Maj's blog: "just random things"

Amphibians Frogs are members of the zoological class called Amphibia. Amphibians are cold-blooded (or poikilothermic) vertebrate animals. They differ from reptiles in that they lack scales and generally return to water to breed. They are one of three types of Amphibians. Anura, also called Salientia, (frogs and toads), caudate (salamanders and newts) and caecilians (worm-like amphibians). Herps and Herpetology Amphibians together with reptiles make up a larger group called Herps. The study of reptiles and amphibians is called Herpetology. Herp comes from the Greek word herpeton, which basically means "creepy crawly things that move about on their bellies." A herptile is an individual herp. A person who keeps and breeds herps is called a herpetoculturist and the hobby is called herpetoculture. Frogs Generally speaking, though, when we think of frogs, we generally picture what are called "True Frogs".... members of the family Ranidae, containing more than 400 species. These frogs have the characteristics of: two bulging eyes strong, long, webbed hind feet that are adapted for leaping and swimming smooth or slimy skin (generally, frogs tend to like moister environments) Frogs tend to lay eggs in clusters. Frogs from this family can be found on every continent except Antarctica. They are referred to as the "true frogs" because of their generalized body form and life history: the so-called generic frog. Members of this family include the bullfrog, common frog, green frog, leopard frog, marsh frog, pickerel frog, and wood frog. Toads The term toads tends to refer to "True Toads".... members of the family Bufonidae, containing more than 300 species. These types of frogs have are characterized by: stubby bodies with short hind legs (for walking instead of hopping) warty and dry skin (usually preferring dryer climates) paratoid (or poison) glands behind the eyes The chest cartilage of toads is different also. Toads tend to lay eggs in long chains. (There are some toads (genera Nectophrynoides), however, that are the only types of anurans to bear live young!) True Toads can be found worldwide except in Australasia, polar regions, Madagascar, and Polynesia, though Bufo marinus has been artificially introduced into Australia and some South Pacific islands. Besides Bufo, the family includes 25 genera, all of which, like the frogs, are anura! Do frogs have teeth? Actually, yes! But not like in this silly picture! Most frogs do in fact have teeth of a sort. They have a ridge of very small cone teeth around the upper edge of the jaw. These are called Maxillary Teeth. Frogs often also have what are called Vomerine Teeth on the roof of their mouth. They don't have anything that could be called teeth on their lower jaw, so they usually swallow their food whole. The so-called "teeth" are mainly used to hold the prey and keep it in place till they can get a good grip on it and squash their eyeballs down to swallow their meal. Toads, however, do NOT have any teeth. Some frogs have tongues that are long and sticky that can be used to catch bugs. These roll out like an upside-down party horn and snap at the bug! (YUMMY!) Frogs with long tongues go by the "see it, snap at it" technique of feeding. Toads, on the other hand, like my firebellied toads, have tiny tongues and have to snap at their food using their mouth. They often will stalk their food, much like a cat...creeping up to it and then just as dinner is about to take off, they will *SNAP* and eat their meal! DID YOU KNOW: When a frog swallows a meal, his bulgy eyeballs will close and go down into his head! This is because the eyeballs apply pressure and actually push a frog's meal down his throat! *GULP* There are about 6 to 14 species of tongueless, aquatic African frogs (family Pipidae) too Life Cycle of a Frog True Love? When Frogs mate, the male frog tends to clasp the female underneath in an embrace called amplexus. He literally climbs on her back, reaches his arms around her "waist", either just in front of the hind legs, just behind the front legs, or even around the head. Amplexus can last several days! Usually, it occurs in the water, though some species, like the bufos on the right mate on land or even in trees! While in some cases, complicated courting behavior occurs before mating, many species of frogs are known for attempting to mate with anything that moves which isn't small enough to eat! Spawn (egg-mass) While in the amplexus position, the male frog fertilizes the eggs as they get are laid. Frogs tend to lay eggs single eggs in masses, whereas toads usually lay eggs in long chains. Some frogs leave after this point, but others stick around to watch over the little ones. Some have very unusual ways of caring for their young. You'll learn about some of those later in this tour!. Egg Frogs and Toads tend to lay many many eggs because there are many hazards between fertalization and full grown frogness! Those eggs that die tend to turn white or opaque. The lucky ones that actually manage to hatch still start out on a journey of many perils. Life starts right as the central yolk splits in two. It then divides into four, then eight, etc.- until it looks a bit like a rasberry inside a jello cup. Soon, the embryo starts to look more and more like a tadpole, getting longer and moving about in it's egg. Usually, about 6-21 days (average!) after being fertilized, the egg will hatch. Most eggs are found in calm or static waters, to prevent getting too rumbled about in infancy! Some frogs, like the Coast foam-nest treefrog, actually mate in treebranches overlooking static bonds and streams. Their egg masses form large cocoon-like foamy masses. The foam sometimes cakes dry in the sun, protecting the inside moisture. When the rain comes along, after developement of 7 to 9 days, the foam drips down, dropping tiny tadpoles into the river or pond below. Shortly after hatching, the tadpole still feeds on the remaining yolk, which is actually in its gut! The tadpole at this point consists of poorly developed gills, a mouth, and a tail. It's really fragile at this point. They usually will stick themselves to floating weeds or grasses in the water using little sticky organs between its' mouth and belly area. Then, 7 to 10 days after the tadpole has hatched, it will begin to swim around and feed on algae. After about 4 weeks, the gills start getting grown over by skin, until they eventually disappear. The tadpoles get teeny tiny teeth which help them grate food turning it into soupy oxygenated particles. They have long coiled guts that help them digest as much nutrients from their meadger diets as possible. By the fourth week, tadpoles can actually be fairly social creatures. Some even interact and school like fish! Tadpole with legs After about 6 to 9 weeks, little tiny legs start to sprout. The head becomes more distinct and the body elongates. By now the diet may grow to include larger items like dead insects and even plants. The arms will begin to bulge where they will eventually pop out, elbow first. After about 9 weeks, the tadpole looks more like a teeny frog with a really long tail. It is now well on it's way to being almost fullgrown! Young Frog, or Froglet By 12 weeks, the tadpole has only a teeny tail stub and looks like a miniature version of the adult frog. Soon, it will leave the water, only to return again to laymore eggs and start the process all over again! Frog By between 12 to 16 weeks, depending on water and food supply, the frog has completed the full growth cycle. Some frogs that live in higher altitudes or in colder places might take a whole winter to go through the tadpole stage...others may have unique development stages that vary from your "traditional" tadpole-in-the-water type life cycle: some of these are described later in this tour. Now these frogs will start the whole process again...finding mates and creating new froggies. frog tracks When a bullfrog scuttles across your garden, the marks he'll leave will look like the ones above! They aren't really footsteps though, they're more like - belly and toe marks! Look for them near wet marshes, ponds and streams wherever frogs are common! Frogs have variable kinds of eye types. The colored part of the eye is called the iris (EYE-riss). They can be brown, green, silver, red, bronze, and even gold. The pupils come in all kinds of shapes too! (2) Round pupils: Some frogs have round pupils just like you and me. Newts and Salamanders also have round pupils. (2) Vertical pupils: Vertical pupils that look like a cats eye are really good for night vision and respond quickly to changes in light. 3) Horizontal-Shaped pupils: These are the more common pupil, good for normal day-vision. (4) Heart-Shaped pupils: I'm not sure if it serves any purpose, but it sure looks neat! Oriental fire-bellied Toads have this type of pupil. Some frogs have Triangular pupils, and some even have Star-Shaped pupils! ((((( 2 be continued... .dang)