Ecology of large piscivorous fishes in Guri Reservoir, Venezuela, with notes on fish community structure /

a detritivorous characiform, was the dominant species

Bibliographic Details
Main Author: Williams, John David
Format: Thesis eBook
Language:English
Published: [Place of publication not identified] : [publisher not identified] ; 1995.
Subjects:
Online Access:Link to OAKTrust copy
Description
Summary:a detritivorous characiform, was the dominant species
and fishing pressure all influence fish ecology in Guri
Blackwater physicochemistry, the reservoir "boombust" cycle,
captured in gillnets. Cichla spp. appear to breed throughout
Cichla cf orinocensis, Plagioscion squamosissimus and
compare current fish community structure with a previous
Conversely, catch per unit effort for Cichla in gillnets
currently has the second largest hydroelectric facility in
decreased in the current study. Prochilodus rubrotaeniatus,
exhibited heightened fish production immediately after
feeding, and survival. The primary sportfishes in the
for all species were low. Claims of declining Cichla
growing need for electricity which has largely been met with
Guri began complaining about decreased catches. To
Hemigrammus micropterus. In these samples, Cichla temensis,
hydroelectric power, and yet the full effects of river
Hydrolycus scomberoides had greater body condition compared
impoundment on river ecosystems are not known. Venezuela
inundation. However, during the 1990's, sportfishermen at
investigate claims of declining Cichla populations and to
level fluctuations associated with hydroelectric facility
low nutrients, and high dissolved organic matter. Water
operations may have large effects on tropical fish spawning,
Plagioscion squamosissimus had high diet overlap among prey
populations in Guri appear to have some foundation.
reservoir are the peacock basses (Cichla spp.), that
reservoir had 50 species representing 18 different families.
Reservoir.
resources, with the former consuming the largest prey and the
scomberoides and Plagioscion squamosissimus partitioned
smallest prey consumed by the latter. Cichla temensis and
survey, the four large piscivorous fishes of Guri Reservoir
the blackwater Caroni River, Guri is characterized by low pH,
The dominant species in seine samples was the characid
the world, the Raul Leoni Dam (Guri Reservoir). Formed by
the year with a peak before the rainy season. Hydrolycus
types but consumed prey of different sizes. Niche breadths
Venezuela's growing human population is accompanied by a
were sampled. Samples from the northern area of the
with values for conspecifics from a previous study.
Item Description:"Major subject: Wildlife and Fisheries Sciences".
Vita.
Physical Description:x, 77 leaves : illustrations, maps ; 28 cm.
Also available online.
Issued also on microfiche from Lange Micrographics.
Bibliography:Includes bibliographical references.