Strategic Management Prospects v4.0 Species Forecast Report created on 01 February, 2024

A Species Forecast Report is a summary of currently available information, the predicted 50-year outlook for the species, and potential pathways to recovery through species-specific and landscape-scale actions.

The report collates data from a range of sources including the Victorian Biodiversity Atlas, Strategic Management Prospects (SMP), Specific Needs Assessments, Threatened Species Action Statements, the Genetic Risk Index, and the IUCN Common Assessment Method.

Species Forecast Reports are intended to be used in conjunction with SMP and other spatial outputs in NatureKit, and Action Statements where relevant.

For more information on Species Forecast Reports, SMP and other biodiversity decision support tools, including user guides, visit Choosing actions for nature webpage on the DEECA website.


Species Overview

Taxon ID 5058
Scientific name Mogurnda adspersa
Common name Southern Purple-spotted Gudgeon
Group Fish
FFG status Critically Endangered
EPBC status
Southern Purple-spotted Gudgeon (Image Source: Atlas of Living Australia)

Southern Purple-spotted Gudgeon (Image Source: Atlas of Living Australia)


Species description

Description and life history

Southern Purple Spotted Gudgeon are small and robust with a rounded head, a relatively small mouth and a rounded tail. They are generally dark chocolate in colour along the back, fading to pale fawn on the belly, with a number of distinguishing markings. These include black to grey patches on the sides, which are surrounded by numerous white and red spots that brighten during breeding. The fins are yellow in colour, darkening towards the extremities. They are non-migratory, found in freshwater, and exhibit a cryptic, demersal behaviour. This taxon spawns in summer when water temperature is greater than 20 degrees C (Lintermans 2007). Timing of spawning is speculated to be influenced by increasing water temperatures and day length, abundance of food and availability of spawning sites (Hansen 1988). Females may produce 7-10 succession broods in one season, where clusters of eggs are deposited on firm substrates and guarded by the male. Total fecundity (which is significantly related to fish size) is estimated at 267-727 eggs in south-east Queensland and 66-1,778 eggs in northern Queensland (Pusey et al. 2004) and 284-1,300 in the Murray-Darling Basin (Llewellyn 2006).

Distribution

The taxon was historically recorded from Benalla ,near Bendigo, Dinner Creek near Stawell and at Wangaratta. The fish have been presumed extinct in Victoria since 1997-98, when a population at Cardross Lakes died out (Raadik 1996, Raadik and Harrington 1996, Raadik and O’Connor 1996, Raadik and Fairbrother 1997, 1999, Raadik et al. 1999ab, Raadik 2000, 2001). In late October 2019 two fish were found at Third Reedy Lake near Kerang.

Habitat

This taxon has been found in slow moving or still waters of small streams, rainforest streams, large rivers and dune lake systems, as well as slow-flowing weedy pools (Pusey et al. 2004). It is commonly collected over mud and sand, close to cover. In the lower Murray-Darling Basin, the species is known from wetlands, or backwater areas next to rivers, in still or low flowing areas, amongst dense aquatic vegetation and timber debris, and over mud or coarse sand, abnd gravel (Raadik)

Genetic Risk Index

This table contains information on the genetic health of Southern Purple-spotted Gudgeon, informed by recent work conducted by Monash University and cesar Pty Ltd (Kriesner et al. 2019; Kriesner and Weeks 2020). The project undertook genetic risk assessments of ~1,100 species of flora and fauna found in Victoria and generated a large database of available genetic and demographic data for these species. A framework was developed for combining these parameters into a Genetic Risk Index that classified species broadly into ‘Low’, ‘Moderate’, ‘High’, ‘Very High’ and ‘Uncertain’ risk categories. The Genetic Risk Index will continue to undergo refinement and validation to provide further insight into the genetic health of species in Victoria.

Total Australian population size Greater than 10,000 individuals
Australian distribution Most of the population occurs outside of Victoria
Dispersal capacity Low: ~1km
Reproductive mode Sexual: species reproduces sexually via male and female gametes
Average generation time One generation every 2 - 5 years
Victorian population trend since ~1975 Unknown
Inbreeding evidence Significant inbreeding (i.e. ‘Moderate’ or ‘High’) evident for one or only a few populations, but not the majority
Genetic diversity Moderate
Genetic rescue potential Uncertain
Genetic Risk Index Very high


Species maps

Habitat Distribution Model

The Habitat Distribution Model (HDM) layer shows the modelled distribution of habitat for Southern Purple-spotted Gudgeon in Victoria. Red shading indicates areas of habitat with relatively higher suitability, compared with yellow shaded areas. HDMs are developed by combining Victorian Biodiversity Atlas (VBA) occurrence records for the species with a range of environmental variables to predict where the most suitable habitat for the species is in Victoria. Species may not always occupy areas of suitable habitat. Threatening processes (prior or ongoing) and disturbance regimes (e.g. fire, timber harvesting) may stop species from occupying otherwise suitable habitat for periods of time. Management actions often focus on currently occupied areas, however management of unoccupied areas can also be important to allow populations to re-establish.

No Habitat Distrabution Model is currently available.


Species Forecast

No Species Forecast data is available because Southern Purple-spotted Gudgeon is not yet included in our decision-support tools.

About Species Forecast

A Species Forecast is the estimated likelihood of a species being present in 50 years time. The data for Species Forecasts is drawn from DEECA’s decision support tools, Strategic Management Prospects and Specific Needs Assessments.

Many species benefit from the management of widespread threats, such as weeds and pests, and the benefit of these landscape-scale actions to ~4,200 species is modelled in Strategic Management Prospects. In addition to landscape-scale actions, some species also need actions that improve or protect habitat at certain sites, such as nest boxes or hollow logs, or actions to improve certain populations, such as gene mixing or translocation.

As part of a continuous improvement program for our decision-support tools, we are working to expand the scope of actions modelled in Strategic Management Prospects, and to build the dataset of species benefits from location-specific and population-specific actions.

We can use this data to consider how different actions may benefit a species and examine how different types of on-ground management may contribute to a species’ recovery in 50 years, to develop a Species Forecast.


Potential actions for species recovery

No Species Forecast data is available because Southern Purple-spotted Gudgeon is not yet included in our decision-support tools.


Species prospects in SMP

The benefit data in SMP can be used to consider what the Southern Purple-spotted Gudgeon’s prospects are if the landscape scale management actions in SMP are implemented.

No Species Prospects figure is available becuase Southern Purple-spotted Gudgeon is not yet included in SMP.


How to get further information and provide feedback

For more information on the decision support tools, products and underlying data used in this report, and how the data is collected and developed into products, please visit the following links:

These links include information on how to provide data and feedback into these products.

The Species Forecast Reports will be updated periodically to reflect changes and improvements in the products and tools that inform them (e.g., following updates to SMP).

As the data contained in Species Forecast Reports is drawn from multi-species datasets, it is not currently possible to incorporate species-specific information or feedback directly.

For help or further information get in touch by visiting Choosing actions for nature webpage on the DEECA website.


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