Description
Eurycea sphagnicola is a small salamander with a snout-vent length ranging from 16.4 – 25.7 mm. The snout-vent length is approximately 37.8% of the total body length. The snout is rounded when viewed dorsally and slightly protruding when viewed laterally. The eyes protrude and are barely visible when viewed ventrally. There are 12 to 14 costal grooves along the body. The forelimbs are about 20% of the snout-vent length, and hindlimbs are slightly longer at approximately 26% of the snout-vent length. Individuals have four digits on their hands and feet. The tail is approximately 62% of the snout-vent length. The base of the tail is square, and the distal end is rounded. The fracture plane of the tail is approximately at the last third of the entire tail length (Wray et al. 2017).

The heads of E. sphagnicola larvae appear rounded from a dorsal view and protuberant in a lateral view. The ventral fin inserts around the anterior third of the tail, and the dorsal tail fin inserts above the cloaca (Wray et al. 2017).

DIAGNOSIS:

Eurycea salamanders can be differentiated from all other plethodontid salamanders in the United States except Hemidactylium scutatum because it has four digits on the hindlimb (as opposed to five digits in all other species). Furthermore, H. scutatum lacks basial constriction of the tail and has a white venter with black spotting instead of the yellow smudging in E. sphagnicola. Eurycea sphagnicola is unique from other members of the E. quadridigitata complex (E. chamberlaini, E. hillisi, E. paludicola, and E. quadridigitata) by several minor morphological differences such as the dorsal fin insertion point is above the cloaca in larvae and the average total body size is smaller than the averages of other species. However, these differences are very minute and genetic analysis is the only accurate way of differentiating them from other species of Eurycea (Wray et al. 2017).

COLORATION:

In life, the dorsal side of E. sphagnicola has a tannish color on the head that becomes more coppery-orange towards the posterior end. Light gray flecks are concentrated in the eye and snout regions. A dark vertebral line can be seen along the vertebral column and is darkest just above the cloacal region. The dark line fades to a series of spots after the cloaca and is absent from the tail itself. The ventral coloration is white with light yellow smudging between the cloaca the first two-thirds of the tail. The last third of the tail is a light gray. The limbs have a tan background with darker spots on the dorsal side and are completely white on the ventral side. In preservation, the dorsal coloration fades to a tannish-gray color and the darker markings become fainter. The ventral coloration becomes a cream color that lacks the yellow pigmentation E. sphagnicola has in life (Wray et al. 2017).

In life, larval E. sphagnicola have a brown dorsal surface with yellow flecks. The ventral surfaces are yellowish with dark melanophore suffusions. The limbs are dark brown to almost black with minimal yellow flecks. The posterior regions of the body and tail have large irregular yellow spots that become smaller and dense at the end of the tail. The tail fins have dark mottling and small transparent flecks that become larger spots at the end of the tail. The iris is gold with a horizontal black bar (Wray et al. 2017).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: Alabama, Florida

View distribution map in BerkeleyMapper.

Eurycea sphagnicola has been documented within 50 miles of the Gulf Coast in Mississippi, Alabama, and the Western Florida Panhandle. They are found on dense mats of sphagnum moss on hillside seepage bogs. They appear to be the most geographically restricted species of Eurycea (Wray et al. 2017).

Life History, Abundance, Activity, and Special Behaviors
Only 36 confirmed individuals of E. sphagnicola have been documented. All individuls (larvae, juveniles, adults) have been found on sphagnum moss in bogs, which indicates that they rarely drift from breeding habitat. These bogs are have sluggish, but flowing, seepage water, and are dominated by acid-loveing plants such as Sarracenia sp., Pinguicula sp., and Drosera sp. (Wray et al. 2017).

Eurycea sphagnicola can be found in the same locality, but different microhabitats, as E. quadridigitata in western Mississippi and the western Florida pandhandle. Eurycea sphagnicola also likely shares localities with E. paludicola in Mississippi (Wray et al. 2017).

Trends and Threats
The main threats to the survival of E. sphagnicola include climate change and destruction of habitat. These salamanders are specifically found on mats of sphagnum moss that grows on acidic soils, and factors such as climate change and introduction of pesticides and other chemicals may change the environment they inhabit (Wray et al. 2017).

Possible reasons for amphibian decline

General habitat alteration and loss
Urbanization
Subtle changes to necessary specialized habitat
Habitat fragmentation
Local pesticides, fertilizers, and pollutants
Long-distance pesticides, toxins, and pollutants
Loss of genetic diversity from small population phenomena
Climate change, increased UVB or increased sensitivity to it, etc.

Comments
Based on Maximum Likelihood and Bayesian Inference analyses on ND2, tRNAs, and partial CO1 genes, E. sphagnicola is sister to the clade composed of E. chamberlaini, E. hillis, and E. quadridigitata. Together they form a clade that is sister to E. paludicola (Wray et al. 2017).

Eurycea sphagnicola is thought to have diverged from other species in the complex 27 – 15 million years ago and may be an intermediate transition between the lotic breeding preference of most Eurycea and lentic breeding preferences of members of the E. quadridigitata complex (Wray et al. 2017)

ETYMOLOGY:

The specific epithet “sphagni-” is derived from the generic name of sphagnum moss. With the Latin suffix “-cola", which means “inhabitant, dweller ”, this name is a reference to the species being found on sphagnum moss in seepage bog areas (Wray et al. 2017).

OTHER INTERESTING COMMENTS:

Eurycea sphagnicola was previously considered to be a color morph of E. quadridigitata before its elevation to full species in 2017 (Wray et al., 2017).

References

Wray, K.P., Means, D.B., Steppan, S.J. (2017). "Revision of the Eurycea quadridigitata (Holbrook 1842) complex of dwarf salamanders (Caudata: Plethodontidae: Hemidactyliinae) with a description of two new species," Herpetological Monographs, 31(1), 18-46. [link]

Species Account Citation: AmphibiaWeb 2022 Eurycea sphagnicola: Bog Dwarf Salamander <https://amphibiaweb.org/species/8646> University of California, Berkeley, CA, USA. Accessed Oct 11, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 11 Oct 2024.

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