Beddomeia fultoni (B. fultoni) is a species of small freshwater snail belonging to the family Tateidae.
The species is endemic to Australia. Commonly known as Farnhams Creek hydrobiid snail, the species used to belong to the family Hydrobiidae sensu lato (s.l.) and is listed as one of 37 threatened Beddomeia species on the Tasmanian Threatened Species Protection Act 1995.Threatened Species Section (2017). Beddomeia fultoni (Hydrobiid Snail (Farnhams Creek)): Species Management Profile for Tasmania's Threatened Species Link. https://www.threatenedspecieslink.tas.gov.au/Pages/Hydrobiid-Snail-(Farnhams-Creek).aspx. Department of Primary Industries, Parks, Water and Environment, Tasmania. Accessed on 21/3/2021.
Found within north-western Tasmania, the species has a somewhat small range. Previously, they have only been identified in sites within six different streams which are separated by a maximum of 4 km.Richards, K. (2010) An ecological, morphological and molecular investigation of Beddomeia species (Gastropoda: Hydrobiidae) in Tasmania (PhD). University of Tasmania. A large portion of the Beddomeia species, including B. fultoni fall into the category of narrow-range endemic species. These narrow-range taxa are generally poorly reserved due to limitations caused by small distributions, size, mobility, biogeographical boundaries and highly specific habitat requirements.Richards, K. (2013). Listing Statement for Beddomeia fultoni (Hydrobiid Snail (Farnhams Creek)). Retrieved 26 April 2021, from https://www.naturalvaluesatlas.tas.gov.au/downloadattachment?id=13550 Habitat disturbance from agricultural and domestic land use, climate change and invasive species are currently the principal threats contributing to the vulnerability of the species.Ponder, W., & Colgan, D. (2002). What makes a narrow-range taxon? Insights from Australian freshwater snails. Invertebrate Systematics, 16(4), 571−582.
Taxonomy Freshwater Mollusca can be divided into two classes, the bivalves (mussels, clams and pea shells and the gastropods (snails). These two classes differ significantly in physical appearance, biology and ecology but are grouped due to similarities found between body plans.Ponder, W.F., Walker, K. (2003). From Mound Springs to Mighty Rivers: The conservation Status of Freshwater Molluscs in Australia. Aquatic Ecosystem Health & Management, 6(1), 19-28.
The Hydrobiidae family, in which used to belong the Beddomeia genus and Beddomeia fultoni species, is the most diverse group of the taxonomic subclass Caenogastropoda and has over 267 known species.Smith, B. J. (1992) Non-Marine Mollusca. In: W. W. K. Houston (Ed.), Zoological Catalogue of Australia. Australian Government Publishing Service, Canberra The Beddomeia complex can be separated into found distinct genera; These genera include Beddomeia, Phrantela, Nanocochlea and Victodrobia. Of the 67 species that belong within the Beddomeia complex, 47 of these species are of the Beddomeia genus. This genus is endemic and restricted to Tasmania and occupies the northern areas of the state.
Within this clade the family Planorbidae is the next largest with about 40 species.Ponder, W.F. (1997). Conservation status, threats and habitat requirements of Australian terrestrial and freshwater molluscs. Memoirs Of The Museum Of Victoria, 56(2), 421-430. Approximately half of the known hydrobiids are located in Tasmania, however, speciose faunas occur in south-eastern Australia and in the Great Artesian Basin. While some Hydrobiids have widespread and abundant populations, others, like B. fultoni are restricted to singular streams where genetic divergences occur within the same habitat.
Description Hydrobiid snails are often around 1.0 -7.0 mm in length and often have smooth shells that can be opaque to a darker brown in colour. B. fultoni has a shell that is 3.07-3.78 mm in length and 2.24 – 2.78 mm in width and have a protoconch of approximately 1.5 whorls. The umbilicus of the shell is not sexually dimorphic and is either very small or closed and is characterized by 0.16-0.39mm wide chink.Ponder, W.F, Clark, G.A, Miller, A.C & Toluzzi, A (1993). On a major radiation of fredhwater snails in Tasmania and eastern Victoria: a preliminary overview of the Beddomeia group (Mollusca: Gastropoda: Hydrobiidae). Invertebrate Taxonomy 7 :501-750
Due to their small size and cryptic nature, information surrounding the ecology and biology of hydrobiid snails is relatively limited. At a species level, the identification of hydrobiids and other closely related families can be challenging. Distinguishing factors include a number of defined anatomical and shell characteristics, however, in more recent times a move from morphological taxonomy has seen a rise in the use of allozyme electrophoresis and DNA-based techniques for species identification. A study conducted in 2005 used a variety of Tasmanian species, including Pseudotricula, Nanocochlea, Austropyrgus and Beddomeia species in order to phylogenetically analyse the subterranean genera and is currently the only reported sequencing of Beddomeia species.Perez, K., Ponder, W., Colgan, D., Clark, S., & Lydeard, C. (2005). Molecular phylogeny and biogeography of spring-associated hydrobiid snails of the Great Artesian Basin, Australia. Molecular Phylogenetics And Evolution, 34(3), 545-556. Due to high variability within each species of the Beddomeia family, certain morphological traits are referred to as 'plastic'. These traits and characteristics are also convergent as multiple similarities can be seen between two or more species and therefore, cannot reliably be used as a direct indication of species.Hershler, R. & Ponder, W.F. (1998). A review of morphological characters of Hydrobioid snails. Smithsonian Contributions to Zoology, Number 600, 55.
B. fultoni co-exist with some species of Austropyrgus which may cause confusion due to similar appearances. However, B. fultoni can usually be identified by the absence of operculum peg, a characteristic not appearing on any Beddomeia species.
Distribution and habitat Patterns of high diversity are generally presented by gastropods with increasing species richness and increasing endemicity at lower latitudes. However, an exception of this is Tasmania, which holds the most diverse freshwater fauna in Australia.Strong, E., Gargominy, O., Ponder, W., & Bouchet, P. (2007). Global diversity of gastropods (Gastropoda; Mollusca) in freshwater. Hydrobiologia, 595(1), 149-166. Through the use of anatomical traits to investigate speciation within a hydrobiid complex located in south-eastern Australia, 67 hydrobiid species were classified by Ponder et al. and the Beddomeia complex was categorised into four genera; three of which (Beddomeia, Phrantela and Nanocochlea) are endemic to Tasmania, with Victoria being the sole habitat of the fourth genus, Victodrobia . There is a minimal geographical separation between these four genera particularly between the morphologically similar Austropyrgus and Nanocochlea and the supposedly closely related Beddomeia and Phrantela genera. The B.fultoni species can be described as cryptic in habitat due to the tendency to be located within environments within small and large streams of low hydrological variation.
B. fultoni is geographically restricted to the Montagu catchment in north-western Tasmania, where it has been located within the headwater tributaries of Fixters and Farnhams creeks. Within Fixters Creek the species is generally found on roots, wood, leaves and stones at Farnhams Creek. B.fultoni have only been identified within only 6 different streams with a maximum of 4 km separating these sites, revealing the extremely narrow range of the species. This can be seen in Table 1, a population summary for Beddomeia fultoni assembled by K. Richards. Currently, the length of stream that the species occurs in unknown; however, inhospitable environments downstream of these catchments, caused by factors such as intensive dairy production, limit further radiation. Inhospitable environments such as wide streams, areas with high levels of agricultural development, production forestry, and domestic residences further separate subpopulations occurring within these catchments.
Species such as B.fultoni which exhibit small ranges of distribution do so as a result of limitation by size, dispersal capabilities and mobility. Historical biogeographical obstructions often determine the small ranges of species, however for those with minimal dispersal capabilities, migration between suitable habitats is significantly hindered. The presence of substances such as root mates, various substrates, CWD, and detritus have been associated with the occurrence of B. fultoni within its known habitats.DPIWE, 2003. Aquatic Ecology of the Montagu River Catchment. Hobary: The Department of Primary Industries, Water and Environment. +Table 1. Population summary for Beddomeia fultoniLocationTenureNRM region *1:25 000 MapsheetYear Last (first) SeenExtent of Subpopulation (ha)Abundance1Farnhams Creek, on the Bass Highway, west of Christmas
HillsPrivate PropertyCradle CoastTogari1989unknownLow2Tributary of Fixters Creek, north end of Brittons SwampState ForestCradle CoastTogari1989unknownLow3Tributary of Fixters Creek, southern end of Brittons
SwampState ForestCradle CoastTogari2006unknownLow4Tributary of Fixters Creek, central Brittons Swamp
(informal reserve)State ForestCradle CoastTogari2010unknownModerate5Tributary of Fixters Creek, central Brittons Swamp
(informal reserve)State ForestCradle CoastTogari2010unknownHigh6Tributary of Farnhams Creek, off Riseborough Road, Togari
State ForestState ForestCradle CoastMella2010unknownLow * NRM region = Natural Resource Management region
Conservation and threats In 1995 Beddomeia fultoni was listed as rare on the Tasmanian Threatened Species protection Act 1995.Tasmanian Legislation Online. (2020). Retrieved 26 April 2021, from https://www.legislation.tas.gov.au/view/html/inforce/current/act-1995-083 In 2009 this status was elevated to endangered due to the species meeting the listing criterion for in two sections of criterion B. This includes criterion B1, as the species distribution is extremely fragmented and has been identified at no more than 5 locations and B2, as the species has a shown that a continuous population decline could be observed, inclined or projected due to occurrence and quality of habitat. Species are regarded as endangered when factors that have contributed to its decline continue to operate in the same manner and minimise the long-term chances of the species' survival prospects.
Key factors that have been identified as threats to B.fultoni and other Beddomeia species include habitat modification and destruction, interspecific competition from introduced species, climate change and stochastic effects.
Habitat disturbance