Lower hypoxia thresholds of cuttlefish early life stages living in a warm acidified ocean.
The combined effects of future ocean acidification and global warming on the hypoxia thresholds of marine biota are, to date, poorly known. Here, we show that the future warming and acidification scenario led to shorter embryonic periods, lower survival rates and the enhancement of premature hatching in the cuttlefish Sepia officinalis. Routine metabolic rates increased during the embryonic period, but environmental hypercapnia significantly depressed pre-hatchling's energy expenditures rates (independently of temperature). During embryogenesis, there was also a significant rise in the carbon dioxide partial pressure in the perivitelline fluid (PVF), bicarbonate levels, as well as a drop in pH and oxygen partial pressure (pO₂). The critical partial pressure (i.e. hypoxic threshold) of the pre-hatchlings was significantly higher than the PVF oxygen partial pressure at the warmer and hypercapnic condition. Thus, the record of oxygen tensions below critical pO₂ in such climate scenario indicates that the already harsh conditions inside the egg capsules are expected to be magnified in the years to come, especially in populations at the border of their thermal envelope. Such a scenario promotes untimely hatching and smaller post-hatching body sizes, thus challenging the survival and fitness of early life stages.
Laboratório Marítimo da Guia, Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal. rrosa@fc.ul.pt
Rui
R
Rosa
Katja
K
Trübenbach
Tiago
T
Repolho
Marta
M
Pimentel
Filipa
F
Faleiro
Joana
J
Boavida-Portugal
Miguel
M
Baptista
Vanessa M
VM
Lopes
Gisela
G
Dionísio
Miguel Costa
MC
Leal
Ricardo
R
Calado
Hans O
HO
Pörtner
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D015687:Cell Hypoxia; D057231:Climate Change; D049832:Decapodiformes / Q000196:embryology / Q000502:physiology*; D047108:Embryonic Development; D004734:Energy Metabolism; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010313:Partial Pressure; D013696:Temperature
D002245:Carbon Dioxide
cephalopods; critical oxygen partial pressures; early life stages; global warming; hypoxia; ocean acidification