Euastacus yanga

The maximum recorded size was 61.2 mm (2.41 in) OCL (Occipital Carapace Length) which is used to measure the species' size. The rostrum is short and in individuals over 50 mm (2.0 in) OCL usually does not reach the base of the third antenna segment. In those measuring 20–140 mm (0.79–5.51 in) OCL the rostrum is to the base or midpoint of that segment and, in some under 20 mm (0.79 in), goes to the end of the third segment. The cephalon is spiny on most organisms but less so on specimens under 20 mm (0.79 in) OCL. In southern populations the spines are larger and more numerous. Their thorax has up to 20 spines on each side in one or two irregular rows although this is usually absent on smaller individuals (under 20 mm (0.79 in) OCL). The spines are generally longer and sharper in southern populations. The tubercles are moderately to densely distributed on specimens over 30 mm (1.2 in) OCL, very sparse to moderately on smaller examples, occasionally absent. Their abdomen has one, or very occasionally, two, dorsal-lateral spines on somite 1 of individuals over 20 mm (0.79 in) OCL. Dorsal spine often present on somite 1, especially on larger specimens. Somite 2 has three to seven (very occasionally two) in lateral line 1, often absent on smaller specimens. Somites 3-5 of larger specimens, over 30 mm (1.2 in) OCL and most over 20 mm (0.79 in), have a single spine in line 1. …

The variable spiny cray is found in New South Wales from the Robertson to Bundanoon area in the Southern Highlands south to just inside the Victorian border near Genoa. E. Yanga is the third most widely distributed Euastacus species behind E. armatus and E. spinifer.

Berried females (those that are carrying eggs) have been collected in late October through November. The eggs are burgundy with white patches where the developing embryo was located and each female carries 43 to 164.