Plants and Animals
Acella haldemani Spindle lymnaea
Key Characteristics
Spindle lymnaea is a medium-sized freshwater snail with a long, slender, almost needle-like shell reaching almost 1 inch (25 mm) high and only 0.2 in (5 mm) wide. The whorls on the shell are flat-sided, oblique, descending rapidly, and with impressed sutures that lie at 45 degrees relative to the shell axis. The shell aperture is long and narrow, not laterally expanded, acute above, and flared below. The periostracum (flaky, leathery covering on the outside of the shell) is yellowish white to brown.
Status and Rank
US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G3 - Vulnerable
State Rank: SH - Possibly extirpated
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Calhoun | 1 | Historical |
| Eaton | 1 | Historical |
| Huron | 1 | Historical |
| Kent | 1 | Historical |
| Muskegon | 1 | Historical |
Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.
Habitat
This snail is found among reeds in eutrophic lakes and ponds generally around 12 to 39 inches (0.3 to 1.0 m) deep. The snail clings tightly to underwater stems of rushes 6 to 10 inches (15 to 25 cm) from the bottom.
Specific Habitat Needs
Rushes needed in: Inland lake, littoral, midwater.
Natural Community Types
- Emergent marsh
- Inland lake, littoral, midwater
For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.
Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.
Management Recommendations
The spindle lymnaea is likely vulnerable to pollution from excess nutrients, chemicals, etc. Maintaining good water quality would likely benefit this species. Draining and filling of sensitive aquatic habitat should be avoided. Invasion by zebra mussels should be prevented in suitable habitat. Snail-killing chemical molluscicides (e.g., copper sulfate or copper carbonate) that are used to treat lakes with swimmer's itch should be strictly avoided in lakes and streams occupied by rare snails. The introduction of fish species for recreational or commercial fishing is also strongly discouraged since many fish prey on aquatic snails and could greatly reduce populations or cause local, state, or global extirpation.
Survey Methods
This species can be surveyed using several techniques. One survey method consists of sweeping aquatic vegetation or scraping the substrate with a fine mesh aquatic sampling net or dip net (e.g., D-frame net) anytime from late September through December, but earlier surveys also would likely be effective. Another survey technique consists of vigorously shaking aquatic vegetation over a pail of water causing the various snails clinging to the plants to drop to the bottom of the pail. Visual surveys also can be conducted for this species by looking for snails attached to vegetation, rocks, woody debris and other cover. Glass bottomed buckets may be used to see snails clinging to vegetation or rocks underwater. Rocks, vegetation, and other cover also should be picked up, examined for snails, and returned to their original positions.
Shaking vegetation survey
Survey Period: From first week of May to fourth week of August
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
Sweep with dip net
Survey Period: From first week of May to fourth week of August
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
Survey Period: From fourth week of September to fourth week of December
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
Visual surveys
Survey Period: From first week of May to fourth week of August
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
References
Survey References
- Clarke, A.H. 1981. The Freshwater Molluscs of Canada. National Museum of Natural Science, National Museums of Canada, Ottawa. 446pp.
Technical References
- Clarke, A.H. 1981. The Freshwater Molluscs of Canada. National Museum of Natural Science, National Museums of Canada, Ottawa. 446pp.
- Dillon, R.T. Jr. 2000. The Ecology of Freshwater Molluscs. Cambridge University Press, Cambridge, UK. 509pp.
- Goodrich, C. 1932. The Mollusca of Michigan. The University of Michigan Press, Ann Arbor. 121pp.