FRESHWATER FISH Nannoperca Australis Southern Pygmy Perch
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FRESHWATER FISH Nannoperca australis Southern Pygmy Perch AUS SA AMLR Endemism extinctions. The range and area of occupancy of the Murray-Darling lineage continues to decline. Genetic - - E - evaluation of the populations of the Murray lineage indicates five genetically distinct sub-populations that are separated by land barriers of 10km or less. The remaining populations include: patchy distribution in swampy edges and drains around Lake Alexandrina, with core populations on eastern Hindmarsh Island, Black Swamp and near Milang (presumed extinct along the River Murray itself; some local declines in Lake Alexandrina), and four stream catchments Inman River ; two disjunct populations, both small and affected by stream drying Tookayerta Creek; populations are reasonably Photo: © Michael Hammer continuous but in a small catchment Finniss River; a few highly restricted sites Conservation Significance Angas River; a single core pool, with recent loss of The AMLR distribution is part of a limited extant fish from two tributary streams (Dawson and distribution in adjacent regions within SA.2 Middle creeks). Recommended for listing as Rare under NPW Act as Populations within individual streams are fragmented, part of the threatened species status review in 2003.1 especially the Inman, Finniss and Angas catchments and habitat conditions continue to deteriorate or have 3 Under the SA Fisheries Act 2007 its status is Protected. a high potential for deterioration with habitat drying. Description Within the AMLR, only occurs in the Fleurieu Peninsula Small, deep bodied species to 10 cm (commonly 3-5 and Lower Murray River Basins, within the South 2 cm), with a large eye and brilliant red fins during Australian Gulf and Murray-Darling Drainage Divisions. spawning (males). Distinguished from Yarra Pygmy Perch by a larger mouth reaching below the eye and Numerous records from the South East; most are post- a regular (round) eye pupil; from Variegated Pygmy 1970. Two earlier records were from swamps at Perch by having scales on top of the head and the Kalangadoo (1912) and Kingston (1928). Records after second dorsal spine longer than the third, and from the 1970s (post drainage) are from across the region Chanda Perch by having a rounded rather than and the species was widespread in the former forked tail.3 extensive wetland habitat. In the SAMDB, the species was widespread in the fringing swamps and tributary Recent genetic studies identified that ‘Southern streams of the lower River Murray and Lake Pygmy Perch’ comprises two distinct species with an Alexandrina (e.g. historically plentiful in the smaller eastern species in Gippsland (VIC), Flinders Island backwaters and swampy lowlands of the Finniss River), and north-east TAS, and a western species occurring and is also likely to have been found commonly in coastally west of Wilsons Promontory and in the MDB. areas associated with the River Murray through to VIC. The western species has two distinct genetic lineages A new population in southern Fleurieu Peninsula divided by the Great Dividing Range (i.e. coastal and (Inman Catchment) was first documented in 2001; Murray-Darling) that warrant recognition at the long-term presence was subsequent confirmed by oral 3 subspecies level. Hence there are two distinct units of history. management in SA, (a) Murray lineage and (b) SE lineage.3 Habitat Habitat is varied but generally comprises smaller pools, Distribution and Population swamps and wetlands (plus some artificial refuges In the SE region suitable habitat is much reduced due including drains) with dense structure, either physical to extensive drainage and there are presumed local such as rock and snags or submerged plants such as Further information: Biodiversity Conservation Unit, Adelaide Region Phone: (61 8) 8336 0901 Fax: (61 8) 8336 0999 http://www.environment.sa.gov.au/ Department for Environment and Heritage FIS 90346 May 2008 Prepared as part of the Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia 2009 - 2014 algae and Pond Weeds (Potamogeton), but most Regional Distribution often emergent or overhanging edge vegetation such as grasses, Water Ribbons (Triglochin), Club Rush (Schoenoplectus) and Cumbungi (Typha). Preferred habitat can include large pools with edge cover where large predatory fish are absent. Habitat often comprises areas with cooler water temperatures; the highest densities are in fenced or ungrazed areas. Benefits from the seasonal inundation (winter/spring) of edge and emergent vegetation as prime habitat and cover for juveniles and shelter for adults during floods.3 Biology and Ecology The SAMDB lineage seems to be more sensitive to habitat and flow changes. Individuals in spawning condition have been noted in spring and occasionally through summer in sites with permanent cool flows. Feed on small invertebrates picked from underwater surfaces. Individuals are short lived (approximately four years) with only a small percent of most populations older than one or two years (they Map based on filtered post-1983 records.2 Note, this map does not reach sexual maturity within a year). Movement is necessarily represent the actual species’ distribution within the AMLR. fairly limited, especially in the streams of the MLR, with dispersal occurring across inundated shallows rather References than against the flow.3 Note: In some cases original reference sources are not included in this list, however they can be obtained from the Aboriginal Significance reference from which the information has been sourced (the Post-1983 records indicate the AMLR distribution reference cited in superscript). occurs in Peramangk and Ngarrindjeri Nations.2 1 Department for Environment and Heritage (2003 ). Review of the Status of Threatened Species in South Australia. Threats Proposed Schedules under the South Australian National Parks Reasons for population decline and continuing and Wildlife Act 1972 Discussion Paper. National Parks and threats include: Wildlife Council in partnership with the Department for loss or degradation of habitat, notably swamps Environment and Heritage. altered flow regimes, delayed onset of seasonal flows due to water abstraction from 2 Department for Environment and Heritage (2007). Adelaide watercourses and the occurrence of unnatural and Mount Lofty Ranges Regional Recovery Pilot Project Database. Unpublished data extracted and edited from cycles of drying, can impede movement BDBSA, SA Herbarium (July 2007) and other sources. between riparian areas and are likely to become more pronounced with climate 3 Hammer, M., Wedderburn, S. and Van Weenen, J. (2007). change Action Plan for South Australian Freshwater Fishes: 2007-2012 loss or degradation of stream-side vegetation Draft. Native Fish Australia (SA) Inc., Adelaide. and silting of watercourses, e.g. impact of livestock major barriers or disruptions to dispersal due to instream structures, such as dams, reservoirs, vertical weirs, road culverts predation by and competition from introduced fish species (trout, Eastern Gambusia and possibly Redfin).3 Additional current direct threats have been identified and rated for this species. Refer to the main plan accompanying these profiles. Further information: Biodiversity Conservation Unit, Adelaide Region Phone: (61 8) 8336 0901 Fax: (61 8) 8336 0999 http://www.environment.sa.gov.au/ Department for Environment and Heritage FIS 90346 May 2008 Prepared as part of the Regional Recovery Plan for Threatened Species and Ecological Communities of Adelaide and the Mount Lofty Ranges, South Australia 2009 - 2014 .