Study finds cortisol hormone in North Pacific spiny dogfish blood
Researchers from the University of Manitoba and Bamfield Marine Sciences Center detected cortisol in North Pacific spiny dogfish blood on October 16, 2026.
Old beliefs about shark hormones challenged
Scientists previously thought sharks relied on a different steroid hormone instead of cortisol. New experiments using diluted seawater and antibiotics helped the team identify the hormone in blood samples. This discovery questions assumptions made during research conducted in the 1960s and 1970s.
Methodology separates hormones for accuracy
The team used high-performance liquid chromatography to separate components before measuring hormone levels. This process reduced the risk of mistaking a similar steroid called 1α-hydroxycorticosterone for cortisol. Molecular evidence now hints that these sharks can produce the hormone themselves.
Findings apply to one species only
The study focused specifically on the North Pacific spiny dogfish rather than all shark types. It remains unclear if other rays or shark species share this ability. The paper was published in Proceedings of the Royal Society B.
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