Oecologia DOI 10.1007/s00442-015-3251-4
BEHAVIORAL ECOLOGY - ORIGINAL RESEARCH
Inducers of settlement and moulting in post‑larval spiny lobster Jenni A. Stanley · Jan Hesse · Iván A. Hinojosa · Andrew G. Jeffs
Received: 26 May 2014 / Accepted: 28 January 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract The rapid and often remote location of suitable habitats used by migrating organisms is often critical to their subsequent recruitment, fitness and survival, and this includes in the marine environment. However, for the non-feeding post-larval stage of spiny lobsters, effective settlement cues for habitat selection are critical to their success but are poorly described. Therefore, the current study examined whether acoustic and substrate cues have the potential to shorten the time to moulting and affect their subsequent nutritional condition in the pueruli of the southern spiny lobster, Jasus edwardsii. Individuals moulted to first instar juveniles up to 38 % faster when exposed to the underwater sound from two types of typical settlement habitat (coastal kelp- and urchin-dominated reefs) compared to those with no underwater sound. The settlement delay in the post-larvae without underwater sound also resulted in juveniles in poorer survival and nutritional condition as measured by their protein and lipid contents. In a separate experiment, post-larvae presented with seaweed and rock substrates were found to complete settlement and moult to juvenile by as much as 20 % faster compared to those on the sand and control treatments. Overall, the results are the first to demonstrate that the pueruli of J. edwardsii have the ability to detect and respond to underwater sound, as well as determining that both acoustic and substrate cues Communicated by Aaron J. Wirsing. J. A. Stanley (*) · J. Hesse · A. G. Jeffs Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, PO Box 349, Warkworth 0941, New Zealand e-mail: [email protected] I. A. Hinojosa Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, Australia
play a role in modulating physiological development during settlement. Keywords Underwater sound · Spiny lobster · Settlement cues · Moulting · Puerulus
Introduction The pelagic larval phase of the lifecycle of most benthic marine organisms typically involves dispersal away from parental habitats, ending with the larvae selecting a suitable benthic habitat in which to settle (O’Connor and Gregg 1998). An extreme example is the lifecycle of spiny lobsters which have a complex and extended pelagic larval phase (i.e., phyllosoma) lasting 12–22 months, and passing through up to 11 distinct developmental stages, the majority of which occur while the larvae are in oceanic waters tens to hundreds of kilometres offshore (Phillips and Sastry 1980; Booth 2006). The pelagic larval phase of spiny lobsters ends at metamorphosis from an oceanic planktonic larva, or phyllosoma, to a nektonic post-larva, known as a puerulus, which migrates onshore into coastal waters, settling and moulting to become a benthic dwelling first-instar juvenile (Jeffs et al. 2005; Wahle and Fogarty 2006). Settlement of the pueruli has been described to occur in structurally complex habitats in shallow coastal waters, such as crevices and small holes in reefs, or in some species of spiny lobster among macroalgae and mangrove roots (Acosta and Butler 1997; Jeffs and Davis 2003; Booth 2006). The mechanisms by which the pueruli of the Australasian southern spiny lobster, Jasus edwardsii, move inshore to settle is unclear, but is thought to involve a combination of active onshore swimming and the passive use of natural
13
Oecologia
onshore advection processes that are guided by a range of environmental directional cues (Phillips and Macmillan 1987; Butler and Herrnkind 2000; Booth 2001; Jeffs et al. 2005; Wilkin and Jeffs 2011). The potential onshore orientation cues that might be used by pueruli include underwater sound, magnetic fields, water chemistry, physical cues, celestial cues, and hydrodynamic cues; however, there is little evidence in support of the use of any particular one of these orientation cues (Jeffs et al. 2005). After migrating into shallow coastal water, the pueruli must locate suitable settlement habitat, usually consisting of crevices in rocky reefs or among boulders, usually in
BEHAVIORAL ECOLOGY - ORIGINAL RESEARCH
Inducers of settlement and moulting in post‑larval spiny lobster Jenni A. Stanley · Jan Hesse · Iván A. Hinojosa · Andrew G. Jeffs
Received: 26 May 2014 / Accepted: 28 January 2015 © Springer-Verlag Berlin Heidelberg 2015
Abstract The rapid and often remote location of suitable habitats used by migrating organisms is often critical to their subsequent recruitment, fitness and survival, and this includes in the marine environment. However, for the non-feeding post-larval stage of spiny lobsters, effective settlement cues for habitat selection are critical to their success but are poorly described. Therefore, the current study examined whether acoustic and substrate cues have the potential to shorten the time to moulting and affect their subsequent nutritional condition in the pueruli of the southern spiny lobster, Jasus edwardsii. Individuals moulted to first instar juveniles up to 38 % faster when exposed to the underwater sound from two types of typical settlement habitat (coastal kelp- and urchin-dominated reefs) compared to those with no underwater sound. The settlement delay in the post-larvae without underwater sound also resulted in juveniles in poorer survival and nutritional condition as measured by their protein and lipid contents. In a separate experiment, post-larvae presented with seaweed and rock substrates were found to complete settlement and moult to juvenile by as much as 20 % faster compared to those on the sand and control treatments. Overall, the results are the first to demonstrate that the pueruli of J. edwardsii have the ability to detect and respond to underwater sound, as well as determining that both acoustic and substrate cues Communicated by Aaron J. Wirsing. J. A. Stanley (*) · J. Hesse · A. G. Jeffs Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, PO Box 349, Warkworth 0941, New Zealand e-mail: [email protected] I. A. Hinojosa Institute for Marine and Antarctic Studies, University of Tasmania, Taroona, Australia
play a role in modulating physiological development during settlement. Keywords Underwater sound · Spiny lobster · Settlement cues · Moulting · Puerulus
Introduction The pelagic larval phase of the lifecycle of most benthic marine organisms typically involves dispersal away from parental habitats, ending with the larvae selecting a suitable benthic habitat in which to settle (O’Connor and Gregg 1998). An extreme example is the lifecycle of spiny lobsters which have a complex and extended pelagic larval phase (i.e., phyllosoma) lasting 12–22 months, and passing through up to 11 distinct developmental stages, the majority of which occur while the larvae are in oceanic waters tens to hundreds of kilometres offshore (Phillips and Sastry 1980; Booth 2006). The pelagic larval phase of spiny lobsters ends at metamorphosis from an oceanic planktonic larva, or phyllosoma, to a nektonic post-larva, known as a puerulus, which migrates onshore into coastal waters, settling and moulting to become a benthic dwelling first-instar juvenile (Jeffs et al. 2005; Wahle and Fogarty 2006). Settlement of the pueruli has been described to occur in structurally complex habitats in shallow coastal waters, such as crevices and small holes in reefs, or in some species of spiny lobster among macroalgae and mangrove roots (Acosta and Butler 1997; Jeffs and Davis 2003; Booth 2006). The mechanisms by which the pueruli of the Australasian southern spiny lobster, Jasus edwardsii, move inshore to settle is unclear, but is thought to involve a combination of active onshore swimming and the passive use of natural
13
Oecologia
onshore advection processes that are guided by a range of environmental directional cues (Phillips and Macmillan 1987; Butler and Herrnkind 2000; Booth 2001; Jeffs et al. 2005; Wilkin and Jeffs 2011). The potential onshore orientation cues that might be used by pueruli include underwater sound, magnetic fields, water chemistry, physical cues, celestial cues, and hydrodynamic cues; however, there is little evidence in support of the use of any particular one of these orientation cues (Jeffs et al. 2005). After migrating into shallow coastal water, the pueruli must locate suitable settlement habitat, usually consisting of crevices in rocky reefs or among boulders, usually in
