Leptoxis foremani

Interrupted Rocksnail

FWS Focus

Overview

Characteristics
Overview

The interrupted rocksnail is a small to medium sized pleurocerid snail that historically occurred throughout the Coosa River drainage of Alabama and Georgia. It grows to about 20 millimeters (1 in) in length. The interrupted rocksnail lives attached to bedrock, boulders, cobbles and gravel. Individuals tend to move slowly, except in response to changes in water level. This species is currently found in the Oostanaula River.

Scientific Name

Leptoxis foremani
Common Name
Interrupted Rocksnail
Interrupted (=Georgia) Rocksnail
FWS Category
Snails
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The interrupted rocksnail may be ornamented by partial costae or folds in the surface of the shell. The shell is thick and subglobose, or not quite spherical. The spire or apex of the shell is very low and the aperture or shell opening is large, subrotund, and covered with an operculum when the snail withdraws into the shell.

Measurements
Length: 22 mm (1 in)

Color & Pattern

It is dark brown to olive in color, occasionally spotted and generally covered with fine striae or small ridges that extend around the whorls.

Characteristic category

Habitat

Characteristics
Habitat

Rocksnails live in shoals, riffles and reefs or bedrock outcrops of medium to large rivers of eastern North America to the Rockies. Their habitats are generally subject to moderate currents during low flows and strong currents during high flows. The interrupted rocksnail lives attached to bedrock, boulders, cobbles and gravel.

River or Stream
Characteristic category

Food

Characteristics
Food

Pleurocerid snails are considered generalist scrapers and generally feed by ingesting periphyton and biofilm detritus scraped off the substrate by the snailโ€™s radula. In 2000, J.B.T. Morales and A.K. Ward described radula is a horny band with minute teeth that snails use to pull food into the mouth. Interrupted rocksnails have been observed grazing on silt-free gravel, cobble and boulders, as documented in 2004 by P.D. Johnson.

Characteristic category

Life Cycle

Characteristics
Reproduction

Interrupted rocksnails lay their adhesive eggs within the same habitat they occupy, as documented by P.D. Johnson in 2004. In a hatchery setting, mean clutch size for 2 year old interrupted rocksnails is around 8.83 (3 to 18 eggs per clutch), and clutch size of females greater than 3 years is 13.63 (2 to 21 eggs per clutch), as documented by Johnson in 2009.

Geography

Characteristics
Range

The interrupted rocksnail was historically found in colonies on reefs and shoals of the Coosa River and several of its tributaries in Alabama and Georgia. It is currently found in the Oostanaula River.

Launch Interactive Map

Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

22 Items

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Listing

Critical Habitat

Notice

Notice

Listing

Critical Habitat

Recovery Plan

Recovery Plan

Five Year Review

Recovery Plan

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Listing

Nov 21, 1991

Nov 21, 1991 Listing
ETWP; Animal Candidate Review for Listing as Endangered or Threatened Species; 56 FR 58804 58836
  • Publication type: CNOR
  • Population:
Item 1

Listing

Nov 15, 1994

Nov 15, 1994 Listing
ETWP; Animal Candidate Review for Listing as Endangered or Threatened Species.
  • Publication type: CNOR
  • Population:
Item 2

Listing

Nov 15, 1994

Nov 15, 1994 Listing
ETWP; Animal Candidate Review for Listing as Endangered or Threatened Species.
  • Publication type: Candidate Removal
  • Population:
Item 3

Listing

Oct 25, 1999

Oct 25, 1999 Listing
Review of Plant and Animal Taxa That Are Candidates or Proposed for Listing as Endangered or Threateโ€ฆ
  • Publication type: CNOR
  • Population:
Item 4

Listing

Oct 30, 2001

Oct 30, 2001 Listing
ETWP; Review of Plant and Animal Species That Are Candidates or Proposed for Listing as Endangered oโ€ฆ
  • Publication type: CNOR
  • Population:
Item 5

Listing

Jun 13, 2002

Jun 13, 2002 Listing
Endangered and Threatened Wildlife and Plants; Review of Species That Are Candidates or Proposed forโ€ฆ
  • Publication type: CNOR
  • Population:
Item 6

Listing

May 4, 2004

May 4, 2004 Listing
Review of Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Noโ€ฆ
  • Publication type: CNOR
  • Population:
Item 7

Listing

May 11, 2005

May 11, 2005 Listing
Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates or Proโ€ฆ
  • Publication type: CNOR
  • Population:
Item 8

Listing

Sep 12, 2006

Sep 12, 2006 Listing (Warranted But Precluded: Resubmitted)
Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Anโ€ฆ
  • Publication type: 12m petition finding
  • Population:
Item 9

Listing

Sep 12, 2006

Sep 12, 2006 Listing
Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Anโ€ฆ
  • Publication type: CNOR
  • Population:
Item 10

Listing

Dec 6, 2007

Dec 6, 2007 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticโ€ฆ
  • Publication type: CNOR
  • Population:
Item 11

Listing

Dec 10, 2008

Dec 10, 2008 Listing
Review of Native Species That Are Candidates for Listing as Endangered or Threatened; Annual Noticโ€ฆ
  • Publication type: CNOR
  • Population:
Item 12

Listing

Jun 29, 2009

Jun 29, 2009 Listing (Endangered)
Proposed Endangered Status for the Georgia Pigtoe Mussel, Interrupted Rocksnail, and Rough Hornsnaiโ€ฆ
  • Publication type: Proposed
  • Population:
Item 13

Critical Habitat

Jun 29, 2009

Jun 29, 2009 Critical Habitat
Proposed Endangered Status for the Georgia Pigtoe Mussel, Interrupted Rocksnail, and Rough Hornsnaiโ€ฆ
  • Publication type: Proposed
  • Population:
Item 14

Notice

Feb 10, 2010

Feb 10, 2010 Notice
Proposed Rule: Listing with Designation of Critical Habitat for the Georgia Pigtoe Mussel, Interruptโ€ฆ
  • Publication type: Comment Period Reopening
  • Population:
Item 15

Notice

Feb 10, 2010

Feb 10, 2010 Notice
Proposed Rule: Listing with Designation of Critical Habitat for the Georgia Pigtoe Mussel, Interruptโ€ฆ
  • Publication type: Public Hearing
  • Population:
Item 16

Listing

Nov 2, 2010

Nov 2, 2010 Listing (Endangered)
Determination of Endangered Status for the Georgia Pigtoe Mussel, Interrupted Rocksnail, and Rough Hโ€ฆ
  • Publication type: Final
  • Population:
Item 17

Critical Habitat

Nov 2, 2010

Nov 2, 2010 Critical Habitat
Determination of Endangered Status for the Georgia Pigtoe Mussel, Interrupted Rocksnail, and Rough Hโ€ฆ
  • Publication type: Final
  • Population:
Item 18

Recovery Plan

Jul 3, 2013

Jul 3, 2013 Recovery Plan (Document Availability (non-FR))
Notice of Availability of a Technical/Agency Draft Recovery Plan for Georgia Pigtoe Mussel, Interruโ€ฆ
  • Publication type: Draft
  • Population:
Item 19

Recovery Plan

Nov 6, 2014

Nov 6, 2014 Recovery Plan (Document Availability (non-FR))
Endangered and Threatened Wildlife and Plants; Final Recovery Plan for Georgia Pigtoe Mussel, Interrโ€ฆ
  • Publication type: Final
  • Population:
Item 20

Five Year Review

Aug 30, 2016

Aug 30, 2016 Five Year Review (Information Solicitation)
5-Year Status Reviews of 22 Southeastern Species; Notice of initiation of reviews; request for inforโ€ฆ
  • Publication type: Notice
  • Population:
Item 21

Recovery Plan

Jun 27, 2019

Jun 27, 2019 Recovery Plan (Document Availability (non-FR))
Endangered and Threatened Wildlife and Plants; 29 Draft Recovery Plan Revisions for 42 Species Acrosโ€ฆ
  • Publication type: Draft
  • Population:
Item 22