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BjÖRnberg, T. K. S., & Wilbur, K. M. (1968). Copepod Phototaxis And Vertical Migration Influenced By Xanthene Dyes. The Biological Bulletin, 134(3), 398–410.
Abstract: 1. Phototaxis of the copepods Paracalanus crassirostris, Calanopia americana, and Acartia lillijeborgi has been measured by determining the percentage of a population moving toward or away from a point source of light per unit time. Quantitative differences in positive phototaxis were found between the species. Photopositive responses differed during the day and night in Acartia but not in Paracalanus and Calanopia.
2. Rhodamine B (8.4 x 10-6 M) brought about the following effects: (a) Locomotor activity was reversibly inhibited in all species. (b) Photopositive responses were increased in Calanopia and Acartia but decreased in Paracalanus. (c) The difference between day and night responses to a point source of light was abolished in Acartia and induced in Calanopia. (d) Somersaulting was induced in Paracalanus but not in the other species.
3. Pyronine B (8.4 x 10-6 M) also decreased locomotor activity. Fluorescein sodium (1.1 x 10-5 M and 1.1 x 10-4 M) was without significant effect.
4. Paracalanus, Calanopia, and Acartia exhibited characteristically distinct diurnal migratory cycles in vertical cylinders, which correlated well with behavior in natural waters. Calanopia and Acartia migrated to the bottom in the daylight whereas Paracalanus and young forms of Acartia were widely distributed vertically during daylight. Specimens of Calanopia and Acartia kept in the dark did not migrate.
5. The effects of rhodamine B (8.4 x 10-6 M) on vertical migration depended upon species, developmental stage, and time of day. In general, rhodamine increased the concentration of animals at the surface at night and at the bottom in daylight. Fluorescein sodium (1.1 x 10-5 M and 1.1 x 10-4 M) had little effect on vertical migration.
6. The effectiveness of rhodamine B and pyronine B is probably related to the presence of diethylamine groups lacking in fluorescein.
Hastings, J. W., & B. M. Sweeney. (1958). A persistent diurnal rhythm of luminescence in Ganyaulax Polyedra. The Biological Bulletin, 115(3), 440–458.
Abstract: 1. The characteristics of a persistent diurnal rhythm of luminescence in the dinoflagellate Gonyaulax polyedra are described.
2. The light emission upon stimulation, from cultures which are kept in alternating light and dark periods of 12 hours each (= LD), is 40 to 60 times greater during the dark period than during the light period. If LD cultures are placed in continuous dim light (100 foot-candles) a diurnal rhythm of luminescence persists. If LD cultures are placed in continuous bright light (> 1500 foot-candles) the rhythm is damped, and no fluctuations occur in the amount of light emitted.
3. The occurrence of rhythmicity is not dependent upon prior exposure to LD conditions. Cultures which have been grown in bright light for as long as one year show a diurnal rhythm when placed in constant dim light or darkness. Cultures kept in alternating light and dark cycles which are greater or less than 24 hours similarly show a diurnal rhythm when returned to constant dim light or darkness. “Training” or “memory” is therefore not involved.
4. The rhythm can be entrained by light-dark cycles which are different from 24 hours. The period of the luminescence rhythm corresponds to light-dark cycles which have periods ranging between 12 and 32 hours.
5. The period of the rhythm is always close to 24 hours when the cells are kept under constant conditions, but it varies slightly depending upon the temperature and light intensity.
6. The phase of the rhythm under constant conditions is related to the time at which the previous lightand dark periods occurred. Moreover, the phase may be shifted by interposing a non-repeated exposure to a different light intensity. The number of hours by which the phase is shifted in such an experiment is dependent upon the intensity and duration of the light treatment, and the time in the cycle when it is administered.
7. Exhaustive mechanical stimulation does not alter the phase of the rhythm.
8. When cultures having different phases were mixed, no evidence was found which would indicate that there was any interaction between them.
9. The evidence presented indicates that the diurnal rhythmicity is the consequence of a basic oscillatory mechanism which is inherent to the cell.
Weiss, C. M. (1947). The effect of illumination and stage of tide on the attachment of barnacle cyprids. The Biological Bulletin, 93(3), 240–249.
Abstract: 1. The cyprid larvae of Balanus improvisus were found to settle in a diurnal rhythm with maximum numbers attaching during daylight hours.
2. No consistent pattern of vertical distribution of the cyprids was found.
3. The normal diurnal cycle in rate of attachment of barnacle cyprids was nullified by the use of artificial illumination over the collecting surfaces at night.
4. The magnitude of the cyprid collection on the artificially illuminated surfaces was equal to the collection on the sun-illuminated surfaces in daylight.
5. The intensity of artificial light necessary to produce large cyprid attachments at night was of an order as low as 1 footcandle at the water surface.
6. No correlation was found between the quantity of artificial light at night and the numbers of cyprids attached.
7. The highest rate of cyprid attachment relative to the phase of the tide was found to occur when the waters of upper Biscayne Bay were sampled at the collecting station. This body of water reached the sampling station at low tide and was characterized by a high cyprid population.