Studies on southern Australian abalone (genus Haliotis) XVIII. Ring formation in H. scalaris

Abstract

The abalone Haliotis scalaris deposits two fine rings a year in the spire, one in about December and the other from May to July, corresponding roughly to summer and winter sea temperature extremes. Additional fine rings, and in particular brown rings, are deposited in response to boring annelids and drilling muricid gastropods. Multiple regression analysis revealed a relationship between the number of rings in the spire and the variables: age of the shell, extent of infestation by annelids, and the number of brown rings. The analysis showed that additional fine rings’ and brown rings are deposited according to the degree of parasitic attack.

Keywords:

• Haliotis scalaris
• rings
• shell aging
• parasite attack
• endobionts
• muricid drilling