Linked Life Data

16320259

Source:http://linkedlifedata.com/resource/pubmed/id/16320259

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2005-12-6
pubmed:abstractText
The Australian lungfish Neoceratodus forsteri (Dipnoi) is an ancient fish that has a unique phylogenetic relationship among the basal Sarcopterygii. Here we examine the ultrastructure, histochemistry, and distribution of the retinal photoreceptors using a combination of light and electron microscopy in order to determine the characteristics of the photoreceptor layer in this living fossil. Similar proportions of rods (53%) and cones (47%) reveal that N. forsteri optimizes both scotopic and photopic sensitivity according to its visual demands. Scotopic sensitivity is optimized by a tapetum lucidum and extremely large rods (18.62 +/- 2.68 microm ellipsoid diameter). Photopic sensitivity is optimized with a theoretical spatial resolving power of 3.28 +/- 0.66 cycles degree(-1), which is based on the spacing of at least three different cone types: a red cone containing a red oil droplet, a yellow cone containing a yellow ellipsoidal pigment, and a colorless cone containing multiple clear oil droplets. Topographic analysis reveals a heterogeneous distribution of all photoreceptor types, with peak cone densities predominantly found in temporal retina (6,020 rods mm(-2), 4,670 red cones mm(-2), 900 yellow cones mm(-2), and 320 colorless cones mm(-2)), but ontogenetic changes in distribution are revealed. Spatial resolving power and the diameter of all photoreceptor types (except yellow cones) increases linearly with growth. The presence of at least three morphological types of cones provides the potential for color vision, which could play a role in the clearer waters of its freshwater environment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9967
pubmed:author
pubmed:copyrightInfo
Copyright 2005 Wiley-Liss, Inc
pubmed:issnType
Print
pubmed:day
20
pubmed:volume
494
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
381-97
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Morphology, characterization, and distribution of retinal photoreceptors in the Australian lungfish Neoceratodus forsteri (Krefft, 1870).
pubmed:affiliation
School of Biomedical Sciences, The University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia. h.bailes@uq.edu.au
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't