Wicker ancylid
Encyclopedia
The wicker ancylid, Rhodacmea filosa, is a species of small, air-breathing, freshwater snail
or limpet
, a pulmonate gastropod in the family
Planorbidae
.
Rhodacmea filosa is the type species
of the genus Rhodacmea.
and was thought to be extinct, until its rediscovery in 2011. It occurred in the Mobile River
Basin rivers and their tributaries. The type locality is the Black Warrior River
, south of Blount Springs, Alabama
.
Over the past 20 years, extensive surveys that included hundreds of collecting sites in the drainages of the Coosa River
, Cahaba River
and Black Warrior River
(its type locality) had failed to find Rhodacmea filosa. However, it does still persist in a Choccolocco Creek, a Coosa River
tributary. Morphometric and phylogenetic analyses confirm the taxonomic validity of this material. Its survival in Choccolocco Creek is somewhat surprising, given the serious episodes of industrial pollution
experienced by this watershed.
in 1834. Conrad's type description reads as follows:
Rhodacmea filosa has an elevated patelliform shell
with ribbing in the form of strong radiating lines running from the apex
to the aperture
.
Freshwater snail
A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....
or limpet
Limpet
Limpet is a common name for a number of different kinds of saltwater and freshwater snails ; it is applied to those snails that have a simple shell which is more or less conical in shape, and either is not spirally coiled, or appears not to be coiled in the adult snails.The name limpet is most...
, a pulmonate gastropod in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Planorbidae
Planorbidae
Planorbidae, common name the ramshorn snails or ram's horn snails, is a family of air-breathing freshwater snails, aquatic pulmonate gastropod mollusks....
.
Rhodacmea filosa is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus Rhodacmea.
Distribution
This species is endemic to the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and was thought to be extinct, until its rediscovery in 2011. It occurred in the Mobile River
Mobile River
The Mobile River is located in southern Alabama in the United States. Formed out of the confluence of the Tombigbee and Alabama rivers, the approximately river drains an area of of Alabama, with a watershed extending into Mississippi, Georgia, and Tennessee. Its drainage basin is the...
Basin rivers and their tributaries. The type locality is the Black Warrior River
Black Warrior River
The Black Warrior River is a waterway in west central Alabama in the southeastern United States. The river rises in the extreme southern edges of the Appalachian Highlands and flows 178 miles to the Tombigbee River, of which the Black Warrior is the primary tributary...
, south of Blount Springs, Alabama
Blount Springs, Alabama
-History:Blount Springs's mineral springs and rural setting made it a summer resort for thousands of wealthy people from Alabama and elsewhere in the late 19th and early 20th centuries. The sulfur springs were renowned for their curative properties...
.
Over the past 20 years, extensive surveys that included hundreds of collecting sites in the drainages of the Coosa River
Coosa River
The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long altogether.The Coosa River is one of Alabama's most developed rivers...
, Cahaba River
Cahaba River
The Cahaba River is the longest free-flowing river in Alabama and is among the most scenic and biologically diverse rivers in the United States. The Cahaba River is a major tributary of the Alabama River and part of the larger Mobile River Basin...
and Black Warrior River
Black Warrior River
The Black Warrior River is a waterway in west central Alabama in the southeastern United States. The river rises in the extreme southern edges of the Appalachian Highlands and flows 178 miles to the Tombigbee River, of which the Black Warrior is the primary tributary...
(its type locality) had failed to find Rhodacmea filosa. However, it does still persist in a Choccolocco Creek, a Coosa River
Coosa River
The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long altogether.The Coosa River is one of Alabama's most developed rivers...
tributary. Morphometric and phylogenetic analyses confirm the taxonomic validity of this material. Its survival in Choccolocco Creek is somewhat surprising, given the serious episodes of industrial pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
experienced by this watershed.
Description
Rhodacmea filosa was originally discovered and described (under the name Ancylus filosus) by Timothy Abbott ConradTimothy Abbott Conrad
Timothy Abbott Conrad was an American geologist, malacologist and carcinologist.- External links :* at Internet Archive...
in 1834. Conrad's type description reads as follows:
Rhodacmea filosa has an elevated patelliform shell
Gastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
with ribbing in the form of strong radiating lines running from the apex
Apex (mollusc)
Apex is an anatomical term for the tip of the mollusc shell of a gastropod, scaphopod, or cephalopod mollusc.-Gastropods:The word "apex" is most often used to mean the tip of the spire of the shell of a gastropod...
to the aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
.
External links
- University of Michigan (2011, June 3). Mass extinction victim survives: Snail long thought extinct isn't. ScienceDaily.com. Retrieved June 5, 2011.