Hemocyanin from the Australian freshwater crayfish Cherax destructor. Characterization of a dimeric subunit and its involvement in the formation of the 25S component

Biochemistry ◽  
1978 ◽  
Vol 17 (15) ◽  
pp. 3078-3084 ◽  
Author(s):  
Peter D. Jeffrey ◽  
Denis C. Shaw ◽  
G. Barbara Treacy
Keyword(s):  
Freshwater Crayfish ◽  
Cherax Destructor ◽  
Dimeric Subunit ◽  
Australian Freshwater

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.

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.

Growth in the Australian freshwater crayfish, Cherax destructor Clark, under laboratory conditions

1988 ◽  
Vol 39 (4) ◽  
pp. 555 ◽  
Author(s):  
MC Geddes ◽  
BJ Mills ◽  
KF Walker
Keyword(s):  
Water Quality ◽  
Culture System ◽  
Artificial Diet ◽  
Freshwater Crayfish ◽  
Lower Growth ◽  
Average Growth ◽  
Cherax Destructor ◽  
Australian Freshwater ◽  
Discrete Populations ◽  
Variable Water

Small (0.08 to 6.1 g) crayfish were grown at 26�C under three treatments: held individually and fed 3% or 10% of body weight per day, or held communally and fed the higher ration. Moult increments, expressed as length or weight increment (%), were smaller and intermoult periods were longer in the crayfish held communally or, particularly, in crayfish fed low rations; this resulted in lower growth in these treatments. Crayfish from three geographically discrete populations held individually and fed the higher ration showed relationships between log moult increment in weight and log premoult weight; further, the length of the intermoult period increased with size for these populations. Models for average growth showed that C. destructor may grow from 0.1 g to 40 g in approximately 230 days. Growth may have been suppressed in the culture system because of the size of containers, the entirely artificial diet and the variable water quality.

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