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.

Description

Sirens are quite distinct from other salamanders, and in some classifications they form their own suborder, Sirenoidea, or as a completely distinct order (Meantes or Trachystomata). Genetic analysis variously places them as the sister to other Salamandroidea or as sister to all other salamanders. Many of their unique characteristics seem to be partly primitive and partly derivative.

Sirens are generally eel-like in form, with two tiny, but otherwise fully developed, fore limbs. They range from in length. proving they likely evolved from a terrestrial ancestor with an aquatic larval stage. Like amphiumas, they are able to cross land on rainy nights.

These amphibians are omnivorous, feeding mainly on worms, small snails, shrimps, and filamentous algae. They are notable among salamanders (and most amphibians, aside from a few frog species) due to their semi-herbivorous habits.

If the conditions of a water source are unsuitable, a larva will shrink its gills to mere stumps, and these may not function at all. Parental care among sirens is paternal due to external fertilization. In S. intermedia males circle around females and may rub or bite her flank region.

Taxonomy

The siren family (Sirenidae) is subdivided into five genera, three extinct, and two extant with two and three extant species, respectively:

  • Genus †Habrosaurus <small>Gilmore 1928</small>
  • †H. dilatus <small>Gilmore 1928</small>
  • †H. prodilatus <small>Gardner 2003</small>
  • Genus †Kababisha <small>Evans et al. 1996</small>
  • †K. humarensis <small>Evans et al. 1996</small>
  • †K. sudanensis <small>Evans et al. 1996</small>
  • Genus †Noterpeton <small>Rage et al. 1993</small>
  • †Noterpeton bolivianum <small>Rage et al. 1993</small>
  • Genus Pseudobranchus <small>Gray 1825</small> dwarf sirens
  • †P. robustus <small>Goin and Auffenberg 1955</small>
  • †P. vetustus
  • P. axanthus <small>Netting & Goin 1942</small> southern dwarf siren
  • P. striatus <small>LeConte 1824</small> northern dwarf siren
  • Genus Siren <small>Österdam 1766</small> sirens
  • †S. dunni <small>Goin and Auffenberg 1957</small>
  • †S. hesterna
  • †S. miotexana
  • †S. simpsoni
  • S. intermedia <small>Barnes 1826</small> lesser siren
  • S. lacertina <small>Linnaeus, 1766</small> greater siren
  • S. nettingi <small>Goin, 1942</small> western siren
  • S. reticulata <small>Graham, Kline, Steen & Kelehear, 2018</small> reticulated siren
  • S. sphagnicola <small>Fedler, Enge, & Moler, 2023</small> seepage siren

References

  • Tree of Life: Sirenidae