Malacological Society of Australasia

Molluscan Research

Volume 18, Issue 2 (Australasian Abalone): 31 October 1997. Edited by S.A. Shepherd, P.E.McShane and F.E.Wells

A practical chronology for the abalone Haliotis fulgens.

S.A. Shepherd* and J.R. Turrubiates-Morales**.

*South Australian Research and Development Institute, PO Box 120, Henley Beach, South Australia 5022.
**Instituto Nacional de Pesca, Crip-la paz, Km 1 carr. Pichilingua, La Paz, bcs Mexico.

The abalone Haliotis fulgens deposits fine (non-pigmented) and dark (pigmented) rings in the spire that are useful for aging the shell. A dark ring is deposited annually, and in the first 4-5 years is preceded by one or more fine rings which are deposited with decreasing frequency over time. External shell erosion causes the loss of about one ring per 32 mm shell length over about 80 mm length. The El Nio events of 1982-3 and 1991-2 caused growth checks in shells of H. fulgens at La Natividad and Bahia Tortugas, Baja California and were used as a time-stamp to validate the rate of deposition of dark rings in the shell. In about 9% of the shells examined more or less dark rings are deposited than expected. In these cases counts of fine rings as wells as dark rings can reduce the chance of error.

pp. 219-226.