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Richard R Tokarz - One of the best experts on this subject based on the ideXlab platform.
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Relationship between copulation duration and sperm transfer in the lizard Anolis sagrei
Herpetologica, 1999Co-Authors: Richard R TokarzAbstract:I tested the hypothesis that copulation duration and the number of sperm transferred in a copulation are significantly correlated in the lizard Anolis sagrei. I also investigated whether copulation duration and number of sperm transferred in a copulation are affected by when in the breeding season a copulation occurs, by the body masses and snout-to-vent lengths (SVL) of the copulating lizards, and by which Hemipenis is used in a copulation. Reproductively active males and females of A. sagrei were collected monthly in the Miami, Florida area from April through July of 1997 and housed in laboratory animal rooms. Two days after capture, males were allowed to copulate with sexually receptive females. I recorded copulation duration and whether the left or right Hemipenis was used for each copulation. In addition, I estimated the number of sperm that were transferred to the female's cloaca in a copulation. Copulations by 46 different pairs of males and females were observed. Copulation duration varied significantly with the month of capture, but the estimated number of sperm transferred did not. Neither copulation duration nor estimated number of sperm transferred were significantly correlated with male or female body masses or SVL, or were significantly affected by which Hemipenis was used. Copulation duration and the estimated number of sperm transferred in a copulation were not significantly correlated. Thus the hypothesis that copulation duration and sperm transfer are correlated in A. sagrei was not supported.
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importance of intromission in maintaining the alternating pattern of male mounting behavior and Hemipenis use in the lizard anolis sagrei
Journal of Experimental Zoology, 1991Co-Authors: Richard R Tokarz, Sean J KirkpatrickAbstract:Previous studies of the lizard Anolis sagrei have shown that males in a series of copulations exhibit a significant alternating pattern of mounting behavior and Hemipenis use and that this behavior may be adaptive by increasing sperm transfer. To investigate the role sensory feedback from the Hemipenis may play in maintaining this alternation of mounting behavior and Hemipenis use, the effects of preventing intromission, interrupting copulation, and controlling which Hemipenis is used were examined. Males that were allowed to mount, but not to intromit in the first of two successive matings, or bilaterally hemipenectomized males that were allowed to complete four matings, did not exhibit significant alternation of mounting behavior. Significant alternation of Hemipenis use was exhibited by males that were allowed to intromit but were interrupted in copulation immediately after intromission. Males that were allowed to intromit but were forced in the first of two copulations to use either the left Hemipenis, the right Hemipenis, or the Hemipenis that was used in an earlier copulation did not exhibit significant alternation of Hemipenis use. These results suggest that the alternation of male mounting behavior and Hemipenis use observed in A. sagrei is dependent on a Hemipenis being intromitted and which Hemipenis is used, but is independent of copulation duration.
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copulation frequency and pattern of Hemipenis use in males of the lizard anolis sagrei in a semi natural enclosure
Animal Behaviour, 1991Co-Authors: Richard R Tokarz, Sean J KirkpatrickAbstract:Previous laboratory studies of the lizard Anolis sagrei have suggested that the alternating pattern of Hemipenis use in males may serve to increase sperm transfer if a male copulates at least once a day. In this study, the copulation frequency and pattern of Hemipenis use of males housed individually in a seminatural enclosure with different numbers of females was monitored. Behavioural observations began 4 days after the animals were placed into the enclosure. In the first experiment, males were housed individually with three females and were observed during the 12-h light phase for each of 3 consecutive days. In a second experiment, males were housed individually with either one or six females and were observed during the 12-h light phase of 1 day. Males housed with three females copulated at least twice a day for each of the 3 observation days and showed a highly significant alternating pattern of Hemipenis use. Males housed with a single female copulated less frequently than did males that were housed with three or six females. These results suggest that male A. sagrei in the field may copulate with a sufficient frequency to make alternation of Hemipenis use of adaptive value in terms of sperm transfer.
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alternation of Hemipenis use as a behavioural means of increasing sperm transfer in the lizard anolis sagrei
Animal Behaviour, 1990Co-Authors: Richard R Tokarz, Joseph B SlowinskiAbstract:Abstract Male lizards and snakes posses two functionally independent intromittent organs termed hemipenes, only one of which is intromitted into the female's cloaca during copulation. In the lizard Anolis sagrei , a significant proportion of males alternate in the use of the left and right hemipenes when the intercopulatory interval is 24 h or less but not when it is 72 h. This study investigated whether the observed alternating pattern of Hemipenis use in A. sagrei is a behavioural means of increasing sperm transfer to females in successive copulations. Males that were experimentally prevented from alternating in the use of the hemipenes in two copulations separated by 1- or 24-h intercopulatory intervals transferred significantly fewer sperm in the second copulation than did males that were permitted to alternate. This difference was not observed when the intercopulatory interval was 72h. Males that were prevented from alternating in the use of the hemipenes in a series of three copulations, which were separated by 24 h, delivered significantly fewer sperm in the second and third copulations than did males that were permitted to alternate. These results support the hypothesis that alternation of Hemipenis use is a behavioural means of increasing sperm transfer when the interval between copulations is relatively brief.
Robert T Mason - One of the best experts on this subject based on the ideXlab platform.
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are snakes right handed asymmetry in Hemipenis size and usage in gartersnakes thamnophis sirtalis
Behavioral Ecology, 2000Co-Authors: Richard Shine, Mats Olsson, Michael P Lemaster, Ignacio T Moore, Robert T MasonAbstract:Male snakes possess paired reproductive systems (testes, efferent ducts, hemipenes and associated components of the kidneys), with an independent set on either side of the body. Our studies on gartersnakes (Thamnophis sirtalis parietalis) reveal significant morphological asymmetry in this system: testes, kidneys, and hemipenes on the right-hand-side of the body are larger than those on the left. Data from matings in the field, and in outdoor enclosures, suggest that this asymmetry has implications for reproductive behavior and, possibly, reproductive success. Copulations using the right Hemipenis produced a larger gelatinous ‘‘mating plug,’’ and may thus more effectively delay remating by the female. Although the overall usage of the two hemipenes in field matings averaged close to 50/50, Hemipenis usage was not random. Males tended to alternate Hemipenis use in successive matings, perhaps because of depletion of plug material. Also, male gartersnakes preferentially used their larger (right) Hemipenis when mating at high body temperatures, perhaps because they are more able to make subtle postural adjustments (and thus, select the better system) under these conditions.
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Are snakes right-handed ? Asymmetry in Hemipenis size and usage in gartersnakes (Thamnophis sirtalis)
Behavioral Ecology, 2000Co-Authors: Richard Shine, Mats Olsson, Michael P Lemaster, Ignacio T Moore, Robert T MasonAbstract:Male snakes possess paired reproductive systems (testes, efferent ducts, hemipenes and associated components of the kidneys), with an independent set on either side of the body. Our studies on gartersnakes (Thamnophis sirtalis parietalis) reveal significant morphological asymmetry in this system: testes, kidneys, and hemipenes on the right-hand-side of the body are larger than those on the left. Data from matings in the field, and in outdoor enclosures, suggest that this asymmetry has implications for reproductive behavior and, possibly, reproductive success. Copulations using the right Hemipenis produced a larger gelatinous ‘‘mating plug,’’ and may thus more effectively delay remating by the female. Although the overall usage of the two hemipenes in field matings averaged close to 50/50, Hemipenis usage was not random. Males tended to alternate Hemipenis use in successive matings, perhaps because of depletion of plug material. Also, male gartersnakes preferentially used their larger (right) Hemipenis when mating at high body temperatures, perhaps because they are more able to make subtle postural adjustments (and thus, select the better system) under these conditions.
Joseph B Slowinski - One of the best experts on this subject based on the ideXlab platform.
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alternation of Hemipenis use as a behavioural means of increasing sperm transfer in the lizard anolis sagrei
Animal Behaviour, 1990Co-Authors: Richard R Tokarz, Joseph B SlowinskiAbstract:Abstract Male lizards and snakes posses two functionally independent intromittent organs termed hemipenes, only one of which is intromitted into the female's cloaca during copulation. In the lizard Anolis sagrei , a significant proportion of males alternate in the use of the left and right hemipenes when the intercopulatory interval is 24 h or less but not when it is 72 h. This study investigated whether the observed alternating pattern of Hemipenis use in A. sagrei is a behavioural means of increasing sperm transfer to females in successive copulations. Males that were experimentally prevented from alternating in the use of the hemipenes in two copulations separated by 1- or 24-h intercopulatory intervals transferred significantly fewer sperm in the second copulation than did males that were permitted to alternate. This difference was not observed when the intercopulatory interval was 72h. Males that were prevented from alternating in the use of the hemipenes in a series of three copulations, which were separated by 24 h, delivered significantly fewer sperm in the second and third copulations than did males that were permitted to alternate. These results support the hypothesis that alternation of Hemipenis use is a behavioural means of increasing sperm transfer when the interval between copulations is relatively brief.
Djoko Legowo - One of the best experts on this subject based on the ideXlab platform.
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morfometry study of Hemipenis biawak air varanus salvator on length measurement of snouth vent length svl andbody weight
KnE Life Sciences, 2017Co-Authors: Ilham Adi Kusuma, Dicky Beo Alfiyanto, Pudji Srianto, Nusdianto Triakoso, Djoko LegowoAbstract:Varanus salvator is a water reptile that has various kinds depends on the habitat. Varanus salvator has been hunted by people for hundreds or even thousands of years, therefore the populations decreased. People used Varanus salvator as a source of protein and as medicine for particular parts of the body. Informations about Varanus salvator reproductive anatomy was highly needed as the base of conservation. The objective of this research was to know the corelation of snouth vent length and body weight to the size of hemipenes. Forty male Varanus salvator in random sizes was measured in snoth vent length and body weight, then the measurement’s result was analized and correlated with the size of hemipenes. The size of hemipenes was the length of hemipenes, the diameter of radix hemipenes, the diameter of corpus hemipenes and the diameter of glands hemipenes. The datas was processed using Anova test, Linear regression test, correlation test, and double correlation test.The result showed that body weight and snouth vent length correlated to the size of hemipenes because the value of correlation test showed p>0,5. Based on double correlation test, the result showed that snouth vent lengt was more correlated to the size of hemipenes. The value of double corrrelation test showed z<1,96. Keyword : Snouth vent length, Hemipenis, Varanus salvator
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Morfometry Study of Hemipenis Biawak Air Varanus Salvator on Length Measurement of Snouth Vent Length (Svl) Andbody Weight
KnE Life Sciences, 2017Co-Authors: Ilham Adi Kusuma, Dicky Beo Alfiyanto, Pudji Srianto, Nusdianto Triakoso, Djoko LegowoAbstract:Varanus salvator is a water reptile that has various kinds depends on the habitat. Varanus salvator has been hunted by people for hundreds or even thousands of years, therefore the populations decreased. People used Varanus salvator as a source of protein and as medicine for particular parts of the body. Informations about Varanus salvator reproductive anatomy was highly needed as the base of conservation. The objective of this research was to know the corelation of snouth vent length and body weight to the size of hemipenes. Forty male Varanus salvator in random sizes was measured in snoth vent length and body weight, then the measurement’s result was analized and correlated with the size of hemipenes. The size of hemipenes was the length of hemipenes, the diameter of radix hemipenes, the diameter of corpus hemipenes and the diameter of glands hemipenes. The datas was processed using Anova test, Linear regression test, correlation test, and double correlation test.The result showed that body weight and snouth vent length correlated to the size of hemipenes because the value of correlation test showed p>0,5. Based on double correlation test, the result showed that snouth vent lengt was more correlated to the size of hemipenes. The value of double corrrelation test showed z
Richard Shine - One of the best experts on this subject based on the ideXlab platform.
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are snakes right handed asymmetry in Hemipenis size and usage in gartersnakes thamnophis sirtalis
Behavioral Ecology, 2000Co-Authors: Richard Shine, Mats Olsson, Michael P Lemaster, Ignacio T Moore, Robert T MasonAbstract:Male snakes possess paired reproductive systems (testes, efferent ducts, hemipenes and associated components of the kidneys), with an independent set on either side of the body. Our studies on gartersnakes (Thamnophis sirtalis parietalis) reveal significant morphological asymmetry in this system: testes, kidneys, and hemipenes on the right-hand-side of the body are larger than those on the left. Data from matings in the field, and in outdoor enclosures, suggest that this asymmetry has implications for reproductive behavior and, possibly, reproductive success. Copulations using the right Hemipenis produced a larger gelatinous ‘‘mating plug,’’ and may thus more effectively delay remating by the female. Although the overall usage of the two hemipenes in field matings averaged close to 50/50, Hemipenis usage was not random. Males tended to alternate Hemipenis use in successive matings, perhaps because of depletion of plug material. Also, male gartersnakes preferentially used their larger (right) Hemipenis when mating at high body temperatures, perhaps because they are more able to make subtle postural adjustments (and thus, select the better system) under these conditions.
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Are snakes right-handed ? Asymmetry in Hemipenis size and usage in gartersnakes (Thamnophis sirtalis)
Behavioral Ecology, 2000Co-Authors: Richard Shine, Mats Olsson, Michael P Lemaster, Ignacio T Moore, Robert T MasonAbstract:Male snakes possess paired reproductive systems (testes, efferent ducts, hemipenes and associated components of the kidneys), with an independent set on either side of the body. Our studies on gartersnakes (Thamnophis sirtalis parietalis) reveal significant morphological asymmetry in this system: testes, kidneys, and hemipenes on the right-hand-side of the body are larger than those on the left. Data from matings in the field, and in outdoor enclosures, suggest that this asymmetry has implications for reproductive behavior and, possibly, reproductive success. Copulations using the right Hemipenis produced a larger gelatinous ‘‘mating plug,’’ and may thus more effectively delay remating by the female. Although the overall usage of the two hemipenes in field matings averaged close to 50/50, Hemipenis usage was not random. Males tended to alternate Hemipenis use in successive matings, perhaps because of depletion of plug material. Also, male gartersnakes preferentially used their larger (right) Hemipenis when mating at high body temperatures, perhaps because they are more able to make subtle postural adjustments (and thus, select the better system) under these conditions.