Crayfish (aka Freshwater Lobster)

First lets look up the taxanomy of our Crayfish.
I'll go brief and not really into the sub or super classes and orders.

Phylum : Adropoda (Segmented Legs + Hard Outer Shell)
eg. insects, crabs, scorpions

Class : Crustacea

Order : Decapods (10 legged)

Family : Astacidae, Cambaridae (Northern Hemisphere)
Parastacidae (Southern Hemisphere)

Below is an extract from http://tolweb.org showing the distribution of the 3 family.


We will be focusing on Parastacidae as its where our local available Crayfish are from.
Genus : 14 of them, Astacoides, Astacopsis, Euastacus, Gramastacus, Geocherax, Virilastacus, Samastacus, Cherax, Paranephrops, Parastacoides, Tennuibranchiurus, Engaewa, Engaeus, Parastacus

Another extract from http://tolweb.org showing the distribution of Southern Hemisphere Crayfish, Parastacidae

Figure 1. Distribution of the 10 Australian Parastacid genera (from Hobbs 1988). The Tennuibranchiurus and Engaeus are shown only in the second map on the right inset.


Figure 2. Distributions of the remaining Parastacid genera. Note that there is an overlap of Parastacus and Samastacus in central Chile that is not depicted very well in the graphic.

From http://tolweb.org

Cherax in 5 sub groups

Destructor Group
Cherax albidus
Cherax destructor

Punctatus Group
Cherax neopunctatus
Cherax depressus
Cherax cairnsensis
Cherax wasselli
Cherax gladstonensis
Cherax glaber
Cherax urospinosus
Cherax robustus
Cherax cartalacoolah
Cherax punctatus
Cherax rotundus

Dispar Group
Cherax cuspidatus
Cherax dispar

Quinquecarinatus Group
Cherax preissii
Cherax plebejus
Cherax glabrimanus
Cherax neocarinatus
Cherax quinquecarinatus
Cherax crassimanus

Quadricarinatus Group
Cherax divergens
Cherax lorentzi
Cherax quadricarinatus
Cherax tenuimanus
Cherax rhynchotus
Cherax monticola
Cherax barretti
Cherax nucifraga
Cherax parvus

Some pics from http://tolweb.org by Keith A.Crandall

Anatomy from http://www.crayfishworld.com



1. Rostral carinae

2. Mandibles

3. Carpus, leads to the main claw ( chela ), the section between the carpus and the main body is the merus. There are five sets of legs on all decapod, simlply ten legs.

4. Carapace

5. On these legs the female gonopore

6. On these legs if male, the male gonopores

7. Spines

8. Somites, there are five sections

9. Eggs, this particular female is in 'berry'.

10. Telsons, once again five sections

by Pierre Horwitz

Sexing Guide from http://www.crayfishworld.com










photos by Chris

From http://crayfishworld.com


A decent sized euastacus


30+years old....