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The influence of conspecific and heterospecific juveniles on benthic recruitment in a reef-fish.
Hill, Ronald*,1, 1 NOAA/NMFS/Southeast Fisheries Science Center, Galveston, TX
ABSTRACT- Although newly-settled reef fish juveniles demonstrate heterogeneous distributions, little progress has been made in discerning interactions or cues that create these differences. Previous hypotheses and studies have assumed or demonstrated negative interactions, such as competition, between residents and newly settling juveniles, with a few notable exceptions. Habitat selection by newly-settled white grunts, Haemulon plumieri, was tested using experimental manipulation of similar settlement sites: a) Acropora cervicornis with small juveniles, b) unoccupied A. cervicornis colonies, c) A. cervicornis from which residents had been recently removed, and d) coral colonies occupied by older juveniles. Out of 1496 white grunts, significantly more (85.7%) recruited to coral colonies with early stage juveniles than to (b) 4.5%, (c) 8.2%, or (d) 0% (ANOVA, P<0.0001). Recruitment of all newly settled haemulids (4610 total) followed the same pattern: 87.4% to A. cervicornis with young resident juveniles. These results support the hypothesis that settlement of white grunts and other haemulids is facilitated rather than inhibited by the presence of earlier settlers. The conspecific- and heterospecific-attraction hypotheses predict advantages to schooling fish recruiting together based on mutually beneficial behaviors and habitat cues.
Key words: conspecific attraction, coral reef fish, recruitment, habitat selection