In situ swimming and settlement behaviour of larvae of an Indo-Pacific coral-reef fish, the coral trout Plectropomus leopardus (Pisces: Serranidae)

The factors influencing the movement and recruitment of settlement stage larvae are investigated using random walk models. Individual-based sensing and orientating abilities are included explicitly in the model. We consider 2 simple reef environment models consisting of a simple circular reef with and without a constant cross-current. The sensing ability of the larvae is modelled as either fixed or spatially dependent, together with a fixed orientating ability. The survival probability is found to be highly sensitive to both the sensing and orientating abilities of the larvae, as well as to the properties of the reef environment itself. KEY WORDS: Reef fish settlement · Larval swimming ability · Biased random walksResale or republication not permitted without written consent of the publisher

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Random walk models for the movement and recruitment of reef fish larvae

Codling¹,

Hill²,

Pitchford³

et al. 2004

“…No within-species differences in swimming speed were found between areas or times, with the exception that Neopomacentrus cyanomos swam 12 to 20% faster at the leeward than at the windward area. Differences in swimming speed between locations have been reported in other species or situations (Leis & Carson-Ewart 1999 and could have large implications for the ultimate location of the larvae at the end of their pelagic period.…”

Section: Swimming Speedmentioning

confidence: 91%

Orientation of pelagic larvae of coral-reef fishes in the ocean

Leis¹,

Carson-Ewart²

2003

112

105

During the day, we used settlement-stage reef-fish larvae from light-traps to study in situ orientation, 100 to 1000 m from coral reefs in water 10 to 40 m deep, at Lizard Island, Great Barrier Reef. Seven species were observed off leeward Lizard Island, and 4 species off the windward side. All but 1 species swam faster than average ambient currents. Depending on area, time, and species, 80 to 100% of larvae swam directionally. Two species of butterflyfishes Chaetodon plebeius and Chaetodon aureofasciatus swam away from the island, indicating that they could detect the island's reefs. Swimming of 4 species of damselfishes Chromis atripectoralis, Chrysiptera rollandi, Neopomacentrus cyanomos and Pomacentrus lepidogenys ranged from highly directional to nondirectional. Only in N. cyanomos did swimming direction differ between windward and leeward areas. Three species (C. atripectoralis, N. cyanomos and P. lepidogenys) were observed in morning and late afternoon at the leeward area, and all swam in a more westerly direction in the late afternoon. In the afternoon, C. atripectoralis larvae were highly directional in sunny conditions, but nondirectional and individually more variable in cloudy conditions. All these observations imply that damselfish larvae utilized a solar compass. Caesio cuning and P. lepidogenys were non-directional overall, but their swimming direction differed with distance from the reef, implying the reef was detected by these species. Larvae of different species of reef fishes have differing orientations and apparently use different cues for orientation while in open, pelagic waters. Current direction did not influence swimming direction. Net movement by larvae of 6 of the 7 species differed from that of currents in either direction or speed, demonstrating that larval behaviour can result in non-passive dispersal, at least near the end of the pelagic phase.

“…In contrast, relatively few studies have described the feeding ecology of larval fishes in tropical environments where perciform fishes dominate (Leis 1991). Taxonomic differences between these orders of fishes, which correspond to differences in body form (elongate vs. compact) and swimming abilities (fast vs. slow) for a given size of larvae (Leis et al 1996, Fuiman & Higgs 1997, Leis & Carson-Ewart 1999, Fisher et al 2000, Fisher & Bellwood 2001, Leis & McCormick 2002, as well as major differences in temperature and prey communities, may mean that generalisations from temperate studies are unlikely to apply to tropical larvae.…”

Section: Introductionmentioning

confidence: 99%

Glimpse into guts: overview of the feeding of larvae of tropical shorefishes

Sampey¹,

McKinnon²,

Meekan³

et al. 2007

136

Knowledge of the diets of tropical fish larvae is limited to only a few taxa. Here, we describe the diets of 591 individuals from 50 families of tropical larval shorefishes collected off the Northwest Shelf of Australia (21°49' S, 114°14' E), effectively doubling the number of families for which there is dietary data available. The diversity of prey items eaten differed significantly among families. The majority of fish larvae ate copepods but there were some interesting exceptions. Chaetodontids ate only chaetognaths, acanthurids and nemipterids ate appendicularians, and tetraodontids ate predominately non-copepod prey (44% decapod larvae, 20% bivalves and 15% protists). Within the fish families that specialised on copepod prey there were marked differences in the types of copepod prey, with a clear preference shown for calanoid copepods, particularly small calanoids such as Bestiolina similis and Temora spp. Copepod communities in the area are foodlimited and we suggest that the ability of some larval fishes to feed on components of the microbial food web may be an important determinant of their success.