Southern dwarf siren

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Southern dwarf siren
P axanthus USGS.jpg
Status TNC G4.svg
Apparently Secure  (NatureServe) [2]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Urodela
Family: Sirenidae
Genus: Pseudobranchus
Species:
P. axanthus
Binomial name
Pseudobranchus axanthus
Netting & Goin, 1942 [3]
Pseudobranchus axanthus Range.jpg

The southern dwarf siren, (Pseudobranchus axanthus) is a perennibranch salamander lacking hind legs. Found exclusively in Florida, [2] it is one of two currently recognized species of dwarf sirens. Two subspecies are currently recognized; P. a. axanthus, the narrow-striped dwarf siren, and P. a. belli, the Everglades dwarf siren.

Contents

Physical description

Southern dwarf sirens are thin, slimy salamanders that are frequently mistaken for eels. They have long bodies with bushy gills and small, three-toed fore legs. Coloration is generally brown, black, or gray, with yellow or tan stripes on their backs and sides. Adults reach a length of 10 centimetres (3.9 in) to 25 centimetres (9.8 in).

Southern dwarf sirens can easily be distinguished from amphiumas by size and the presence of hind legs, and from Siren spp. salamanders by the presence of three toes on each foot. Distinguishing between P. axanthus and P. striatus is more difficult, requiring comparison of patterns with a field guide, known distribution, or a karyotype test. P. axanthus has 32 chromosomes, while P. striatus has 24. A costal groove count may assist in differentiating P. a. axanthus and P. a. belli, as the former has 34–37 costal grooves, while the latter has 29–33 (Petranka, 1998).

Distribution

P. axanthus is found throughout eastern Florida, with P. a. axanthus located in the northern two-thirds of the range and P. a. belli located in the southern third. P. axanthus prefers cypress ponds, ditches, swamps and marshes, and other aquatic and semiaquatic habitats. [4] P. axanthus is frequently associated with water hyacinth.

Reproduction

Little is known about the reproduction of wild sirenid salamanders. Eggs of P. axanthus have been found from November through March, and are usually attached singly to aquatic plants. Eggs average 3 mm in diameter and have three jelly envelopes. [4]

In captivity, eggs were attached singly at night to floating vegetation in groups of two to five a day. Larvae hatch out at about 5 mm after around three weeks.

Diet

Southern dwarf sirens eat a variety of food items, including small worms, chironomids, amphipods, and ostracods. [4] Dwarf sirens have surprisingly small mouths, but will likely eat any invertebrate they can swallow. In captivity, adult Daphnia magna , whiteworms, blackworms, and tubifex worms are readily taken.

Ecology

During dry spells, P. axanthus is known to aestivate in muddy burrows, and adults have been kept for periods longer than two months in dry soil with no ill effects in the laboratory. [4]

Related Research Articles

<span class="mw-page-title-main">Sirenidae</span> Family of amphibians

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 salamanders, they have external gills bunched together on the neck in both larval and adult states. Sirens are found only in the Southeastern United States and northern Mexico.

<span class="mw-page-title-main">Proteidae</span> Family of amphibians

The family Proteidae is a group of aquatic salamanders found today in the Balkan Peninsula and North America. The range of the genus Necturus runs from southern central Canada, through the midwestern United States, east to North Carolina and south to Georgia and Mississippi. The range of the olm, the only extant member of the genus Proteus, is limited to the Western Balkans. The fossil record of the family extends back to the Late Cretaceous, with Paranecturus being known from the Maastrichtian of North America, and Bishara from the Santonian-Campanian of Central Asia.

<span class="mw-page-title-main">Greater siren</span> Species of amphibian

The greater siren is an amphibian and one of the five members of the genus Siren. The largest of the sirens and one of the largest amphibians in North America, the greater siren resides in the coastal plains of the southeastern United States.

<span class="mw-page-title-main">Two-toed amphiuma</span> Species of amphibian

The two-toed amphiuma is an aquatic salamander widely distributed in the southeastern United States. It is commonly, but incorrectly, called "congo snake", "conger eel" or the "blind eel".

<span class="mw-page-title-main">Northwestern salamander</span> Species of amphibian

The northwestern salamander is a species of mole salamander that inhabits the northwest Pacific coast of North America. These fairly large salamanders grow to 8.7 in (220 mm) in length. It is found from southeastern Alaska on May Island, through Washington and Oregon south to the mouth of the Gualala River, Sonoma County, California. It occurs from sea level to the timberline, but not east of the Cascade Divide. Its range includes Vancouver Island in British Columbia and The San Juan Islands, Cypress, Whidbey, Bainbridge, and Vashon Islands in Washington.

<span class="mw-page-title-main">Long-toed salamander</span> Species of amphibian

The long-toed salamander is a mole salamander in the family Ambystomatidae. This species, typically 4.1–8.9 cm (1.6–3.5 in) long when mature, is characterized by its mottled black, brown, and yellow pigmentation, and its long outer fourth toe on the hind limbs. Analysis of fossil records, genetics, and biogeography suggest A. macrodactylum and A. laterale are descended from a common ancestor that gained access to the western Cordillera with the loss of the mid-continental seaway toward the Paleocene.

<span class="mw-page-title-main">Four-toed salamander</span> Species of amphibian

The four-toed salamander is a lungless salamander native to eastern North America. It is the only species of the monotypic genus Hemidactylium.

<span class="mw-page-title-main">Marbled salamander</span> Species of amphibian

The marbled salamander is a species of mole salamander found in the eastern United States.

<span class="mw-page-title-main">Lesser siren</span> Species of amphibian

The lesser siren is a species of aquatic salamander native to the eastern United States and northern Mexico. They are referred to by numerous common names, including two-legged eel, dwarf siren, and mud eel. The specific epithet intermedia denotes their intermediate size, between the greater siren, Siren lacertina, and the dwarf sirens, Pseudobranchus species.

<span class="mw-page-title-main">Southeastern dwarf salamander</span> Species of amphibian

The southeasterndwarf salamander, formerly known as the dwarf salamander, is a species of salamander native to the southern United States, ranging primarily from southern North Carolina south to northern Florida, with some populations from southwestern Alabama to eastern Louisiana. Some sources refer to it as the four-fingered manculus, dwarf four-toed salamander, or the Florida dwarf salamander.

<span class="mw-page-title-main">Dwarf siren</span> Genus of amphibians

Dwarf sirens are eel-like salamanders of the genus Pseudobranchus. Dwarf sirens possess external gills throughout adulthood and lack hind legs, and can be distinguished from members of the genus Siren in that dwarf sirens have three toes on each foot rather than four. Whereas sirens have three gill slits, dwarf sirens keep just a single slit. Like sirens, dwarf sirens are restricted to the Southeastern United States.

<span class="mw-page-title-main">Northern dwarf siren</span> Species of amphibian

The northern dwarf siren is a perennibranch salamander lacking hind legs. Found in the Southeastern United States, it one of two currently recognized species of dwarf sirens. Three subspecies are currently recognized; P. s. striatus, the broad-striped dwarf siren, P. s. lustricolus, the Gulf Hammock dwarf siren, and P. s. spheniscus, the slender dwarf siren.

The northern banana salamander, also known as common dwarf salamander or rufescent salamander, is a species of salamander in the family Plethodontidae. It is found in the Atlantic slopes of Meso-America from San Luis Potosi, Veracruz, and northern Chiapas in Mexico continuing on to the southern part of Guatemala, Belize, and northern Honduras. However, its range south of Mexico is uncertain because the records may refer to other species.

<i>Desmognathus fuscus</i> Species of amphibian

Desmognathus fuscus is a species of amphibian in the family Plethodontidae. The species is commonly called the dusky salamander or northern dusky salamander to distinguish it from populations in the southern United States which form several distinct species, the southern dusky salamanders. The northern dusky salamander is the most widespread representative of its genus in Canada. It can be found in eastern North America from extreme eastern Canada in New Brunswick south to South Carolina. The size of the species' total population is unknown, but is assumed to easily exceed 100,000. The species' habitat differs somewhat geographically; dusky salamanders in the northern part of the range prefer rocky woodland streams, seepages, and springs, while those in the south favor floodplains, sloughs, and muddy places along upland streams. They are most common where water is running or trickling. They hide under various objects, such as leaves or rocks, either in or near water. Alternatively, they may enter burrows for protection. The dusky salamander lays its eggs close to water under moss or rocks, in logs, or in stream-bank cavities. The larval stage which follows is normally aquatic.

The black mountain salamander is a species of salamander in the family Plethodontidae.

<span class="mw-page-title-main">Northern two-lined salamander</span> Species of amphibian

The northern two-lined salamander is a species of salamander in the family Plethodontidae found in Canada and the United States. Its natural habitats are temperate forests, temperate shrubland, rivers, intermittent rivers, freshwater marshes, freshwater springs, arable land, and urban areas. It is more water-oriented than the related northern redback salamander, and can often be found in and around water such as rain puddles, streams, swamps, and damp stream beds, whereas the northern redback tends to be found in damp ground, but usually not near open water.

<span class="mw-page-title-main">Chamberlain's dwarf salamander</span> Species of amphibian

Chamberlain's dwarf salamander is a species of salamander in the family Plethodontidae, endemic to the United States. It is only found in the states of North Carolina and South Carolina. It was previously thought to be a color morph of the southeastern dwarf salamander, but was described in 2003 as a distinct species based on distinct morphology and behavior. A 2017 study reaffirmed it as being a distinct species. It is estimated that E. chamberlaini diverged from E. quadridigitata anywhere from 27 to 15 million years ago.

<span class="mw-page-title-main">Cave salamander (spotted-tail)</span> Species of amphibian

The cave salamander or spotted-tail salamander is a species of brook salamander in the family Plethodontidae.. It is well known for living in and around caves in the southeast United States. Adult cave salamanders are bright orange with black spots. This species is, somewhat vaguely, referred to by the common name of 'cave salamander'; however, it is not restricted to caves, but is known for inhabiting surface-level, terrestrial, woodland habitats, as well.

References

  1. SSC Amphibian Specialist Group (2022). "Pseudobranchus axanthus". IUCN Red List of Threatened Species . 2022: e.T59489A196342247. doi: 10.2305/IUCN.UK.2022-1.RLTS.T59489A196342247.en . Retrieved 1 November 2022.
  2. 1 2 "Pseudobranchus axanthus". NatureServe Explorer. Retrieved 1 November 2022.
  3. Amphibian Species of the World 5.5. research.amnh.org/vz/herpetology/amphibia.
  4. 1 2 3 4 Petranka, 1998