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:2/1/2016)... YORK , Feb. 1, 2016  Today, the ... Association (AHA) announced plans to develop a first of ... computing power of IBM Watson. In the first application ... AHA, IBM (NYSE: IBM ), and Welltok will ... and health assessments with cognitive analytics, delivered on Welltok,s ...
(Date:1/25/2016)...  Glencoe Software, the world-leading supplier of image data ... provide the data management solution OMERO Plus for the ... Photo - http://photos.prnewswire.com/prnh/20160125/325328LOGO ... Phenotypic analysis measures the characteristics and behavior of ... states such as health and disease, the presence or ...
(Date:1/20/2016)... 2016   MedNet Solutions , an innovative SaaS-based ... clinical research, is pleased to announce the attainment of ... the result of the company,s laser focus on (and ... , it,s comprehensive, easy-to-use and highly affordable cloud-based technology ... Key MedNet growth achievements in 2015 include: ...
Breaking Biology News(10 mins):
(Date:2/10/2016)... ... February 10, 2016 , ... Benchmark Research, a fully-integrated ... of two long-standing principal investigators (PI) to the roles of Chief Medical Officer, ... , Dr. Laurence Chu, a Benchmark Research PI in the Austin office, will ...
(Date:2/10/2016)... ... 10, 2016 , ... LATHAM, NEW YORK... Marktech Optoelectronics will feature ... in San Francisco’s Moscone Center from February 16-18, 2016, and at the healthcare-focused ... latest InGaAs PIN diode standard packages feature a TO-46 metal can with active areas ...
(Date:2/10/2016)... ... February 10, 2016 , ... PatientCrossroads announces ... the secure online PatientCrossroads platform, has exceeded both its one-year and overall recruitment ... PROMPT study, which seeks to advance understanding of the hereditary risks for certain ...
(Date:2/10/2016)... ... 2016 , ... Global Stem Cells Group, a ... Stem Cells Network (GSCN) and its affiliate Global Medical Training Network to ... and bone marrow therapies. , Through the new collaboration, Global Stem Cells ...
Breaking Biology Technology: