Impact of ocean acidification on the early development and escape behavior of marine medaka (Oryzias melastigma)

Highlights

  • No significantly negative growth effects were observed in larvae exposed higher pCO2.
  • Eye defects and abnormal development of brain were obvious in exposed larvae.
  • Escape behavior was vulnerable to ocean acidification.

Abstract

Ocean acidification is predicted to affect a wide diversity of marine organisms. However, no studies have reported the effects of ocean acidification on Indian Ocean fish. We have used the Indian Ocean medaka (Oryzias melastigma) as a model species for a marine fish that lives in coastal waters. We investigated the impact of ocean acidification on the embryonic development and the stereotyped escape behavior (mediated by the Mauthner cell) in newly hatched larvae. Newly fertilized eggs of medaka were reared in seawater at three different partial pressures of carbon dioxide (pCO2): control at 450 μatm, moderate at 1160 μatm, and high at 1783 μatm. Hatching rates, embryonic duration, and larval malformation rates were compared and were not significantly different between the treatments and the control. In the high pCO2 group, however, the yolks of larvae were significantly smaller than in the control group, and the newly hatched larvae were significantly longer than the larvae in the control. In the moderate pCO2 group, the eye distance decreased significantly. No significantly negative growth effects were observed in the larvae when exposed to pCO2 levels that are predicted as a result of ocean acidification in the next 100–200 years. Larvae reared under control conditions readily produced C-start escape behavior to mechanosensory stimuli; however, in the moderate and high pCO2 experimental groups, the probabilities of C-start were significantly lower than those of the control group. Therefore, the sensory integration needed for the C-start escape behavior appears to be vulnerable to ocean acidification. Altered behavior in marine larval fish, particularly behaviors involved in escape from predation, could have potentially negative implications to fish populations, and, further, to the marine ecosystems at the levels of CO2 projected for the future.

Wang X., Song L., Chen Y., Ran H. & Song J., in press. Impact of ocean acidification on the early development and escape behavior of marine medaka (Oryzias melastigma). Marine Environmental Research. Article (subscription required).

0 Responses to “Impact of ocean acidification on the early development and escape behavior of marine medaka (Oryzias melastigma)”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,025,347 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book