Phylogeny of the Australian freshwater crayfish Cherax destructor-complex (Decapoda : Parastacidae) inferred from four mitochondrial gene regions

2005 ◽  
Vol 19 (3) ◽  
pp. 209 ◽  
Author(s):  
Thuy T. T. Nguyen ◽  
Christopher M. Austin
Keyword(s):  
16S Rrna ◽  
Cytochrome Oxidase ◽  
Mitochondrial Gene ◽  
Large Subunit ◽  
Strong Support ◽  
Interspecific Variation ◽  
Rrna Gene ◽  
Freshwater Crayfish ◽  
Cherax Destructor ◽  
Australian Freshwater

The phylogenetic relationships among 32 individuals of Australian freshwater crayfish belonging to the Cherax destructor-complex were investigated using a dataset comprising sequences from four mitochondrial gene regions: the large subunit rRNA (16S rRNA), cytochrome oxidase I (COI), adenosine triphosphatase 6 (ATPase 6), and cytochrome oxidase III (COIII). A total of 1602 bp was obtained, and a combined analysis of the data produced a tree with strong support (bootstrap values 94–100%) for three divergent lineages, verifying the phylogenetic hypotheses of relationships within the C. destructor species-complex suggested in previous studies. Overall, sequences from the 16S rRNA gene showed the least variation compared to those generated from protein coding genes, which presented considerably greater levels of divergence. The level of divergence within C. destructor was found to be greater than that observed in other species of freshwater crayfish, but interspecific variation among species examined in the present study was similar to that reported previously.

The taxonomy and phylogeny of the 'Cherax destructor' complex (Decapoda : Parastacidae) examined using mitochondrial 16S sequences

2003 ◽  
Vol 51 (2) ◽  
pp. 99 ◽  
Author(s):  
C. M. Austin ◽  
T. T. T. Nguyen ◽  
M. M. Meewan ◽  
D. R. Jerry
Keyword(s):  
Phylogenetic Analysis ◽  
New South ◽  
Mitochondrial Gene ◽  
Haplotype Diversity ◽  
Morphological Plasticity ◽  
Phylogeographic Structure ◽  
Freshwater Crayfish ◽  
Cherax Destructor ◽  
South Wales ◽  
Eastern Australia

This study uses nucleotide sequences from the 16S rRNA mitochondrial gene to investigate the taxonomy and phylogeny of freshwater crayfish belonging to the 'Cherax destructor' complex. The sequencing of an approximately 440-bp fragment of this gene region from freshwater crayfish sampled from 14 locations identified significant haplotype diversity. Phylogenetic analysis found three distinct clades that correspond to the species C. rotundus, C. setosus and C. destructor. C. rotundus is largely confined to Victoria, and C. setosus is restricted to coastal areas north of Newcastle in New South Wales. C. destructor is widely distributed in eastern Australia and shows significant phylogeographic structure, with three well supported clades. None of these clades, however, correspond to species previously recognised as C. esculus, C. davisi or C. albidus. The failure to genetically distinguish these morphologically defined species is consistent with reproductive information and morphological plasticity relating to habitat similar to that documented for other Cherax species.

scholarly journals GENETIC CHARACTERIZATION OF LONGTAIL TUNA Thunnus tonggol (BLEEKER, 1851) BASED ON PARTIAL SEQUENCE OF 16S rRNA MITOCHONDRIAL GENE

2018 ◽  
Vol 24 (2) ◽  
pp. 83
Author(s):  
Achmad Zamroni ◽  
Suwarso Suwarso ◽  
Arif Wibowo
Keyword(s):  
16S Rrna ◽  
Nucleotide Diversity ◽  
Genetic Characterization ◽  
Mitochondrial Gene ◽  
Rrna Gene ◽  
Geographic Scale ◽  
Java Sea ◽  
Mitochondrial 16S Rrna Gene ◽  
Longtail Tuna

Although the Longtail tuna (Thunnus tonggol) is an important fish in Indonesia, the population structure has not been investigated. In this study, the genetic differences in geographic scale are analyzed to provide a clear picture of the structure of T. tonggol populations along a transect stretching from Pemangkat (western Kalimantan) to Pekalongan in the Java Sea. We also analyzed SNPs in the mitochondrial 16S rRNA gene of T. tonggol as potential molecular marker for the identification of the origin within species. In total, three polymorphic sites (all represent singleton dimensions) were identified in the sequence analysis of the 570-bp fragment among a total of 97 T. tonggol individuals from Pekalongan and Pemangkat. Based on these polymorphic sites, four haplotypes were identified. The Pemangkat samples had higher amount of haplotype and nucleotide diversity (h = 0.1556 ± 0.0680 and  = 0.000277 ± 0.000432), meanwhile samples Pekalongan showed lower levels of diversity (h = 0.0400 ± 0.0380 and  = 0.000070 ± 0.000209). The study revealed a single, intermixing population of T. tonggol across the sampled location. No significant structuring was observed between other pairwise comparisons, indicating gene flow between geographically adjacent locations.

Physical Properties, Sensory Receptors and Tactile Reflexes of the Antenna of the Australian Freshwater Crayfish Cherax Destructor

1989 ◽  
Vol 141 (1) ◽  
pp. 197-217 ◽  
Author(s):  
DAVID C. SANDEMAN
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Sensory Nerve ◽  
The Body ◽  
Mechanical Resistance ◽  
Freshwater Crayfish ◽  
Sensory Axons ◽  
Cherax Destructor ◽  
The Individual ◽  
Australian Freshwater

1. The antennal flagellum of the crayfish Cherax destructor is very flexible, tapered and is almost as long as the body in mature animals. It consists of a series of short segments, oval in cross-section, that take the form of flattened rings at the base and slender tubes at the tip. There are no muscles in the flagellum. 2. The flagellum's mechanical resistance to being bent is not the same in all directions. It is most easily bent dorsally and least easily bent medially, when held stretched out horizontally in front of the animal. The resistance to bending is 10 times less than that of Astacus. 3. The individual segments of the flagellum form curved articulating surfaces that may assist in reducing torsional movement of the flagellum when it is bent and, together with the tapered form, provide the flagellum with unique mechanical properties. 4. Four main types of hairs are found on the flagellum. They are distributed in a specific manner, and total about 7000 hairs on the flagellum of a mature animal. Cross-sections through the sensory nerve reveal only about 2000 axons. Methylene blue applied to fresh preparations stains dendrites to all smooth hairs but never to procumbent feathered hairs. 5. Physiological recordings from the sensory axons of the flagellar nerve allowed the characterization of the sensory hair response to displacement. Recordings were also made from slowly adapting receptors, sensitive to bending the flagellum in particular directions, but not related to mechanoreceptive hairs. 6. Intracellular recordings from identified extensor and flexor motoneurones revealed the ordered projection of the inputs from the receptor hairs, and also provided a model that correlates specific receptor inputs with particular antennal reflexes, and links the unique mechanical properties of the flagellum with the detection of the distance of near objects.

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