Article

Auditory and olfactory abilities of pre-settlement larvae and post-settlement juveniles of a coral reef damselfish (Pisces: Pomacentridae)

University of New South Wales School of Biological, Earth and Environmental Sciences Sydney NSW 2052 Australia
Marine Biology (Impact Factor: 2.39). 01/2007; 147(6):1425-1434. DOI: 10.1007/s00227-005-0028-z

ABSTRACT The propagules of most species of reef fish are advected from the reef, necessitating a return to reef habitats at the end
of the pelagic stage. There is increasing evidence of active attraction to the reef but the sensory abilities of reef fish
larvae have not been characterized well enough to fully identify cues. The electrophysiological methods of auditory brainstem
response (ABR) and electroolfactogram (EOG) were used to investigate auditory and olfactory abilities of pre- and post-settlement
stages of a damselfish, Pomacentrus nagasakiensis (Pisces, Pomacentridae). Audiograms of the two ontogenetic stages were similar. Pre-settlement larvae heard as well as their
post-settlement counterparts at all but two of the tested frequencies between 100Hz and 2,000Hz. At 100 and 600Hz, pre-settlement
larvae had ABR thresholds 8dB higher than those of post-settlement juveniles. Both stages were able to detect locally recorded
reef sounds. Similarly, no difference in olfactory ability was found between the two ontogenetic stages. Both stages showed
olfactory responses to conspecifics as well as L-alanine. Therefore, the auditory and olfactory senses have similar capabilities in both ontogenetic stages. Settlement stage
larvae of P. nagasakiensis can hear and smell reef cues but it is unclear as to what extent larvae use these sounds or smells, or both, as cues for
locating settlement sites.

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