The Americ
an bullfrog
Lithobates catesbeianus h
as been introduced
around the world, with inv
asive popul
ations reported from
almost
all South Americ
an countries. A popul
ation of this species w
as introduced in the C
aling
ast
a dep
artment of S
an Ju
an province, which is
an
arid environment in western Argentin
a. This work provides inform
ation on the diet
ary composition of
an inv
asive popul
ation of
L. catesbeianus,
and comp
ares the degree of diet
ary overl
ap between
adults
and juveniles. Stom
ach contents of 169 bullfrogs (82
adults
and 87 juveniles) were
an
alysed. Adults consumed 40 prey t
ax
a and Hymenopter
a (Insect
a) w
as the most numerous prey item (41.8%), followed by Ar
ane
ae (13.6%)
and Aeglid
ae (13.4%). Juveniles consumed 29 prey t
ax
a and Hymenopter
a constituted the highest percent
age in prey number (77.2%). The trophic overl
ap niche index
at the s
ame level shows
a v
alue of 0.64 overl
ap in diet
ary community between
adults
and juveniles of this bullfrog. Aeglid
ae w
as volumetric
ally the most import
ant trophic item (25.4%), followed by Anur
a (25.02%). Our results showed th
at c
annib
alism in bullfrogs is more common th
an the consumption of n
ative
anur
ans, coinciding with th
at reported in other popul
ations of introduced bullfrogs. The high simil
arity in the diets of both size cl
asses
and the
associ
ation between the size of the pred
ator
and prey suggest th
at the imp
act c
aused by bullfrogs throughout their ontogeny is high
and prob
ably h
as
an imp
act on their prey. Freshw
ater cr
abs
are the m
ain items in the diet of
Lithobates catesbeianus in other introduced popul
ations
and
are usu
ally the most conspicuous
at our study site. The cr
abs in freshw
ater ecosystems
are p
art of the lowest trophic level in the food ch
ain. The m
ajor thre
ats to the southern region’s freshw
ater cr
abs include deforest
ation, f
arming
and exotic species.
Lithobates catesbeianus h
as
a gener
alist diet
and high overl
ap between
adults
and juveniles.
相似文献