7277

• UCREFRP Catalog Number: 7277
• Author: Papoulias, D.
• Title: Survival and Growth of Larval Razorback Sucker,
• USFW Year: 1988.
• Copyright Material: NO

56
range of larvae sampled (Fig. 8B). Thus, in order to maintain volume,
progressively larger organisms were eaten. Overall, numbers of items
in guts did not differ among ponds for a given size of fish.
The relationship of upper lip length (LL) to TL in larval
razorback suckers between 10 and 26 mm, TL (r2=.94) is described by the
equation:
LL = 0.21 + 0.06(TL).
Maxhmmm widths of organisms in guts increased linearly with increasing
LL (x2=.92), but at a lesser rate (Fig. 9). Mean sizes (= width) of
organisms eaten also increased linearly (r2=.82) friom 0.1 to 0.3 mm
over the TL range of fish studied. There were no statistical
differences in any of these relationships among treatments.
There were similarly no differences among treatments in selection
of prey by taxon or size. Data f±cmt all ponds were therefore pooled
for analysis of larval food selection. Larvae selected rotifers and
tiny chironmids soon after they cmvexxmd feeding (Fig. 10).
Copepods and chironomids were eaten by intermediate-sized fish. The
largest fish clearly selected cladocerans.
Taxonomic trends in organisms eaten were mostly explained by the
sizes of available foods (Fig. 11). Small larvae selected for
organisms 0.1 mm or less in width (largely rotifers and chironomids),
shifted to copepods (--0.2 mm wide) with growth, and ate animals 0.3 mm
or larger (largely cladocerans) when greater than 18 mm M.