7113 ‎(2)‎

• UCREFRP Catalog Number: 7113
• Author: La Rivers, I.
• Title: Fishes and Fisheries of Nevada.
• USFW Year: 1962.
• USFW - Doc Type: Fishes and Fisheries of Nevada.
• Copyright Material: YES

f FISHES AND FISHERIES OF NEVADA 113
cam it now Dissolved solids are high enough to substantially enrich the water as
fiver flowage. far as plankton production is concerned, but are not marked. The pub-
plored quite lished figures of 596 to 766 parts per million (U. S. Geol. Surv. Water
force, is gen- Supply Paper 970) can be compared with 30-40 ppm for rainwater,
ring up to it 300 ppm as a generally accepted freshwater lake maximum, and 4,700
contact with ppm for Pyramid Lake.
eiaeo Garek, Hydrogen-ion (pH) concentration is on the alkaline side-the writer
sda, saw the obtained a reading of pH 8.4 at Fort Mohave in 1951. Moffett (1942:
rder in 1776. 81) noted a pH of 8.2 in the river channel below Hoover Dam before
the impoundment of Lake Mohave.
' SUMMARY
ip longer exist The writer's field tests in 1951 at Fort Mohave below Davis Dam
me-time Jim- showed the following figures: CO, from 2.5 to 5.0 parts per million;
ater environ- IICO, from 159 to 161 ppm; chlorides-sulfates present; chlorine-.
!ations in the Kulfides-iron lacking.
BIOLOGICAL CONDITIONS
BIOTA IN THE FISH FOOD CHAIN
of the Colo- While the river invertebrate and plant life could be expected to
M left is the change at least quantitatively with construction of Hoover and Davis
ire length of Dams, we know little about such changes. Surveys in the river below
tained species latke Mead before Davis Dam was built, and below Davis Dam later on
e reflected in show that the Colorado River still contains supplies of fish foods.
re fishes---the Algae (chiefly Cladophora sp.) is a very common attachment material
all have flat, (in submerged objects and is often found in trout stomachs. Smaller
when pointed planktonic crustacea such as the widespread waterfleas Daphnia and
s dorsal keels Diaptontus occur in locally protected spots while such of the larger
eeuliar fish in aquatic insects as mayflies and true flies were plentiful. The author
lined form of and others (Moffet, 1942, has summarized these earlier efforts) have
collected these as, well as many others of the common types of aquatic
Dam has not in-wets, all utilizable as fish food.
rred consider-
Original Fish Fauna of the Colorado River System Within Historical Times
(A) SALMON AND TROUT FAMILY, Family Salmmridae
hutlly iucreas- 1. Colorado Cutthroat Trout (Salmo clarki plcuriticus)
mr in the lower
cling the river
(B) SUCKER FAMILY, Family Catostomidac
4 basin and 2. Flannelmouth Sucker (Catostomus latipinnis)
: downstream. :1. Razorback Sucker (Xpranchen teaan is)
L

a clearer-a
ind

(C) CARP AND MINNOW FAMILY, Family Cyprinidac
4. Colorado Squaw6slt (Ptpchoche-ilns lncii(s)
5. Colorado Gila (Gila robusta and subspecies)
6. White River Speckle Dace (Rhinichthys oscnlus velifer) (Las
tygen reading Vegas `Wash)
of 6.8 and 7.3 7. Virgin River Spinedace (Lepidonteda mollispinis moll4pin-is)
9the gas. S. Woundfin (Plapopterus-argentissintns)