>  Water velocities in this river change rapidly with precipitation, but at
>some places and times I recorded velocities of around 60 cm/sec.
>Free-swimming young of the species I study (Cichlasoma tuba, TL = roughly
>1 cm to 1.5cm) were maintaining position in these currents (with some
>difficulty).  This comes out to 40 to 60 body lengths per second of
>sustained swimming (for at least a few days before the water slowed down).
>This seems pretty high to me in comparison to the values I seem to be
>encountering in the literature.
>
>My question: is this unusually athletic or are there other fish doing
>similar things?  Any pointers would be gratefully received.


Ron,

There is a good published paper on critical swimming speed on fry from a
sister? family (Pomacentrids),

Stobutzki I, Bellwood DR. 1994. An analysis of the sustained swimming
abilities of pre- and post-settlement coral reef fishes. Journal of
Experimental Marine Biology and Ecology  175: 275-296.

Stobutzki and Bellwood found  swimming speeds comparable to your guestimate
in similar sized pomacentrid larvae.

Good luck,



Jeff

======================================
Jeff Walker
Dept. of Zoology
Field Museum of Natural History
Roosevelt Rd. at Lake Shore Dr.
Chicago, IL 60605, USA
phone: 312-922-9410 x537  fax: 312-427-7269
email: [log in to unmask]

"I like practical applications in mathematics, rather than speculating
about the first ten to the minus something seconds of the universe.
Cosmology seems to be almost too close to theology to be interesting.
To me, it is not quite science, but more like creation myth."

- Sir James Lighthill on Stephen Hawking
======================================