Navigation Links
Spookfish uses mirrors for eyes
Date:1/7/2009

A remarkable new discovery shows the four-eyed spookfish to be the first vertebrate ever found to use mirrors, rather than lenses, to focus light in its eyes.

Professor Julian Partridge from the University of Bristol, said: "In nearly 500 million years of vertebrate evolution, and many thousands of vertebrate species living and dead, this is the only one known to have solved the fundamental optical problem faced by all eyes how to make an image using a mirror."

While the spook fish looks like it has four eyes, in fact it only has two, each of which is split into two connected parts. One half points upwards, giving the spookfish a view of the ocean and potential food above. The other half, which looks like a bump on the side of the fish's head, points downwards into the abyss below. These 'diverticular' eyes are unique among all vertebrates in that they use a mirror to make the image.

Very little light penetrates beneath about 1000m of water and like many other deep-sea fish the spookfish is adapted to make the most of what little light there is. At these depths it is flashes of bioluminescent light from other animals that the spookfish are largely looking for. The diverticular eyes image these flashes, warning the spookfish of other animals that are active, and otherwise unseen, below its vulnerable belly.

Although the spookfish was first discovered 120 years ago, no one had discovered its reflective eyes until now because a live animal had never been caught. When Professor Hans-Joachim Wagner from Tuebingen University caught a live specimen off the Pacific island of Tonga, members of his research team used flash photography to confirm the fish's upward and downward gazes.

Photographs taken by Dr Tammy Frank looking down on the live fish produced eye-shine in the main tubular eyes that point upwards, but not in the diverticular eyes that point downward. Instead, these reflect light when seen from below.

It was when looking at sections of the eye that had been prepared for microscopy that Professor Partridge realised that the diverticular mirrors where something exciting. The mirror uses tiny plates, probably of guanine crystals, arranged into a multi-layer stack. This is not unique in the animal kingdom (it's why silvery fish are silvery) but the arrangement and orientation of the guanine crystals is precisely controlled such that they direct the light to a focus. Partridge's computer simulation showed that the precise orientation of the plates within the mirror's curved surface is perfect for focusing reflected light onto the fish's retina.

The use of a single mirror has a distinct advantage over a lens in its potential to produce bright, high-contrast images. That must give the fish a great advantage in the deep sea, where the ability to spot even the dimmest and briefest of lights can mean the difference between eating and being eaten.


'/>"/>

Contact: Cherry Lewis
Cherry.lewis@bristol.ac.uk
44-117-928-8086
University of Bristol
Source:Eurekalert  

Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Spookfish uses mirrors for eyes
(Date:6/27/2016)... 2016 Research and Markets has announced the ... report to their offering. The ... to grow at a CAGR of 12.28% during the period ... an in-depth market analysis with inputs from industry experts. The report ... years. The report also includes a discussion of the key vendors ...
(Date:6/22/2016)... American College of Medical Genetics and Genomics was once again ... of the fastest-growing trade shows during the Fastest 50 Awards ... Las Vegas . Winners are ... of the following categories: net square feet of paid exhibit ... 2015 ACMG Annual Meeting was ranked 23 out of 50 ...
(Date:6/22/2016)... June 22, 2016   Acuant , ... verification solutions, has partnered with RightCrowd ® ... for Visitor Management, Self-Service Kiosks and Continuous ... that add functional enhancements to existing physical ... and venues with an automated ID verification ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... -- Alex,s Lemonade Stand Foundation (ALSF), a leading national childhood ... state-of-the-art bioinformatics lab, using ,big data, to advance the ... Liz Scott , co-executive director of ALSF and ... Washington, D.C. , hosted by Vice ... of pediatric cancer research and awareness. ...
(Date:6/27/2016)...  Global demand for enzymes is forecast to ... $7.2 billion.  This market includes enzymes used in ... production, animal feed, and other markets) and specialty ... and beverages will remain the largest market for ... products containing enzymes in developing regions.  These and ...
(Date:6/27/2016)... GUELPH, ON , June 27, 2016 /PRNewswire/ - BIOREM ... it has been advised by its major shareholders, Clean ... LP, United States based venture ... common shares of Biorem (on a fully diluted, as ... for the disposition of their entire equity holdings in ...
(Date:6/27/2016)... 27, 2016  Sequenom, Inc. (NASDAQ: SQNM ... lives through the development of innovative products and services, ... the United States denied its petition to ... of Sequenom,s U.S. Patent No. 6,258,540 (",540 Patent") are ... by the Supreme Court,s Mayo Collaborative Services v. Prometheus ...
Breaking Biology Technology: