Taylorconcha serpenticola

Bliss Rapids Snail

FWS Focus


The Bliss Rapids snail (Taylorconcha serpenticola) has a very small ovoid/turbinate shell (approximately 0.08 to 0.16- inches long), with about 3.5 to 4.5 whorls (curls or turns in the shell). The shell is clear to white but appears to have two colors, very light tan to dark brown-red, which results in the “pale” and “orange” forms. The average lifespan of the Bliss Rapids snail is about one year. The Bliss Rapids snail occurs in cold water springs and spring-fed tributaries to the Snake River, and in some reaches of the Snake River. The Bliss Rapids snail is primarily found on cobble boulder substrate, and in water temperatures between 59 and 61 degrees Fahrenheit. The Bliss Rapids snail was listed on December 14, 1992 as a threatened species. The final rule that determined threatened status for the Bliss Rapids snail indicated that the free-flowing, cool water environments required by the species were impacted by, and are vulnerable to, continued adverse habitat modifications and deteriorating water quality. The deterioration of the species’ water quality is from one or more of the following: hydroelectric development, peak-loading effects from existing hydroelectric project operations, water pollution, inadequate regulatory mechanisms, and invasion of the non-native New Zealand mudsnail. A recovery plan for this and other Snake River snail species was completed on November 26, 1995. Recent surveys indicate the species is distributed discontinuously over 22 miles, from River Mile (RM) 547-560, RM 566-572, and at RM 580 on the Snake River. The species is also known to occur in 14 springs or tributaries to the Snake River. The species does not occur in reservoirs. On September 16, 2009, the Service published a 12-month petition finding to remove the Bliss Rapids snail from the Endangered Species List. The Service’s review of the species’ know geographic distribution, habitat requirements and current threats did not support delisting and the Service declared that the species continues to meet the definition of a threatened species under the Act.

Scientific Name

Taylorconcha serpenticola
Common Name
Bliss Rapids Snail
FWS Category

Location in Taxonomic Tree

Identification Numbers



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