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Comparative studies of luminescence in copepods and other pelagic marine animals
678
Oceanographic Abstracts
essentially an underwater gilder that utilizes buoyancy control as a means of propulsion. The vehicle described is 12 feet in length with a maximum range of about 26 nautical miles and a depth capability of 1,000 feet. Performance increases are predicted for various sizes of vehicles using several types of gas generators. CARSON D. L. 1962. Diagnosis and cure of erratic velocity distributions in sonar projector arrays.
J. dcous. Soc. Amer. 34(9): Pt. l : 1191-1196. Often, well-designed arrays of electroacoustic transducer elements radiating into water exhibit erratic behavior in the transmission-frequency band such that the distribution of magnitude and phase of element velocities across the array appears to be independent of the d.:stribution of electrical driving voltages or currents. Even at low drive levels, directivity patterns and source levels deteriorate, and some elements may even experience structural failure because of excessive motion of the radiating face. The cause of this unsatisfactory behaviour is diagnosed and relatively simple curative measures are presented. In particular, the cure requires a separate tuning reactor for each element. The reactors are identical, but must be selected by a new criterion. If modular drive is used, the drivers must have a very low or a very high internal impedance, depending on circumstances.
CHALUPNIK,J. D. and P. S. GREEN 1962. A Doppler-shift ocean-current meter. Marine Sciences Instrumentation, Inst. Soc. Amer. Plenum Press, N.Y. I : 194-199. An ocean-current meter utilizing the Doppler effect has been developed and tested. With this device a collimated beam of ultrasonic energy is projected into the water and a volume reverberation signal received. The meter detects the difference between the transmitted and received frequencies, this difference being proportional to the speed of the water past the meter, q[he device can be made to indicate sense as well as flow rate. CHAPMAN, R. P. and J. H. HARRIS 1962. Surface backscattering strengths measured with explosive sound sources. J. Acous. Soc. Amer. 34(10): 1952-1597. The scattering strength of the sea surface was measured for a range of wind velocities, grazing angles, and frequencies, in octave bands in the frequency range from 400 to 6400 cps. An empirical equation was obtained relating the scattering strength of the sea surface to the above variables, for grazing angles below 40 °. At low grazing angles, scattering of sound from a subsurface layer of isotropic scatterers, probably of biological origin, frequently masked the reverberation due to scattering from surface roughness. For a given wind speed, the scattering strengths measured in this study at grazing angles below 20 ° were appreciably less than those obtained by other observers at higher frequencies. At higher grazing angles, of the order of 400, there was little systematic difference between the measurements made at high and low frequencies. CHAVE, K. E. 1962. Processes of carbonate sedimentation. The Environmental Chemistry of Marine Sediments. Proc. Syrup., Univ. R. I. Jan. 13, 1962, Occ. Papers, Narragansett Mar. Lab. No. 1 : 77-85. Marine geologists have described many of the characteristics of modern carbonate sediments--their distribution, thickness, and biological and mineralogical make-up, q-he processes of carbonate sedimentation are not well understood. There is some evidence that the biological and mineralogical make-up of the sediments is affected by physical and chemical destructive forces on or just below the sea floor, but the quantitative significance of these processes is unknown. The processes controlling rates of sedimentation and areal extent of carbonate deposits are not well understood. It is suggested that, if carbonate sedimentation could be studied over a wide range of environmental conditions, some progress could be made in understanding these processes. ~ E , G. L., R. J. CONOVER, C. N. DAVID and J. A. C. NICOL 1962. Comparative studies of luminescence in copepods and other pelagic marine animals. J. Mar, Biol. Assoc. U.K. 42(3): 541-564. A comparative study of the following luminous copepods was undertaken: Metridia lucens, M. longa,
M. princeps, Pleuromamma robusta, P. xiphias, Heterorhabdus norvegicus, H. robustus, Heterostylites longieornis, Lueieutia grandis, Hemirhabdus grimaldii, Disseta palumboi, Euaugaptilus magnus and Centraugaptilus horridus. Flashes produced by electrical stimulation (a.e. or condenser shocks) and mechanical stimulation were recorded photoelectrically. Flashes lasted from 2 to 37 sec. Latencies of some species (Metridiidae), following electrical stimulation, were very short, 7-9 msec. Intensities ranged from 0.02 × 10-5 to 14.4 × 10-stz W/s cm 2 of receptor surface at 15 cm distance (0.0045 × 10-2 ot 3-24 × 10-2jz W/cm 2 at 1 cm) (10--20°C). Luminous glands of Metridiidae, Lucicutiidae and Augaptilidae are autofluorescent; the location of the luminous glands in these families and in Heterorhabdidae is described. Two kinds of glandular cells (types 1 and 2) occur in the luminescent areas. The cells are large saccular structures containing granular or homogeneous material, and are distinguished by staining peculiarities. Cell types I and 2 open through common pores, and may be the source of luminous reactants. Some measurements of luminescence in other pelagic animals are presented, for comparison with copepods, viz. Aequorea macrodaetyla, Aeginura grimaldii (Hydromedusae), Periphylla periphylla (Scyphomedusa), Meganyctiphanes norvegiea and Aeanthephyra pelagiea (Crustacea), Myctophum punctatum (Teleostei). Our prese~lt knowledge regarding luminescence among copepods is reviewed.
Oceanographic Abstracts
essentially an underwater gilder that utilizes buoyancy control as a means of propulsion. The vehicle described is 12 feet in length with a maximum range of about 26 nautical miles and a depth capability of 1,000 feet. Performance increases are predicted for various sizes of vehicles using several types of gas generators. CARSON D. L. 1962. Diagnosis and cure of erratic velocity distributions in sonar projector arrays.
J. dcous. Soc. Amer. 34(9): Pt. l : 1191-1196. Often, well-designed arrays of electroacoustic transducer elements radiating into water exhibit erratic behavior in the transmission-frequency band such that the distribution of magnitude and phase of element velocities across the array appears to be independent of the d.:stribution of electrical driving voltages or currents. Even at low drive levels, directivity patterns and source levels deteriorate, and some elements may even experience structural failure because of excessive motion of the radiating face. The cause of this unsatisfactory behaviour is diagnosed and relatively simple curative measures are presented. In particular, the cure requires a separate tuning reactor for each element. The reactors are identical, but must be selected by a new criterion. If modular drive is used, the drivers must have a very low or a very high internal impedance, depending on circumstances.
CHALUPNIK,J. D. and P. S. GREEN 1962. A Doppler-shift ocean-current meter. Marine Sciences Instrumentation, Inst. Soc. Amer. Plenum Press, N.Y. I : 194-199. An ocean-current meter utilizing the Doppler effect has been developed and tested. With this device a collimated beam of ultrasonic energy is projected into the water and a volume reverberation signal received. The meter detects the difference between the transmitted and received frequencies, this difference being proportional to the speed of the water past the meter, q[he device can be made to indicate sense as well as flow rate. CHAPMAN, R. P. and J. H. HARRIS 1962. Surface backscattering strengths measured with explosive sound sources. J. Acous. Soc. Amer. 34(10): 1952-1597. The scattering strength of the sea surface was measured for a range of wind velocities, grazing angles, and frequencies, in octave bands in the frequency range from 400 to 6400 cps. An empirical equation was obtained relating the scattering strength of the sea surface to the above variables, for grazing angles below 40 °. At low grazing angles, scattering of sound from a subsurface layer of isotropic scatterers, probably of biological origin, frequently masked the reverberation due to scattering from surface roughness. For a given wind speed, the scattering strengths measured in this study at grazing angles below 20 ° were appreciably less than those obtained by other observers at higher frequencies. At higher grazing angles, of the order of 400, there was little systematic difference between the measurements made at high and low frequencies. CHAVE, K. E. 1962. Processes of carbonate sedimentation. The Environmental Chemistry of Marine Sediments. Proc. Syrup., Univ. R. I. Jan. 13, 1962, Occ. Papers, Narragansett Mar. Lab. No. 1 : 77-85. Marine geologists have described many of the characteristics of modern carbonate sediments--their distribution, thickness, and biological and mineralogical make-up, q-he processes of carbonate sedimentation are not well understood. There is some evidence that the biological and mineralogical make-up of the sediments is affected by physical and chemical destructive forces on or just below the sea floor, but the quantitative significance of these processes is unknown. The processes controlling rates of sedimentation and areal extent of carbonate deposits are not well understood. It is suggested that, if carbonate sedimentation could be studied over a wide range of environmental conditions, some progress could be made in understanding these processes. ~ E , G. L., R. J. CONOVER, C. N. DAVID and J. A. C. NICOL 1962. Comparative studies of luminescence in copepods and other pelagic marine animals. J. Mar, Biol. Assoc. U.K. 42(3): 541-564. A comparative study of the following luminous copepods was undertaken: Metridia lucens, M. longa,
M. princeps, Pleuromamma robusta, P. xiphias, Heterorhabdus norvegicus, H. robustus, Heterostylites longieornis, Lueieutia grandis, Hemirhabdus grimaldii, Disseta palumboi, Euaugaptilus magnus and Centraugaptilus horridus. Flashes produced by electrical stimulation (a.e. or condenser shocks) and mechanical stimulation were recorded photoelectrically. Flashes lasted from 2 to 37 sec. Latencies of some species (Metridiidae), following electrical stimulation, were very short, 7-9 msec. Intensities ranged from 0.02 × 10-5 to 14.4 × 10-stz W/s cm 2 of receptor surface at 15 cm distance (0.0045 × 10-2 ot 3-24 × 10-2jz W/cm 2 at 1 cm) (10--20°C). Luminous glands of Metridiidae, Lucicutiidae and Augaptilidae are autofluorescent; the location of the luminous glands in these families and in Heterorhabdidae is described. Two kinds of glandular cells (types 1 and 2) occur in the luminescent areas. The cells are large saccular structures containing granular or homogeneous material, and are distinguished by staining peculiarities. Cell types I and 2 open through common pores, and may be the source of luminous reactants. Some measurements of luminescence in other pelagic animals are presented, for comparison with copepods, viz. Aequorea macrodaetyla, Aeginura grimaldii (Hydromedusae), Periphylla periphylla (Scyphomedusa), Meganyctiphanes norvegiea and Aeanthephyra pelagiea (Crustacea), Myctophum punctatum (Teleostei). Our prese~lt knowledge regarding luminescence among copepods is reviewed.