7277

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

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below), were ccgMted for each pond. Ponds were assigned, insofar as
possible, to each of three groups according to a stratified block
design (Sokal and Rchlf 1967) to reduce within-treatment effects due
to location. 'Three ponds did not conform with block design because
ponds were unevenly distributed among localities. Each group received
different fertilization treatment prior to filling with pimped
groundwater (Marsh 1985) between 8 and 11 February 1985: 341
rcial alfalfa pellets and 57 kg/hectare giosphate-
phosphoxus ("high" fertilization); 170 and 28 ("medium"), and no
application ("low"). Half the original amounts were applied to
fertilized ponds a week later, then biweekly through 3 April.
Adult, wild--caught (Lake Mohave) female razorback suckers
received three injections of 220 N chorionic gonadotropin/kg of body
weight at 24-h intervals for 3 d beginning 11 February 1985 (Hannan
1985). Eggs could be expelled with slight pressure 24 h after the
third injection, ova were stripped and fertilized by milt from
naturally-ripened, Lake Mohave, males. Fertilized eggs were incubated
at 211C in Heaths trays (Inslee 1982). Hatching began on 18 February,
and larvae began to swim actively on 23 February. On 25 February
z
1985, 9.4- to 10.7 Yarn total length (TL) (X = 9.96±0.04, N---50) larvae
were stocked at 250,000 fish/hectare. Fish were not provided E,
F -
supplemental feeding.
'T'hree of the four ponds in each treatment were selected weekly
fox' sampling by use of a table of random number's. Single, 2.0-L
saInples for chlorophyll a were Obtained between 1000 and 1400 hr from