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  • Bufo arenarum (Anura)  (2)
  • Reproductive success  (2)
  • 1995-1999  (4)
  • 1965-1969
Collection
Keywords
Publisher
Years
  • 1995-1999  (4)
  • 1965-1969
Year
  • 1
    Electronic Resource
    Electronic Resource
    Confirmation of cooperative polyandry in the Galapagos hawk (Buteo galapagoensis) (1995)
    Springer
    Behavioral ecology and sociobiology 36 (1995), S. 83-90 
    Details
    ISSN: 1432-0762
    Keywords: DNA fingerprinting ; Buteo galapagoensis ; Paternity ; Polyandry ; Reproductive success
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Without genetic tests of parentage, descriptions of mating systems must be considered hypothetical. Here we confirm the existence of cooperative polyandry in the Galapagos hawk (Buteo galapagoensis) using multilocus minisatellite DNA fingerprinting. In this species, breeding groups consist of one adult female and from one to eight males (the modal number of males is two). In polyandrous groups, all males copulate with the female and participate in the provisioning of the young. DNA samples from 66 individual hawks from ten breeding groups on the island of Santiago revealed mixed paternity in most groups. Multiple paternity was detected in five of six groups that produced two chicks in one breeding attempt (year). In addition, different males sired young in consecutive years in five of six groups in which male group membership was constant. Patterns of paternity suggest that reproductive success was randomly distributed among males within groups, with males apparently having equivalent probabilities of siring each young. Analysis of genetic similarity indicates that males within groups were typically not close relatives These results demonstrate that the mating system of the Galapagos hawk is polyandrous, with relatively egalitarian relations among unrelated males belonging to the same breeding group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170712
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  • 2
    Electronic Resource
    Electronic Resource
    Confirmation of cooperative polyandry in the Galapagos hawk (Buteo galapagoensis) (1995)
    Springer
    Behavioral ecology and sociobiology 36 (1995), S. 83-90 
    Details
    ISSN: 1432-0762
    Keywords: Key words DNA fingerprinting ; Buteo galapagoensis ; Paternity ; Polyandry ; Reproductive success
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Without genetic tests of parentage, descriptions of mating systems must be considered hypothetical. Here we confirm the existence of cooperative polyandry in the Galapagos hawk (Buteo galapagoensis) using multilocus minisatellite DNA fingerprinting. In this species, breeding groups consist of one adult female and from one to eight males (the modal number of males is two). In polyandrous groups, all males copulate with the female and participate in the provisioning of the young. DNA samples from 66 individual hawks from ten breeding groups on the island of Santiago revealed mixed paternity in most groups. Multiple paternity was detected in five of six groups that produced two chicks in one breeding attempt (year). In addition, different males sired young in consecutive years in five of six groups in which male group membership was constant. Patterns of paternity suggest that reproductive success was randomly distributed among males within groups, with males apparently having equivalent probabilities of siring each young. Analysis of genetic similarity indicates that males within groups were typically not close relatives. These results demonstrate that the mating system of the Galapagos hawk is polyandrous, with relatively egalitarian relations among unrelated males belonging to the same breeding group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002650050127
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Immunocytochemical and morphometric study on the changes of TSH, PRL, GH and ACTH cells during the development of Bufo arenarum (1995)
    Springer
    Cell & tissue research 283 (1995), S. 125-132 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Pituitary hormones ; Immunocytochemistry ; Morphometry ; Metamorphosis ; Bufo arenarum (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The development and dynamics of thyrotropin (TSH), adrenocorticotropic hormone (ACTH), prolactin (PRL), and growth hormone (GH) cells have been studied using immunocytochemical techniques and rabbit antisera, raised against the relevant human hormone, in the pars distalis of Bufo arenarum larvae at different stages of development. The four types of cells studied were identified in different zones of the pars distalis: TSH cells occurred mainly in the centro-ventral zone, ACTH cells in the rostral and dorsal zones, GH cells in the central and caudal zones, and PRL cells in the anterior two-thirds of the gland. This distribution pattern does not show significant changes with development. Morphometry and stereology were used to evaluate the changes observed in the volume of the pars distalis and the immunoreactive cells during development. The former increased during larval growth and decreased throughout the metamorphic climax. The results obtained on cell number, volume density, and total volume suggest that, during larval growth (pre-prometamorphosis) of B. arenarum, TSH, PRL, GH and ACTH cells show a proliferative period with storage of their hormones; a second period involving hormone release occurs at the metamorphic climax.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050520
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  • 4
    Electronic Resource
    Electronic Resource
    Identification and neuroanatomical distribution of immunoreactivity for mammalian gonadotropin-releasing hormone (mGnRH) in the brain and neural hypophyseal lobe of the toad Bufo arenarum (1998)
    Springer
    Cell & tissue research 293 (1998), S. 419-425 
    Details
    ISSN: 1432-0878
    Keywords: Key words Gonadotropin-releasing hormone ; Brain ; Hypophyseal neural lobe (pars nervosa) ; Reproduction ; Bufo arenarum (Anura)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The presence and distribution of gonadotropin-releasing hormone (GnRH) in sexually mature specimens of Bufo arenarum was studied by reverse phase/high performance liquid chromatography (RP-HPLC) combined with radioimmunoassay and immunocytochemistry. The analysis of brain extracts with RP-HPLC followed by radioimmunoassay with PBL#45 antiserum showed the presence of only one peak with immunoreactivity for GnRH (ir-GnRH) having the chromatographic and immunological characteristics of mammalian GnRH (mGnRH). This peak was further analyzed with two mGnRH-specific antisera, EL-15 and m1076, yielding serial dilution displacement curves parallel to those obtained with the mGnRH synthetic standard. Immunocytochemical results with the monoclonal antibody LRH13 showed the presence of a terminal nerve-septo-preoptic system with neurons and fibers distributed from the olfactory bulb, septal area, and anterior preoptic area toward the hypothalamus and hypophyseal neural lobe. The main group of ir-GnRH fibers and neurons was identified in the anterior preoptic area. These neurons appear to be the origin of fibers that, after surrounding the preoptic recess, border the dorsal surface of the optic chiasma, extend through the infundibulum, traverse the external layer of the median eminence, and end in the pars nervosa.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410051133
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