The use of energy stores in the puerulus of the spiny lobster Jasus edwardsii across the continental shelf of New Zealand

Nektonic pueruli of the spiny lobster, Jasus edwardsii , were caught from t wo locations about 20 km apart across the continental shelf on the south ea st of the North Island, New Zealand. The pueruli were assayed for total pro tein, glucose, glycogen, and lipid content. Only the lipid content differed between pueruli caught onshore and offshore (mean difference = 3.1 mg or 3 .4% of dry mass). The average difference in lipid content measured over thi s distance was used to calculate the rate of energy consumption and timing for pueruli to actively swim from the continental shelf to shore. These res ults confirmed previous theoretical estimates and indirect measures. Furthe rmore, the rate of energy consumption would allow all of the pueruli caught offshore to swim to shore based on their total measured lipids. However, s ome individuals with low energy stores may be energetically compromised at arrival which may affect their subsequent moulting and survival. The result s of this study indicate that lipid is the primary format for energy storag e of the nektonic puerulus of the spiny lobster and that these lipid reserv es have sufficient energetic capacity to allow the puerulus to actively swi m the distance across the shelf to settle on the coast. (C) 1999 Elsevier S cience Inc. All rights reserved.