Blue-spotted salamanders are found from eastern central North America and stretch in a broad band across to the Atlantic Provinces and northern New England. They are found around the Great Lakes and west as far as central Manitoba. They reach as far north as James Bay, Ontario (Collicutt 1999).

Biogeographic Regions: nearctic (Native )

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

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (20,000-2,500,000 square km (about 8000-1,000,000 square miles)) Southeastern Quebec to Lake Winnipeg, south through Great Lakes region and New England to northern Indiana and New Jersey. Several apparently disjunct populations occur around the periphery of the range (e.g., see Brownlie [1988] for Nova Scotia record). Hybridizes with A. JEFFERSONIANUM over a large area south of this range. See Nyman et al. (1988) for distribution in New Jersey.

Length: 10-14cm.

Blue-spotted salamanders have a long tail that is approximately 40% of its body length (Collicutt 1999). The salamander's tail is broadly oval at the base and compressed towards the tip. It is fleshier than A. jeffersonianum (Minton 1972). They also have a slimmer body than the tiger salamander A. tigrinum (Collicut 1999). Their feet have relatively long toes (Conant and Collins 1998). They are given their name for the bluish-white spots and flecks on the tides of the trunk and tail and also sometimes on the back. Their skin is bluish-black (Conant and Collins 1998). The spots are also on their limbs and belly (Harding 1997). The belly may be either black or a lighter shade than the dorsum, but the vent is usually black (Harding 1997). There is some slight size difference between the males and the females. The males tend to be slightly smaller than the females, the males also have a longer more flattened tail (Harding 1997). The larvae of blue-spotted salamanders vary in appearance. When the larvae are small and relatively young they have broad tail fins and external gills for living in the water (Collicutt 1999). But once they have developed all four legs they appear to be dark brown, olive or gray on the upper surface with dark mottling on the fail fins. They also may have dull yellow blotches on the dorsum or yellowish stripes down each side of the back. The belly is lighter and unmarked (Harding 1997).

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Length: 13 cm

• Terrestrial
• Freshwater

The blue-spotted salamander lives in deciduous and coniferous forests. They are most abundant in moist woodlands with sandy soil. They differ from other salamanders in that they are found above ground throughout the warmer months (Harding 1997). During the day they stay undercover out of the direct sunlight. They spend the summer and fall in damp forests, searching for food at night (Nova Scotia 1999).

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: forest

Aquatic Biomes: lakes and ponds

Comments: In New England and New Jersey, generally associated with lowland swamps and marshes and surrounding uplands with sandy or loamy soils (Nyman et al. 1988, Klemens 1993). in overgrown pastures. Adults usually under are objects or underground. Eggs are attached to submerged sticks or bottom of shallow forest ponds and pools. At Isle Royale, Michigan, breeds in splash pools on exposed rocky shorelines (Van Buskirk and Smith 1991). In northern Minnesota, successful reproduction in acidic bog water either does not occur or is a rare event (Karns 1992).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: Yes. At least some 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.

Migrates up to several hundred meters between breeding pools and summer range.

The Blue-spotted salamander is a carnivore. The adult eats worms, snails, slugs, insects, centipedes, spiders and other invertebrates. The larvae eat small aquatic invertebrates such as water fleas (cladocerans), copepods, insects and insect larvae, especially mosquito larvae (Harding 1997). The diet suggests that the feeding ground is beneath leaf litter in forests (Collicut 1999). In captivity, blue-spotted salamanders survive on 1 worm a week (Collicut 1999).

Comments: Metamorphosed individuals eat snails, earthworms, beetles, beetle larvae, springtails, spiders, and other small invertebrates. Larvae eat small aquatic animals (zooplankton and benthic invertebrates).

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 81 to >300

Comments: Number of occurrences of pure A. laterale is uncertain, but there are many.

100,000 - 1,000,000 individuals

Comments: Total adult population size is unknown but likely exceeds 100,000.

See Van Buskirk and Smith (1991) for evidence of density-dependent population regulation in a population at Isle Royale, Michigan (increasing larval density in breeding pools resulted in reduced survival and growth, probably due to interference).

Comments: Inactive late fall through most of winter.

The life span of a blue-spotted salamander is unknown (Collicutt 1999). Both male and females reach maturity at about 2 years of age (Harding 1997). The salamander breeds in woodland ponds and ditches (Conant and Collins 1998). They breed in April in small ponds. The female lays as many as 500 eggs individually at bases of sticks, plants or rocks. The eggs take about 1 month to hatch, and when they hatch they have well-developed eyes, mouth, external gills, and broad tail fins. At two weeks old, the front legs form and at 3 weeks the hind limbs are formed. As they get older they look like tiny adult salamanders except they have broad tail fins and external gills. Between 3-5cm in length they transform into the adult form and leave the pond. When they transform they loose their external gills and tail fins and develop the adult coloration (Collicut 1999). They transform in late summer (CCIW 1999).

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous

In most areas, eggs are laid in March-April (early May at Isle Royale, Michigan), singly or in clusters of up to about 35; up to 500 eggs per female. Metamorphosis late June through August, or larvae may overwinter. Aggregates when breeding.

Hybrid offspring are the result of gynogenetic or hybridogenetic reproduction (Bogart and Klemens 1997).

Due to the loss of wetlands and the destruction of forests, the salamanders are threatened. However, there is no evidence of decline in the blue-spotted salamander as of yet (CCIW 1999). Blue-spotted salamanders are more tolerant to human disturbances than other salamanders. They still persist in fragmented forests (Harding 1997).

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Intrinsic Vulnerability: Moderately vulnerable

Environmental Specificity: Narrow. Specialist or community with key requirements common.

Global Short Term Trend: Relatively stable to decline of 30%

Global Long Term Trend: Increase of 10-25% to decline of 50%

Comments: Biggest threat is loss and degradation of habitat as a result of coversion to agricultural and urban use. Roads negatively impact salamander abundance in roadside habitat (deMaynadier and Hunter 2000). Increased acid deposition is a potential threat.

Global Protection: Several to very many (4 to >40) occurrences appropriately protected and managed

Blue-spotted salamanders consume many mosquitoes each year (Harding 1997).

Comments: Ambystoma jeffersonianum and A. laterale comprise a complex that includes pure bisexual diploid populations and populations that may be represented by bisexual diploid individuals, female hybrids with several different combinations of parental chromosomes (including diploids, triploids, tetraploids, and pentaploids), and/or rare male hybrids. Up to at least five different chromosomal combinations have been found at a single site.

In response to the nomenclatural difficulties presented by this complex, an informal system of indicating ploidy and chromosomal makeup has been recommended (Bogart and Klemens 1997). For example, the "LLLJ" designation (or "A. (3) laterale-jeffersonianum") indicates a tetraploid salamander with three sets of laterale chromosomes and one set of jeffersonianum chromosomes. For convenience, all populations including pure laterale (LL) and laterale-dominated genomes (e.g., LLJ) might be included in the species A. laterale (e.g., Klemens 1993).

However, biological complexities confound such a simple treatment. Polyploid hybrid individuals in the complex may produce offspring with diverse chromosomal makeup. For example, an LLJ female can produce offspring that do not have laterale-dominated genomes (e.g., LJJ). And single clutches have been documented with both diploid and triploid embryos. It is even possible for a triploid hybrid to produce pure diploid offspring (e.g., LL or JJ).

Truly intermediate hybrids with equal chromosomal representation (i.e., LJ, LLJJ) are uncommon and are but two of many possible outcomes of hybridization. In New England and New York, hybrids are more common than are the bisexual species, but bisexuals usually (or are presumed to) exist in low numbers in populations composed mostly of hybrids (Bogart and Klemens 1997). Thus, for example, a pond with triploid LLJ should also have at least some LL.

Hybrid populations are maintained by breeding between a hybrid female and a male of one of the diploid bisexual species, and the hybrid offspring are the result of gynogenetic or hybridogenetic reproduction (Bogart and Klemens 1997). In gynogenetic reproduction, male sperm stimulates egg development, but the male genome is not incorporated into the zygote. In hybridogenetic reproduction, the male genome is incorporated, "but upon maturity of the offspring, the paternal genome is eliminated in a meiotic or pre-meiotic event while the rest of the hybrid's genome is passed on to future generations, usually in an altered state" (Bogart and Klemens 1997).

Thus, recent work on hybrid phenomena in these salamanders indicates that the species names "A. platineum" (= LJJ) or "A. tremblayi" (= LLJ) formerly used for the A. jeffersonianum-A. laterale hybrids are inappropriate because LJJ and LLJ are not strictly gynogenetic triploid lineages. Consequently, a recent checklist (Crother et al. 2000) did not recognize either A. platineum or A. tremblayi as valid species.

To accommodate the genetic variation in these salamanders (and the often uncertain genetic composition of particular populations), we have established for this database the following elements: (1) Ambystoma jeffersonianum (JEFFERSON SALAMANDER), used for pure populations only; (2) Ambystoma laterale (BLUE-SPOTTED SALAMANDER), used for pure populations only; (3) Ambystoma HYBRID POP 1 (JEFFERSONIANUM X LATERALE; JEFFERSONIANUM GENOME DOMINATES), used for hybrid populations dominated by the jeffersonianum genome (e.g., populations that include mainly LJJ individuals); this element includes "Ambystoma platineum"; (4) Ambystoma HYBRID POP 2 (JEFFERSONIANUM X LATERALE; LATERALE GENOME DOMINATES), used for hybrid populations dominated by the laterale genome (e.g., populations that include mainly LLJ individuals); this element includes "Ambystoma tremblayi"; (5) AMBYSTOMA POP 3 (JEFFERSONIANUM/LATERALE COMPLEX - UNCERTAIN COMPOSITION), used for populations for which chromosomal representation is unknown. If needed we could establish additional elements for hybrid populations that involve A. laterale, A. texanum, and/or A. tigrinum.

See Kraus (1985), Bogart and Licht (1987), Bogart et al. (1987), Kraus et al. (1991), Lowcock et al. (1991), and Bogart and Klemens (1997) for information on the involvement of A. JEFFERSONIANUM in hybridization with A. TEXANUM, A. TIGRINUM, and/or A. LATERALE. See Lowcock et al. (1987) and Bogart and Klemens (1997) for discussions of nomenclatural treatment of hybrid populations.

See Kraus (1988), Shaffer et al. (1991), and Jones et al. (1993) for phylogenetic analyses of North American Ambystoma.