Digenean trematode cysts within the heads of threatened Galaxiella species (Teleostei : Galaxiidae) from south-eastern Australia

2016 ◽  
Vol 64 (4) ◽  
pp. 285
Author(s):  
R. A. Coleman ◽  
A. A. Hoffmann
Keyword(s):  
Dna Sequences ◽  
Internal Transcribed Spacer ◽  
Fish Host ◽  
Molecular Techniques ◽  
Trematode Species ◽  
Mitochondrial Cytochrome ◽  
Digenean Trematode ◽  
South Eastern ◽  
Eastern Australia ◽  
South Eastern Australia

The dwarf galaxias (Galaxiella pusilla) and little galaxias (Galaxiella toourtkoourt) are both threatened freshwater fish from south-eastern Australia. Occasionally populations have been found with enlarged heads associated with the accumulation of ‘white balls’, but the cause of these deformities has not previously been investigated. In this study, histopathology and molecular techniques were employed to identify cysts extracted from the heads of Galaxiella species across six populations. Histopathology and DNA sequences from both mitochondrial (cytochrome c oxidase subunit I) and nuclear (ribosomal internal transcribed spacer 1) regions identified the cysts as metacercariae of Apatemon gracilis (Rudolphi, 1819), a cosmopolitan digenean trematode species. Heavy infestations of trematode metacercariae within Galaxiella populations are of concern due to the potential to cause increased mortality associated with altered behaviour of the fish host that increases the likelihood of predation. Direct mortality from infestations is also possible, but not quantified in this study.

Colpomenia species from south and south-eastern Australia (Ectocarpales, Phaeophyceae): a DNA barcoding approach

2021 ◽  
Author(s):  
Nuno Tavares Martins ◽  
Carlos Frederico D. Gurgel ◽  
Tracey M. Spokes ◽  
Valéria Cassano
Keyword(s):  
Dna Barcoding ◽  
Dna Sequences ◽  
Species Delimitation ◽  
South Australia ◽  
South Eastern ◽  
Eastern Australia ◽  
Single Marker ◽  
Algal Genus ◽  
Different Populations ◽  
South Eastern Australia

Defining species in the brown algal genus Colpomenia is a challenging endeavour because of their morphological similarity, overlapping phenotypic variation, the absence of conspicuous diagnostic characters, and often lack of reproductive structures crucial for their identification. Thus, the use of molecular tools has become widely used to study Colpomenia taxonomy and evolution. The following four Colpomenia species are described along the Australian coast: C. claytoniae M.Boo, K.M.Lee, G.Y.Cho & W.Nelson, C. ecuticulata M.J.Parsons, C. peregrina Sauvageau, and C. sinuosa (Mertens ex Roth) Derbès & Solier. The objective of this study was to assess the diversity of Colpomenia species in southern and south-eastern Australia by using DNA barcoding techniques and single-marker species delimitation methods. We generated 44 new COI-5P DNA sequences from nine different populations across three Australian states (South Australia, Victoria and Tasmania), and applied 13 variations of four species delimitation methods (ABDG, SPN, PTP, GMYC). Our results recognised three Colpomenia species in the region, namely, C. sinuosa, C. claytoniae, and C. peregrina. Colpomenia sinuosa is the most widely distributed species in Australia. Colpomenia peregrina and C. claytoniae presented high levels of intraspecific genetic divergence. We did not find C. ecuticulata, although it has been previously reported from nearby our sampling area.

scholarly journals Genetic assessment of the variation and distribution of the species of Salinator (Panpulmonata: Amphibolidae) in south-eastern Australia

2020 ◽  
Vol 8 ◽  
Author(s):  
Donald Colgan ◽  
Hugo Lumsdaine
Keyword(s):  
Ribosomal Rna ◽  
Dna Sequences ◽  
Large Range ◽  
Shell Morphology ◽  
Regional Differentiation ◽  
South Eastern ◽  
Eastern Australia ◽  
Genetic Assessment ◽  
Rna Genes ◽  
South Eastern Australia

Amphibolidae is one of the most abundant families of gastropods in estuarine environments of south-eastern Australia. However, the range limits of the species of Salinator, one of the family’s two genera in the region, remain unclear partly due to uncertainty of identifications based solely on shell morphology. Insufficient data have been collected to address questions regarding the genetic variability of any of the species of Salinator. Here, DNA sequences from a segment of the cytochrome c oxidase subunit I and 28S ribosomal RNA genes were collected to investigate the distribution and variation of the three Salinator species in the region, these being S. fragilis, S. rhamphidia and S. tecta. The results demonstrate a large range extension in S. rhamphidia and suggest that S. tecta may have limited distribution in Tasmania. In contrast to previously-studied estuarine Mollusca in the south-eastern coasts of the mainland and Tasmania, S. rhamphidia has regional differentiation. There is evidence of genetic disequilibrium within S. fragilis, suggesting that it may presently comprise contributions from two distinct sets of populations.

Sign in / Sign up

Export Citation Format

Share Document