Red-bellied Newt

Taxobox
name = Red-bellied Newt
status = LC | status_system = IUCN3.1
trend = stable
regnum = Animalia
phylum = Chordata
classis = Lissamphibia
ordo = Caudata/Urodela
familia = Salamandridae
genus = "Taricha"
species = "T. rivularis"
binomial = "Taricha rivularis"
binomial_authority = Twitty, 1935
range_

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range_map_width = 230px
range_map_caption = Red-bellied Newt distribution|

The Red-bellied newt ("Taricha rivularis") is a newt, native to coastal woodlands in northern California, which is terrestrial for most of its life.

Physical description

The Red-bellied Newt, when fullgrown, measures between 2.75 to 3.5 inches from its nose to its vent, and between 5.5 to 7.5 inches from nose to its tail. It has grainy skin, and is brownish black on top with a tomato red underbelly.Californiaherps.com [http://www.californiaherps.com/salamanders/pages/t.rivularis.html "Taricha rivularis - Red-bellied Newt"] ; Accessed 9/16/06] It can be distinguished from other coastal newts by its red belly and a lack of yellow in its eyes. Breeding males develop smooth skin and a flattened tail.

Distribution and habitat

The Red-bellied newts lives in California along the coast from Bodega in Sonoma county, inland to Lower lake, and north to Honeydew, Humboldt county.Stebbins, Robert C.; "Amphibians and Reptiles of California"; University of California Press, Berkley, 1972: pg 52] It lives in coastal woodlands, especially in redwood forests.

Diet

This newt's diet consists mostly of invertebrates such as bloodworms, mosquito larvae, and anything else of suitable size. While in water during breeding season they do not hunt.

Reproduction and ecology

Red-bellied newts lay their eggs in fast flowing streams or rocky rivers. Newts begin their lives as aquatic larvae similar to tadpoles, though elongated and with external gills. Once they have matured into the adult form, which takes about four months, and usually happens in August, they leave the water until the fifth year of their life. Then, as early as January or February, the males start congregating at streambanks. One to three weeks later the females join them and the newts mate. The females lay their eggs in about 12 streamlined clusters with six to sixteen eggs each.enature.com [http://www.enature.com/fieldguides/detail.asp?recnum=AR0049] ; accessed 9/19/06] They usually lay them on the bottoms of rocks, or on branches leaning into the stream. The females, unlike the males, do not breed every year.livingunderworld.com [http://www.livingunderworld.org/caudata/database/salamandridae/taricha/] ; Accessed 11/4/06] Red-bellied newts can live for up to fifteen years.

Homing

Red-bellied newts have a remarkable homing ability. As they always go back to the same spot on the stream, they will make a great effort to go there. They will find their way over several miles of rugged terrain to get back to the spot. [Twitty, V., Grand, D., and Anderson, O. (1964) "Proceedings of the National Academy of Sciences" Proceedings of the National Academy of Sciences 51(1):51-58] It is likely that smell is responsible for the homing ability. [Grant, D., Anderson, O., and Twitty, V. (1968) "Homing Orientation by Olfaction in Newts (Taricha rivularis)" "Science" 160(3834):1354 - 1356]

Defense

Red-bellied newts have a brownish black topside to avoid being noticed. When that fails, and they are seen and disturbed, they pull their head and tail back to reveal their bright red underside. This serves as a warning to potential predators, as red-bellied newts have enough of a neurotoxin called tetrodotoxin in their skin to easily kill an adult human, or 7,500 mice. [Caudata.org [http://www.caudata.org/cc/articles/toxin2.shtml] Accessed 1/10/07] Like other newts, Red-bellied newts have the ability to regenerate several body parts, including their limbs, eyes, hearts, intestines, and upper and lower jaws, and damaged spinal cords. [ [http://www.bioscience.utah.edu/mb/mbFaculty/odelberg/odelberg.html www.bioscience.utah.edu; Odelberg, S.] Accessed 2007-01-24]

Notes

* Database entry includes a range map and justification for why this species is of least concern

See also

* California Newt - "Taricha torosa"
* Rough-Skinned Newt - "Taricha granulosa"

External links

*http://www.californiaherps.com/salamanders/pages/t.rivularis.html
* [http://depts.washington.edu/natmap/maps/CA_maphtml/a008.html Range map]
* [http://www.pwrc.usgs.gov/armiatlas/species.cfm?recordID=173621 Range map]
* [http://www.livingunderworld.org/caudata/database/salamandridae/taricha/]