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For other uses, see Tadpole (disambiguation). Tadpole_sentence_0

"Polliwog" redirects here. Tadpole_sentence_1

For other uses, see Polliwog (disambiguation). Tadpole_sentence_2

A tadpole (also called a pollywog) is the larval stage in the life cycle of an amphibian. Tadpole_sentence_3

Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpole_sentence_4

Tadpoles have some features that may not be found in adult amphibians such as a lateral line, gills, and tails. Tadpole_sentence_5

As they undergo metamorphosis, the diet of tadpoles changes and they will start to breathe air. Tadpole_sentence_6

Having no hard parts, it might be expected that fossil tadpoles would not exist. Tadpole_sentence_7

However, traces of biofilms have been preserved and fossil tadpoles have been found dating back to the Miocene. Tadpole_sentence_8

Tadpoles are eaten in some parts of the world and are mentioned in various folk tales from around the world. Tadpole_sentence_9

Etymology Tadpole_section_0

The name tadpole is from Middle English taddepol, made up of the elements tadde, 'toad', and pol, 'head' (modern English poll). Tadpole_sentence_10

Similarly, pollywog / polliwog is from Middle English polwygle, made up of the same pol, 'head', and wiglen, 'to wiggle'. Tadpole_sentence_11

General description Tadpole_section_1

The life cycle of all amphibians involve a larval stage that is intermediate between embryo and adult. Tadpole_sentence_12

Tadpoles of frogs are mostly herbivorous, while tadpoles of salamanders and caecilians are carnivorous. Tadpole_sentence_13

Anura Tadpole_section_2

Tadpoles of frogs and toads are usually globular, with a laterally compressed tail and internal gills. Tadpole_sentence_14

When first hatched, anuran tadpoles have external gills that are eventually covered by skin. Tadpole_sentence_15

Newly hatched tadpoles are also equipped with a cement gland which allows them to attach to objects. Tadpole_sentence_16

The tadpoles have a cartilaginous skeletons and a notochord which eventually develops into a proper spinal cord. Tadpole_sentence_17

Most tadpoles have a flattened tail with which they swim by lateral undulation. Tadpole_sentence_18

Tadpoles have spiracles through which water exits the opercular chamber. Tadpole_sentence_19

Depending on the species, there can be two spiracles on both sides of the body, a single spiracle on the underside near the vent, or a single spiracle on the left side of the body. Tadpole_sentence_20

Anuran tadpoles are usually herbivorous, feeding on soft decaying plant matter. Tadpole_sentence_21

The gut of most tadpoles is long and spiral shaped to efficiently digest organic matter, and can be seen through the bellies of many species. Tadpole_sentence_22

Though many tadpoles will feed on dead animals if it is available to them, only a few species of frog have strictly carnivorous tadpoles. Tadpole_sentence_23

An example being the frogs of the family Ceratophryidae, their cannibalistic tadpoles having wide gaping mouths with which they devour other organisms, including other tadpoles. Tadpole_sentence_24

Another example is the tadpoles of the New Mexico spadefoot toad (Spea multiplicata) which will develop a carnivorous diet along with a broader head, larger jaw muscles, and a shorter gut if food is scarce, allowing them to consume fairy shrimp and their smaller herbivorous siblings. Tadpole_sentence_25

A few genera such as Pipidae and Microhylidae have species whose tadpoles are filter feeders that swim through the water column feeding on plankton. Tadpole_sentence_26

Megophrys tadpoles feed at the water-surface using unnusual funnel-shaped mouths. Tadpole_sentence_27

As a frog tadpole matures it gradually develops its limb, with the back legs growing first and the front legs second. Tadpole_sentence_28

The tail is absorbed into the body using apoptosis. Tadpole_sentence_29

Lungs develop around the time as the legs start growing, and tadpoles at this stage will often swim to the surface and gulp air. Tadpole_sentence_30

During the final stages of metamorphosis, the tadpole's mouth changes from a small, enclosed mouth at the front of the head to a large mouth the same width as the head. Tadpole_sentence_31

The intestines shorten as they transition from a herbivorous diet to the carnivorous diet of adult frogs. Tadpole_sentence_32

Tadpoles vary greatly in size, both during their development and between species. Tadpole_sentence_33

For example, in a single family, Megophryidae, length of late-stage tadpoles varies between 3.3 centimetres (1.3 in) and 10.6 centimetres (4.2 in). Tadpole_sentence_34

The tadpoles of the paradoxical frog (Pseudis paradoxa) can reach up to 27 centimetres (11 in), the longest of any frog, before shrinking to a mere snout-to-vent length of 3.4–7.6 cm (1.3–3.0 in). Tadpole_sentence_35

While most anuran tadpoles inhabit wetlands, ponds, vernal pools, and other small bodies of water with slow moving water, a few species are adapted to different environments. Tadpole_sentence_36

Some frogs have terrestrial tadpoles, such as the family Ranixalidae, whose tadpoles are found in wet crevices near streams. Tadpole_sentence_37

The tadpoles of Micrixalus herrei are adapted to a fossorial lifestyle, with a muscular body and tail, eyes covered by a layer of skin, and reduced pigment. Tadpole_sentence_38

Several frogs have stream dwelling tadpoles equipped with a strong oral sucker that allows them to hold onto rocks in fast flowing water, two examples being the Indian purple frog (Nasikabatrachus sahyadrensis) and the tailed frogs (Ascaphus) of Western North America. Tadpole_sentence_39

Although there are no marine tadpoles, the tadpoles of the crab-eating frog can cope with brackish water. Tadpole_sentence_40

Some anurans will provide parental care towards their tadpoles. Tadpole_sentence_41

Frogs of the genus Afrixalus will lay their eggs on leaves above water, folding the leaves around the eggs for protection. Tadpole_sentence_42

Female Pipa frogs will embed the eggs into their backs where they get covered by a thin layer of skin. Tadpole_sentence_43

The eggs will hatch underneath her skin and grow, eventually leaving as either large tadpoles (such as in Pipa parva) or as fully formed froglets (Pipa pipa). Tadpole_sentence_44

Female marsupial frogs (Hemiphractidae) will carry eggs on her back for various amounts of time, with it going as far as letting the tadpoles develop into tiny froglets in a pouch. Tadpole_sentence_45

Male African bullfrogs (Pyxicephalus adspersus) will keep watch over their tadpoles, attacking anything that might be a potential threat, even though he may eat some of the tadpoles himself. Tadpole_sentence_46

Males of the Emei mustache toads (Leptobrachium boringii) will construct nests along riverbanks where they breed with females and keep watch over the eggs, losing as much as 7.3% of their body mass in the time they spend protecting the nest. Tadpole_sentence_47

Male midwife toads (Alytes) will carry eggs between their legs to protect them from predators, eventually releasing them into a body of water when they are ready to hatch. Tadpole_sentence_48

Poison dart frogs (Dendrobatidae) will carry their tadpoles to various locations, usually phytotelma, where they remain until metamorphosis. Tadpole_sentence_49

Some female dart frogs such as the strawberry poison dart frog (Oophaga pumilio) will regularly lay unfertilized eggs for the developing tadpoles to feed on. Tadpole_sentence_50

Fossil record Tadpole_section_3

Despite their soft-bodied nature and lack of mineralised hard parts, fossil tadpoles (around 10 cm in length) have been recovered from Upper Miocene strata. Tadpole_sentence_51

They are preserved by virtue of biofilms, with more robust structures (the jaw and bones) preserved as a carbon film. Tadpole_sentence_52

In Miocene fossils from Libros, Spain, the brain case is preserved in calcium carbonate, and the nerve cord in calcium phosphate. Tadpole_sentence_53

Other parts of the tadpoles' bodies exist as organic remains and bacterial biofilms, with sedimentary detritus present in the gut. Tadpole_sentence_54

Tadpole remains with telltale external gills are also known from several labyrinthodont groups. Tadpole_sentence_55

Human use Tadpole_section_4

Some tadpoles are used as food. Tadpole_sentence_56

Tadpoles of megophryid frog Oreolalax rhodostigmatus are particularly large, more than 10 cm (3.9 in) in length, and are collected for human consumption in China. Tadpole_sentence_57

In India, Clinotarsus curtipes are collected for food, and in Peru Telmatobius mayoloi tadpoles are collected for food and medicine. Tadpole_sentence_58

Mythology and history Tadpole_section_5

According to Sir George Scott, in the origin myths of the Wa people in China and Myanmar, the first Wa originated from two female ancestors Ya Htawm and Ya Htai, who spent their early phase as tadpoles ("rairoh") in a lake in the Wa country known as Nawng Hkaeo. Tadpole_sentence_59

In the Ancient Egyptian numerals, a hieroglyphic representing a tadpole was used to denote the value of 100,000. Tadpole_sentence_60

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Tadpole.