Use of blubber as matrix to measure sexual steroid levels of humpback whales (Megaptera novaeangliae)

• Grant number: 11/11050-3
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2013
• End date: March 31, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Claudio Alvarenga de Oliveira
• Grantee: Claudio Alvarenga de Oliveira
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The Abrolhos bank (16°40' to 19°30'S; 37°25 to 38°57'W) comprises the greatest coral reef biodiversity not only in Brazil, but in all South Atlantic. It is also the main calving and mating area of Humpback whales (Megaptera novaeangliae) in South Western Atlantic. The whales migrate from feeding areas in low latitudes to warmer waters to breed and give birth in the winter. A better understanding of reproductive physiology of the species can increase information on population reproductive rates and provide tools that could be effectively applied on conservation of the species. However, there is a great difficulty of collecting samples that accurately reflects the reproductive status of free-living cetaceans. The analysis of steroid hormones levels in blubber, trough the measurement in blubber, appears as an alternative for this standoff. It is known that steroid hormones have a great affinity to adipose tissue, and tend to accumulate on blubber. The present study aims to develop extraction and measurement techniques of steroid hormones from blubber of Humpback whales. The study will provide comparison of hormone concentration from the beginning of reproductive season in Brazil (July, August) to hormone concentration at the end of the season (October, November). Moreover, a comparison with animals in reproductive absence during feeding season in Antarctica and Chilean Patagonia will occur from January to May. The animals will be grouped by age and sex: adult female with calf; adult female without calf; adult male; female juvenile; male juvenile; female calves and male calves. The hormonal concentration will be compared among the groups in both feeding and mating seasons. The study will provide new information regarding sexual steroid levels on blubber of humpback whales from South Atlantic and Southeast Pacific at both breeding and feeding grounds. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MELLO, DANIELA; COLOSIO, ADRIANA; MARCONDES, MILTON; VIAU, PRISCILA; OLIVEIRA, CLAUDIO. Feasibility of using humpback whale blubber to measure sex hormones. Journal of Experimental Marine Biology and Ecology, v. 486, p. 32-41, JAN 2017. (11/11050-3, 11/12209-6)