Can larval snapper, Pagrus auratus, smell their new home?

Abstract

Abstract. The ability to find a suitable settlement habitat after a pelagic larval period represents a significant challenge to marine settlement-stage larvae, and the mechanisms by which they achieve this are poorly understood. There is good evidence that olfactory cues are used by some coral reef fish larvae to locate suitable settlement habitats; however, the same understanding is lacking for marine temperate fish. Here we show for the first time that the larvae of an important commercial and recreational marine temperate fish, Pagrus auratus, can use olfactory cues to orient to appropriate settlement habitat. Using pairwise choice experiments, naive hatchery reared fish were offered water collected from a range of habitats in the Kaipara Harbour, an important nursery area for P. auratus. Larvae selected to swim towards water taken from over seagrass beds, their preferred settlement habitat, than water taken from the harbour entrance, Asian date mussel habitat, artificial seawater or artificial seawater in which seagrass had been soaked. The preference by the fish for water from the seagrass habitat over artificial seawater in which seagrass had been soaked strongly suggests that chemical cues from sources other than seagrass, such as from prey or conspecifics present in the seagrass habitat, may also be involved.

Response of Gilthead Seabream (Sparus aurata L., 1758) Larvae to Nursery Odor Cues as Described by a New Set of Behavioral Indexes

“…However, in a similar experiment, hatchery-reared larvae preferred seagrass habitat water in detriment of other water types (Radford et al, 2012). The capture of wild larvae in different stages of larval development and controlled conditions of food availability would be impossible given our experimental design.…”

“…However, most of the research done about habitat selection focused on coral reef fish larvae (see Teodósio et al, 2016 for a review), which suggests the existence of an olfactory-driven homing behavior (Gerlach et al, 2007). Such behavior is also relevant for the understudied temperate fish species (James et al, 2008;Radford et al, 2012), as proposed by the SAAB hypothesis (Teodósio et al, 2016).…”

“…Chemical signatures are determined by abiotic or biotic factors, as type of substrate (V. Baptista, CCMAR, unpublished data), vegetation (Radford et al, 2012), or chemical signals released by conspecifics (Døving et al, 2006). However, most of the research done about habitat selection focused on coral reef fish larvae (see Teodósio et al, 2016 for a review), which suggests the existence of an olfactory-driven homing behavior (Gerlach et al, 2007).…”

“…The development of these indexes is of prime importance because so far there is no consistent methodology to analyze data obtained with choice-chamber experiments. For example, Radford et al (2012) present their results as the mean percentage of time larvae spent in the preferred water type, while Atema et al (2002) and Gerlach et al (2007) calculated a preference index that varied between -100 and +100% and calculated as the difference between the relative mean time spent in waters from two different habitats. Furthermore, and as far as we perceive them, none of these works accounted for unresponsive and inconclusive behavior (Atema et al, 2002;Gerlach et al, 2007;Radford et al, 2012).…”

Contributions of the Leigh Marine Laboratory to marine science, 1962–2012: sensory neuroethology

“…. As one recent local example, Radford et al (2012b) have shown that snapper (Pagrus auratus) can use olfactory cues to orient to an appropriate seagrass settlement habitat. In addition to the olfactory cues produced by specific habitat types, established populations may also provide a good 'proxy' for suitable migration and settlement destinations.…”