Ž . Aquaculture 160 1998 259–272 Effect of ammonia on the growth rate and oxygen consumption of juvenile greenlip abalone, Haliotis laeÕigata Donovan James O. Harris a, ) , Greg B. Maguire a , Stephen Edwards b , Stephen M. Hindrum a a Department of Aquaculture, UniÕersity of Tasmania, PO Box 1214, Launceston, Tasmania 7250, Australia b Department of Physical Sciences, UniÕersity of Tasmania, PO Box 1214, Launceston, Tasmania 7250, Australia Accepted 1 November 1997 Abstract Ž Juvenile greenlip abalone, Haliotis laeÕigata, mean whole weight 4.48 "1.9 g, mean "s.d., . n s953 were highly sensitive to ammonia as indicated by depressed growth rate and food consumption measured over 2–3 months in bioassay tanks. For growth rate expressed on a whole Ž . y1 weight basis, the EC and EC values 5 and 50% growth reductions were 0.041 mg FAN l 5 50 Ž . y1 Free Ammonia–Nitrogen and 0.158 mg FAN l , respectively. Shell growth rates declined over Ž y1 . the entire experimental range 0.006–0.188 mg FAN l . At the end of the bioassay, groups of abalone were transferred to respiratory chambers. Oxygen consumption rate increased to a maximum of 188% of control values at 0.235 mg FAN l y1 and decreased slightly at the highest concentration of 0.418 mg FAN l y1 . q 1998 Elsevier Science B.V. Keywords: Abalone; Haliotis laeÕigata; Ammonia; Growth—molluscs; Oxygen Ž q . Ž . Abbreviations: TAN, total ammonia nitrogen NH -N plus NH -N ; FAN, free unionised ammonia 3 4 Ž . Ž y1 . nitrogen NH -N ; NO -N, nitrite nitrogen; SGRW, specific growth rate wet whole body weight% day , 3 2 w Ž . Ž .x Ž . y1 Ž y1 . ln final weight yln initial weight no. of days =100; SGRL, specific growth rate shell length% day , wŽ . Ž .x Ž . y1 ln final length yln initial length no. of days =100 ) Corresponding author. Tel.: q 61-03-63243852; fax: q 61-3-63243804; e-mail: jharris1@postoffice.utas.edu.au. 0044-8486r98r$19.00 q 1998 Elsevier Science B.V. All rights reserved. Ž . PII S0044-8486 97 00249-4