8142

• UCREFRP Catalog Number: 8142
• Author: Horn, M. J.
• Title: Nutritional Limitation of Recruitment in the Razorback Sucker ‎(
• USFW Year: 1996.
• Copyright Material: NO

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always obvious, a "yolk-check" circulus (much darker than others; Figure 11) commonly
marked the time of first food intake. Slopes of regressions differed significantly from 1.0
for all treatments, indicating increments were not formed daily (Table 3). An ANCOV A
indicated slopes of regression lines also differed from each other based on significant
AGE and AGE*FEED interactions (Table 4). However, no significant FEED effect
existed.
There were significant relationships between otolith size and TL for each
treatment (Table 5, Figure 12). Based on analysis of residual plots, the best-fit model
was 10~ of saggitiU diameter as a function ofTL. When analyzed by ANCOV A (Table
6), treatment intercepts and slopes were significantly different. Regressions for Ad
libitum larvae had a shallower slope than others; Starved and Suboptimal larvae did not
differ.

Relationships between otolith diameter and age had a different pattern. Again, all

regressions were significant (Table 7, Figure 13). An ANCOV A indicated significant

AGE and AGE*FEED interactions (Table 8), which, when incorporated into the model,

makes FEED non-significant. In this case, the slope for the Ad libitum treatment is

steeper than either of the other two, indicating well-fed larvae had otoliths which

increased faster in size relative to the others based on age.

IV. Summary and Discussion

Both sagitta and lapillus are present at hatching in larval razorback suckers.

Asterisci do not appear until 14 to 15 d of age, independent of nutritional condition. As