Herring Aids

These are pictures of the left and right ears of the blue antimora (Antimora rostrata), a deep-sea cod. In the picture of the right ear (on the right), you can clearly see the three otolith organs as white objects. The saccular otolith in this species is very large and heavy. Copyright Xiaohong Deng, Neuroscience and Cognitive Science Program, University of Maryland. http://www.life.umd.edu/biology/popperlab/research/deepsea.htm.

Left and right ears of the blue antimora (Antimora rostrata), a deep-sea cod. In the pictures you can clearly see the three otolith organs as white objects and the three semicircular canals. Courtesy of Xiaohong Deng, Neuroscience and Cognitive Science Program, University of Maryland. http://www.life.umd.edu/biology/popperlab/research/deepsea.htm.

Obviously, fish do not possess the big fleshy ears. Talk about swimmer’s ear? Instead, sound transmits from the water into the fish body and to a set of internal ears. Keep in mind a fish’s body is about the same density as water, so the sound passes easily.  These ‘ears’ are divided into the pars superior, the upper bit, and utriculus, the lower bit. The pars superior contains three fluid-filled semicircular canals, each filled with sensory hairs, allowing a fish to determine yaw, pitch, and roll. The utriculus possesses the otoliths, little bony plate that are denser than water.  The difference between the movement in the fish and otoliths stimulate the cilia on the sensory hair cells.

Deep-sea fish may be better than their shallow water cousins at hearing. A graduate student at University of Maryland, Xiaohong Deng, will present in May at the Acoustical Society of America Meeting will present evidence that some deep-sea fish specialized structures to heighten their hearing, herring aids if you will. These adaptations included:

• a connection between the ears and swim bladder, the latter acting like a resonating chamber,
• elaborately-oriented hair bundles in the inner ear,
• exceptionally rigid ears and stalks projecting from stones in the ear, not seen in shallow-water fish and still bewildering.

Deng states, “We have already found many specializations and adaptations in the eyes and olfactory systems of deep-sea fishes; it is reasonable to think that their hearing should also be important in the dark,” says Deng.

Those trying for the Mile-Down Club may want to be a little quieter.

Dr. M (1748 Posts)

Craig McClain is the Assistant Director of Science for the National Evolutionary Synthesis Center, a National Science Foundation supported initiative. He has conducted deep-sea research for 20 years and published over 50 papers in the area. He has participated in and led dozens of oceanographic expeditions taken him to the Antarctic and the most remote regions of the Pacific and Atlantic. Craig’s research focuses on how energy drives the biology of marine invertebrates from individuals to ecosystems, specifically, seeking to uncover how organisms are adapted to different levels of carbon availability, i.e. food, and how this determines the kinds and number of species in different parts of the oceans. Craig’s research has been featured on National Public Radio, Discovery Channel, Fox News, National Geographic and ABC News. In addition to his scientific research, Craig also advocates the need for scientists to connect with the public and is the founder and chief editor of the acclaimed Deep-Sea News (http://deepseanews.com/), a popular ocean-themed blog that has won numerous awards. His writing has been featured in Cosmos, Science Illustrated, American Scientist, Wired, Mental Floss, and the Open Lab: The Best Science Writing on the Web. His forthcoming book, Science of the South (http://www.scienceofthesouth.com/), connects cultural icons of South such as pecan pie with the science behind them.


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