TY - JOUR
T1 - Physiological markers suggest energetic and nutritional adjustments in male sharks linked to reproduction
AU - S. Rangel, Bianca
AU - Hammerschlag, Neil
AU - Sulikowski, James A.
AU - Moreira, Renata Guimarães
N1 - Funding Information:
We deeply acknowledge the members of the University of Miami Shark Research and Conservation Program, especially Abigail Tinari, for research support. We also thank Kelly Quinn and Alexandre Huber for the courtesy of allowing us to use the illustrations.
Funding Information:
Disney Conservation Fund, The Batchelor Foundation, Save Our Seas Foundation, Fundação de Amparo à Pesquisa do Estado de São Paulo- FAPESP (Grants #2014/16320-7 and #2017/25273-0, PhD’s scholarship to BSR).
Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/8
Y1 - 2021/8
N2 - Energetic condition is one of the most important factors that influence fitness and reproductive performance in vertebrates. Yet, we lack evidence on how energetic states change in response to reproduction in large marine vertebrates. In the present study, we used a non-lethal approach to assess relationships among reproductive stage, circulating steroid hormones (testosterone and relative corticosteroid levels), plasma fatty acids, and the ketone body β-hydroxybutyrate in male sharks of two species with divergent ecologies, the benthic nurse shark (Ginglymostoma cirratum) and the epipelagic blacktip shark (Carcharhinus limbatus). We found higher relative corticosteroid levels in adult nurse sharks during the pre-mating period and in blacktip sharks during the mating period. Higher levels of β-hydroxybutyrate were found in adult nurse sharks during the mating period, but concentrations of this ketone body did not significantly vary across reproductive stages in blacktip sharks. We also detected reduced percentages of essential fatty acids during the mating period of both nurse and blacktip sharks. Taken together, our findings suggest that nurse and blacktip sharks differ in their energetic strategy to support reproduction, however, they likely rely on physiologically important fatty acids during mating, to support spermatogenesis.
AB - Energetic condition is one of the most important factors that influence fitness and reproductive performance in vertebrates. Yet, we lack evidence on how energetic states change in response to reproduction in large marine vertebrates. In the present study, we used a non-lethal approach to assess relationships among reproductive stage, circulating steroid hormones (testosterone and relative corticosteroid levels), plasma fatty acids, and the ketone body β-hydroxybutyrate in male sharks of two species with divergent ecologies, the benthic nurse shark (Ginglymostoma cirratum) and the epipelagic blacktip shark (Carcharhinus limbatus). We found higher relative corticosteroid levels in adult nurse sharks during the pre-mating period and in blacktip sharks during the mating period. Higher levels of β-hydroxybutyrate were found in adult nurse sharks during the mating period, but concentrations of this ketone body did not significantly vary across reproductive stages in blacktip sharks. We also detected reduced percentages of essential fatty acids during the mating period of both nurse and blacktip sharks. Taken together, our findings suggest that nurse and blacktip sharks differ in their energetic strategy to support reproduction, however, they likely rely on physiologically important fatty acids during mating, to support spermatogenesis.
KW - Dietary patterns
KW - Elasmobranchs
KW - Lipid metabolites
KW - Reproductive hormones
KW - Trophic markers
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U2 - 10.1007/s00442-021-04999-4
DO - 10.1007/s00442-021-04999-4
M3 - Article
C2 - 34328556
AN - SCOPUS:85111675529
SN - 0029-8549
VL - 196
SP - 989
EP - 1004
JO - Oecologia
JF - Oecologia
IS - 4
ER -