Effect of stage of larval development on the settlement of the abalone, Haliotis iris

Larvae of the abalone, Haliotis iris, settle on Lithothamnion-covered surfaces in preference to bare rock and acrylic surfaces. The number of rows of chitinised teeth in the radula was used to stage the larvae. Larvae with 3 or more rows of teeth will rapidly settle but larvae with 8 or more rows of teeth settle, slay, and survive up to 5 days in greater numbers than earlier stages. The behaviour of different stage larvae at settlement is described. These results are discussed in relation to hatchery production of juvenile abalone and the use of larvae to enhance natural populations of abalone.