Literature for 1914 on the behavior of the lower invertebrates (original) (raw)
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Helgoländer Wissenschaftliche Meeresuntersuchungen, 1978
Photo-reception and sensitivity to light were studied in two Japanese hagfishes, Eptatretus burgeri living in shallow water and Paramyxi.ne atami living in water of about 100 m depth. Both species responded to general illumination by first moving the tail or head and then by swimming. Local illumination revealed that regions most sensitive to light were the skin of the tail in both species and a line of unpigmented skin running down the back of E. burgeri. The light sensitivity of the lensless eyes, which are situated below the skin, was very weak in both species. P. atami showed shorter reaction time to light than E. burgeri. No change in Skin colour was iMuced either by almost complete hypophysectomy or by continuous illumination against a white ba&ground. Underwater observations with SCUBA revealed that free moving E. burgeri responded well to illumination uncovered during the night, but the ones buried in mud, with only the heads uncovered did not. water of about 100 m depth (Strahan & Honma, 1960). Thus their natural habitats are quite different from each other, and therefore, some differences in photoreception and sensitivity are to be expected between these two species. In this investigation, studies were carried out to determine: (a) the mode of reaction of Eptatretus and Pararnyxine to general illumination, (b) light sensitivity of their eyes and skin, (c) the dermal light sensitivity of the two Japanese species as compared to Myxine, (d) the light intensity preferences in Eptatretus and Para
The Selection of Random Movements as a Factor in Phototaxis
Psychological Bulletin, 1906
Contri6utions from the Zoo/ogictif L a h w o f u~~, <!f fhLz ~' t t i w~s i f i~ q. ,llich('w~t, ,\-(J, 91. ' I I o m i E i s r m , W. Die biz jetzt bekannten Arten aus der Familie der Re-~I) A K W I S , C. The Formation of Vegetable Mould through the Action of 'GRABEX, V. Grundlinien zur Erforschung des Helligskeits und Farben
High light exposure leads to a sign change in gravitaxis of the flagellate Euglena gracilis
2002
The unicellular flagellate Euglena gracilis orients itself in the water column by means of pronounced phototaxis and gravitaxis. The antagonism of phototaxis and gravitaxis brings the cells in a position in the water column providing them with optimal light conditions for their photosynthetic apparatus (about 30 Wm -2 ). Long exposure to solar or artificial radiation induces a loss of the negative gravitactic orientation in Euglena gracilis or very often a pronounced, persistent (> 4 h) sign change in gravitaxis. The effects on gravitaxis are exclusively due to UV and intensive blue light as experiments with different light qualities revealed. This phenomenon is not caused by the phototaxis photoreceptor or chloroplast processes, because also the colorless and blind (no photoreceptor) Euglena gracilis 1f mutant and Astasia longa reverse the sign of gravitaxis upon strong radiation. The sign change is oxygen-dependent, because gravitaxis is not affected in oxygen free medium (in wild type Euglena gracilis, as well as in the 1f mutant and Astasia longa). This indicates the involvement of oxygen radicals as a trigger of gravitaxis sign reversal. As the destruction of the photoreceptor molecules by light leads to a loss of phototaxis, the switch from negative to positive gravitaxis might be an adaptation mechanism of the cells to escape from deleterious radiation even after loss of the ability to perceive the light direction.
Fundamental questions and concepts about photoreception and the case of Euglena gracilis
Integr. Biol., 2012
This review describes the universal structural, behavioral and physiological features necessary for the proper functioning of photoreceptor systems in algae, and how they have been investigated by means of different analytical techniques such as for example electron microscopy and Fourier analysis, microspectroscopy, digital fluorescence microscopy, two photons FLIM. The insight of the photoreceptive response mechanism is explained using the unicellular alga Euglena gracilis, in which the different structural, behavioral and physiological features combine to achieve a concerted, efficient response to light stimuli.
Light and the Behavior of Organisms
Science, 1911
of speculation in guiding and unifying experimental work; on the other he saw the necessity of founding philosophical speculation on experimental facts. This broad view resulted in much comparative work especially in physiology and psychology, work which had a direct bearing on the nature of psychic processes as well as on the nature of physiological activity. Miiller worked on the higher animals almost exclusively. His aim was to analyze the phenomena of life as he found them in these organisms. His followers, Wohler, Liebig, Helmholtz, du Bois-Reymond, Lotze, Weber, Fechner and others, perpetuated this aim, but they did not retain his breadth of spirit. Some confined their investigations to the chemical side of physiology, others to the physical side, and still others to pure psychology. The question as to the origin and evolution of vital phenomena, especially psychic phenomena, was not 8 HISTORICAL REVIEW 49 not a primitive condition, but a product of development." " To a change leading away from the optimum (in either plus or minus direction)" the organism responds in such a way as to tend to return to the optimum. " Thus are produced the so-called positive and negative reactions." The essential characteristics in behavior, as analyzed by Jennings, are clearly set forth in the following quotations (1906, pp. 283-292). Internal factors: ** Activity does not require present external stimulation.. .. Activity may change without external cause.. .. Changes in activity depend on changes in physiological states.. .. Reactions to external agents depend on physiological states.. .. The physiological state may be changed by progressive internal processes, particularly those of metabolism.. .. The physiological state may be changed by the action of external agents.. .. The physiological state may be changed by the activity of the organism.. .. External agents cause reaction by changing the physiological state of the organism.. .. The behavior of the organism at any moment depends upon its physiological state at that moment.. .. Physiological states change in accordance with certain laws.. .. The resolution of one physiological state into another becomes easier and more rapid after it has taken place a number of times." Different factors on which behavior depends : "We have seen that the behavior of the organism at a given moment depends on its physiological state, and that it therefore secondarily depends upon all the factors upon which the physiological state depends. Hence we cannot expect the behavior to be determined alone by the present external stimulus, as is sometimes maintained, for this is only one factor in determining the physiological state. The behavior at a given moment may depend on the following factors, since these all affect the physiological state of the organism : " I. The present external stimulus. ''2. Former stimuli.
Journal of Eukaryotic …, 1986
ABSTRAn. Ekhavioral responses to light at different oxygen tensions were studied in the ciliate Lox& striatus. In the absence of Ox it does not react to light. In the presence of 0, it reacts to light as if the p0, had been further incrtasod, with the induction of positive geotaxif a transient phobic response, and finally with a permanent kinetic response (increased swimming velocity and a decnastd rate of tumbling). Cells treated with cyanide behave as cells in an anoxic environment and do not react to light. It is concluded that the light response is due to the photochemical produdon of oxygen radicals and that the sensory rcccptors for O2 and for light are identical. The thru types of behavioral response (gmtaxis, transient, and kinetic responses) are discussed in terms of their adaptive significance for the orientation of Luxodes in the natural environment.
Phototaxis in the flagellates, Euglena gracilis and Ochromonas danica
Archives of Microbiology, 1981
Oriented movement with respect to laterally impinging white light of the flagellates Euglena gracilis and Ochromonas danica has been analyzed in an individual cell study with a microvideographic technique. Using the deviation of track segments (in given time intervals of 1 s) from the light direction as raw data allowed a computer based analysis of the direction distribution. A number of statistical methods employed to test the significance of the obtained results demonstrated an obvious phototactic orientation in Ochromonas which was positive (toward the light source) in low illuminance (1.25 lx = 5.3 • 10-3 Wm-z) and negative in higher illuminance (> 12.5 lx = 5.3 x 10 -z Wan-z). Since in this flagellate the threshold for negative phototaxis is much lower than that for the step-up photophobic response, the hypothesis that negative phototaxis may be brought about by repetitive step-up phobic responses can be rejected for at least this organism. In Euglena positive phototaxis was observed in _< 50 lx (= 0.21 Wm-2), while an illuminance of 500 lx (= 2.1 Wm 2) caused a negative phototaxis.
Eye/Photophore Coordination and Light-following in Krill, Euphausia Superba
Journal of Experimental Biology
Eight of the 10 photophores of the Antarctic krill, Euphausia superba, are located at the ends of muscular stalks and exhibit coordinated orientation responses to incident white light; light emitted from the photophores is directed away from the incident light. Moreover, eye rotation occurs synchronously with photophore movement. Immobilization of one or both eyes eliminated the photophore light-following response in 40% of the trials, but in the remaining 60%, photophores continued to exhibit oriented, but less stable responses. In the presence of a stationary light source the eyes could be passively rotated without affecting photophore position. Furthermore, eye removal or covering the head with an opaque hood eliminated coordinated photophore movement. We conclude that vision is necessary for light-following responses by the photophores. In addition, the control signal for that movement is CNS-derived, may occur spontaneously or may be lightinduced, and appears to be accompanied ...