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Psittacula cyanocephala

About: Psittacula cyanocephala is a(n) research topic. Over the lifetime, 17 publication(s) have been published within this topic receiving 101 citation(s).

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Journal ArticleDOI
TL;DR: The results indicated that the Pineal gland activity varied inversely with the seasonal testicular weight cycle and the antigonadal influence of melatonin appeared to be phase dependent, which corroborated the inverse temporal relationship of the pineal gland and male reproductive activity examined in the two tropical avian species.
Abstract: The aim of the present comparative investigation was to examine annual pineal cytological changes and the action of melatonin in relation to testicular activity in two wild tropical avian species. The findings revealed that in both blossomheaded parakeets (Psittacula cyanocephala) and Indian weaver birds (Ploceus philippinus) the pineal gland was inactive, with reduced karyometric values during the breeding season. A pinealoactive phase showing significantly increased pinealocyte nuclear diameter corresponded with the nonbreeding phase. Administration of melatonin (250 μg/100 g body wt) for 10 consecutive days caused significant involution of testes during the breeding phase, although it failed to alter reproductive activity during the nonbreeding phase. The results indicated that the pineal gland activity varied inversely with the seasonal testicular weight cycle and the antigonadal influence of melatonin appeared to be phase dependent, which corroborated the inverse temporal relationship of the pineal gland and male reproductive activity examined in the two tropical avian species.

18 citations

Journal ArticleDOI
TL;DR: Comparison of the annual cycles of reproductive parameters with those of different climatological variables could show that duration of solar‐day, in contrast to ambient temperature and rainfall, through its cyclicity parallels, though in part, the gonadal cycle of male blossomheaded parakeet.
Abstract: Histophysiological studies of the annual testicular events in an Indian Psittaciform bird, blossomheaded parakeet Psittacula cyanocephala, under natural environmental conditions revealed that the bird is a seasonal breeder with a single peak in a year. Active spermatogenesis takes place only during February and March, but maximum seasonal maturation of the Leydig cells occurs at least one month before the onset of active production of sperm. Comparison of the annual cycles of reproductive parameters with those of different climatological variables could show that duration of solar‐day, in contrast to ambient temperature and rainfall, through its cyclicity parallels, though in part, the gonadal cycle of male blossomheaded parakeet.

16 citations

Journal ArticleDOI
TL;DR: It is evident that the same amount of exogenous testosterone may exert, possibly through pituitary gonadotrophic agent(s), either pro- or anti-gonadal influences depending upon the sexual status of the bird.
Abstract: Testosterone propionate (1 mg per 100 g body weight per day) was administered for 15 days, by injection into the pectoral muscles, to male blossomheaded parakeets during both the spermatogenetically active (February-March) and resting (August) phases of the annual cycle. It caused marked testicular atrophy when it was injected in the sexually active birds. In sexually regressed parakeets it resulted in spermatokinesis and differentiation of Leydig cells. It is evident that the same amount of exogenous testosterone may exert, possibly through pituitary gonadotrophic agent(s), either pro- or anti-gonadal influences depending upon the sexual status of the bird.

11 citations

Journal ArticleDOI
TL;DR: It was demonstrated that stress decreased the growth and activity of the pinel cells when induced as hyperosmolality (water deprivation, salt ingestion), and influence on the pineal gland was not inhibited by previous treatment of a sympatholytic agent, 6‐hydroxydopamine.
Abstract: A study of the pineal gland of adult male blossomheaded parakeets was conducted with the aid of light microscopic examination to determine the influence of stress on pineal cells. It was demonstrated that stress decreased the growth and activity of the pinel cells when induced as hyperosmolality (water deprivation, salt ingestion). This influence on the pineal gland was not inhibited by previous treatment of a sympatholytic agent, 6-hydroxydopamine.

10 citations

Journal ArticleDOI
TL;DR: The haemoproteids of the avian family Psittacidae (the parrots) are reviewed and H. handai is redescribed from the type host.
Abstract: The haemoproteids of the avian family Psittacidae (the parrots) are reviewed. Haemoproteus handai Maqsood, 1943 is redescribed from the type host, Psittacula cyanocephala (L.). Parahaemoproteus desseri Miltgen, Landau, Rabanaworbhan and Yenbutra, 1981 is designated a synonym of H. handai.

9 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20211
20201
19961
19943
19931
19921