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Energy allocation patterns in Bufo marinus from two habitats in Venezuela

Published online by Cambridge University Press:  10 July 2009

Margarita Lampo
Affiliation:
Centro de Ecología, Institute Venezolano de Investigations Científicas, Apartado 21827, Caracas 1020-A, Venezuela
Victoria Medialdea
Affiliation:
Centro de Ecología, Institute Venezolano de Investigations Científicas, Apartado 21827, Caracas 1020-A, Venezuela

Abstract

Patterns of energy allocation in the cane toad, Bufo marinus, were explored by analysing the seasonal variations in fat bodies and gonads in two populations subjected to different rainfall regimes and water permanency. In both populations, fat deposition occurred shortly after the rainy season due to an increase in feeding activity. In contrast, the timing of reproduction varied between sites according to the availability of suitable water bodies. Nevertheless, females with mature oocytes were predominant during the dry season, even in populations that bred throughout the year in permanent ponds. This suggests that seasonal variations in the nutritional condition of adults may also result in a tendency towards cyclicity in the reproduction of B. marinus in tropical regions. Analyses of allometric relationships of reproductive and storage tissues with body weights indicated that the fractions of weights in reproductive tissues did not vary either with the size of females or between populations. On the contrary, not only did larger toads have proportionally larger fat bodies, but those from wet sites had greater fractions of weight allocated to fat bodies than those from dry sites. This suggests that reproductive output may be fixed in this species and, therefore, excess energy is allocated to fat bodies. Given that the initiation of ovarian cycles depends on the restoration of proper nutritional levels, energy stored in fat bodies during breeding may allow females to resume a new ovarian cycle shortly after spawning and thus maximize the number of reproductive events.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1996

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References

LITERATURE CITED

Bellis, E. D. 1961. Growth in the wood frog, Rana sylvatica. Copeia 1961:7477.CrossRefGoogle Scholar
Berry, P. Y. 1964. The breeding patterns of seven species of Singapore Anura. Journal of Animal Ecology 33:227243.CrossRefGoogle Scholar
Caldwell, J. P., Thorp, J. H. & Jervey, T. O. 1980. Predator-prey relationships among larval dragon flies, salamanders and frogs. Oecologia 46:285289.CrossRefGoogle Scholar
Church, G. 1960. Annual and lunar periodicity in the sexual cycle of the Javanese toad, Bufo melanostictus Schneider. Zoologica 45:181188.Google Scholar
Freeland, W. J. & Kerin, S. H. 1991. Ontogenetic alteration of activity and habitat selection by Bufo marinus. Wildlife Research 18:431443.CrossRefGoogle Scholar
Hearnden, M. N. 1991. The reproductive and larval ecology of Bufo marinus (Anura: Bufonidae). PhD Dissertation, James Cook University of North Queensland, Townsville, Australia.Google Scholar
Heyer, W. R. 1979. Annual variation in larval amphibian populations within a temperate pond. Journal of the Washington Academy of Science 69:6574.Google Scholar
Jorgensen, C. B. 1975. Factors controlling the anuran ovarian cycle in the toad Bufo bufo bufo (L.). General and Comparative Endocrinology 25:264273.CrossRefGoogle Scholar
Jorgensen, C. B. 1982. Factors controlling the ovarian cycle in temperate zone anurans, the toad Bufo bufo: food uptake, nutritional state and gonadotropin. Journal of Experimental Zoology 224:437443.CrossRefGoogle ScholarPubMed
Jorgensen, C. B. 1992. Growth and reproduction. Pp. 378394 in Feder, M. E. & Burggren, W. W. (eds). Environmental physiology of the amphibians. The University of Chicago Press, Chicago.Google Scholar
Jorgensen, C. B., Shakuntala, K. & Vijayakumar, S. 1986. Body size, reproduction, and growth in a tropical toad, Bufo melanostictus, with a comparison of ovarian cycles in tropical and temperate zone anurans. Oikos 46:379389.CrossRefGoogle Scholar
Kaplan, R. H. 1987. Developmental plasticity and maternal effects of reproductive characteristics in the frog, Bombina orientalis. Oecologia 71:273279.CrossRefGoogle ScholarPubMed
Kaplan, R. H. & Cooper, S. C. 1984. The evolution of developmental plasticity in reproductive characteristics: an application of the ‘adaptive coin-flipping’. The American Naturalist 123:393409.CrossRefGoogle Scholar
Kaplan, R. H. & Salthe, S. N. 1979. The allometry of reproduction: an empirical view in salamanders. The American Naturalist 113:671689.CrossRefGoogle Scholar
Larsen, L. O. 1992. Feeding and digestion. Pp. 378394 in Feder, M. E. & Burggren, W. W. (eds). Environmental physiology of the amphibians. The University of Chicago Press, Chicago.Google Scholar
Levins, R. 1968. Evolution in changing environments. Princeton University Press, Princeton.CrossRefGoogle Scholar
Newman, R. A. 1987. Effects of density and predation on Scaphiolus couchi tadpoles in desert ponds. Oecologia 71:301307.CrossRefGoogle ScholarPubMed
Parichy, D. M. & Kaplan, R. H. 1992. Maternal effects on offspring growth and development depend on environmental quality in the frog, Bombina orientalis. Oecologia 91:579586.CrossRefGoogle Scholar
Systat, . 1992. Version 5.2 edition. Systat Inc., Evanston, IL, USA.Google Scholar
Tejedo, M. 1992. Effect of body size and timing of reproductive success of the natterjack toad (Bufo calamita). Journal of Zoology (London) 228:545555.CrossRefGoogle Scholar
Tevis, L. Jr., 1966. Unsuccessful breeding by desert toads (Bufo punctatus) at the limit of their ecological tolerance. Ecology 47:766775.CrossRefGoogle Scholar
Vijayakumar, S. C., Jorgensen, C. B. & Kjaer, K. 1971. Regulation of ovarian cycle in the toad Bufo bufo bufo (L.): effects of autografting pars distalis of the hypophysis, of extirpating gonadotropic hypothalamic region, and partial ovariectomy. General and Comparative Endocrinology 17:432443.CrossRefGoogle ScholarPubMed
Wells, K. D. 1979. Reproductive behavior and male mating success in a neotropical toad, Bufo typhonius. Biotropica 11:301307.CrossRefGoogle Scholar
Wilbur, H. M. & Collins, J. P. 1973. Ecological aspects of amphibian metamorphosis. Science 182:13051314.CrossRefGoogle ScholarPubMed
Zug, G. R., Lindgren, E. & Pippet, J. R. 1975. Distribution and ecology of the marine toad, Bufo marinus, in Papua New Guinea. Pacific Science 29:3150.Google Scholar
Zug, G. R. & Zug, P. B. 1979. The marine toad, Bufo marinus: a natural history resumé of native populations. Smithsonian Contributions to Zoology 284:154.Google Scholar