Systematics of the Freshwater Crayfish Genus Cherax Erichson (Decapoda: Parastacidae) in South-Western Australia: Electrophoretic, Morphological and Habitat Variation

1996 ◽  
Vol 44 (3) ◽  
pp. 223 ◽  
Author(s):  
CM Austin ◽  
B Knott
Keyword(s):  
Western Australia ◽  
Morphological Variability ◽  
Distinct Species ◽  
General Level ◽  
Freshwater Crayfish ◽  
Widespread Species ◽  
South West ◽  
Habitat Variation ◽  
Habitat Differences ◽  
Taxonomic Studies

A detailed study of electrophoretic, morphological and habitat variation amongst species of Cherax in south-western Australia supported the recognition of only five of the eight species currently recognised and revealed that morphological and habitat variation within these crayfish is more extensive and complicated than was previously realised. Within several species morphological and habitat variation was found to be as great as that between species. Furthermore, a major component of the morphological variability, both within and between species, was found to be associated with habitat variation. Three of the five species of Cherax recognised in this study correspond to the consistently recognised and widespread species, C. preissii Erichson, C. quinquecarinatus (Gray) and C. tenuimanus Smith. The two other species are C. crassimantus Riek and C. glaber Riek which have restricted distributions in the extreme south-west of Western Australia. The species C. glabrimanus Riek and C. neocarinatus Riek could not be distinguished from C. quinquecarinatus, nor could C. plebejus (Hess) be distinguished from C. preissii. On a general level, the results of this study question the value of morphological information in systematic studies of freshwater crayfish. Morphologically based taxonomic studies of freshwater crayfish need to be interpreted with caution because, firstly, taxonomic characters may be far more variable than realised; secondly, morphological and habitat differences cannot necessarily be equated with specific distinctions; and thirdly, genetically distinct species that occupy similar habitats need not be morphologically distinct.

Phylogeographic structure of a freshwater crayfish (Decapoda:Parastacidae:Cherax preissii) in south-western Australia

2006 ◽  
Vol 57 (8) ◽  
pp. 837 ◽  
Author(s):  
Gavin Gouws ◽  
Barbara A. Stewart ◽  
Savel R. Daniels
Keyword(s):  
Gene Flow ◽  
Western Australia ◽  
Molecular Dating ◽  
Phylogeographic Structure ◽  
Freshwater Crayfish ◽  
The North ◽  
South West ◽  
Biogeographical Regions ◽  
Freshwater Decapods ◽  
North Western

Although phylogeographic patterns of freshwater decapods elsewhere in Australia are well documented, little is known of the phylogeography and biogeography of the endemic freshwater fauna of south-western Australia. Here, the phylogeographic structure of a freshwater crayfish, Cherax preissii Erichson, 1846, was investigated to determine contemporary and historical patterns of gene flow and to examined evolutionary and biogeographical scenarios. Allozyme and cytochrome c oxidase subunit I mitochondrial DNA data were collected from 15 populations, sampled across the known C. preissii distribution. Both markers revealed a clear distinction and separation among populations occurring in the north-western and southern portions of the distribution. Inferences of allopatric fragmentation and molecular dating attributed the divergence of the aquatic fauna of these regions to periods of Pliocene–Pleistocene aridity. Connectivity appeared to be greater within each of these regions. Evidence suggested contemporary, but not ongoing, gene flow, particularly within the southern region. This was possibly facilitated by dispersal during pluvial Pleistocene periods or drainage connectivity during episodic marine regressions. The divergence and distributions of these lineages parallels patterns seen in other freshwater crayfish of the region. More explicit investigation of these and further fine-scale phylogeographic studies may contribute to the understanding of biogeography and evolution in the south-west, and may further refine currently recognised biogeographical regions.

Allozyme evidence for a new species of freshwater crayfish of the genus Cherax Erichson (Decapoda : Parastacidae) from the south-west of Western Australia

2002 ◽  
Vol 16 (3) ◽  
pp. 357 ◽  
Author(s):  
C. M. Austin ◽  
S. G. Ryan
Keyword(s):  
New Species ◽  
River System ◽  
Original Description ◽  
Distinct Species ◽  
Freshwater Crayfish ◽  
Allozyme Data ◽  
Genetic Studies ◽  
South West ◽  
The Common ◽  
A New Species

The marron, Cherax tenuimanus (Smith), is one of the most easily recognisable members of the freshwater crayfish genus Cherax. Since its description in 1912, the taxonomy of the species has not been in dispute, but recent genetic studies have demonstrated that the species is not homogenous and consists of two genetically distinct forms. One of these forms is widespread and exploited via aquaculture and the other is restricted to a single river system, the Margaret River. This paper presents allozyme data, collected over a 19-year period, which documents the introduction of the widespread form into the Margaret River and the subsequent reproductive interactions between the two forms. These data indicate minimal interbreeding between the two forms of marron and so justify their recognition as distinct species. As the original description of the marron was based on specimens collected from the Margaret River, the form native to this river retains the name C. tenuimanus and a new species, Cherax cainii Austin is described for the common, widespread form of marron. An additional outcome of this study is that C. tenuimanus has been rapidly displaced by the introduced C. cainii within the Margaret River. Consequently, urgent conservation measures are required to protect C. tenuimanus and prevent its possible extinction.

A New Species in Trillium subgen. Delostylium (Melanthiaceae, Parideae)

Phytotaxa ◽  
2017 ◽  
Vol 296 (3) ◽  
pp. 287
Author(s):  
EDWARD E. SCHILLING ◽  
AARON FLODEN ◽  
JAYNE LAMPLEY ◽  
THOMAS S. PATRICK ◽  
SUSAN B. FARMER
Keyword(s):  
New Species ◽  
Species Complex ◽  
Morphological Variability ◽  
Drainage System ◽  
Distinct Species ◽  
Sequence Variability ◽  
Habitat Differences ◽  
Complicated Pattern ◽  
A New Species ◽  
Formal Recognition

The Trillium pusillum Michaux (1803: 215) species complex exhibits a complicated pattern of morphological variability and geographic distributions in southeastern North America (Farmer 2007). In contrast to earlier studies based on isozymes (Cabe and Werth 1995; Timmerman-Erskine et al. 2003), analyses of DNA sequence variability provide evidence of clear boundaries that correspond with morphological and habitat differences to suggest that the group is best recognized as a series of distinct species (Farmer 2007). Species names have been proposed for some of these, and they are recognized as varieties in some taxonomic treatments (e.g. Weakley 2015), but several still are known only from informal designations. One of the rarest, and perhaps most threatened, is the sole representative of the complex in Georgia that is known from only a single creek drainage system in an area being developed for industrial usage. In the current study we provide formal recognition for it, both to emphasize the need to preserve this unique entity, as well as to stimulate searches for further populations of it.

scholarly journals Three new species of mouse spider (Araneae: Actinopodidae: Missulena Walckenaer, 1805) from Western Australia, including an assessment of intraspecific variability in a widespread species from the arid biome

2021 ◽  
Vol 79 ◽  
pp. 509-533
Author(s):  
Marleen R. Greenberg ◽  
Joel A. Huey ◽  
Volker W. Framenau ◽  
Danilo Harms
Keyword(s):  
New Species ◽  
Western Australia ◽  
Morphological Variability ◽  
Intraspecific Variability ◽  
Genetic Data ◽  
Phylogeographic Structure ◽  
Small Range ◽  
Widespread Species ◽  
Need To Evaluate ◽  
Three New Species

Abstract Mouse spiders (genus Missulena Walckenaer, 1805) are a lineage of trapdoor spiders with males of many species having a brightly coloured red cephalic region, an abdomen that is tinged metallic blue, and the habit of wandering during the day in search of a mate. A total of 17 species of Missulena have been described in Australia to date but most descriptions are based exclusively on males and always small numbers of specimens. Here, we describe three new species of Missulena from the Pilbara and Goldfields regions of Western Australia based on morphology and genetic data: Missulena davidisp. nov. (male and female), M. iugumsp. nov. (male) and M. manningensissp. nov. (male). One of them is presently known only from its type locality and another one from a small range based on two specimens but M. davidi sp. nov. has a linear range of almost 300 km and is genetically highly structured. We use genetic data for 75 specimens as a foundation to evaluate morphological variability in this species and note substantial variation in several characters commonly used to identify species such as body size, colouration, rastellum shape and eye distances. This variation does not necessarily relate to phylogeographic structure as inferred from the genetic data, but rather seems to reflect natural variability both within and between localised populations. Overall, our results stress the need to evaluate a large series of specimens for mygalomorph taxonomy and provide an interesting example of intraspecific variability in hard-to-collect species that are usually underrepresented in museum collections.

The freshwater crayfish of Western Australia (Decapoda : Parastacidae)

1967 ◽  
Vol 15 (1) ◽  
pp. 103 ◽  
Author(s):  
EF Riek
Keyword(s):  
Coastal Zone ◽  
Western Australia ◽  
New Genus ◽  
Freshwater Crayfish ◽  
The South ◽  
South West

A new genus, allied to Engaeus, is erected for three small burrowing species from the south-west coastal zone and the number of recognized species of Cherax is increased from three to eight.

Survey of feral honey bee (Apis mellifera) colonies for Nosema apis in Western Australia

2007 ◽  
Vol 47 (7) ◽  
pp. 883 ◽  
Author(s):  
Rob Manning ◽  
Kate Lancaster ◽  
April Rutkay ◽  
Linda Eaton
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Western Australia ◽  
Honey Bees ◽  
Nosema Apis ◽  
The South ◽  
South West ◽  
Feral Populations ◽  
Significant Difference

The parasite, Nosema apis, was found to be widespread among feral populations of honey bees (Apis mellifera) in the south-west of Western Australia. The location, month of collection and whether the feral colony was enclosed in an object or exposed to the environment, all affected the presence and severity of infection. There was no significant difference in the probability of infection between managed and feral bees. However, when infected by N. apis, managed bees appeared to have a greater severity of the infection.

scholarly journals Our New Cathedrals: Spirituality and Old-Growth Forests in Western Australia

2006 ◽  
Vol 3 (1) ◽  
Author(s):  
David Worth
Keyword(s):  
Social Movements ◽  
Western Australia ◽  
The State ◽  
The South ◽  
Old Growth ◽  
The Past ◽  
South West ◽  
Old Growth Forests ◽  
Heated Debate ◽  
Policy Proposals

Over the past 30 years in Western Australia (WA), there has been heated debate about the future use of the remaining karri and jarrah forests in the south-west of the State. This debate revolves around policy proposals from two social movements: one wants to preserve as much of the remaining old-growth forests as possible, and an opposing movement supports a continued

Behavioural responses of Australian freshwater crayfish (Cherax cainii and Cherax albidus) to exotic fish odour

2006 ◽  
Vol 54 (6) ◽  
pp. 399 ◽  
Author(s):  
S. G. Height ◽  
G. J. Whisson
Keyword(s):  
Western Australia ◽  
Predatory Fish ◽  
Behavioural Plasticity ◽  
Current Debate ◽  
Freshwater Crayfish ◽  
Indigenous Species ◽  
Exotic Fish ◽  
Behavioural Responses ◽  
Invasive Crayfish ◽  
Australian Freshwater

Exotic finfish and crayfish have been translocated into Western Australia for more than 100 years. Deliberate stocking and subsequent escape from man-made impoundments have resulted in widespread distribution of non-native yabbies (Cherax albidus) and the exotic redfin perch (Perca fluviatilis) in the State’s south-west. Both species are considered invasive and are known to compete with indigenous species for resources. The nature and degree of impact on native marron (Cherax cainii) is unclear and the subject of current debate. Other researchers have hypothesised that invasive species modify their behaviour in the presence of predators in a more rapid and advantageous manner than native species. This greater behavioural plasticity can result in displacement of indigenous species and successful colonisation of invaders. The aim of this study was to investigate behavioural responses of an indigenous crayfish (C. cainii) and an invasive crayfish (C. albidus) to odours from a native predator (Tandanus bostocki) and an exotic predatory fish (P. fluviatilis) present in Western Australia. Crayfish behaviour was observed in individual glass tanks following the addition of odours from native (T. bostocki) or exotic (P. fluviatilis) finfish predators. Marron exhibited minor behavioural modifications when presented with odours from native or exotic finfish. In contrast, the invasive yabby showed greater detection of odours, displaying significant changes in behaviour (P < 0.05). Yabbies also appeared to distinguish between food odour (commercial crayfish feed) and predator odour; however, neither marron nor yabbies displayed behaviour indicating that they could distinguish between a native or exotic fish predator. Results support the hypothesis that invasive crayfish species have a greater capacity for behavioural plasticity than non-invasive crayfish.

A Bayesian hierarchical downscaling model for south-west Western Australia rainfall

2014 ◽  
Vol 63 (5) ◽  
pp. 715-736 ◽  
Author(s):  
Yong Song ◽  
Yun Li ◽  
Bryson Bates ◽  
Christopher K. Wikle
Keyword(s):  
Western Australia ◽  
Bayesian Hierarchical ◽  
South West
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