ENERGY ALLOCATION PATTERNS IN BUFO-MARINUS FROM 2 HABITATS IN VENEZUELA

Patterns of energy allocation in the cane toad, Bufo marinus, were exp lored by analysing the seasonal variations in at bodies and gonads in two populations subjected to different rainfall regimes and water perm anency. 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 availabi lity of suitable water bodies. Nevertheless, Females with mature oocyt es were predominant during the dry season, even in populations that br ed 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 trop ical regions. Analyses of allometric relationships of reproductive and storage tissues with body weights indicated that the fractions of wei ghts in reproductive tissues did nor vary either with the size of fema les or between populations. On the contrary, not only did larger toads have proportionally larger far bodies, bur those from wet sites had g reater fractions of weight allocated to Fat bodies than those from dry sites. This suggests that reproductive output may be fixed in this sp ecies and, therefore, excess energy is allocated to Fat bodies. Given that the initiation of ovarian cycles depends on the restoration of pr oper nutritional levels, energy stored in fat bodies during breeding m ay allow females to resume a new ovarian cycle shortly after spawning and thus maximize the number of reproductive events.