Greater Siren Fact File
The siren is an amphibian which resembles an eel having an elongated body with a long tail and short legs.
One of their most prominent features are the feathery gills on either side of the head which are colored red. These gills are retained in to adulthood.
Their body is colored grey, greenish or olive-brown with some individuals have a pattern of spots and others having flat color. Juvenile individuals have a yellow stripe running along the body that fades as they age.
They only have one pair of legs which sit just behind the head. These limbs each feature four toes.
Their body measures between 50 and 90cm (20-35in) long. Males have an enlarged jaw muscle and this makes their head seem larger than that of the female.
Greater sirens are carnivores. Their diet includes crawfish, aquatic insects, snails and small fish. Some individuals have been found with algae in their stomach leading some researchers to conclude they may be omnivorous.
During periods of drought they are able to survive for up to two years without eating.
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North America is the native home of the greater siren where they can be found in the United States and Mexico. Here they live along the east coast from Virginia in the north down south to Florida and west to Alabama.
The Mexican population is a small population near the US border with Texas that was tentatively assigned to this species in 1992.
Greater sirens are an aquatic species which make use of shallow muddy, weed-choked waterways such as swamps, ponds, lakes, streams and ditches. They will rest among vegetation, under rocks and logs or burrow in mud.
Breeding takes place in early spring. Mating takes place in the water. The eggs are laid in small clusters on the bottom of the water. It is thought that fertilization occurs externally but mating in this species has not been observed.
The clutch may include up to 500 eggs which resemble small grapes. The mother will provide protection for these till they hatch.
The eggs will hatch after a two month gestation period following which the young are independent.
Young do not undergo a metamorphosis to become adults like most amphibians and retain the external gills for their entire life.
Sexual maturity is reached between two and three years old.
During times of drought they will cocoon themselves in mud and can remain there for two years until it rains. While in this state they do not eat.
At night they will emerge to forage for food. The day is spent resting in a covered spot.
Almost their entire life is spent on the water though they may come to land for short periods of time.
Breathing is mostly achieved through the gills but they do have lungs and have been seen gulping air at the surface.
Predators and Threats
They can avoid predators by creating sounds to try and intimidate them. Otherwise they swim away aided by their powerful tail or bite the attacker.
Humans affect their population through the loss of wetlands along with disturbance and alteration of their habitat.
Greater sirens are one of the five siren species with all living in North America.
Sirens are considered the most primitive of the salamanders which are currently alive.
Top and Middle One
By Qualiesin – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=86982000
Middle Two and Bottom
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McKenzie, K. 2012. "Siren lacertina" (On-line), Animal Diversity Web. Accessed January 20, 2021 at https://animaldiversity.org/accounts/Siren_lacertina/
Herpsofnc.org. 2021. Greater Siren. [online] Available at: <https://herpsofnc.org/greater-siren/> [Accessed 21 January 2021].
AmphibiaWeb 2001 Siren lacertina: Greater siren <http://amphibiaweb.org/species/4316> University of California, Berkeley, CA, USA. Accessed Jan 20, 2021.
Thealexandriazoo.com. 2021. Greater Siren | Alexandria Zoo. [online] Available at: <https://www.thealexandriazoo.com/GreaterSiren.html> [Accessed 21 January 2021].
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