
of large fish desirable for angling and food, 
ed where sufficient predatory fishes are 
jlizes enough of the larger ones to keep the 
small fish and does not provide the quantities 
The most satisfactory fishing is usually obtain 
resent to feed on the young, and where man ut : 
fish population sufficiently reduced in numbers to permit rapid growth. Otherwise, the 
j j i f old age before they reach 
i ow so slowly that the major portion of them die o 
a eerie see for angling and food. In the Southern United States most game and food 
j i i d three years of life. In most 
fishes die a natural death by the time they have complete 
species, less than three to five per cent of the individuals live long enough to begin their 
fourth year of life. 
Qur observations of the fishes in the waters of Guatemala indicate that the same 
principles apply there for the desirable food fishes such as the mojarras (Cichlasoma) 
have a high reproductive potential as indicated usually by tremendous numers of small 
individuals and a limited number of sizes suitable for food. It is betteved that the over— 
population results also from the sml1l nunber of predator fishes of sufficient size to be 
effective in interior waters. Exceptions to this rule occur in Iago Izabal and other waters 
near the coast, including the coastal lagoons of the Pacific area. In the fresh waters of 
the coastal areas, anadromous fishes such as the robalos (Centropomus), sharks (Carcharhinus), 
sabalo (Tarpon), and others perform the necessary predation, in part at least. 
The most useful species to man are those which are satisfactory as food and sport 
because of large size, palatability of flesh, and habits that make them easily captured by 
inexpensive and readily obtainable gear. It is the author's belief that the low utiliza- 
tion of the inland fisheries of Guatemala is due primarily to the fact that there are few 
excellent game fishes that can be caught readily and in quantity by hook-and-line fishing. 
With the exception of the guapote, and two or three of the other mojarras (Cichlasoma), 
Guatemalan fresh-water fishes cannot be taken readily by hook-and-line fishing. It is true 
that the robalo and some of the other anadromous forms that occur in the lowland waters are 
excellent sport fishes when hooked, but they are rather difficult to take, except at certain 
periods of the year. 
Species Recommended for Introduction 
For reasons given below, it is recommended that introductions of exotic species 
be made only in Lago Atitlan and Rio Motagua in the immediate future. If these trial 
introductions prove successful, other introductions could be made as outlined in the report. 
The introduction of a species of fish into a water where it does not occur often 
produces results not anticipated. In most instances, such introductions have been made 
without knowledge of the fishes already present, and without knowledge of the habitat or of 
the ecologic relationship that must be established between predatory and nonpredatory fishes 
in order to develop and maintain a fish population most suitable for man's use. The 
successful introduction of fishes involves four important considerations, namely: the 
ecologic relationship between predators and the fishes they take principally as food; 
whether sport or food fishes are desired; the type of habitat involved; and the selection 
of fishes that are adapted to the habitat and purpose for which the introduction is made. 
When species never before associated together are introduced in the same water, only a 
guess can be made as to their success in complementing each other and satisfying man's pur- 
poses. Hence, common sense dictates that introductions be made on a closely limited basis, 
and the results used as an index of the desirability of similar introductions in other 
waters. Accordingly, recommendations for planting of exotic species other than those for 
Lago Atitlan and Rio Motagua must be regarded as provisional and subject to change. 
For developing the resources of Lago Atitlan, we have recommended the introduction 
of smallmouth bass (Micropterus dolomieu), and the black crappie (Pomoxis nigro-maculatus). 
Lago Atitlan was chosen because it is an interior drainage where the introduced fishes 
cannot escape to other waters. 
The smallmouth bass, (Micropterus dolomieu), is similar to the largemouth bass 
but suitable for cool water such as that in Lagos Atitlan and Ayarza, and the more rapid. 
streams where gradients are between one-half and five meters per kilometer. It does not 
grow as large as the largemouth bass, but is excellent sport and food fish. 
100 
