A large, eel-like, aquatic salamander. Greater sirens, like other members of the family Sirenidae, lack hindlimbs and eyelids, have horny beaks on the upper and lower jaws, and are gilled throughout life (Martof 1974). Greater sirens have four toes on the front limbs and three gill slits (Martof 1973; 1974; Petranka 1998). Adults range from 50 - 98 cm total length but most are less than 70 cm (Petranka 1998). The tail is 26 - 40% of the total length (Martof 74). There are ventral and dorsal fins on the tail (Martof 1973). Modal number of costal grooves is 37-38 (Martof 1973; Petranka 1998). Adult males have enlarged jaw (masseter) muscles which make the head appear larger than in females (Petranka 1998). Hatchlings are 16 cm total length (13 cm snout to vent length), and possess a relatively shorter tail than adults and a tail fin which extends from the base of the head to the tip of the tail (Martof 1973).

Adult coloration varies from olive green to light gray above and sometimes there are dark spots on the head, back and sides. The sides are lighter colored than the dorsum and usually have flecks of pale green. The venter is bluish grey and often has pale green flecks. Description from Petranka (1998). Juveniles have light, often yellow, body stripes that fade with age (Martof 1973; Petranka 1998).
 
No subspecies are currently recognized, but geographic variation is poorly understood (Petranka 1998). The recent report (Flores-Villela and Brandon 1992) that greater sirens occur in Texas and Mexico (previously specimens were thought to be S. intermedia) is a large extension to the known range and suggests that detailed surveys across the distribution of greater sirens may uncover interesting patterns.

This species occurs in the coastal plain from the District of Columbia through Florida and southern Alabama, USA (Conant and Collins 1991). Large sirens occurring in the Rio Grande Valley (from Upson, Maverick county to Brownsville, Texas, and Matamoros, Tamaulipas, Mexico) were tentatively assigned to this species by Flores-Villela and Brandon (1992).

Siren lacertina, the greater siren, occurs on the coastal plains of the southeastern United States, ranging from the District of Columbia south through Florida and the southern tip of Alabama.

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) This species occurs in the coastal plain from the District of Columbia through Florida and southern Alabama (Conant and Collins 1991). Large sirens occurring in the Rio Grande Valley (from Upson, Maverick county to Brownsville, Texas, and Matamoros, Tamaulipas, Mexico) were tentatively were assigned to this species by Flores-Villela and Brandon (1992).

Occurs in coastal plain habitats from the vicinity of Washington, D. C., to southern Florida and westward to southwestern Alabama (Petranka1998). Greater sirens have also been documented from localities in southern Texas and northeastern Mexico (Tamaulipas) (Flores-Villela and Brandon 1992).

Greater sirens inhabit a variety of permanent and semi-permanent aquatic habitats, including ditches canals, marshes, rice fields, lakes, and slow-moving streams and rivers (Petranka 1998). Sites are often muddy or heavily vegetated. Young are often found among water hyacinth roots (Martof 1973)

Siren lacertina is an aquatic species with a stout, eel-like body. Adults are usually gray or olive, with dark spots on the head, back, and sides. The sides are lighter in color, and have many faint greenish-yellow dashes and blotches. These salamanders have external gills with 3 gill slits. They have front limbs with 4 toes. The tail is compressed with a rounded tip. Greater sirens can range from 49 to 97 cm in length. The common name "greater" comes from the fact that the other species in the genus, the Lesser Siren (Siren intermedia) measures less than 2 feet in total length, in contrast to the "greater" sirens which can exceed 3 feet in length. It's very difficult to distinguish small Greater Sirens from adult Lesser Sirens just by looking at them. Authorities suggest counting costal grooves, these are external grooves along the sides of the animal between the forelimbs and the vent which correspond roughly to the number of ribs. Greater sirens usually have more than 36 costal grooves whereas lesser sirens have less than 35 grooves.

Length: 98 cm

Paratype for Siren lacertina
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Sex/Stage: Female;
Preparation: Ethanol
Year Collected: 1880
Locality: Upson, Maverick, Texas, United States, North America

Paratype for Siren lacertina
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: Matamoros, Tamaulipas, Mexico

Paratype for Siren lacertina
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: Matamoros, Tamaulipas, Mexico

Paratype for Siren lacertina
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: Matamoros, Tamaulipas, Mexico

Paratype for Siren lacertina
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Sex/Stage: Female;
Preparation: Ethanol
Locality: Matamoros, Tamaulipas, Mexico

Paratype for Siren lacertina
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Preparation: Ethanol
Locality: Matamoros, Tamaulipas, Mexico

Habitat and Ecology

Systems

• Terrestrial
• Freshwater

Sirens are most common in ditches, lakes, ponds and other slow-moving fresh water. This nocturnal species spends most of the day hidden under debris or rocks, burrowed in mud or thick vegation. Young are often seen amid water-hyacinth roots. In times of drought they aestivate in mud burrows. Their skin glands secrete a moisture-sealing cocoon over their entire body, except the mouth.

Aquatic Biomes: lakes and ponds; rivers and streams

Comments: It lives in shallow, muddy, weed-choked water: swamps, ponds, lakes, streams, ditches. It is found among thick vegetation, under rocks and logs, or burrowed in bottom mud by day. It burrows into bottom and estivates if water recedes or dries up during drought. The eggs are laid in water in small clusters on bottom.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

Sirens, like amphiumas, are effective predators of many small aquatic animals. They feed primarily on aquatic invertebrates, such as crustaceans and insect larvae. They also eat amphibian eggs and larvae, and small fish, and may consume aquatic plants.

Comments: Eats various small aquatic animals and also plant material. Sometime preys heavily on small snails and bivalves (Moler, 1994, Herpetol. Rev. 25:62).

Comments: May remain inactive (burrowed in substrate) for extended periods during drought.

Average lifespan

Status: captivity: 25.0 years.

Average lifespan

Sex: female

Status: captivity: 14.8 years.

Maximum longevity: 25 years (captivity)

Little research has been done regarding Siren lacertina reproduction. Eggs are usually laid sometime during the months of February and March. The larvae hatch approximately two months later, in April or May. The newly hatched larvae are about16mm long.

Lays clutch averaging about 500 eggs in February-March Hatching occurs in April-May. Paedomorphic.

Greater sirens do not seem to be currently threatened. The most serious threats to their populations are drainage of wetlands and the use of herbicides to clear aquatic vegetation.

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Moderate to broad.

Population

Population Trend

Courship and mating have not been observed. Fertilization is presumed to be external (Martof 1974; Sever et al. 1996). Few nests have been found in nature. Females apparently lay eggs in late winter to early spring (February to March) (Petranka 1998). Eggs are laid in small groups of less than 10 eggs, although a single female may lay more than 100 eggs total (Petranka 1998 and references therein).

Greater sirens eat a range of prey items, including a high proportion of molluscs (snails and freshwater clams). Animals are active primarily at night and retreat to burrows during the day. When temporary pools of water dry up, sirens will aestivate underground and can easily survive for months. Greater sirens vocalize using clicks and yelps, as do lesser sirens. These sounds are produced when animals are disturbed and also may serve for intraspecific communication. Greater sirens are locally abundant in Florida, Georgia, and eastern South Carolina. See Petranka (1998) and references therein.

Despite their large size and abundance in some regions, relatively little is known about the biology and ecology of greater sirens.

Major Threats

Comments: It is unthreatened overall, but many local populations have been reduced or extirpated by loss of wetlands (Petranka 1998) (e.g., as a result of industrial development). The extent to which flood control has reduced opportunities for dispersal among local populations is unknown (Petranka 1998).

In northern and western portions of the range, greater sirens are patchily distributed. More understanding of these peripheral populations is needed (Petranka 1998). Diminshing availability of wetland habitats is a threat to greater siren populations.

Conservation Actions

Management Requirements: The use of herbicides to control aquatic vegetation should be avoided.

This species has no negative effect on humans.

Sirens are mid-level predators in their habitats, and may help control insect and invertebrate populations.

Comments: Large sirens occurring in the Rio Grande Valley of Texas and Mexico tentatively were assigned to SIREN LACERTINA by Flores-Villela and Brandon (1992); they were unable to find any differences that separated these specimens from other S. LACERTINA from the southeastern U.S.