The reticulated siren (''Siren reticulata''), also known commonly as the leopard eel, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of aquatic

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Sirenidae Sirenidae, the sirens, are a family of neotenic aquatic salamanders. Family members have very small fore limbs and lack hind limbs altogether. In one species, the skeleton in their fore limbs is made of only cartilage. In contrast to most other ...

. The species, which is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the

southeastern United States The Southeastern United States, also referred to as the American Southeast or simply the Southeast, is a geographical region of the United States. It is located broadly on the eastern portion of the southern United States and the southern por ...

, was first formally described in 2018. This cryptic salamander is known only from three localities in southern

Alabama (We dare defend our rights) , anthem = "Alabama" , image_map = Alabama in United States.svg , seat = Montgomery , LargestCity = Huntsville , LargestCounty = Baldwin County , LargestMetro = Greater Birmingham , area_total_km2 = 135,765 ...

and the Florida panhandle and is one of the largest animals in the United States to be newly described in the past 100 years.

Description

The reticulated siren is one of the largest species of extant (living) salamanders worldwide, reaching up to in total length, which rivals the

hellbender The hellbender (''Cryptobranchus alleganiensis''), also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of the ...

of the

Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...

as both the largest amphibian in North America and the fourth largest salamander in the world. It has a greenish grey, eel-like body, large external gills, and two small front legs. The sides and belly are a lighter yellowish green. It has an average snout to vent length (SVL) of . ''S. reticulata'' differs from other ''

Siren Siren or sirens may refer to: Common meanings * Siren (alarm), a loud acoustic alarm used to alert people to emergencies * Siren (mythology), an enchanting but dangerous monster in Greek mythology Places * Siren (town), Wisconsin * Siren, Wisc ...

'' species in its skin patterning: a patchwork of dark, leopard-like spots covering its back. It also has a relatively smaller head and a longer tail.

Genetic analysis Genetic analysis is the overall process of studying and researching in fields of science that involve genetics and molecular biology. There are a number of applications that are developed from this research, and these are also considered parts of ...

from mitochondrial and nuclear sequencing supported it as a separate species from '' S. intermedia'' and '' S. lacertina'', and further suggested that additional species are yet to be discovered in this group.

Biology

Almost nothing is known about the life history or ecology of ''S. reticulata''.

Habitat

The

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

of ''S. reticulata'' includes wetlands within the

longleaf pine ecosystem The longleaf pine ecosystem is a climax savanna habitat found within the Southern United States; it includes many rare plant and animal species, and is one of the most biodiverse in North America. Once the largest ecosystem in North America, it n ...

Discovery

The first known reticulated siren was collected in 1970, in

Baldwin County, Alabama Baldwin County is a county located in the southwestern part of the U.S. state of Alabama, on the Gulf coast. It is one of only two counties in Alabama that border the Gulf of Mexico, along with Mobile County. As of the 2020 census, the pop ...

, described by herpetologist Robert Hughes Mount as not conforming to the typical physical description of ''S. lacertina''. It was not formally named at that time and was treated as somewhat of a legend, colloquially referred to as the "leopard eel". Another sighting of numerous individuals was made in the 1990s by the herpetologist John Jensen, who reportedly sighted dozens of reticulated sirens and amphiumas moving across a road during a rainstorm near Florala, Alabama. In September 2009, American herpetologist David A. Steen was studying ''

Nerodia ''Nerodia'' is a genus of nonvenomous colubrid snakes commonly referred to as water snakes due to their aquatic behavior. The genus includes nine species, all native to North America. Description ''Nerodia'' species vary greatly, but all are ...

'' (water snakes) and turtles at Eglin Air Force Base in Okaloosa County, Florida, when he captured a single specimen of ''S. reticulata'' in a crayfish trap. Additional trapping efforts between 2009 and 2014 were unsuccessful until three more sirens were found in June 2014 near Lake Jackson in

Walton County, Florida Walton County is located on the Emerald Coast in the northwestern part of the U.S. state of Florida, with its southern border on the Gulf of Mexico. As of the 2020 census, the population was 75,305. Its county seat is DeFuniak Springs. The c ...

. The reticulated siren is one of the largest animals in the United States to be newly described in the past 100 years.

Taxonomy

The leopard eel was formally described as ''Siren reticulata'' in December 2018. The specific epithet ''reticulata'' refers to the reticulated (meaning network-like or patchwork) patterning typical of this species. The authors of the 2018 paper coined the name reticulated siren as a "more appropriate formal common name", as it is neither a leopard nor an eel. It is one of three extant species in the genus ''Siren''. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

is a female captured in Walton County, Florida, measuring from snout to vent and weighing . The type locality habitat was a shallow

marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found a ...

vegetated with floating and emergent plants.

References

{{Taxonbar, from=Q59490209 Sirenoidea Amphibians described in 2018 Amphibians of the United States Endemic fauna of the Southeastern United States