CAECILIANS

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CAECILIANS

• The Unknown Amphibian

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Who are they?

• Order Gymnophiona
• Family 5 families
• Genus 26
• Species 124
• Habitat loose soil, leaf litter in tropical
  forests or rivers and streams

• Length up to 2.4m
• shortest 3.5 in.
• Up to 2.2 lbs
• Life span up to 13
• yrs in zoos
• Offspring 30 60
• eggs 2 - 25 young
• born

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Range
Central Africa, Southeast Asia, Southern Mexico
to Argentina
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Description

• Caecilians are tropical amphibians that look like
  large worms or slick snakes. They have no arms or
  legs, and sometimes its hard to tell which end
  is the head and which is the tail! Their shiny
  skin is ringed with skin folds called annuli, and
  they usually come in shades of gray, brown,
  black, orange, or yellow. Some species have tiny,
  fishlike scales (dermal scales) within the rings.

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Annuli and Smooth
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Dermal Scale Present in Some Caecilians
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Oviparous Species

• Some female caecilians lay eggs in damp holes
  near water. When the larvae hatch they have gills
  and a short, finned tail to help them swim in the
  water, feeding on plankton. Through a series of
  changes the gills are replaced by a single lung,
  the skin becomes thicker, the annuli develop, and
  sensory tentacles appear. At this point the newly
  developed adult returns to the land and goes
  underground.

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Caecilian Embryo
Embryo removed from egg. Yolk is visible as well
as sensory structures along head and side of
body. These include mechano- and electrical
receptors of the lateral line. Eggs are laid
in burrows near streams. hatch, larval stage
lives in streams until metamorphosis a
year later.
Icthyophis kohtaoensis
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Viviparous Species

• Some species give birth to live young that are
  fully developed inside the mother before they are
  born.

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Larval Caecilian
Aquatic stage with gills that are transient.
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Senses

• A hard, thick, pointy skull helps these
  amphibians dig in soft dirt. Because of their
  underground lifestyle, caecilians have little
  need to see or hear. Therefore, their eyes are
  very tiny in some species, or hidden under the
  skin or skull in other species, making just tiny
  gray bumps for eyes. Some species in South
  America spend their lives in water instead of on
  land. Caecilians dont have ear openings, so it
  is doubtful they can hear sounds.

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Tentacles

• Tentacles, located between the nostrils and the
  eyes, are used to locate prey and detect
  surroundings.

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Diet

• Inside a caecilians mouth are dozens of
  needle-sharp teeth. The teeth are used to grab
  worms, termites, beetle pupae, mollusks, small
  snakes, frogs, lizards, and even other
  caecilians. All food is swallowed whole.

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Eating tubifex worms
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Skin Glands

• Caecilians have toxic glands in their skin that
  sometimes protect them from being eaten by other
  animals.

Mucus glands
Toxic glands
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Fossorial
Adult caecilian can bury itself in a matter of
minutes. Fossorial animals spend most of their
time underground.
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Caecilian Head
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Families of Caecilians

• Rhinatrematidae South America
• Ichthyophiidae Southeast Asia
• Uraeotyphlidae Southern India
• Scolecomorphidae Subsahara Africa
• Caeciliaidae South and Central America,
• Subsahara Africa, Southern Asia
• Typhlonectidae South America

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Rhinatrematidae

• Small, terrestrial caecilian with aquatic larvae

_at_1998 Marvalee H. Wake
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Ichthyophiidae

• Large terrestrial caecilian with aquatic larvae

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Uraeotyphlidae

• 30cm, oviparous, all are gray brown in color

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Scolecomorphidae

• 45 cm, terrestrial, brown and black in color
• Ovoviviparous, possibly viviparous
• Eyes are very reduced

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Caeciliaidae

• Very varied with small (10cm) to large (1.5m)
  organisms.
• Terrestrial, aquatic, oviparous, viviparous.
• Most are gray black but some are more colorful.

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Typhlonectidae

• Aquatic caecilian, viviparous
• Larval gills

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Typhlonectes
Sometimes sold in fish stores. Aquatic. Female
with young.
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Aquatic Species