The early life history of labroid fishes at Lizard Island, Northern Great Barrier Reef

摘要: Adult labrids showed distinctive patterns of distribution and abundance among habitat zones at Lizard Island, which were consistent in space (among sites) time (annually seasonally). Patterns labrid diversity habitats not clearly influenced by substrate characteristics such as percent live cover, complexity. However depth was an important factor influencing use, with 7 abundant species present higher densities either shallow (Halichoeres spp., Stethojulis bandanensis, Thalassoma hardwicke T. jansenii) or deep (Cons schroederi, H. melanurus, lunare). Only one species, Labroides dimidiatus ubiquitous all depths. Most used the same different life history stages (adults recruits), suggesting that adults determined recruitment this scale. In contrast, two (Labroides lunare) ontogenetic shifts indicating their modified post-settlement processes. Labroid recruits (labrids scarids) also microhabitats within. 2 (Reef Base Sand Flat). Three taxa: (Coris schroederi Halichoeres melanurus) a group scarids (Scares spp.), significantly within stands macroalgae territories herbivorous damselfish (Dischistodus prosopotaenia D. perspicillatus) than they adjacent (reef matrix rubble/sand patches). The provided excellent replicate units for studying early these species. Many rare most territories. Each facilitated growth excluding trophic competitors disruptive carnivores. established on reef matrix/sand interface bottom slope, characterised multispecific green, red brown algae. perspicillatus sand flat, monospecific stand blue-green contrast to territories, almost devoid macroalgae. Both occurred large aggregations ( >20 individuals), where covered > 20% areas 250m²). result labroids aggregations, without aggregations. C. Scarus spp. both types high densities, while melanurus only territories. A manipulative experiment using artificial indicated may have discriminated between basis microhabitat characteristics, rather location profile. further studies are required test hypothesis. Labrids heavily did so times summer. Scarids them summer, C. mid-summer late These spatially temporally (between years) consistent, probably decreased possibility inter-specific interactions labroid during, first few weeks benthic life. Scarid before evicted resident damselfish. This coincided size became herbivores carnivorous continued use throughout lives, (C. schroederi) spending >50% behaviour appeared be tolerated damselfish, attacked occasions. Living had no negative effects diet, survivorship during months life, despite densities. because resources (food shelter) much other microhabitats. overall reinforced unchanged processes, suggested sizes adult populations should been vicinity case, processes operating after spatial recruitment. One some individuals moved out onto absent. results suggest act focal sites recruitment, local abundances labroids, reefal areas.