Non‐lethal assessment of reproductive stage for female blue sharks

Non‐lethal assessment of reproductive stage for female blue sharks Prionace glauca using sex steroid hormones

Y. Fujinami, Y. Semba

ABSTRACT:

We analysed plasma concentrations of progesterone (P₄) and 17β‐oestradiol (E₂) in juvenile, pre‐ovulatory, early, mid‐, or late‐pregnancy stages of female blue sharks Prionace glauca. Concentrations of P₄ were significantly higher in pregnant than in non‐pregnant individuals, while E₂ concentrations increased with embryonic and follicular development. We develop a highly accurate (86.1%) random forest classification model to predict shark pregnancy. We propose that hormone concentrations could be used for subsequent non‐lethal determination of female P. glauca reproductive state.

Journal of Fish Biology (2020), DOI: 10.1111/jfb.14312

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