RECOMMENDATIONS FOR THE DEVELOPMENT OF THE FISHERY RESOURCES 
OF GUATEMALA 
BY 
Ancil D. Holloway 
Aquatic Biologist 
U. S. Fish and Wildlife Service 
Introduction 
The objectives of the fishery investigations were to determin j 
fishes present, their relative abundance, food habits, and the amount of peteati en ts 
evaluate pool, riffle, cover, spawning grounds » and food conditions; and to make physical 
and chemical observations in order to determine the suitability of specific waters for 
fishery developments; to discover the factors involved in developing and increasing the 
utilization of the fishery resources; and finally, to make suggestions for fishery 
developments and for the formulation of stocking and management policies. | 
The methods employed in the investigations were - dictated limi 
by the mode of travel and by the available time. Waters were ce Mae oat age Y 
visited by truck wherever circumstances permitted. Seines, traps » hook-and-line fishing 
and poisons were used for sampling the fish populations. Data were collected on the c 
acidity or alkalinity, carbonates, temperatures, bottom foods, exterit of areas in deep and 
shallow water, and on pool, riffle, and cover conditions. 
To my colleagues, Dr. Robert R. Miller, Assistant Curator, Division of Fisheries 
U. S. National Museum and Senor Julio Midence, assistant and interpreter, both of whom / 
were with the author throughout both expeditions, much credit is due for the success of 
the work. Dr. Robert R. Miller's knowledge and assistance in the identification of fishes 
in the field was indispensable. Without his constant interest and inexhaustible energy, 
mich less would have been accomplished. Senor Julio Midence contributed immeasurably to 
expediting the work of the mission. Seldom is the privilege granted of working with one 
who combines the many admirable qualities of friendly fellowship, humor, and proficiency in 
expediting the planned program. I am indebted to Dr. George B. Saunders, Chief of the 
mission for his kindly suggestions and help in editing the manuscript and assistance given 
during the expeditions. 
Fish Management Problems in the Fresh Waters of Guatemala 
The purpose of fish management is to produce the maximum number of desirable fish, 
with as much utilization as is commensurate with a sustained annual yield. The basic con 
ception that a body of water will support a definite weight of fish has become so well 
established as to be axiomatic. This weight depends on such factors as fertility, temper- 
ature, length of growing season, and the combination of species present, granted that they 
are suitable to the purposes and habitats involved. Fertility, temperature, and length of 
growing season are factors that usually are impracticable to control in most streams and 
large lakes. The combination of species often can be controlled by planting the appropriate 
kinds and numbers. Other well established methods, such as fishing regulations, when 
properly applied, assist in maintaining a balance between the predatory and nonpredatory 
species, as well as between the desirable and nonuseful species. 
The recommendations for introductions and the species to be propagated in this 
case have been based primarily on the principles of fish management developed in the United 
States during the past 50 years. One of the primary facts in an understanding of these 
principles is that most fishes in their proper environment have a very high reproductive 
potential. Unless a high percentage of the young are devoured by large fish and other 
predators, or reduced in numbers by some other factor, the water supports a population of 
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