QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online November 5, 2004
Journal of Experimental Biology 207, 4175-4183 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.01285

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Thorsen, D. H. Articles by Hale, M. E. Search for Related Content PubMed PubMed Citation Articles by Thorsen, D. H. Articles by Hale, M. E.

Swimming of larval zebrafish: fin–axis coordination and implications for function and neural control

Dean H. Thorsen¹, Justin J. Cassidy¹ and Melina E. Hale^1,2,3,*

¹ Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL 60637, USA
² Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, USA
³ Committee on Computational Neuroscience, The University of Chicago, Chicago, IL 60637, USA

View larger version (51K): [in a new window]   Fig. 1. Fin and axial locomotion during slow swimming of the larval zebrafish. Fins are actuated in alternating abduction–adduction cycles. The axial muscle bends the body with the same frequency as the fins so that one axial cycle corresponds to one abduction–adduction cycle of the fins. The timing of fin abduction and adduction coincides with maximum axial bending. At 0 ms the right fin is maximally abducted, ready to initiate adduction toward the body. The left fin is in its adducted position against the body. At 10 ms (mid-stroke), the right fin is adducting while the left is abducting. By 20 ms the right fin is fully adducted while the left fin is at fully abducted. This cycle is repeated with the right fin abducting forward and the left adducting back.

View larger version (9K): [in a new window]   Fig. 2. Slow and fast straight swimming of zebrafish larvae demonstrating the distinct swimming gaits during straight swimming. (A) Average velocity across one locomotor cycle, (B) distance traveled in a locomotor cycle, (C) duration of a locomotor cycle, (D) Reynolds (Re) number. All comparisons are significantly different (P<0.0001). All values are given as mean of three trials for each of 10 individuals for slow (N=30) and five individuals for fast swimming (N=15). All data consist of one analyzed tail beat from a longer swimming event. Fish effects were present in two individuals and were not correlated to length.

View larger version (15K): [in a new window]   Fig. 3. Coordination of the fin–axis during slow swimming. (A) Duration of an abduction–adduction cycle. FE, fin cycle excluding refractory period; FER, fin cycle including refractory period; TB, tail beat. *Significantly different (P<0.05). (B) Duration of fin abduction vs adduction (ms). Black bars, adduction; white bars, abduction. EF1 is significantly different (P<0.05) from FE1 and FE2. Values are plotted as mean ± S.E.M.

View larger version (88K): [in a new window]   Fig. 4. Optical sections through pectoral fin muscle of an -actin transgenic zebrafish expressing GFP. Rostral is to the left in all images. Pectoral fin muscle is in the middle of the images. (A) Planar section through the abductor muscle. (B) Adductor muscle (right) and cross section although abductor muscle (left, with arrow), (C) Cross sections through the abductor muscle (left with arrow) and adductor muscle (right), (D) Orientation of the muscle sections A through C of the entire pectoral fin, (E) abductor muscle, (F) abductor muscle and fin membrane. Scale bars, 50 µm.

View larger version (12K): [in a new window]   Fig. 5. Limb–body axis coordination illustrating the similarity in limb–axis locomotor patterns among tetrapods and fishes. (A) Slow swimming in 5 dpf larval zebrafish (N=10) and (B) fast swimming (N=5), (C) running (N=16) and (D) walking (N=20) for the salamander Dicamptodon tenebrosus (modified from Ashley-Ross, 1994). Scale bar in A,B, 20 ms; C,D, 100% of step cycle; LF, left fore foot/fin; RF, right fore foot/fin. Standard errors are indicated. Black bars indicate fin/limb extension. Fin adduction is followed by a short refractory period (open bars) characterized by limb position indeterminably adjacent to body. Body bending, represented as a wave form, and limb extension continues until maximum axial curvature.