Comparison of the species of Pisinna


This suumary compares all the species of Pisinna that occur in NSW. Some of the species are quite variable, particularly in the presence/absence and strength of axial ribs, so quite a few specimens are needed for a definite identification.

Continental shelf species - Not found shallower than about 20 m depth, and never in beach washup:

P. laseroni Mid-sized for genus; blunt, smooth shell with very strong varix.

P. nitida Largest species in the genus; smooth, straight sided.

P. paucirugosa Large for genus; like P. nitida but wider and with weak axials

P. tasmanica Mid-sized for genus, smooth or ribbed.

P. varicifera relata Large for genus; fine axials, sutures often deeply grooved.

Intertidal and shallow water species

 1. With axial ribs, even if faint; in order of decreasing abundance in NSW.

P. olivacea Axials absent on at least first whorl. Spiral groove below suture making row of nodules.

P. albizona Either smooth or axially ribbed. White band below suture.

P. frauenfeldi Large for genus (3.7 mm), axials on all whorls, usually white spiral band on middle of last whorl.

P. salebrosa The widest species in the genus; strong oblique ribs with a depression around middle of whorls.

P. kershawi Close-set axials on all whorls, sometimes weak on first whorl. Like P. olivacea but no spiral groove below suture.

P. castella Three spiral rows of strong nodules.

P. oblata Very fine oblique axials on last whorl.

P. tumida Similar to P. olivacea but stronger axials and colour bands. Very rare in NSW.

2. Without axial ribs

P. approxima Small, translucent reddish-brown.

P. vincula Usually with 1-2 spiral cords and angled periphery on last whorl, but sometimes smooth and then very similar to P. approxima.


Copyright Des Beechey 2014