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Photoperiod Stock Photos and Images
RF2R67YCC–The chrysanthemum is a plant that adapts very well to photoperiod management when grown in a greenhouse and allows flowering throughout the year
RMW22KE8–Archive image from page 22 of Day length and crop yields. Day length and crop yields daylengthcropyie507park Year: 1942 A greenhouse equipped for present-day photoperiod studies on economic plants at the Bureau of Plant Industry Station, Beltsville, Md. The results of many studies here and elsewhere have helped to eliminate crop failure and have modified agricultural practices throughout the world. Recently crosses were made between a wild species of sugarcane (Saccharum spontavevm) from Turkistan, which blooms in July, with cultivated sugarcane (S. officinaL i, which blooms in November or D
RFH6BK96–Coldenia Procumbens. Family: Boraginaceae. A small hairy prostate herb.,It is found in winter in paddy fields after the paddy harveting
RMHBA8H2–Two white-tailed jackrabbits in different stages of turning from brown to white color in autumn. (Lepus townsendi)
RF2WW7YBE–An intricate pattern of LED lights dominates this image, showcasing the precise matrix within a large agricultural greenhouse. The harmonious alignment of light strips with the blue-tinted panels reflects a dedication to efficient plant nurturing and futuristic farming practices. Architectural Harmony: A Matrix of LED Lights in an Agricultural Greenhouse. High quality photo
RMRHMPCX–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND DAILY RHYTHM 81 to account for other responses of the rhythmic mechanism of Uca; in fact, they even exhibit the same intrinsic characteristics. They are, therefore, assumed to be the same and this work is considered to provide striking support for the earlier hypothesis and to describe further properties of these two postulated centers. Figure 3 is a diagrammatic representation of the mechanism which has been hypothesized to account for the responses of the daily rhythmicity observed during these experiments.
RMPFG3B1–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. Leaf fall of the tuliptree and many others may be delayed when the photoperiod is long. profitable production. New and more specifically adapted varieties of soybeans are constantly being selected, so increasing acreages of this very important crop are being grown more economically through- out wider and wider areas. Recent experiments to develop sugar-beet seed furnish one of the most striking examples of the possibilities of securing newer and better varieties of a crop that is very sensitive in its responses to photo-
RMW22JFA–Archive image from page 20 of Day length and crop yields. Day length and crop yields daylengthcropyie507park Year: 1942 Some of the earlier equipment employed by Garner and Allard, who used many kinds of wild and cultivated plants. Photoperiod an Aid in Plant Breeding The photoperiodic behavior of many varieties i plants is of great economic significance in the developmenl of new varieties. In many localities the common potato as grown in the field frequently produ large numbers of flowers bul lew seeds. In the commercial produc- tion of potatoes this is no detrimenl because they are grown b
RMRN5ND8–. Animal Ecology. Animal ecology. Paleogeography Upper Cretaceous, showing land bridges and epeiric seas (Ross 1951). present tropical fauna and flora was greater than it is at the present time. Another difficulty that southern species would en- counter on the bridge would be the very long days of the summer and the very short ones of the winter. Tropical species are adjusted to fairly equal photo- periods at all seasons of the year. Seasonal differences in photoperiod are due to the inclination of the earth's axis and there is no positive evidence that this inclina- tion has changed during ge
RMPFG3BH–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. r«r Pyrethrum produces flowers, which are the source of insect powder, only when grown in localities where the photoperiods are long. Under short photoperiods the plants remain as rosettes. vail in any given region arc as important as moisture and soil fertility in determining the specific behavior and economic value of varieties which it may be desired to grow. Although the length of photoperiod in any particular locality changes from day to day throughout the season, the photoperiods of corresponding days in successive
RMW22H3A–Archive image from page 16 of Day length and crop yields. Day length and crop yields daylengthcropyie507park Year: 1942 its production. Foi ex- ample, ery excellent yields ill sugar-beel seed are now being produced in certain areas of the Pacific Xorth- Wes where the 1 cm | x â i;i- tures are sufficiently mild to permit overwintering and the longer summer photo- periods are especially favor- able. As a result of these recent developments the United States now produces enough sugar-beet seed for its own use. Onions also show a range in sensitivity and adjust- ment to photoperiod, not only
RMRHNX8F–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND DIAPAUSE to 46. As the larvae reached maturity, daily pupation records were taken. Diapause incidence was measured as the per cent of mature larvae that failed to pupate. This was determined on the basis of the sigmoid configuration of the pupation record (Fig. 1); when the curve had remained unchanged for several days, pupation was considered to have been completed. The remaining mature larvae were considered to be in diapause. The experiments were carried out in B.O.D. constant temperature incubators that h
RMPFG3A3–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. A greenhouse equipped for present-day photoperiod studies on economic plants at the Bureau of Plant Industry Station, Beltsville, Md. The results of many studies here and elsewhere have helped to eliminate crop failure and have modified agricultural practices throughout the world. Recently crosses were made between a wild species of sugarcane (Saccharum spontavevm) from Turkistan, which blooms in July, with cultivated sugarcane (S. officinaL i, which blooms in November or December, By appropriate manipulations of photoper
RMRWRKFA–Elements of ecology (1954) Elements of ecology elementsofecolog00clar Year: 1954 Seasonal Periodicity 225 cereals, and timothy. If such plants are grown under daylengths shorter than the critical photoperiod, stems tend to be shorter and flowering is suppressed (Fig. 6.21). Other effects may also be pro- duced in the plant, as illustrated by long-day potatoes which produce the best tubers when daylength is below the optimum for shoot growth. Fig. 6.21. Control of flowering and of vegetative growth by daylength in timothy, a typical long-day plant. The daily exposures (in hours) to light ar
RMRHKY2T–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND DIAPAUSE phases of from 10 to 14 hours, with maximum effectiveness at 12 hours. These findings are in agreement with those of Danilyevsky and Glinyanaya (1950), who worked with Acronycta spp. Otuka and Santa (1955), experimenting with Barathra brassicac L., concluded that, although the absolute length of the phases was of importance, phase ratio also influenced diapause induction; their data on this point are not all convincing, however, as they tested only 1 : 1 ratios. A series of experiments was run in whi
RMPFG3AF–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. Some of the earlier equipment employed by Garner and Allard, who used many kinds of wild and cultivated plants. Photoperiod an Aid in Plant Breeding The photoperiodic behavior of many varieties i plants is of great economic significance in the developmenl of new varieties. In many localities the common potato as grown in the field frequently produ large numbers of flowers bul lew seeds. In the commercial produc- tion of potatoes this is no detrimenl because they are grown bj planting whole tubers or pieces of them. But if
RMRHMJY7–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 480 WILLIAM E. BRADSHAW 2 and 6 days exposure elicited a significantly greater amount of pupation than did the control (Duncan's Multiple Range Test after arcsin transformation: F — 5.00; P < 0.05; D --- 12.8%). These results suggest the photoperiodic information may be accumulated to some extent by C. americanus but that the synergistic interaction of food and photoperiod requires both parameters simultaneously rather than sequentially. Persistent effects of food The following experiments reciprocate the ones above and a
RMPFG3A7–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. ft* 4 Mm fen*. 4 *^ *. The effects of photoperiod may be localized. The half of each plant which is bloom- ing received a relatively long photoperiod each day,- the other a short one of but 1 0 hours. 18. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Parker, M. W. (Marion Wesley), 1907-; Borthwick, H. A. (Harry Alfred), 1898-. Washington, D. C. : U.
RMRHN734–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Time (weeks) FIGURE 1. Growth (average weight). MIH may be photoregulatecl (Aiken, 1969). Photoregulation of the X-organ may be achieved in one of four ways: by a particular wavelength, the amount of energy, the photoperiod, or through combined interactions. The equivalent number of total exuviae among the groups indicated that the photoperiod, wavelength, or a combination did not markedly affect the rate of molting, but rather, influenced the time molting took place. Most exuviae were found from 1200-2400, but because monit
RMPFA9B5–. The developmental ecology of Mantispa uhleri Banks (Neuroptera: Mantispidae). Mantispa uhleri; Insects; Mantispa uhleri; Insects. Egg Sac Penetration 35 nopsis sp. collected from beneath the loose bark of Osage orange trees and prepared as detailed for Experiment 3 (p. 28). We used adult crab spiders, Philodromus vulgaris Hentz, taken from the same habitats as the Agelenopsis sacs. All three spider species were collected in the vicinity of Urbana, Illinois. All experiments were carried out at a temperature of 25°C with 80% relative humidity and a photoperiod of L:D = 16:8. Frequencies were a
RMRHN99D–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIODIC RHYTHM COXTROL 181 Stages 1, 2, 3, and 4 (Figs. 2-5 I. Our observation- have led us to believe that the cells are capable of liberating their products after they reach either Stage 3 or 4. For the purposes of studying the effects of photoperiod on the secretory cycle, Stages 0 and 1 were of the greatest interest, and their occurrence was contrasted to the occurrence of the other secretory stages. Proctodeal tissue samples were taken hourly from group* of diapau.Miig borer larvae that were maintained under eithe
RMPFG3AK–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. its production. Foi ex- ample, ery excellent yields ill sugar-beel seed are now being produced in certain areas of the Pacific Xorth- Wes where the 1 cm | x â i;i- tures are sufficiently mild to permit overwintering and the longer summer photo- periods are especially favor- able. As a result of these recent developments the United States now produces enough sugar-beet seed for its own use. Onions also show a range in sensitivity and adjust- ment to photoperiod, not only in flowering but par- ticularly in bulh produc- t
RMRHNTTH–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DIAPAUSE DEVELOPMENT 181 over the administration of a single massive dnse. The addition of different amounts of ammonium acetate to the larval rearing medium did not reduce the incidence of diapause among borer larvae reared under a short-day photoperiod. A possible explanation for the ammonium effect on diapause development is that ammonium ions are required for the synthesis of other nitrogenous compounds, and a massive influx of ammonium forces the synthetic process to an effective nondiapause rate of production. Accordin
RMRHN6BW–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND CHILLING 151 the colder temperature and were subjected in samples of 10 each to various photophases at 21° C; photophases were determined from the results of ongoing experiments. After 180 days of chilling, samples of 14 larvae each were used to compensate for expected mortality. Figure 2 shows that the critical photoperiod for development within 50 days of transfer to 21° C decreased consistently with prolonged chilling at 7° C. Prior to chilling, the critical photoperiod was 13.20 hours of light per day; af
RMRHNRRH–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 82 LEONARD G. EPP AND CHARLES F. LYTLE exceptions: Culture medium in those maintained under starvation conditions vas changed daily, and the period of illumination in the photoperiod experiment was altered manually. Cultures referred to in the results as having been maintained in continuous darkness actually received 10 minutes of ambient laboratory light j j o per day due to the need for light during feeding and counting. Reproduction was measured each day by counting and removing buds dropped from the five parent hydra in
RMRHMJXT–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. INTERACTION OF FOOD AND PHOTOPERIOD 481 correlated with the number of days feeding on short day. This observation indi- cates that food is stored—as long as 15 days—and may be called upon to support larval life or adult development. The following experiments, designed to further elucidate the long-term effects of food, employed the duplicate experiments started on 5-11-68 as described above. At the end of 16 days total experimental time, the duplicates were split into two groups of 7 experimental populations each, having rec
RMRHKB1P–. Biology and migratory behavior of Agraulis vanillae (L.) (Lepidoptera, Nymphalidae). Lepidoptera; Beneficial insects; Insect pests. 65. Figure 24. Cutaway view of controlled photoperiod cabinet used in clock resetting experiments. (A) time switch, (B) light chamber, (C) dead air space, (D) air inlet, (E) hous- ing chamber.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Arbogast, Richard Terrance, 1937-.
RMRFRX09–. The Caribbean forester. Forests and forestry Caribbean Area Periodicals; Forests and forestry Tropics Periodicals. Vol. 24 No. 1 - 1963 The Response of Honduras Pine to Various Photoperiods J. A. VOZZO Forest Physiology Laboratory U. S. Forest Service Eeltsville, Maryland By and C. B. BRISCOE Institute of Tropical Forestry SUMMARY Height growth of Honduras pine (P. caribaea v. hondurensis) seedling's is shown to be significantly influenced by photoperiod. Maximum initial effect was obtained by the longest period tested, 16 hours; but by 7 weeks, greatest growth was obtained by an interrupted
RMRHNWDJ–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 86 D. G. R. McLEOD AND STANLEY D. BECK the maximum temperature took one hour. The performance of the temperature- controlling apparatus was verified by a recording thermograph. Throughout this paper the term short-day refers to a photoperiod consisting of 13 hours of photophase and 11 hours of scotophase, and the term long-day refers to a photoperiod with a 16!-hour photophase and a 7^-hour scotophase. These experi- mental conditions were employed because previous work had shown that over 90% incidence of diapause was induce
RMRHM7GF–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EXTENDED MALE PHASE IN A HERMAPHRODITIC SHRIMP 351 then placed in aquaria of the suboptimal treatment to in- crease water temperature to that of the optimal treatment, and photoperiod was changed to 14-h light: 10-h dark, simulating a change from fall/winter to spring/summer con- ditions. The experiment then continued for another 8 weeks. The shrimps were maintained and checked for molts as in the previous experiment. Male-phase individuals that changed to FP (brood of embryos observed) were removed from the experiment and p
RMRHN9M9–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CARROLL M. WILLIAMS AXI) I'KKRY L. ADKISSON )J ) recent review, insect pupae (unlike all other stages in the life history) are thought to be insensitive to photoperiod. Some reservations on this point are provoked by a more detailed examination of ./. fcrnyi. Thus, when the cocoon is cut open, the pupa is always facing up- ward in the chamber. Moreover, on inspecting the pupa, itself, one cannot fail to be impressed by the unpigmented, transparent cuticle overlying the brain (Fig. 1). Even if the rest of the pupa is jet-blac
RMRHKTMR–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIODIC ACTION SPECTRA 15 As shown in Figure 3, 30 minute light breaks were most effective at two times during the dark period. Seventy-six and 71 per cent of the larvae were stimulated to pupate by light pulses ending 14| and 16^- hours after dawn, respectively. A higher percentage of larvae were stimulated to develop by 17 hours of continuous illumination per day than by any asymmetric skeleton photoperiod. DISCUSSION Previous data (Bradshaw, 1969) indicated only that the transition from photo- period-dependent to ph
RMRHMXR8–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. I I TRIDACNA. 05 10 15 20 25 5 10 15 20 25 CELL DIAMETER (//m) FIGURE 2. Cell-size distributions of zooxanthellae isolated from a variety of reef invertebrates collected from different locations. Replicate algal size distributions are presented for several of the hosts sampled. under a variety of nutrient conditions (nutrient concentrations, rates of supply and sources) and light regimes (light quantity, quality, and photoperiod). Inasmuch as most studies employing cultured algae are done with clones maintained in the labo-
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 518 CARROLL M. WILLIAMS AND PERRY L. ADKISSON 3. The "fine structure" oj ilic photoperiod response As is amply demonstrated in Figures 2 and 3, an abrupt transition betveen "short-" and "long-day" conditions occurs at or near a photophase of 14 hours. This finding was examined in further detail by exposing two groups of 50 un- chilled pupae to daily photophases of 13.50 and 13.75 hours, respectively. At the end of eight weeks, 2% of the former group and 22% of the latter group had initiated adu Stock Photo](https://c8.alamy.com/comp/RHN9J0/the-biological-bulletin-biology-zoology-biology-marine-biology-518-carroll-m-williams-and-perry-l-adkisson-3-the-quotfine-structurequot-oj-ilic-photoperiod-response-as-is-amply-demonstrated-in-figures-2-and-3-an-abrupt-transition-betveen-quotshort-quot-and-quotlong-dayquot-conditions-occurs-at-or-near-a-photophase-of-14-hours-this-finding-was-examined-in-further-detail-by-exposing-two-groups-of-50-un-chilled-pupae-to-daily-photophases-of-1350-and-1375-hours-respectively-at-the-end-of-eight-weeks-2-of-the-former-group-and-22-of-the-latter-group-had-initiated-adu-RHN9J0.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 518 CARROLL M. WILLIAMS AND PERRY L. ADKISSON 3. The "fine structure" oj ilic photoperiod response As is amply demonstrated in Figures 2 and 3, an abrupt transition betveen "short-" and "long-day" conditions occurs at or near a photophase of 14 hours. This finding was examined in further detail by exposing two groups of 50 un- chilled pupae to daily photophases of 13.50 and 13.75 hours, respectively. At the end of eight weeks, 2% of the former group and 22% of the latter group had initiated adu Stock Photo")
RMRHN9J0–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 518 CARROLL M. WILLIAMS AND PERRY L. ADKISSON 3. The "fine structure" oj ilic photoperiod response As is amply demonstrated in Figures 2 and 3, an abrupt transition betveen "short-" and "long-day" conditions occurs at or near a photophase of 14 hours. This finding was examined in further detail by exposing two groups of 50 un- chilled pupae to daily photophases of 13.50 and 13.75 hours, respectively. At the end of eight weeks, 2% of the former group and 22% of the latter group had initiated adu
RMRHN2K8–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FEB. MAR. APR. MAY. 11 12 13 14 PHOTOPERIOD (hr light) 15 FIGURE 1. The fractions of female Diaptomus sanguineus from three Rhode Island ponds making subitaneous (immediately hatching) eggs, as opposed to diapausing eggs, as a function of time of year. A. Egg type versus date of collection. The lines are summaries of data from Hairston and Munns (1984), Hairston el al. (1985), and Hairston (1986) showing the annual variation in timing of diapause. Data points after the switch to production of diapausing eggs are omitted here
RMRHKRPD–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CRANGON FRANCISCOftUM PALAEHON UACRODACTYLUS. STATION NUMBER FIGURE 10. Abundance of Crangon franciscorum, Palacinon inacrodactylus, and Neomysis mcrccdis at stations 42-70, on selected dates, May, 1977-September, 1978. Arrow pointing upward marks f/ce salinity, arrow pointing downward marks 18%f salinity. the photoperiod was above 12 hr light: 12 hr dark, i.e. March, and occurred repeatedly at 20°C under 16 hr photoperiod (Barclay, 1978). Laboratory bioassay indicates optimum salinity for adult C. franciscorum to be around
RMRHN6AD–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 154 W. E. BRADSHAW AND C. M. HOLZAPFEL TTH == 6 + (£) (TAt + 2TAt i).. with no decrease in the coefficient of multiple cor- relation (R == 0.93) (Fig. 5A). Therefore, at least during the month of May and June, tree-hole temperature was closely correlated with air temperature. DISCUSSION Prior to chilling, larval diapause in T. rutilus is maintained primarily by photoperiod (Figs. 1A and 2; Bradshaw7 and Holzapfel, 1975; McCrary, 1965). The critical photoperiod of this response varies as little as plus or minus 7.5 minutes ov
RMRHN9KJ–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 516 CARROLL M. WILLIAMS AND PERRY L. ADKISSON 100-. 0 - 0 8 12 14 16 PHOTOPHASE (HOURS) 20 FIGURE 2. The effects of photoperiod on the termination of diapause by unchilled pupae of A. fcniyi at 25° C. The termination of diapause was recognized or computed in terms of the zero day of adult development. by the initiation of epidermal retraction, may be recognized with a precision of 4 to 6 hours. A similar calibration of the diapausing second-brood pupae revealed a slightly faster pace of adult development in that the moths em
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 182 S. D. BECK, I. I'.. COLVIN l> I). !•.. SWINTON secretory rliythni is teui]»>rallv adjusted through tlic insect's response to tlie lights- ot'l stimulus provided bv the extrinsic photoperiod. The proctodeal secretory rhythm is not. in itself, a cireadian rhythin. because il displas a period approximating S rather ti.an 24 liours. It is phase-set (temporally adjusted) bv tin- 24-hour rhythm of daylight and darkness, and is most certainly a component of the in>ect's photoperiodism. The ])ossible significance of Stock Photo](https://c8.alamy.com/comp/RHN98P/the-biological-bulletin-biology-zoology-biology-marine-biology-182-s-d-beck-i-i-colvin-lgt-i-!-swinton-secretory-rliythni-is-teui-gtrallv-adjusted-through-tlic-insects-response-to-tlie-lights-otl-stimulus-provided-bv-the-extrinsic-photoperiod-the-proctodeal-secretory-rhythm-is-not-in-itself-a-cireadian-rhythin-because-il-displas-a-period-approximating-s-rather-tian-24-liours-it-is-phase-set-temporally-adjusted-bv-tin-24-hour-rhythm-of-daylight-and-darkness-and-is-most-certainly-a-component-of-the-ingtects-photoperiodism-the-ossible-significance-of-RHN98P.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 182 S. D. BECK, I. I'.. COLVIN l> I). !•.. SWINTON secretory rliythni is teui]»>rallv adjusted through tlic insect's response to tlie lights- ot'l stimulus provided bv the extrinsic photoperiod. The proctodeal secretory rhythm is not. in itself, a cireadian rhythin. because il displas a period approximating S rather ti.an 24 liours. It is phase-set (temporally adjusted) bv tin- 24-hour rhythm of daylight and darkness, and is most certainly a component of the in>ect's photoperiodism. The ])ossible significance of Stock Photo")
RMRHN98P–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 182 S. D. BECK, I. I'.. COLVIN l> I). !•.. SWINTON secretory rliythni is teui]»>rallv adjusted through tlic insect's response to tlie lights- ot'l stimulus provided bv the extrinsic photoperiod. The proctodeal secretory rhythm is not. in itself, a cireadian rhythin. because il displas a period approximating S rather ti.an 24 liours. It is phase-set (temporally adjusted) bv tin- 24-hour rhythm of daylight and darkness, and is most certainly a component of the in>ect's photoperiodism. The ])ossible significance of
RMRHN2JN–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DIAPAUSE IN A FRESHWATER COPEPOD 139 100 Bullhead Pond. 10 11 12 13 14 PHOTOPERIOD (hr light) 15 16 FIGURE 2. The fractions of subitaneous (immediately hatching) clutches of eggs produced by female Diaptomus sanguineus reared at the photoperiods illustrated. Data are for all clutches regardless of order of production. For sequence of clutch production see Table I. Experiments at intermediate day lengths were run at 9 ± 1°C, whereas those at 8L:16D and 16L:8D were run at 4 ± 1°C and 20 ± 1°C respectively. The levels of respon
RMRHM3PF–. The Biological bulletin. Biology; Zoology; Marine biology. L=D 0 = 24 1 0 20 MARCH. 10 20 MAY Figure 7. Procedural artifact in measuring the time of diapause termination in constant dark as opposed to that in a short-day photoperiod (L:D 11:13). Hatching, as shown by the cumulative hatch, is delayed in short-day photoperiod as a result of delayed transfer of sub- samples from the stock containers. The reverse is apparently the case in constant dark. apparently the case when the embryos are held in constant dark (Fig. 7). The interaction of light and aeration is most dramatically illustrated
RMRHMA20–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 20 £2 13:00 -• x Miami Harbor - Key West. 10:00 M O N D Figure 9. Monthly average salinity and temperature (upper panel) measured at the sea surface at the time of fish collection. Error bars are 95% confidence limits. Seasonal change in photoperiod for Miami Harbor entrance and Key West (lower panel: data source: National Oceanic and Atmospheric Administration Tide Tables). prolonged reproductive season has been noted for other hemiramphids (Ling, 1958; Coates and Van Zwieten. 1992). this study provides the first conclusive
RMRGAT9K–. Bulletin of the Southern California Academy of Sciences. Science; Natural history; Natural history. Figure 5. Mean levels of vocal activity in relation to time of day of an isolated mature female T. truncatus fed at noon each day for seven days. Figure 6. Mean levels of vocal activity in relation to time of day of five T. trun- catus fed on a random daylight hour schedule. tion that the photoperiod is solely responsible for the periodicity in vocal activity in view of the results obtained in Situation 2 during the shift in feeding schedule. Although the changed feeding time appeared to resul
RMRHN69R–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND CHILLING 155 22- 20- i; 18- E 16- x 14- 12- 10. 10 12 14 16 18 Air Temperature(°C)=6 + -^ 20 22 + 2TAM). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 189
RMRG0DH2–. The Canadian field-naturalist. . Figure 3. Growth of the cranberry cultivar Pilgrim at three temperature regimes in a 16 h photoperiod: A. ll°Cdark 16°C light, B. 16°C dark 21°C light and C. 21 °C dark and 26° C light. Plants placed in growth chambers on 23 November 1981 and photographed on 8 December 1981. Light intensity was 6800 lux.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Ottawa Field-Naturalists' Club. Ottaw
RMRHN9H7–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 522 CARROLL M. WILLIAMS AND PERRY L. ADKISSON 100 80 60 LJ O (T LU 0- 40 20 0 —A A A & A Induction of Diapause (Tanaka) Termination of Diapause. - A—- 8 10 12 14 15 PHOTOPHASE(HOURS) 16 17 18 FIGURE 5. The solid line records the effects of photoperiod on the termination of pupal diapause by previously chilled A. pernyi. The hatched line shows the influence of photoperiod on the induction of diapause (data of Tanaka). The same short-day conditions which induce pupal diapause are also effective in stabilizing diapause.
RMRHMME7–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. OVARIAN GROWTH IN ZONOTRICHIA 73 First-Year Females o outdoor, natural • outdoor, aviary D indoor, 8L I6D. D J Months M FIGURE 2. Non-photoperiodic growth of the ovary of the first-year white-crowned sparrow (Zonotrichia leucophrys ganibclii'). Ovarian weight is plotted as a function of time in months; during this period the birds did not receive stimulatory photoperiods. O, birds taken from the field; •, birds from outdoor aviaries under natural conditions of temperature and photoperiod: fj, birds held indoors under 8L 16D.
RMRG3P03–. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 172 CALIFORNIA FISH AND CAME observed in the present study suggest some involvement of endogenous pat- terns. I suggest that the timing of this migration is a function of rate of change of photoperiod subject to the control of a temperature-related, endogenous size threshold. I^^r -r 1,0 X 8 u o LlI J o A 8UI6D â I2L:I2D ⢠leUBD. 20 TEMPERATURE (*C) FIGURE 3: The relationship between mean thyroid follicle cell height in acclinnated
RMRHN33F–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 104 CHARMANT1BR ET AL Canadian and French groups who performed the experi- ments. Animals Homan lU larvae were obtained during the summer ftvi -lers captured in Passamaquoddy Bay and held i: . lobster culture facility at the Biological Statii Andrews. After hatching, larvae were trans- ferred to 40-1 planktonkreisels (Hughes et at., 1974) sup- plied with flow-through seawater at a salinity of 30-31 %o, a temperature of 20°C under natural photoperiod. Lar- <. ac v ere fed three times a das w ith frozen adult Anemia. As ea
RMRHN432–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 316 NANCY H. MARCUS Hours of Daylength 10 12 14 15 14 12 10 9.5 SUBITANEOUS DIAPAUSE ADULTS. J FMAMJ J ASQN D Month FIGURE 1. Schematic diagram of seasonal occurrence of adults and production of sub- itaneous and diapause eggs of Lahuloccni ucstii'a in Vineyard Sound, MA, with respect to day length. summer when surface water temperatures have reached 18°-20°C (Marcus, 1979) and the photoperiod is 15L:9D (U. S. Dept. of Commerce, 1979). In August, daylength is somewhat shorter (14L), and water temperature is maximal (22°- 23°
RMRHNA67–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. EFFECTS OF PHOTOPERIOD ON SPARROWS 339 16- 8 §.14 I 2-. Long Short 1 Short 2 Photoperiodic cycle Short 3 FIGURE 3. Gonadotropin content of the anterior pituitary of males (Zonotrichia leucophrys gambclii) in fj.g. equivalents of NIH-LH in a cycle consisting of one long day (20L 4D) followed by three short days (8L 16D). Black and white bars depict dark and light periods, respectively. Vertical bars define the 95% confidence limits. In Experiment I there was a close linear relationship between the concentration of pituitary
RMRHKTPE–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 12 13 14 HOURS LIGHT PER DAY 2-. 12 Hour Photophase 1-15 Ill-l 111-15 IV-1 r IV-15 DATE PLACED ON EXPERIMENTAL PHOTOPERIOD FIGURE 1. Responsiveness of diapausing larvae to photoperiod. (1A) Responsiveness (per cent pupation per day of exposure to experimental regimen) of larvae caught January 20 and February 25, 1968, and exposed to various photophases April 12 and April 22, 1968, respectively. (IB) Responsiveness of larvae caught February 13, 1969, stored under short-day conditions at 5°C, and exposed to long- or short-day
RMRHN9PW–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CYCLIC ACTIVITY IN ONCOPELTUS 517 16-8 -o. 10 12 14 16 18 20 22 DAYS AFTER ADULT MOLT 24 26 28 30 32 FIGURE 6. Maximum mating levels achieved by 4 groups of Oncopeltus fasciatns reared under 4 different temperature-photoperiod regimens. The maximum per cent possible pairs mating on a given day following the adult molt was plotted for each group and in every case the maximum occurred within 2 hours of light off. Note that photoperiod alone determines the maximum level of mating achieved within a regimen while both photoperiod
RMRHN46E–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. -I 1 1 -I L. FIGURE 6. Effect of photoperiod and food quality on ovarian weight of H. convergent under either a 12L: 12D (A) or 16L: 8D (B) environmental regime. Each day three females were sacrificed and the weight of the fixed reproductive tract was determined. Solid circles, broken lines indicate females fed frozen aphids while solid circles, solid lines indicate females fed live aphids (P = 0.025 for A, P < 0.001 for B; Mann Whitney U test). animals were fed for only 3 days prior to starvation, flight activity was sig
RMRHMCCF–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. DAYLENGTH. DEGREES. AND DIAPAUSE 43 100r M Q> O w D O 9) C CO 15 3 CO. 20 • 10 11 12 13 Daylength (h) 14 15 16 Figure 1. The timing of the switch from production of subitaneous (immediately hatching) eggs to diapausing eggs by Diaplomus sanguineus from Bullhead Pond. Rhode Island. The continuous line connecting error bars shows the mean trajectory- over 9 years (± 95% CI) for copepods in the lake, expressed as a function of photoperiod on the date that the animals were collected. The line connecting individual open data p
RMRHN2DD–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 12 18 8 12 18 8 12 18 FORT PIERCE. 8 12 18 8 10 12 18 8 12 18 14.5° 18.0° 24.0° PHOTOPERIOD/ TEMPERATURE. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, A
RMRHN6C7–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 00 O 15 I I I I I 15 17 19 21 23 25 Temperature (°C) FIGURE 1. Effects of temperature and photoperiod on development. Left-hand graphs (A) show percentage of development in response to various photoperiods at 25°, 21°, and 16.5° C. Only photoperiod has a significant effect on percentage development. Right-hand plots (B) show rate of development in response to long (14 hour) and intermediate (13 hour) photophases at 25°, 21°, and 16.5° C. The horizontal line at each temperature shows the time interval of the experiment, i.e.,
RMRG0DHH–. The Canadian field-naturalist. 96 The Canadian Field-Naturalist Vol. 100 Table 2. Total shoot length (cm) of five Oxycoccus macrocarpus cultivars grown in a 16-h photoperiod at three temperature regimes in growth chambers at the Kentville Research Station. Light intensity in each chamber was 6800 lux and there were five plants of each cultivar grown from a 20 cm cutting in each chamber. Shoot length was recorded after 57 days. Regime #1 Regime #2 Regime #3 ll°Cindark 16°Cindark 21°C in dark 16°C in light 21°C in light 26°C in light Cultivar (mean ± SE) (mean ± SE) (mean + SE) Black Veil Pilg
RMRHN841–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 100 THOMAS L. BEITINGER. -100% - 75% 50% - 25% sx LD 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 TIME (hrs) FIGURE 2. Median activity (0.5-hour, tunnel pass frequency) of 7 bluegill during the day experiment. The arrow indicates when photoperiod was switched from LD 12: 12 to 6:6:6:6. Activity patterns During the LD 12:12 (control) period, a distinct diurnal activity pattern was apparent (Figures Ic and 2). Day and night median activity levels (tunnel passes 0.5 hr) ranged between 15-33 and 1-10, respect
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 316 DOUCI.AS R. kOI'.KKTSnX ]ina temporaria appears to be controlled by temperature and not by light (van Oordt and van Oordt, 1955) ; but the spermatogenic cycle in the salamander PIctJiodon cincreus is primarily regulated by photoperiod (Werner, 1969). The .4 I— r.2 (52°). 50 100 200 300 r.2 — / HLM / ' 1 I A f (l L L A i 1 . I / 1 1 r i / • l /' -: :. i / — x 1 :' '. f 1 I / ,' i ': ' / > i ' N ,'' ? ;-; MV; / ./ ;i / / - i l • : : » ' ..-• 1 1 VJ ."••" / .!•' / : / ': .••'' Stock Photo](https://c8.alamy.com/comp/RHN519/the-biological-bulletin-biology-zoology-biology-marine-biology-316-doucias-r-koikktsnx-ina-temporaria-appears-to-be-controlled-by-temperature-and-not-by-light-van-oordt-and-van-oordt-1955-but-the-spermatogenic-cycle-in-the-salamander-pictjiodon-cincreus-is-primarily-regulated-by-photoperiod-werner-1969-the-4-i-r2-52-50-100-200-300-r2-hlm-1-i-a-f-l-l-l-a-i-1-i-1-1-r-i-l-i-x-1-f-1-i-i-gt-i-n-mv-i-i-l-1-1-vj-quotquot-!-RHN519.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 316 DOUCI.AS R. kOI'.KKTSnX ]ina temporaria appears to be controlled by temperature and not by light (van Oordt and van Oordt, 1955) ; but the spermatogenic cycle in the salamander PIctJiodon cincreus is primarily regulated by photoperiod (Werner, 1969). The .4 I— r.2 (52°). 50 100 200 300 r.2 — / HLM / ' 1 I A f (l L L A i 1 . I / 1 1 r i / • l /' -: :. i / — x 1 :' '. f 1 I / ,' i ': ' / > i ' N ,'' ? ;-; MV; / ./ ;i / / - i l • : : » ' ..-• 1 1 VJ ."••" / .!•' / : / ': .••'' Stock Photo")
RMRHN519–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 316 DOUCI.AS R. kOI'.KKTSnX ]ina temporaria appears to be controlled by temperature and not by light (van Oordt and van Oordt, 1955) ; but the spermatogenic cycle in the salamander PIctJiodon cincreus is primarily regulated by photoperiod (Werner, 1969). The .4 I— r.2 (52°). 50 100 200 300 r.2 — / HLM / ' 1 I A f (l L L A i 1 . I / 1 1 r i / • l /' -: :. i / — x 1 :' '. f 1 I / ,' i ': ' / > i ' N ,'' ? ;-; MV; / ./ ;i / / - i l • : : » ' ..-• 1 1 VJ ."••" / .!•' / : / ': .••''
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 102 THOMAS L. BELTINGER 100. - 100% - 75% 50% - 25% i . 1 -^i ••—i •—"n <• r— -r— —1 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 TIME (hrs) FIGURE 3. Median hourly activity of 8 bluegill exposed to a LD 15:9 photoperiod for three days and constant light for 4 days. The spaces between pairs of diagonal lines in the abcissa indicate when darkness would have occurred under the LD 15: 9 photoperiod regime. Activity patterns The influence of simulated cliel changes in light intensity on blu Stock Photo](https://c8.alamy.com/comp/RHN83B/the-biological-bulletin-biology-zoology-biology-marine-biology-102-thomas-l-beltinger-100-100-75-50-25-i-1-i-i-quotn-lt-r-r-1-1200-0000-1200-0000-1200-0000-1200-0000-1200-0000-1200-0000-1200-0000-1200-time-hrs-figure-3-median-hourly-activity-of-8-bluegill-exposed-to-a-ld-159-photoperiod-for-three-days-and-constant-light-for-4-days-the-spaces-between-pairs-of-diagonal-lines-in-the-abcissa-indicate-when-darkness-would-have-occurred-under-the-ld-15-9-photoperiod-regime-activity-patterns-the-influence-of-simulated-cliel-changes-in-light-intensity-on-blu-RHN83B.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 102 THOMAS L. BELTINGER 100. - 100% - 75% 50% - 25% i . 1 -^i ••—i •—"n <• r— -r— —1 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 TIME (hrs) FIGURE 3. Median hourly activity of 8 bluegill exposed to a LD 15:9 photoperiod for three days and constant light for 4 days. The spaces between pairs of diagonal lines in the abcissa indicate when darkness would have occurred under the LD 15: 9 photoperiod regime. Activity patterns The influence of simulated cliel changes in light intensity on blu Stock Photo")
RMRHN83B–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 102 THOMAS L. BELTINGER 100. - 100% - 75% 50% - 25% i . 1 -^i ••—i •—"n <• r— -r— —1 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 0000 1200 TIME (hrs) FIGURE 3. Median hourly activity of 8 bluegill exposed to a LD 15:9 photoperiod for three days and constant light for 4 days. The spaces between pairs of diagonal lines in the abcissa indicate when darkness would have occurred under the LD 15: 9 photoperiod regime. Activity patterns The influence of simulated cliel changes in light intensity on blu
RMRHN6D5–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND CHILLING 149 IOO-, 80- Jeo- o Q. o> o 20-. 8- 7- 6- 5- O o 3- O) £ Q. u> a •*- o a> o a: 2- 10 T I 12 13 Hours Light per Day I 14 -• —14 hours -O—13 hours. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952
RMRHNTYY–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 100 WILLIAM L. ENGELS -15 Dates by which beak became black A- None (2) F- Feb. 12,19, Mar. 19 G - Dec. 7, Feb. 19 H- Jan. 29, Feb. 2,12 a o IT LLl a. o 36° N -13 -12. AUG 1 SEPTEMBER 1 OCTOBER NOVEMBER DEC FIGURE 4. Experiments to determine length of photoperiod, and duration of treatment, which may release bobolinks from photorefractoriness during October and November. On October 2 ten birds were removed, from the natural day-lengths (including civil twilight) of Lat. 36° N., to constant daily photoperiods of different leng
RMRHN9N2–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 4 6 8 10. 12 HOURS AFTER LIGHT ON 14 .08 . 4 6 8 10 12 HOURS AFTER LIGHT ON 14 16 FIGURE 7. A. Feeding. B. Oviposition. Feeding and oviposition activity observed under 4 temperature-photoperiod regimens in 40 pairs of Oncofcltns per condition. Points represent the means of values taken over a 10-day period. Note that in all groups oviposition reached maximum 8 hours after light on while feeding reached maximum 16 hours after light on (4 hours after light off for 12L-12D regimens). small transitory rise lasting about two hou
RMRHE0XC–. Bonner zoologische Beiträge : Herausgeber: Zoologisches Forschungsinstitut und Museum Alexander Koenig, Bonn. Biology; Zoology. Heft 3—4 30/1979 Ecology and Range of Rousettus 263. Fig. 25: (a) Diurnal heart rate in 5 adult Rousettus aegyptiacus measured by telemetry (acclimation at 30^ C, body mass 145 g) at half hourly intervals for at least 5 days. Photoperiod 13 L: 11 D, 10 lx : 1 mix, L 07.00—20.00. Adapted from Noll 1979. (b) Relation of resting heart rate (RHR) to ambient temperature (Ta) in warm acclimated bats (acclimation at 30° C, body mass 137 g). The equation of the least square
RMRHN2CT–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 8 12 18 8 10 12 18 8 12 18 14.5° 18.0° 24.0° PHOTOPERIOD/ TEMPERATURE. PHOTOPERIOD/TEMPERATURE SUBITANEOUS DIAPAUSE NON-VIABLE SUBITANEOUS DIAPAUSE NON-VIABLE FIGURE 2. Subitaneous, diapause, and non-viable egg production (percent) by females reared under 8L-16D, 10L-14D, 12L-12D, or 18L-6D at 14.5°C, 18.0°C, or 24.0°C (±1.0°C). a) Vineyard Sound and Delaware Bay, b) Beaufort and Fort Pierce. Data for Vineyard Sound from Marcus (1980a, 1982b). consistently produced by these females. Females that were collected from the field
RMRHN15R–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD1SM IN AN OL1GOCHAETE 113 u T> O CL 03 L X (D to 100 50 A) LD = 6ilB T=20 t .« B) LD = 6,18 T=20 °C A) LO = 12,12 T=20 t * B) LO = 12,12 T=20 °C. 14 21 28 t I me (d) 35 42 Figure 1. Examples for the time course of switching from the vege- tative to the bisexual mode of reproduction induced by the photoperiod in Sty/aria lacusiris. Vegetatively reproducing worms from the field were exposed to short-day conditions of either LD = 12:12 or LD = 6: 18 at day 0 in the figure; A = Weddel 1985, B = Ilmenau 1986 popula-
RMRHN8WG–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 266 RAYMOND G. STROSS 100 * 80 Q 8 60 cc 00 CD co 40 2 20 10 •+• i LEGEND: + = 1/20 ml • = 1/20ml-1/4 LIGHT *= 3/20 o= 5/20 - = 45°N - = 7I°N INTENSITY I 1 0. 4 8 12 16 HOURS OF LIGHT/24 HOURS 20 22 24 FIGURE 1. Reproductive shift of Daphnia middendorffiana in response to daylength and culture density. First and second-generation young born in constant light and transferred to photoperiod indicated. Photoperiod response of winter diapausing population of D. pulex at 45° N is shown for comparison. All experiments at 12° C. St
RMRHMMEW–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 70 FARMER, FOLLETT, KING AND MORTON 1.8 r 1.6 1.4 C 1-2 g o O o o> i.o 0.8 0.6 -. Begin 20L 4D o o o o 8 8 o 10 20 30 40 50 Days FIGURE 1. Ovarian weights (W) of first-year white-crowned sparrows as a function of time after a change in daily photoperiod from 8 (8L 16D) to 20 hours (20L 4D). Closed circles represent birds subjected to 20L 4D; open circles represent birds continued on 8L 16D. natural conditions of temperature and photoperiod (Table I; also King et al., in press). Migrating females taken in Pullman in early
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION IN HARMOTHOE IMBKICATA 53 00 c 'S o eo u 100 -, 80- 60- 40- 20- 0-. •—LD16:8 control o—LD8:16 control . LD8: ,„""">"«' . LD8:16™ <'•""« o—LD8:16 donor x—LD16:8 donor •B-B(n=S) u, 6 c3 a rt 2! 2 S Date Figure 2. Cumulative percentage of spawning female Harmothoe imhricata after exposure to various treatments at 10°C. LD16:8 control, females maintained in long-day photoperiod (LD16:8); LD8:16 control, females maintained in short-day photoperiod (LD8:16): LD8:16PM|LD168'. females Stock Photo](https://c8.alamy.com/comp/RHKNKM/the-biological-bulletin-biology-zoology-biology-marine-biology-reproduction-in-harmothoe-imbkicata-53-00-c-s-o-eo-u-100-80-60-40-20-0-ld168-control-old816-control-ld8-quotquotquotgtquot-ld816-ltquotquot-old816-donor-xld168-donor-b-bn=s-u-6-c3-a-rt-2!-2-s-date-figure-2-cumulative-percentage-of-spawning-female-harmothoe-imhricata-after-exposure-to-various-treatments-at-10c-ld168-control-females-maintained-in-long-day-photoperiod-ld168-ld816-control-females-maintained-in-short-day-photoperiod-ld816-ld816pmld168-females-RHKNKM.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION IN HARMOTHOE IMBKICATA 53 00 c 'S o eo u 100 -, 80- 60- 40- 20- 0-. •—LD16:8 control o—LD8:16 control . LD8: ,„""">"«' . LD8:16™ <'•""« o—LD8:16 donor x—LD16:8 donor •B-B(n=S) u, 6 c3 a rt 2! 2 S Date Figure 2. Cumulative percentage of spawning female Harmothoe imhricata after exposure to various treatments at 10°C. LD16:8 control, females maintained in long-day photoperiod (LD16:8); LD8:16 control, females maintained in short-day photoperiod (LD8:16): LD8:16PM|LD168'. females Stock Photo")
RMRHKNKM–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. REPRODUCTION IN HARMOTHOE IMBKICATA 53 00 c 'S o eo u 100 -, 80- 60- 40- 20- 0-. •—LD16:8 control o—LD8:16 control . LD8: ,„""">"«' . LD8:16™ <'•""« o—LD8:16 donor x—LD16:8 donor •B-B(n=S) u, 6 c3 a rt 2! 2 S Date Figure 2. Cumulative percentage of spawning female Harmothoe imhricata after exposure to various treatments at 10°C. LD16:8 control, females maintained in long-day photoperiod (LD16:8); LD8:16 control, females maintained in short-day photoperiod (LD8:16): LD8:16PM|LD168'. females
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RECRUDESCENCE OF BOBOLINK TESTES 259 250 100 50 25 10 5 1.0 en Ld t- CO UJ. c/> a °m ' o 18 hr p • l7 " 2 5h — ^/ • Q 16 A A | ni t ia I 0 10 20 30 40 50 60 1 i I i i i i i | i i i i DAYS OF LONG PHOTOPERIOD (p) NOV. i DEC. i JAN FIGURE 2. Recrudescence of bobolink testes, as indicated by weight, when exposed in early November to photoperiods of 15, 16, 17 and 18 hours. Lines indicate k values of 0.09, 0.07 and 0.04 (see text). already developed the black beak pigmentation indicative of the production of mal Stock Photo](https://c8.alamy.com/comp/RHKW62/the-biological-bulletin-biology-zoology-biology-marine-biology-recrudescence-of-bobolink-testes-259-250-100-50-25-10-5-10-en-ld-t-co-uj-cgt-a-m-o-18-hr-p-l7-quot-2-5h-q-16-a-a-ni-t-ia-i-0-10-20-30-40-50-60-1-i-i-i-i-i-i-i-i-i-i-i-days-of-long-photoperiod-p-nov-i-dec-i-jan-figure-2-recrudescence-of-bobolink-testes-as-indicated-by-weight-when-exposed-in-early-november-to-photoperiods-of-15-16-17-and-18-hours-lines-indicate-k-values-of-009-007-and-004-see-text-already-developed-the-black-beak-pigmentation-indicative-of-the-production-of-mal-RHKW62.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RECRUDESCENCE OF BOBOLINK TESTES 259 250 100 50 25 10 5 1.0 en Ld t- CO UJ. c/> a °m ' o 18 hr p • l7 " 2 5h — ^/ • Q 16 A A | ni t ia I 0 10 20 30 40 50 60 1 i I i i i i i | i i i i DAYS OF LONG PHOTOPERIOD (p) NOV. i DEC. i JAN FIGURE 2. Recrudescence of bobolink testes, as indicated by weight, when exposed in early November to photoperiods of 15, 16, 17 and 18 hours. Lines indicate k values of 0.09, 0.07 and 0.04 (see text). already developed the black beak pigmentation indicative of the production of mal Stock Photo")
RMRHKW62–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. RECRUDESCENCE OF BOBOLINK TESTES 259 250 100 50 25 10 5 1.0 en Ld t- CO UJ. c/> a °m ' o 18 hr p • l7 " 2 5h — ^/ • Q 16 A A | ni t ia I 0 10 20 30 40 50 60 1 i I i i i i i | i i i i DAYS OF LONG PHOTOPERIOD (p) NOV. i DEC. i JAN FIGURE 2. Recrudescence of bobolink testes, as indicated by weight, when exposed in early November to photoperiods of 15, 16, 17 and 18 hours. Lines indicate k values of 0.09, 0.07 and 0.04 (see text). already developed the black beak pigmentation indicative of the production of mal
![. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 258 WILLIAM L. ENGELS 100 50 25 10 5 2.5 1.0 0.5 o Immature • Adult + Age Uncertain x "Spring-caught" CO UJ •|- CO LJ o - CO h- X CD 8 8 o • • o. o o o 0 25 i 50 '75 100 i 125 i SEPT. OCT. DAYS OF 14-HR. PHOTOPERIOD NOV. | DEC. | JAN. | FEB. | MAR. FIGURE 1. Recrudescence of bobolink testes, as indicated by weight, when exposed to 14-hour photoperiods beginning in early November. Sloping line indicates a k value of 0.04 beginning at day 80. The birds were killed by decapitation, the testes removed and fixed in Hell Stock Photo](https://c8.alamy.com/comp/RHKW6C/the-biological-bulletin-biology-zoology-biology-marine-biology-258-william-l-engels-100-50-25-10-5-25-10-05-o-immature-adult-age-uncertain-x-quotspring-caughtquot-co-uj-co-lj-o-co-h-x-cd-8-8-o-o-o-o-o-0-25-i-50-75-100-i-125-i-sept-oct-days-of-14-hr-photoperiod-nov-dec-jan-feb-mar-figure-1-recrudescence-of-bobolink-testes-as-indicated-by-weight-when-exposed-to-14-hour-photoperiods-beginning-in-early-november-sloping-line-indicates-a-k-value-of-004-beginning-at-day-80-the-birds-were-killed-by-decapitation-the-testes-removed-and-fixed-in-hell-RHKW6C.jpg ". The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 258 WILLIAM L. ENGELS 100 50 25 10 5 2.5 1.0 0.5 o Immature • Adult + Age Uncertain x "Spring-caught" CO UJ •|- CO LJ o - CO h- X CD 8 8 o • • o. o o o 0 25 i 50 '75 100 i 125 i SEPT. OCT. DAYS OF 14-HR. PHOTOPERIOD NOV. | DEC. | JAN. | FEB. | MAR. FIGURE 1. Recrudescence of bobolink testes, as indicated by weight, when exposed to 14-hour photoperiods beginning in early November. Sloping line indicates a k value of 0.04 beginning at day 80. The birds were killed by decapitation, the testes removed and fixed in Hell Stock Photo")
RMRHKW6C–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 258 WILLIAM L. ENGELS 100 50 25 10 5 2.5 1.0 0.5 o Immature • Adult + Age Uncertain x "Spring-caught" CO UJ •|- CO LJ o - CO h- X CD 8 8 o • • o. o o o 0 25 i 50 '75 100 i 125 i SEPT. OCT. DAYS OF 14-HR. PHOTOPERIOD NOV. | DEC. | JAN. | FEB. | MAR. FIGURE 1. Recrudescence of bobolink testes, as indicated by weight, when exposed to 14-hour photoperiods beginning in early November. Sloping line indicates a k value of 0.04 beginning at day 80. The birds were killed by decapitation, the testes removed and fixed in Hell
RMRHMC9W–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 8 9 10 11 12 13 14 15 16 17 18 3°C 8°C. 8 9 10 11 12 13 14 15 16 17 18 Daylength (h) Date Feb 1 10 21 Mar 6 18 29 Apr 10 20 May 5 20 Daylight (h) Temp (°C) 10 10.5 11 333 11.5 12 12.5 468 13 13.5 10 11 14 14.5 13 18 Figure 3. Three patterns of springtime diapause responses under varying combinations of photoperiod and temperature. (A) Strict critical-photoperiod response with thermal effect. (B) Critical-photoperiod response with a graded transition from 100% non-diapause to 100% diapause covering a photoperiod range of abou
RMRHMPDD–. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. PHOTOPERIOD AND DAILY RHYTHM 77 30 25 2.0 I 5 3.0 2.5 LJ CO 2.0 Q LJ CO QC 1.5 u CL 0 L o Ld Q h- 3.0 2.5 1.5 3.0 25 2 0 I 5 CONTROL O. NORMAL CONTROL O O O O O 18-HOUR LIGHT O O O O O o- 6-HOUR LIGHT O O I 2 3456 DAYS O O O 7 8 9 10 FIGURE 2. The responses of the magnitude of the dispersed phase of the chromatophore rhythm in the four groups of the second series of experiments. The white and black blocks beneath each curve have the same significance as in Figure 1.. Please note that these images are extracted from scanned
RMRD0DPE–. Day length and crop yields. Plants; Crop yields; Plant photoperiodism. r«r Pyrethrum produces flowers, which are the source of insect powder, only when grown in localities where the photoperiods are long. Under short photoperiods the plants remain as rosettes. vail in any given region arc as important as moisture and soil fertility in determining the specific behavior and economic value of varieties which it may be desired to grow. Although the length of photoperiod in any particular locality changes from day to day throughout the season, the photoperiods of corresponding days in successive
RMRCM6FX–. Elements of ecology. Ecology. Seasonal Periodicity 225 cereals, and timothy. If such plants are grown under daylengths shorter than the critical photoperiod, stems tend to be shorter and flowering is suppressed (Fig. 6.21). Other effects may also be pro- duced in the plant, as illustrated by long-day potatoes which produce the best tubers when daylength is below the optimum for shoot growth.. Fig. 6.21. Control of flowering and of vegetative growth by daylength in timothy, a typical long-day plant. The daily exposures (in hours) to light are indicated on each container; C = natural daylength
RMRCW9P2–. The developmental ecology of Mantispa uhleri Banks (Neuroptera: Mantispidae). Mantispa uhleri; Insects; Mantispa uhleri; Insects. Egg Sac Penetration 35 nopsis sp. collected from beneath the loose bark of Osage orange trees and prepared as detailed for Experiment 3 (p. 28). We used adult crab spiders, Philodromus vulgaris Hentz, taken from the same habitats as the Agelenopsis sacs. All three spider species were collected in the vicinity of Urbana, Illinois. All experiments were carried out at a temperature of 25°C with 80% relative humidity and a photoperiod of L:D = 16:8. Frequencies were a
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