, whereas that for the removal of oxygen from water was only 11-30%.
2. Most of the carbon dioxide is removed from the blood as it passes through the gills, but the effectiveness of carbon dioxide uptake by water is very low, because of the high capacity of water for carbon dioxide compared with oxygen.
3. Moderate exercise had little effect on the effectiveness of gas exchange across the gills. The increased oxygen uptake was facilitated by an increase in the transfer factor of the gills for oxygen. There were small increases in the capacity-rate ratio of blood to water at the gills during moderate exercise.
4. Hypoxia resulted in a marked decrease in the effectiveness of oxygen uptake by the blood, but had little effect on oxygen removal from the water. Gas exchange was facilitated during hypoxia by an increase in transfer factor of the gills, but hindered by an increasing capacity-rate ratio of blood to water at the gills.
5. Gas exchange in an aquatic environment was compared with that in an aerial environment.
To understand how the many environmental factors influence growth, the basic rate functions should never be lost sight of, despite the general simplicity of growth measurements. As far as possible, the individual functions have been introduced in the chapter to provide some explanation of the response to environmental factors, without deviating from the major purpose of examining the recorded trends in the activity of growing. In relation to environmental effects, quite obviously growth cannot be studied without involving food consumption, even though the latter may not necessarily be measured. In this respect, growing—unlike such activities as swimming or respiring—is inseparably coupled with a powerful biotic factor, so that any abiotic factor is necessarily involved in some form of interaction between the two. Growth rate may either increase or decrease depending on the nature of the food × metabolism × temperature relation; on analysis it can be seen that the energy demand of elevated metabolic rate could have exceeded the gain from increased food uptake resulting in reduced growth rate. Furthermore, the act of growing necessarily alters size so that another important biotic factor continually changes with time. An understanding of these inherent involvements is necessary before any clear insight of the environmental relation to the growth process can be achieved.
The early-stage annual rings in otoliths from some cold-temperate fish consist of thin growth bands, the number of which corresponds
to that of the days in a year. This indicates that growth takes place by daily increments. Other recurrent patterns show a
fortnightly and monthly periodicity. Spawning rings are microscopically distinguishable from winter rings.
The growth rate (weight) of 70 juvenile rainbow trout, monitored on a weekly basis for a period of 4 months, was observed to cycle, with alternating phases of accelerated and reduced growth every 3 to 4 weeks. The significance of this phenomenon is discussed in relation to recent studies on growth physiology in rats.
1. Continuous recordings of oxygen consumption were made in order to determine ontogenetic, daily, seasonal, temperature, and other relationships of metabolic variability in chick embryos.2. Statistical treatment involving linear regression analysis facilitated resolution of daily cycle forms and allowed various comparisons.3. The pattern of metabolic variation during days four and five has several peaks, but by days seven and eight a more markedly diurnal pattern appears. Day six appears to be an intermediate or transitional stage.4. Seasonal differences in the form of the daily cycle resemble those reported for other organisms.5. Lowering the temperature 5° C. does not affect the period length of the metabolic variations. A suppression of nighttime metabolism relative to daytime metabolism suggests the expression of a diurnal variation in temperature sensitivity.6. Initiation of incubation at different times of day does not result in different basic cycle forms.7. Results obtained with chick embryos are...
Studied the distinct surge in plasma thyroxine as exhibited by anadromous salmonid fish during the smoltification period prior to their migration to the sea. Analysis of 27 groups of hatchery-reared salmon and anadromous trout indicated that thyroxine levels peak coincident with the new moon. The implications for the ability to predict migratory readiness by lunar calendar and the efficient culture of this economically important protein resource are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
- BROWN M.E.
- FARBRIDGE K.
- RANDALL D.J.
- FARBRIDGE K.J.