The Amphibians and Reptiles of Sinaloa, Mexico - Smithsonian ...

98 UNIVERSITY OF KANSAS PUBLS., MUS. NAT. HIST.
Single males were encountered at night in early July, immediately
following heavy rains. On August 18, several calling males were
collected in a pond near La Cruz. A few nights later a large series
of both sexes was collected in the same area. The breeding ponds
were all temporary rain-filled pools, usually on the forest floor. The
water was dirty brown and contained much floating debris. The
majority of males were calling from the water. The tiny frogs would
hang on floating debris, arch their backs and call; sometimes the
black and white mottled vocal pouch was all that was visible of the
songster. The call begins with a peep and continues as a highpitched
buzz of about two seconds duration. Males calling from
the shore usually were concealed in deep grass or in a depression.
All amplexing pairs were taken in shallow water near shore.
Distribution in Sinaloa.—Throughout the lowlands, below 250
meters north of Villa Union. See Fig. 30.
Specimens examined,—5 km. SW Concordia ( e KU 75461); 16 mi. N
fcoyotitan (LACM 6429); 32 km. N Cuhacan ("KU 73928-32): 12 mi. N
(by hwy. 15) Rio EJota (LACM 6457); 15.5 mi. N (by hwy. 15) Rio Elota
(LACM 6458-63); 5 mi. E La Cruz (LACM 6436-56); 10 mi. E La Cruz
(LACM 6430-35); 10.9 mi. N La Cruz turnoff [Las Teposanas] on hwy. 15
(LACM 6428); 5 km. N Los Modus (* KU 73922-27); 2.3 mi. NE (by hwy.
15) Villa Union (CSCLB 1875); 9 km. NE Villa Union (°KU 75451-60);
0.8 mi. S Villa Union (CSCLB 1721).
Literature records.—El Dorado (Fugler and Dixon 1961:8); 13 mi. NE Los
Mochis (Chrapliwy, etal, 1961:89); Mazadan (Hechtand Matalas, 1946;6);
2 mi. E Mazadan (Taylor, 1938:516); 18.6 mi. NNW Mazadan (Wake,
1961:90).
Additional records.—I mi. NE El Fuerte (FMNH 71465-67); 6 mi. S Los
Mochis (SDSNH 19892-93); Mazatlan (USNM 147964-65).
Gastrophryne usta usta (Cope)
Engystoma ustum Cope, Froc. Acad. Nat. Sci. Philadelphia, 18:131, 1866
(type locality, Guadalajara, Jalisco).
Gastrophryne usta: Stejneger, Proc. Biol. Soc. Washington, 23:166, December
29, 1910.
Gastrophryne usta usta: Lynch, Trans. Kansas Acad. Sci., 68:397, November
10, 1965.
Remarks.—Two males and three females have snout-vent lengths
of 25.0, 25.7, 26.9, 27.0, and 25.3 (USNM 73267), respectively. All
females contain eggs. The five frogs examined have a narrow, middorsal
line that is faintly cream-colored and that resembles the middorsal
line in frogs illustrated by Taylor and Smith (1945; plate 32,
figs. 2 and 4); however, there is no trace of a fine line on the posterior
surface of the femur, tibia or foot. All five frogs have two welldeveloped
metatarsal tubercles.
On June 30, a single male was located as it called from beneath