9338

• UCREFRP Catalog Number: 9338
• Author: Schler, P. J.
• Title: Colorado Pikeminnow Culture Manual.
• USFW Year: 2001.
• USFW - Doc Type: FY92-37,
• Copyright Material: NO

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INTRODUCTION

The proposal to create this culture manual for Colorado pikeminnow originated in the early
1990s, prior to any significant efforts to raise Colorado River endangered fishes in the Upper Basin
for augmentation or restoration stocking. It was perceived that these initial efforts were part of a
learning experience and documentation of the results would prove useful to subsequent efforts. This
manual is intended to be a source of information for future propagation of this species. Techniques
or approaches or hatchery conditions reported herein were found to have acceptable results. These
findings should be regarded as starting points for future experimentation, not absolute requirements.

HATCHERY W ATER SUPPLY

WATER QUALITY

Temperature
Fish Research Hatchery (FRH) water temperatures ranging from 53 -700 F were used. Cold
water (530F) was piped to six instantaneous natural gas hot water heaters (Fastomatic, International
Technology Sales Corp., Denver, CO and E.L.M. Aquastar, Controlled Energy Corp., Waitsfield,
UT), with each heater producing 3 gpm of hot water (110-1200 F). This hot water is collected into
one line, then distributed via valves into nine independent mixing troughs. Each of these valve sites
also has an independent cold (530 F) water source. Depending on flows needed, desired temperatures
from 53-1200 F can be achieved by mixing water from these two lineS.

Dissolved Gases Criteria
Oxygen - FRH did not work on minimum/maximum oxygen levels. FRH personnel tried to
provide optimum levels of oxygen for each rearing container (see Treatment Of Incoming Water).
One-hundred percent oxygen gas saturation is 8.8 ppm for 530 F, 7.3 ppm for 680 F, and 7.2 ppm for
700F at the FRH (elevation of5124 feet above sealevel). Incoming oxygen levels were 7.5-8.6 ppm,
and the lowest out-going recorded was 6.4 ppm at 68-700F. The wanner the water, the harder it was
to increase oxygen levels by injecting pure oxygen from an oxygen concentration machine because
of the change in partial pressure.

Nitrogen - It was determined that nitrogen gas,. present in the water at 104-105% saturation
at 68 -700 F, caused gas bubble disease in Colorado pikeminnow at the FRH elevation. Fish had air
bubbles under the skin and on the gill surface. A very small percentage of these fish would recover
completely when put into water with less nitrogen gas. If at all possible, nitrogen gas levels (total gas
pressure) should be kept below 100 percent.

Acidity-Hydrogen Ion Concentration (pH)
The range for pH in rearing tanks during culturing was 7.5 -8.0 . No specific evaluation of pH
variation was performed.

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