Listing Statement for Beddomeia waterhouseae (Hydrobiid Snail (Claytons Rivulet)) Beddomeia waterhouseae

Hydrobiid Snail (Claytons Rivulet)

T A S M A N I A N T H R E A T E N E D S P E C I E S L I S T I N G S T A T E M E N T

Beddomeia sp. image © Karen Richards

Common name: Hydrobiid Snail (Claytons Rivulet) Scientific name: Beddomeia waterhouseae (Ponder & Clark) Group: Invertebrate, Mollusca, Gastropoda, Sorbeoconcha, Hydrobiidae s.l.

Status: Threatened Species Protection Act 1995: endangered Environment Protection and Biodiversity Conservation Act 1999: Not listed IUCN Red List: Vulnerable

Distribution: Endemic status: Endemic Tasmanian NRM Regions: Cradle Coast

Figure 1. The distribution of Beddomeia waterhouseae, Plate 1. Specimen of Beddomeia waterhouseae (image showing NRM regions by Stephanie Clark for Winston Ponder). Scale = 1 mm

1 Threatened Species & Marine Section – Department of Primary Industries, Parks, Water and Environment

Listing Statement for Beddomeia waterhouseae (Hydrobiid Snail (Claytons Rivulet))

SUMMARY The principal characters used to separate Beddomeia waterhouseae is a freshwater snail species of Beddomeia are the male and female occurring in tributaries of Little Claytons reproductive systems. Rivulet, near Kindred, in central northern Information on the breeding habits of Tasmania. The species has a very narrow range, B. waterhouseae is limited. Beddomeia reproduce known only from three streams, with a sexually, laying single eggs, contained within a maximum 0.5 km separation between the capsule formed of sand grains secreted together known sites. (Plate 2). The egg capsules of B. waterhouseae are The threats to B. waterhouseae are associated with undescribed; however, generally Beddomeia egg domestic and agricultural practices, resulting in capsules are approximately 30% of adult body habitat modification or degradation. size. Individual egg capsules have broad B. waterhouseae is also impacted by competition attachment bases and are attached to the with and displacement by the exotic species underside of submerged stable rocks or Potamopyrgus antipodarum (New Zealand allochthonous material. The period of egg hydrobiid). incubation is unknown; however, eggs develop The principal management objectives for into fully formed juvenile snails prior to B. waterhouseae include preventing the loss or emergence from capsules. There is currently no degradation of habitat supporting known available information on the fecundity of these populations, identification of new species, although it is thought to be low, based subpopulations, increasing public awareness of on the proportions of egg capsules to snail the species, and improving its reservation status. abundance recorded at many sites (K. Richards, IDENTIFICATION AND ECOLOGY unpubl. data). B. waterhouseae is a member of the B. waterhouseae is known from headwater Hydrobiidae s.l., a family of freshwater snails tributaries of Little Claytons Rivulet, where they with cosmopolitan distribution (sensu lato (s.l.) = are located on submerged allochthonous in the broad sense; placement of Beddomeia with material (leaves) and rocks, where it feeds this family is currently under review). actively, grazing on periphyton. Field B. waterhouseae is one of 37 Beddomeia species observations indicate these snails have a listed as threatened on the Tasmanian Threatened preference for the underside and lower margins Species Protection Act 1995. of rocks and stream debris. While no specific life history information is Hydrobiid snails are small, (1.0 -7.0 mm), often available for B. waterhouseae, it is presumed to be cryptic species that are difficult to identify to similar to other headwater stream-inhabiting species level in the field, being distinguished by Beddomeia species. Species of Beddomeia are a number of shell and anatomical characters. capable of breeding throughout the year, with They possess conical to compressed trochiform no evidence of a seasonal reproductive peak shells of between 4 and 8 whorls (Plate 1). observed (Richards 2010). Some Beddomeia Their shells can be opaque to dark brown in species are known to live for over 5 years and colour, often depending on the age of the develop slowly, reaching sexual maturity only individual. The shells are most often smooth, after 2-3 years (K. Richards unpubl. data). but may possess faint sculpturing. Like a number of other Beddomeia species, Due to the method of reproduction, limited B. waterhouseae has an ovate-conic shape. This fecundity and specific habitat requirements shell is 2.74-3.30 mm long; 2.07-2.37 mm wide, species of Beddomeia are unable to disperse and has a protoconch of about 2.0 whorls with widely, unlike other aquatic molluscs with a a smooth microsculpture. The umbilicus is free-swimming larval stage (Bryant & Jackson small, 0.11-0.27 mm wide. The species is 1999). This apparent inability to disperse into sexually dimorphic in length (Ponder et al. new habitat renders these species vulnerable to 1993). several threatening processes.

2 Threatened Species & Marine Section – Department of Primary Industries, Parks, Water and Environment

Listing Statement for Beddomeia waterhouseae (Hydrobiid Snail (Claytons Rivulet))

exotic species Potamopyrgus antipodarum may also occur where these species co-occur.

Plate 2. Egg capsule of Beddomeia sp., scale 200 µm (image © Karen Richards)

Survey techniques B. waterhouseae is a small, cryptic species that can be difficult to tell apart from other species of Beddomeia, and identification to species-level normally requires a specialist. A survey protocol guiding collection methods has been developed by DPIPWE and is available to ecological consultants via the DPIPWE website; however, Plate 3. Habitat of Beddomeia waterhouseae (image by only suitably qualified people capable of field Karen Richards) identification of hydrobiids to genus-level should undertake surveys for Beddomeia. DISTRIBUTION AND HABITAT B. waterhouseae occurs in tributaries of Little Confusing species Claytons Rivulet, near Kindred, in central northern Tasmania (Figure 1, Table 1). The B. waterhouseae co-occurs with two species of species has a very narrow range, known only Austropyrgus and Potamopyrgus antipodarum; from three streams, with a maximum 0.5 km however, it can be readily distinguished from separation between the known sites (Plate 3). Austropyrgus in its markedly broader, larger shell The total length of stream in which the species and lack of operculum peg, a feature not occurs is unknown. Subpopulations occurring in possessed by any Beddomeia species. Due to the three streams are separated by topography their diminutive size and distinguishing and inhospitable environments (large stream, characters, Beddomeia and Phrantela species cleared land and domestic residence). cannot easily be identified in the field; however, they are readily distinguishable from most of the native freshwater genera. B. waterhouseae may POPULATION PARAMETERS be confused with other species of Beddomeia of Population estimates are not available. No similar external appearance (B. hermansi, comprehensive surveys have as yet been B. camensis, B. turnerae, B. hallae, B. fallax, undertaken to estimate the population size at B. lodderae, B. averni, B. forthensis) (Ponder et al. the known localities, although snail densities are 1993), but identification requires microscopic known to differ between locations. dissection, and the ranges of these species are geographically separated. Confusion between the more conical of Beddomeia species and the 3 Threatened Species & Marine Section – Department of Primary Industries, Parks, Water and Environment

Listing Statement for Beddomeia waterhouseae (Hydrobiid Snail (Claytons Rivulet))

RESERVATION STATUS P. antipodarum has been observed to co-occur in The known records for B. waterhouseae occur in one of the two streams from which streams on private property. B. waterhouseae is known. (Ponder et al. 1993). Owing to the restricted subpopulations of B. waterhouseae, they are considered vulnerable to CONSERVATION STATUS interspecific competition and displacement B. waterhouseae was listed in 1995 as rare on the from P. antipodarum, particularly as they occur in Tasmanian Threatened Species Protection Act 1995. areas already subjected to water quality The species was uplisted to endangered in 2009, degradation which is favoured by the exotic following a review of available information, species (Schreiber et al. 2003). meeting the criteria for listing criterion B, Climate change: The trend towards a warmer specifically B1 (severely fragmented or known climate and fluctuations in precipitation may to exist at no more than 5 locations) and B2 impact on the habitat availability for (continuing decline inferred, observed or B. waterhouseae by reducing stream flow and projected, in extent of occurrence (estimated to 2 modification of riparian vegetation be less than 0.1 km ) and quality of habitat). communities. Stochastic risk: The fragmented distribution THREATS, LIMITING FACTORS & MANAGEMENT ISSUES of the subpopulations of B. waterhouseae offer no opportunity for genetic exchange between The principal identified threats to freshwater subpopulations, thus exposing the species to a molluscs are agricultural clearing, forestry, risk of extinction. mining and impoundment construction (Ponder & Colgan 2002, Ponder & Walker MANAGEMENT STRATEGY 2003, Strong et al. 2008). For B. waterhouseae, the limiting factors are associated with domestic Management objectives and agricultural land management practices, resulting in habitat modification or degradation. The main objective for the management of the This species is confined to small order streams B. waterhouseae is to decrease the risk of subject to agricultural and residential land use extinction by maintaining the integrity of and consequently are at higher risk of being habitat at known sites through appropriate land impacted by habitat degradation and management. Specific management objectives modification (Richards 2010). The two known include: sites occur in remnant native riparian • Prevent the loss or degradation of habitat vegetation in cleared agricultural land. supporting known populations; Habitat modification and destruction: • Identify new subpopulations of the species; B. waterhouseae occurs in areas previously subjected to anthropogenic disturbance • Increase the level of information and data brought about by agricultural practices; available on the location, size and condition consequently it is highly vulnerable to habitat of known subpopulations; destruction and modification. Permanent • Improve the understanding of the removal of riparian vegetation increases stream ecological requirements of the species; temperatures and siltation, thus reducing habitat suitability for B. waterhouseae. • Improve reservation status and/or develop management agreements with land Interspecific competition from introduced managers to minimise the degradation of hydrobiids: An additional threat is interspecific subpopulations. competition and displacement from the exotic New Zealand species, P. antipodarum in degraded waterways on the margins of forested areas (K. Richards unpubl. data).

4 Threatened Species & Marine Section – Department of Primary Industries, Parks, Water and Environment

Listing Statement for Beddomeia waterhouseae (Hydrobiid Snail (Claytons Rivulet))

Table 1. Population summary for Beddomeia waterhouseae Year last Extent of NRM 1:25 000 Location Tenure (first) subpopulation Abundance region* mapsheet recorded (ha) Tributary of Little Private Cradle (1989) 1 Claytons Rivulet, Kindred Unknown Low Property Coast 2003 Kindred Tributary of Little Private Cradle 2 Claytons Rivulet, Kindred 1995 Unknown Low Property Coast Kindred Tributary of Little Private Cradle 3 Claytons Rivulet, Kindred 2003 Unknown Low Property Coast Kindred *NRM region = Natural Resource Management region

What has been done? • To increase understanding of the ecology of the species - conduct more precise Targeted surveys & monitoring: The type assessment of population size, distribution, locality was re-surveyed in 2003, when ecological requirements and the relative specimens were obtained for DNA analysis impacts of threatening processes. (Richards 2010). To date no subsequent surveys for the species have been conducted. BIBLIOGRAPHY Forestry management: B. waterhouseae is Bryant, S.L. & Jackson, J. (1999). Tasmania's included in the Threatened Fauna Adviser, a Threatened Fauna Handbook: What, Where and decision-support system used by forest industry How to Protect Tasmania's Threatened Animals. to take account of threatened fauna in wood Threatened Species Unit, Parks and production forests managed under the Wildlife Service, Hobart. Tasmanian Forest Practices Code (FPB 2000, 2001), and areas subject to landuse changes e.g. Forest Practices Board (2000). Forest Practices plantation establishment. Code. Forest Practices Board, Hobart, Tasmania. What is needed? Forest Practices Board (2001). Threatened Fauna Adviser. Expert System program., Forest • To improve protection of the species - Practices Authority and Department of provide information and extension support Primary Industries, Water and to relevant natural resource management Environment, Hobart. committees, local councils, government agencies, the local community and Ponder, W.F, Clark, G.A., Miller, A.C. & development proponents on the locality, Toluzzi, A. (1993). On a major radiation of significance and management of hydrobiid freshwater snails in Tasmania and eastern species and potential habitat. Victoria: a preliminary overview of the Beddomeia group (Mollusca: Gastropoda: • To improve protection of the species - raise Hydrobiidae). Invertebrate Taxonomy, 7, awareness of Beddomeia spp. within local 501−750. communities and promote good hygiene Ponder, W.F & Walker, K.F. (2003). From practices for equipment used in and around mound springs to mighty rivers: the waterways to reduce translocation of exotic conservation status of freshwater mollusks snail species. in Australia. Aquatic Ecosystem Health and • To improve protection of the species - Management 6: 19−28. undertake extension surveys outside the known range in potential habitat to locate

any additional subpopulations. 5 Threatened Species & Marine Section – Department of Primary Industries, Parks, Water and Environment

Listing Statement for Beddomeia waterhouseae (Hydrobiid Snail (Claytons Rivulet))

Ponder, W.F. & Colgan, D.J. (2002). What Species Protection Act 1995. Approved by the makes a narrow-range taxon? Insights from Secretary and published in November 2013. Australian freshwater snails. Invertebrate Cite as: Threatened Species & Marine Section Systematics 16: 571−582. (2013). Listing Statement for Beddomeia Richards, K. (2010). An Ecological, waterhouseae (Hydrobiidae s.l.). Department of Morphological and Molecular Investigation Primary Industries, Parks, Water and of Beddomeia Species (Gastropoda: Environment, Tasmania. Hydrobiidae) in Tasmania. PhD View: Dissertation, School of Zoology, http://www.dpipwe.tas.gov.au/threatenedspecieslists University of Tasmania, Hobart. Contact details: Threatened Species & Marine Schreiber, E.S.G., Quinn, G.P. & Lake, P.S. Section, Department of Primary Industries, (2003). Distribution of an alien aquatic Parks, Water and Environment, GPO Box 44, snail in relation to flow variability, human Hobart, Tasmania, Australia, 7001. activities and water quality. Freshwater Biology 48: 951−961. Ph. (03) 6165 4340; fax (03) 6233 3477; [email protected] Strong, E.E., Gargominy, O., Ponder, W.F. & Bouchet, P. (2008). Global diversity of Permit: A permit is required under the gastropods (Gastropoda: Mollusca) in Tasmanian Threatened Species Protection Act 1995 to freshwater. Hydrobiologia 597: 149−166. knowingly “take” (which includes kill, injure, catch, damage, destroy and collect), keep, trade in or process any specimen of a listed species.

Prepared in July 2010 by Karen Richards under the provisions of the Tasmanian Threatened

6 Threatened Species & Marine Section – Department of Primary Industries, Parks, Water and Environment