
The lower basin was examined between 3:30 and 4:30 p.m., March 20, 1946. The air 
enperature was 24.4 degrees Centigrade; the surface water, 23.3; and the bottom (30 meters), 
2.2 degrees. Oxygen was determined in parts per million as follows: 1 meter, 9.8; 
nevers, 6.2; 10 meters, 5.2; 15 meters, 4.2; 20 meters, 2.8; 25 meters, 3.4; and 30 meters, 
The Secchi disk (20 centimeters in diameter) disappeared at 3.04 meters. 
i 
Meek (1908) gives the results of an analysis of water from Laguna de Amatitlan as 
w 
Ln AD ce 
~ 
f 
om 
ele 
follows: 
140.0 parts per million 
Magnesium carbonate 27.3 parts per million 
Sodium and potassium chlorides 210.0 parts per million 
Potassium nitrate 2.0 parts per million 
Total, including miscellaneous substances 421.0 parts per million 
Calcium carbonate 
Amphipods, locally called "pulgas", are abundant and constitute an important food of the 
guapote. Shrimps or "camarones" (Palaemon carcinus) and crabs or “cangrejos" (Potamocarcinus 
guatemalensis) are common. The camarones and cangrejos are abundant near shore during the 
breeding season, which is said by Meek (1908) to be in April, May, and June for the 
canarones, and February, March, and April for the cangrejos. After the breeding season, 
these forms enter deeper water and are more difficult to capture. . 
Stocking Recommendations.—-The guapote is furnishing a considerable quantity of 
food, but the lake would produce more food if it contained fishes that utilize additional 
habitats, particularly deeper water. For increasing the food production, we suggest the 
introduction of the crappie (Pomaxis nigro-maculatus ) and the channel catfish (Ictalurus 
lacustris punctatus). In order to prevent an over-abundance of the above forms, and to 
provide sport fishing, the smallmouth (Micropterus dolomieu) and largemouth (M. salmoides) 
bass are recommended. It is essential to have the largemouth bass present as a predator, 
to reduce the numbers and permit more rapid growth of the crappie and mojarras. Although 
the lake appears well suited for smallmouth bass, this species has not proved as satis- 
factory as the largemouth bass in regulating populations. A combination of both the basses 
makes for improved sport fishing, as there are times when one species will take a hook and 
the other will not. These recommendations are tentative and provisional. 
Lago de Atitl&n 
Lago Atitldn is a mountain lake about five kilometers south of Solola, at an 
altitude of 1,554 meters. It is about twenty kilometers long and seven wide. ‘Two arms, 
one at each end, extending southward. The total area is more than 200 square kilometers. 
The lake is surrounded by mountains which rise directly from the water's edge to an eleva- 
tion of about 760 meters above its surface. To the south, the summits of the volcanoes 
Toliman and Atitlan reach altitudes of 3,153 and 3,525 meters, respectively; and to the 
southwest, the volcanoes San Pedro and Santa Clara reach 3,024 and 2,127 meters. Lake 
Atitlan has no surface drainage to the sea. A number of small streams enter the lake, 
At the west and east ends, the lake bottom descends rapidly to depths of 100° 
meters or more within 130 meters of the shore. Along the south shore between San Lucas and 
Santiago Atitlan, the bottom slopes are less steep, and there are several smll coves. In 
the coves and along mich of the shore in shallow water are tules (Typha and Scirpus). 
Potamogeton and Chara are abundant in the coves and along mich of the rock shore lines out 
to depths of six or seven meters. The north shore from Santa Cruz to Santa Catalina consists 
largely of wave-swept sandy and gravelly beaches. The littoral areas between one and one- 
_half and seven meters are covered with Potamogeton and Chara. Much of the lake bottom is 
more than 300 meters in depth, and rather flat. The greatest depth found was approximately 
320 meters. 
Chemical Data.—Oxygen samples taken at various depths and recorded in parts per 
million were as follows: May 8, 1946, 8:00 to 10:00 a.m., 1 meter - 4.9; 10 meters - 6.6; 
20 meters — 6.1; 40 meters - 6.1; 60 meters - 5.6; 80 meters - 5.33; 100 meters ~ 5.0. 
May 9, 1946, 8:00 to 10:00 a.m., 120 meters - 4.33 150 meters ~- 4.7; 190 meters - 5.0; 230 
meters - 4.1; 270 meters ~ 3.2; 320 meters (bottom) - 3.9. May 15, 1947, 8:30 to 9:30 a.m, 
1 meter - 7.0; 30 meters ~ 8.3; 60 meters — 3.6; 90 meters - 5.13 213 meters -~ 2.2. 
108 
