State Rarity Rank:
Global Rarity Rank:
Did you know?
Some freshwater snails can survive the passage through the digestive sytem of birds and fish.
|State Ranking Justification||
This small freshwater snail has mysteriously and precipitously declined throughout the state and elsewhere over the past 100+ years. As a tempoary pond specialist, it is susceptible to changes in hydrology and habitat destruction as these habitats receive no formal protection in New York. The overall range of this boreal species is clearly retreating northward toward Canada suggesting that a warming climate is having adverse effects on its life history strategy in the mid latitudes. The S2 ranking could be revised in light of any potential future survey efforts confirming its status.
There is virtually no information on the status of this species since surveys in the lower Hudson watershed (Strayer 1987) and statewide (Jokinen 1992) showed a drastic reduction in occupancy throughout the 1900s.
At least 20 widely scattered site records were known from the mid 1800s to the 1970s across the state. Robertson and Blakeslee (1948) reported it at seven different locales in the Niagara Frontier region alone, describing it as common and abundant. Likewise Harman and Berg (1971) reported it as common at 19 different locales in the Finger Lakes region, but none in the Susquehanna watershed. But by about 1990, only two extant occurrences were known throughout the state.