PUBLICATION
The contribution of the swimbladder to buoyancy in the adult zebrafish (Danio rerio): A morphometric analysis
- Authors
- Robertson, G.N., Lindsey, B.W., Dumbarton, T.C., Croll, R.P., and Smith, F.M.
- ID
- ZDB-PUB-080306-26
- Date
- 2008
- Source
- Journal of morphology 269(6): 666-673 (Journal)
- Registered Authors
- Croll, Roger P.
- Keywords
- teleost, cyprinid, gas bladder, stereology, anatomy, morphology
- MeSH Terms
-
- Air Sacs/anatomy & histology*
- Animals
- Body Weights and Measures
- Female
- Male
- Pressure
- Swimming*
- Zebrafish/anatomy & histology*
- Zebrafish/physiology
- PubMed
- 18302241 Full text @ J. Morphol.
Citation
Robertson, G.N., Lindsey, B.W., Dumbarton, T.C., Croll, R.P., and Smith, F.M. (2008) The contribution of the swimbladder to buoyancy in the adult zebrafish (Danio rerio): A morphometric analysis. Journal of morphology. 269(6):666-673.
Abstract
Many teleost fishes use a swimbladder, a gas-filled organ in the coelomic cavity, to reduce body density toward neutral buoyancy, thus minimizing the locomotory cost of maintaining a constant depth in the water column. However, for most swimbladder-bearing teleosts, the contribution of this organ to the attainment of neutral buoyancy has not been quantified. Here, we examined the quantitative contribution of the swimbladder to buoyancy and three-dimensional stability in a small cyprinid, the zebrafish (Danio rerio). In aquaria during daylight hours, adult animals were observed at mean depths from 10.1 +/- 6.0 to 14.2 +/- 5.6 cm below the surface. Fish mass and whole-body volume were linearly correlated (r(2) = 0.96) over a wide range of body size (0.16-0.73 g); mean whole-body density was 1.01 +/- 0.09 g cm(-3). Stereological estimations of swimbladder volume from linear dimensions of lateral X-ray images and direct measurements of gas volumes recovered by puncture from the same swimbladders showed that results from these two methods were highly correlated (r(2) = 0.85). The geometric regularity of the swimbladder thus permitted its volume to be accurately estimated from a single lateral image. Mean body density in the absence of the swimbladder was 1.05 +/- 0.04 g cm(-3). The swimbladder occupied 5.1 +/- 1.4% of total body volume, thus reducing whole-body density significantly. The location of the centers of mass and buoyancy along rostro-caudal and dorso-ventral axes overlapped near the ductus communicans, a constriction between the anterior and posterior swimbladder chambers. Our work demonstrates that the swimbladder of the adult zebrafish contributes significantly to buoyancy and attitude stability. Furthermore, we describe and verify a stereological method for estimating swimbladder volume that will aid future studies of the functions of this organ.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping