In 1998,a study on forty-five four-eyed turtles(Sacalia quadriocellata) was initiated to gather preliminary biological data of this species and to investigate the feasibility of its captive reproduction.In the followi...In 1998,a study on forty-five four-eyed turtles(Sacalia quadriocellata) was initiated to gather preliminary biological data of this species and to investigate the feasibility of its captive reproduction.In the following six years,no courtship behavior was found occurring in males and no oviposition in females.From 2004 to 2007,two successful techniques were applied to initiate reproductive behavior:1) injecting exogenous reproductive hormones; and 2) reducing the stress of living in captivity.As a result of the hormone treatments,courtship behavior and copulation were observed during September and October,2005.However,no courtship displays were seen from the CK males,which were not treated with hormones.Ovulation occurred between December and March,and the correlation was not significant between behavior of ovulation and food intake.Females laid only one clutch of eggs each year,with 2.47 eggs(n=34,range=1–4) at average,and 84 eggs were totally obtained,of which 13 were damaged,52 were infertile and 19 fertile.Of the fertile eggs,nine were hatched with mean incubation period of 105.9 days(n=9,range=89–122 days) at temperature ranging from 24 to 27℃.展开更多
Luteinizing hormone-releasing hormone(LHRH) is known to influence sexual behavior in many vertebrate taxa, but there have been no systematic studies on the role of LHRH in sexual behavior of turtles. We tested the hyp...Luteinizing hormone-releasing hormone(LHRH) is known to influence sexual behavior in many vertebrate taxa, but there have been no systematic studies on the role of LHRH in sexual behavior of turtles. We tested the hypotheses that exogenous LHRH analogues would induce sexual behavior of male Four-eyed turtle, Sacalia quadriocellata. We examined this by challenging males with intramuscular injections of mammalian luteinizing hormone-releasing hormone analogue(LHRH-A), human chorionic gonadotropin(HCG), or a combination of the two, and subsequently exposing them to sexually receptive females for behavioral observation. Our data show that the injection of only HCG could not, while that of only LHRH-A could, facilitate sexual behavior along with testicular recrudescence and spermatogenesis in S. quadriocellata. The injection of both LHRH-A and HCG would induce more drastic sexual behavior of the animals than that of LHRH-A alone, indicating HCG enhances the effects of LHRH-A induced sexual behavior. However, different pharmacological dosages of LHRH-A(0.5 μg, 1 μg, 2 μg per 100 g bodyweight) did not correspond to different activity levels. Though the mechanism of LHRH effect was not determined, this study may support that the sexual behavior of S. quadriocellata which occurs at the beginning of the injection despite regression of the gonads. This is the first report on the exogenous LHRH-A induced sexual behavior for this species.展开更多
基金supported by the National Natural Science Foundation of China(30910103916)the Key Project of Science and Technology Program of Hainan,China(06122)
文摘In 1998,a study on forty-five four-eyed turtles(Sacalia quadriocellata) was initiated to gather preliminary biological data of this species and to investigate the feasibility of its captive reproduction.In the following six years,no courtship behavior was found occurring in males and no oviposition in females.From 2004 to 2007,two successful techniques were applied to initiate reproductive behavior:1) injecting exogenous reproductive hormones; and 2) reducing the stress of living in captivity.As a result of the hormone treatments,courtship behavior and copulation were observed during September and October,2005.However,no courtship displays were seen from the CK males,which were not treated with hormones.Ovulation occurred between December and March,and the correlation was not significant between behavior of ovulation and food intake.Females laid only one clutch of eggs each year,with 2.47 eggs(n=34,range=1–4) at average,and 84 eggs were totally obtained,of which 13 were damaged,52 were infertile and 19 fertile.Of the fertile eggs,nine were hatched with mean incubation period of 105.9 days(n=9,range=89–122 days) at temperature ranging from 24 to 27℃.
基金supported by the National Natural Science Foundation of China(30910103916)the Key Project of the Science and Technology Program of Hainan,China(06122)
文摘Luteinizing hormone-releasing hormone(LHRH) is known to influence sexual behavior in many vertebrate taxa, but there have been no systematic studies on the role of LHRH in sexual behavior of turtles. We tested the hypotheses that exogenous LHRH analogues would induce sexual behavior of male Four-eyed turtle, Sacalia quadriocellata. We examined this by challenging males with intramuscular injections of mammalian luteinizing hormone-releasing hormone analogue(LHRH-A), human chorionic gonadotropin(HCG), or a combination of the two, and subsequently exposing them to sexually receptive females for behavioral observation. Our data show that the injection of only HCG could not, while that of only LHRH-A could, facilitate sexual behavior along with testicular recrudescence and spermatogenesis in S. quadriocellata. The injection of both LHRH-A and HCG would induce more drastic sexual behavior of the animals than that of LHRH-A alone, indicating HCG enhances the effects of LHRH-A induced sexual behavior. However, different pharmacological dosages of LHRH-A(0.5 μg, 1 μg, 2 μg per 100 g bodyweight) did not correspond to different activity levels. Though the mechanism of LHRH effect was not determined, this study may support that the sexual behavior of S. quadriocellata which occurs at the beginning of the injection despite regression of the gonads. This is the first report on the exogenous LHRH-A induced sexual behavior for this species.
