Recent studies have demonstrated that some hormones are present in baleen powder from bowhead (Balaena mysticetus) and North Atlantic right (Eubalaena glacialis) whales. To test the potential generalizabilit​y of this technique for studies of stress and reproduction in large whales, researchers sought to determine whether all major classes of steroid and thyroid hormones are detectable in baleen, and whether these hormones are detectable in other mysticetes.

Powdered baleen samples were recovered from single specimens of North Atlantic right, bowhead, blue (Balaenoptera [B.] musculus), sei (B. borealis), minke (B. acutorostrata), fin (B. physalus), humpback (Megaptera novaeangliae) and gray (Eschrichtius robustus) whales. Hormones were extracted with a methanol vortex method, after which researchers tested all species with commercial enzyme immunoassays (EIAs, Arbor Assays) for progesterone, testosterone, 17-estradiol, cortisol, corticosterone, aldosterone, thyroxine and triiodothyronin​e, representing a wide array of steroid and thyroid hormones of interest for whale physiology research.

In total, 64 parallelism tests (8 species × 8 hormones) were evaluated to verify good binding affinity of the assay antibodies to hormones in baleen. Researchers also tested assay accuracy, although available sample volume limited this test to progesterone, testosterone and cortisol. All tested hormones were detectable in baleen powder of all species, and all assays passed parallelism and accuracy tests. Although only single individuals were tested, the consistent detectability of all hormones in all species indicates that baleen hormone analysis is likely applicable to a broad range of mysticetes, and that the EIA kits tested here perform well with baleen extract.

Quantification of hormones in baleen may be a suitable technique with which to explore questions that have historically been difficult to address in large whales, including pregnancy and inter-calving interval, age of sexual maturation, timing and duration of seasonal reproductive cycles, adrenal physiology and metabolic rate.

Authors: Hunt, K.E.; Lysiak, N.S.; Robbins, J.; Moore, M.J.; Seton, R.E.; Torres, L.

Short Description: 
Researchers sought to determine whether all major classes of steroid and thyroid hormones are detectable in baleen, and whether these hormones are detectable in other mysticetes.
Product Number: 
ORESU-R-17-020
Entry Date: 
Monday, April 2, 2018
Length: 
14 pages
Source (Journal Article): 
Conservation Physiology, Volume 5(1):1-14, 2017
DOI Number (Journal Article): 
10.1093/conphys​/cox061
Year of Publication: 
2017
How to Order: