Browsing by Author "Aronson, Lester R. (Lester Ralph), 1911-"
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ItemFactors influencing the spawning frequency in the female cichlid fish Tilapia macrocephala. American Museum novitates ; no. 1484(New York : American Museum of Natural History, 1951) Aronson, Lester R. (Lester Ralph), 1911- ItemFunction of forebrain and cerebellum in learning in the teleost Tilapia heudelotii macrocephala. Bulletin of the AMNH ; v. 142, article 2(New York : [American Museum of Natural History], 1969) Kaplan, Harriett, 1929-; Aronson, Lester R. (Lester Ralph), 1911-"The function of the forebrain and the cerebellum in learning in the teleost fish Tilapia heudelotii macrocephala was studied. An avoidance conditioning paradigm with light or sound as the CS and shock as the US was used. The design of the four experiments performed was: Experiment I -- operations performed prior to training; forebrain ablated in experimental subjects; sham operations performed or olfactory bulbs ablated in controls; CS was light. Experiment II -- operations performed prior to training; forebrain ablated in experimental subjects; sham operations performed on controls; CS was sound. Experiment III -- operations performed after training; subjects first underwent sham operation and then olfactory bulb ablation, or only the latter; following a period of retesting, both lobes of the forebrain were ablated; CS was sound. Experiment IV, a and b -- operations performed prior to training; body of the cerebellum ablated in experimental subjects; sham operations performed on controls; CS was light. All subjects were trained to avoid or escape from intermittent shock by swimming through a hole in a partition that divided the test tank into two equal compartments. Intact, sham, and olfactory bulb-ablated controls quickly learned to avoid the shock, and performance was stabilized soon after, with a high percentage of avoidance responses and consistently low latencies. These were achieved by the efficient intertrial behavior of the subjects, as well as by their speed and accuracy. When the forebrain was ablated prior to training, subjects took much longer to acquire the avoidance response. Even after long periods of testing, performance remained unstable, with variable latencies and fewer avoidance responses than those of the controls. When the operations were performed after training, it was found that sham operation had no effect on performance, whereas ablation of the olfactory bulbs had only a slight, transitory effect on the performance of some subjects. Ablation of the forebrain, however, resulted in marked and long-lasting deficits. Immediately after operation, avoidances dropped to a low level with a concurrent increase in the number of trials in which subjects neither avoided nor escaped. With continued testing, the performance of some subjects of Experiments I to III improved, but none reached the consistently high levels of avoidance responses and low latencies characteristic of the performance of the controls. On the other hand the performance of a few animals deteriorated in an erratic manner. Ablation of the body of the cerebellum had, at most, only a very transitory effect on equilibrium. It did, however, result in more severe deficits in the acquisition of a conditioned avoidance response than did ablation of the forebrain. Some cerebellum-ablated subjects never avoided at all, but those that did, performed at a very low level. Even escape performance was below that of a typical forebrain operate with higher latencies and fewer responses. Unlike the forebrain operates, cerebellum-ablated subjects showed no improvement with continued testing. Results are interpreted as being consistent with our hypothesis that the forebrain acts as a facilitator of behavior which is organized in other brain centers. The subsequent improvement noted in the performance of many forebrain-ablated subjects is regarded as an indication that a compensatory process is taking place in some other part of the brain. The body of the cerebellum appears to play a more essential role in the acquisition of a conditioned avoidance response and may, in fact, be directly concerned with learning processes"--P. 201. ItemMating behavior patterns in two sympatric species of xiphophorin fishes : their inheritance and significance in sexual isolation. Bulletin of the AMNH ; v. 103, article 2(New York : [American Museum of Natural History], 1954) Clark, Eugenie.; Aronson, Lester R. (Lester Ralph), 1911-; Gordon, Myron, 1899-1959. ItemOral incubation in Tilapia macrocephala. 1, Embryological studies. Bulletin of the AMNH ; v. 103, article 5(New York : [American Museum of Natural History], 1954) Shaw, Evelyn S.; Aronson, Lester R. (Lester Ralph), 1911-"Embryos of the mouthbreeding cichlid fish Tilapia macrocephala do not survive, extra-orally, in aquarium water taken from the tank in which the spawning occurred. Experiments were performed to determine the role of oral incubation in embryonic survival. The approach used was to find methods of raising the embryos extra-orally and to relate extra-oral survival with the factors of survival in the milieu of the oral cavity. To facilitate this study, a series of embryological stages were described and defined from fertilization to hatching. Certain of the more obvious microscopic changes were described in conjunction with the gross descriptions of the stages. The most effective experimental media were 40 per cent sea water and sterile aquarium water in which mean embryonic survival ranged between 80 and 85 per cent. The common factor found in these media was their capability of keeping the bacterial growth that killed the embryos to a minimum. The limited effectiveness of other experimental media, e.g., NaCl, artificial sea water, methylene blue, and lysozyme, was dependent on a balance between their toxic properties and their bactericidal (or bacteriostatic) properties. Fungus mycelia usually appeared on embryos raised extra-orally in aquarium water. However, it was demonstrated experimentally that the fungus was a secondary invader, since survival was high when embryos were raised in sterile aquarium water to which a fungus culture had been introduced. Conversely, no embryos survived when they were raised in sterile water to which a culture of bacteria had been introduced. The churning action of the mouth was found to be one of the survival factors in oral incubation. When embryos were placed in a small quantity of aquarium water in a mechanical shaker, survival rates were good. On the other hand, embryos that remained stationary while a large quantity of water flowed over them never survived. These experiments show that the slow mechanical churning of the embryos in the mouth is a factor in survival, whereas the quantity of water flowing over the embryos during respiration of the parent is not critical. The oral epithelium may secrete mucus which protects the embryos. However, experiments designed to test the protective nature of mucus were not conclusive. Special pharyngeal glands, described in this paper, may secrete a bactericidal agent. Similar glands were found in Tilapia ovalis and have been described in two other mouthbreeding cichlids, while we were unable to find them in two non-mouthbreeding species of the genus Tilapia"--P. 413. ItemOrientation and jumping behavior in the gobiid fish Bathygobius soporator. American Museum novitates ; no. 1486(New York : American Museum of Natural History, 1951) Aronson, Lester R. (Lester Ralph), 1911-; Lerner Marine Laboratory."A preliminary field study of the jumping behavior of the tide-pool gobiid fish Bathygobius soporator revealed that, except for certain unusual circumstances, these fish are so well oriented before jumping that they always land safely in a neighboring pool or in the open water. The conditions are such that the fish could not possibly see the neighboring pools before leaping. Various factors that might contribute to this orientation were examined and eliminated. These included (1) orientation to the open water, to the original outlet, or to a notch or similar configuration in the rim of the pool; (2) the position of the sun or shadows cast by the sun; (3) trial and error learning of the jumps. As a working hypothesis it is suggested that these gobies swim over the tide pools at high tide and acquire an effective memory of the general features of the topography of a limited area around the home pool which they are able to utilize when locked in their pools at low tide"--P. 20-21. ItemThe sexual behavior of Anura. 1, The normal mating pattern of Rana pipiens. Bulletin of the AMNH ; v. 80, article 5.(New York : The American Museum of Natural History, 1942) Noble, Gladwyn Kingsley, 1894-1940.; Aronson, Lester R. (Lester Ralph), 1911- ItemThe sexual behavior of Anura. 2, Neural mechanisms controlling mating in the male leopard frog, Rana pipiens. Bulletin of the AMNH ; v. 86, article 3(New York : [American Museum of Natural History], 1945) Aronson, Lester R. (Lester Ralph), 1911-; Noble, Gladwyn Kingsley, 1894-1940. ItemThe sexual behavior of Anura. 5, Oviposition in the green frog, Rana clamitans, and the bull frog, Rana catesbeiana. American Museum novitates ; no. 1224(New York City : The American Museum of Natural History, 1943) Aronson, Lester R. (Lester Ralph), 1911-"The oviposition behavior of the green frog, Rana clamitans, and the bull frog, Rana catesbeiana, induced by injections of homoplastic anterior pituitaries and witnessed in a laboratory habitat, is described. A possible course of evolution from the plinth type of spawning to the surface film type is discussed"--P. 6. ItemThe sexual behavior of Anura. 6, The mating pattern of Bufo americanus, Bufo fowleri, and Bufo terrestris. American Museum novitates ; no. 1250(New York City : The American Museum of Natural History, 1944) Aronson, Lester R. (Lester Ralph), 1911-; Noble, Gladwyn Kingsley, 1894-1940."Three distinct vocalizations are recognized in the male toads, namely, the sex trill, the chirp, and the warning vibration. These calls are seasonal, being most easily elicited at the height of the breeding season. After the season they dsappear in the following order: sex trill first, chirp second, and warning vibration last. 2. In an experimental situation, sexually active male toads do not discriminate at a distance between other males or females but attempt to clasp members of either sex with equal frequency. There is, however, a slight tendency to clasp pairs more frequently than individuals, the clasps in these cases being directed almost entirely to the male of the pair. This preference for pairs is probably due to greater activity on the part of the pairs. 3. The sex-recognition mechanism (discrimination of a male from a female after amplexus is attempted) is found to be very efficient. The mechanism depends almost exclusively on the warning vibration of a male being clasped. These vibrations act as tactual stimuli of the ventral pectoral region and medial surfaces of the forelimbs of the clasping male, causing him to reject the clasp object. Females do not emit these vibrations, and therefore the clasping male maintains amplexus. Relative girths of male and female, relative 'repulsive actions' of both sexes, and the male's chirp are found not to be efficacious in sex recognition. 4. The positions and movements of the male and female during the oviposition are described in detail. 5. Release of the female by the male at the termination of the oviposition follows a severe concave arching of the back of the female, which partially lifts the male off the female. 6. Pseudo-oviposition (oviposition movements without the deposition of eggs) can sometimes be induced in anterior pituitary injected but unovulated females when clasped by males"--P. 13-14.