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: 2.47). 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.

  • 01/2008;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The larval phase of most species of coral reef fishes is spent away from the reef in the pelagic environment. At the time of settlement, these larvae need to locate a reef, and recent research indicates that sound emanating from reefs may act as a cue to guide them. Here, the auditory abilities of settlement-stage larvae of four species of coral reef fishes (families Pomacentridae, Lutjanidae and Serranidae) and similar-sized individuals of two pelagic species (Carangidae) were tested using an electrophysiological technique, auditory brainstem response (ABR). Five of the six species heard frequencies in the 100–2,000Hz range, whilst one carangid species did not detect frequencies higher than 800Hz. The audiograms of the six species were of similar shape, with best hearing at lower frequencies between 100 and 300Hz. Strong within-species differences were found in hearing sensitivity both among the coral reef species and among the pelagic species. Larvae of the coral reef species had significantly more sensitive hearing than the larvae of the pelagic species. The results suggest that settlement-stage larval reef fishes may be able to detect reef sounds at distances of a few 100m. If true hearing thresholds are lower than ABR estimates, as indicated in some comparisons of ABR and behavioural methods, the detection distances would be much larger.
    Coral Reefs 01/2010; 29(1):235-243. · 3.66 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Temperature-induced coral bleaching is a major threat to the biodiversity of coral reef ecosystems. While reductions in species diversity and abundance of fish communities have been documented following coral bleaching, the mechanisms that underlie these changes are poorly understood. The present study examined the impacts of coral bleaching on the early life-history processes of coral reef fishes. Daily monitoring of fish settlement patterns found that ten times as many fish settled to healthy coral than sub-lethally bleached coral. Species diversity of settling fishes was least on bleached coral and greatest on dead coral, with healthy coral having intermediate levels of diversity. Laboratory experiments using light-trap caught juveniles showed that different damselfish species chose among healthy, bleached and dead coral habitats using different combinations of visual and olfactory cues. The live coral specialist, Pomacentrus moluccensis, preferred live coral and avoided bleached and dead coral, using mostly visual cues to inform their habitat choice. The habitat generalist, Pomacentrus amboinensis, also preferred live coral and avoided bleached and dead coral but selected these habitats using both visual and olfactory cues. Trials with another habitat generalist, Dischistodus sp., suggested that vision played a significant role. A 20days field experiment that manipulated densities of P. moluccensis on healthy and bleached coral heads found an influence of fish density on juvenile weight and growth, but no significant influence of habitat quality. These results suggests that coral bleaching will affect settlement patterns and species distributions by influencing the visual and olfactory cues that reef fish larvae use to make settlement choices. Furthermore, increased fish density within the remaining healthy coral habitats could play an important role in influencing population dynamics. KeywordsCoral bleaching-Settlement patterns-Climate change-Coral reef fish-Vision-Olfaction
    Coral Reefs 29(3):537-546. · 3.66 Impact Factor

Full-text (2 Sources)

Available from
Jun 5, 2014