The annual migration of Christmas IslandÂÌñ»»ÆÞ™s red crabs ÂÌñ»»ÆÞ“ where millions of creatures cover its beaches as they make their way from land to sea ÂÌñ»»ÆÞ“ is a true natural spectacle.
However, little is known about whether and how the species might be impacted under the future environmental conditions created by the changing global climate.
A new study by scientists and graduates at the ÂÌñ»»ÆÞ has investigated one aspect of how such shifts might affect its earliest development.
Specifically, the research focused on whether lower salinity ÂÌñ»»ÆÞ“ caused by future increased rainfall during the tropicsÂÌñ»»ÆÞ™ monsoon season, which would in turn dilute coastal waters ÂÌñ»»ÆÞ“ might delay the development of crab embryos.
To understand that, the researchers exposed fertilised late-stage embryos of the crab (Gecarcoidea natalis) to four different levels of sea water salinity.
Over the space of 24 hours, they then used a specially-developed and autonomous analysis technology ÂÌñ»»ÆÞ“ the
LabEmbryoCam ÂÌñ»»ÆÞ“ to measure a number of the embryosÂÌñ»»ÆÞ™ key developmental and physiological traits.
Previous research had shown that environmental drivers such as salinity can impact the timing and duration of developmental events in aquatic early life stages of crustaceans.
However, the results of this new study found that changes in salinity had no impact on the time of first heartbeat, time of hatching, first in-egg embryonic and post-hatch heart rate, or post-hatch movement.
Writing in the study, published in the Journal of Experimental Biology, the researchers say the findings may ÂÌñ»»ÆÞ“ on the face of it ÂÌñ»»ÆÞ“ appear positive for the red crabsÂÌñ»»ÆÞ™ future survival.
However, with the study focused on just one environmental stressor ÂÌñ»»ÆÞ“ and one period of embryo development ÂÌñ»»ÆÞ“ they also highlighted the importance of considering all early life stages when fully characterising the effects of environmental drivers on crustacean development.
Dr Lucy Turner
