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Frog -- Development of American Bullfrog Specimen
A set of real 8 stages Development of American
Bullfrog (Rana catesbeiana)specimen encased in our proprietary developed lucite material. The specimen is crystal clear, indestructible and transparent. Safe,authentic and completely unbreakable specimen put realFrogright at your fingertips! Anyone can safely explore theFrogfrom every angle. It is clear enough for microscope observation.
Size of thelucite block is 13.5x7.5x2.0 cm (5.3x3.0x0.8 inch).
Each one comes with a cardboard box for easy storage. Weight of thelucite block is260 g and470 g with the box.
It is an ideal learning aid for students and kids and also a very good collectible item for every body.
is a handmade real animal specimen craft. Each one will be a bit different (specimen size, color and posture) even in the same production batch.
The picture in my listing is just for reference as we are selling multiple pieces with the same picture.
I have a lot more animal specimenitems in my you may log in my store to view the details.
1. One Cell
Stage 2. Tailbud Stage 3. Tadpole with External Gill
4. Tadpole with Internal 5. Tadpole with
6. Tadpole with Forelimb 7.
Tadpole Shortened Tail 8. Froglet
Bullfrog - Rana catesbeiana
American bullfrogs (Rana catesbeiana) are only native to the Nearctic
region. They are found from Nova Scotia to central Florida, from the East coast
to Wisconsin, and across the Great Plains to the Rockies. The natural western
limits of this species are now confused due to their introduction into places
as far west as California and Mexico. It is known that bullfrogs were
introduced to areas of California and Colorado in the early 1900's. The species
has also been introduced (accidentally or on purpose) into southern Europe,
South America, and Asia.
North American bullfrogs must live in water and are therefore usually
found near some source of water, such as a lake, pond, river, or bog. Warm,
still, shallow waters are preferred. Bullfrogs are becoming increasingly common
in areas that have been modified by humans. Increased water temperatures and
increased aquatic vegetation, which are common factors of lakes polluted by
humans, favor bullfrogs by providing suitable habitats for growth,
reproduction, and escape from predators.
About four days
after fertilization, spotted tadpoles emerge from the floating egg mass. The
tadpoles have gills and a tail, which eventually disappears as the tadpole
transforms into a froglet. Tadpole development is quite slow; it may take
between one to three years to begin transformation from the tadpole stage into
the adult stage. Adults reach sexual maturity after an
additional two years.
Bullfrogs breed once each year.
May to July in the north and February to October in the south
Number of offspring
4 days (average)
Age at sexual or reproductive maturity
3 to 5 years
Age at sexual or reproductive maturity
3 to 5 years
Breeding takes place in May to July in the north, and
from February to October in the south. Fertilization is external, with the
females depositing as many as 20,000 eggs in a foamy film in quiet, protected
waters. Fertilization is usually, but not always, by one male. Tadpoles emerge
about four days after fertilization. These tadpoles may remain in the tadpole
stage for almost 3 years before transforming into frogs. Adults reach sexual
maturity after 3 to 5 years.
Females provide the eggs with yolk before they are laid.
There is no parental involvement in offspring after the eggs are laid. Newly
hatched tadpoles can take care of themselves right away.
The average bullfrog lives seven to nine years in the
wild. The record lifespan of an animal in captivity is 16 years.
North American bullfrogs prefer warm weather and will
hibernate during cold weather. A bullfrog may bury itself in mud and construct
a small cave-like structure for the winter. Their hunting style is 'sit and
wait.' Bullfrogs can wait for a long time for some type of prey to come by,
then, with a flash of the tongue, they grab it and bring it back into their
mouths. Bullfrogs are active both during the day and at night; they are most
active when the weather is moist and warm.
Adult males are very aggressive and defend their
territories, which can range from 3 to 25 meters of shoreline, by physically
wrestling with others.
The call of a male bullfrog has a low frequency and can
be heard for over one kilometer. The sound is often described as a low rumbling
"jug-o-rum". Bullfrogs also have a good sense of vision and sense
Bullfrogs are predators. They usually eat snakes, worms, insects, crustaceans, frogs, tadpoles, and
aquatic eggs of fish, frogs, insects, or salamanders. They are
cannibalistic and will not hesitate to eat their own kind. There have also been
a few cases reported of bullfrogs eating bats. Bullfrog tadpoles
mostly graze on aquatic plants.
great blue heron
hunt bullfrogs for frog legs, but they have a limited hunting season in most
states. Bullfrogs are also eaten by a wide variety of other
animals, depending on the region. These include herons, such as great blue herons and great egrets, turtles, water snakes, raccoons, and belted kingfishers. Most
fish are averse to eating bullfrog tadpoles because of their undesirable taste.
Importance for Humans: Negative
Introduced bullfrogs may be driving native frogs to
extinction in some areas. Colorado, among many other places, is experiencing
problems due to the introduced bullfrog population. Bullfrogs may have been
introduced accidentally to trout streams and lakes during the Colorado
Divisions of Wildlife fish stocking operations. Bullfrogs occasionally invade
fish hatchery ponds and their larvae are caught along with the fishes that are
routinely stocked in ponds.
Economic Importance for Humans: Positive
North American bullfrogs help to control insect pests.
They are important for medical research because their skeletal, muscle,
digestive, and nervous systems are similar to those of other animals. They are often
hunted for meat (frog legs).
Bullfrogs do well with changes in the environment that
have occured due to human modification, and are becoming increasingly common in
areas modified by humans. Bullfrogs have a much higher critical thermal maximum
than most other frogs, meaning that they are able to thrive in higher water
temperatures. Bullfrogs have a longer breeding season and a higher rate of
pre-metamorphic survivorship, which also allows them to be more successful than
other frogs. In some areas, such as California, bullfrogs are driving other
frog populations to extinction. One possible reason to explain why bullfrogs in
California might have an advantage over other species native to that state is
that bullfrogs evolved with a diverse predatory fish fauna in eastern North
America. In California there have been attempts to control bullfrog populations
by introducing new fish species that are their predators. Bullfrogs have
evolved mechanisms to avoid predation by fish, such as less palatable eggs and
tadpoles, and tadpoles that are not active much of the time, which reduces
their exposure to predators. Native frog species of California are also
suffering a decline because bullfrogs are efficient predators of frogs and
Bullfrogs are well known
for their enormous legs. They are some of the best jumpers in the world and are
used in frog racing in some parts of the United States.
Free shipping cost.
Goods will be sent by airmail from Hong Kong and it may take 12-18 days to arrive.
Full refund within 30 days.
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