FLAT REACTION NORMS AND “FROZEN” PHENOTYPIC VARIATION IN CLONAL SNAILS (POTAMOPYRGUS ANTIPODARUM)

The Frozen Niche-Variation hypothesis (FNV) suggests that clones randomly sample and “freeze” the genotypes of their ancestral sexual populations. Hence, each clone expresses only a fraction of the total niche-use variation observed in the sexual population, which may lead to selection for ecological specialization and coexistence of clones. A generalized form of the FNV model suggests that the same is true for life-history (as well as other) traits that have important fitness consequences, but do not relate directly to niche use. We refer to the general form of the model as the Frozen Phenotypic Variation (FPV) model. A mixed population of sexual and parthenogenetic snails (Potamopyrgus antipodarum) in a New Zealand lake allowed us to examine the phenotypic variation expressed by coexisting clones in two benthic habitats, and to compare that variation to the sexual population. Three clones were found primarily in an aquatic macrophyte zone composed of Isoetes kirkii (1.5–3.0 m deep), and three additional clones were found in a deeper macrophyte zone composed of Elodea canadensis (4.0–6.0 m deep). These clones showed significant variation between habitats, which mirrored that observed in the sexual population. Specifically, clones and sexuals from the deeper habitat matured at a larger size and had larger broods. There was also significant among-clone variation within habitats; and as expected under the FPV model, the within-clone coefficients of variation for size at maturity were low in both habitats when compared to the sexual population. In addition, we found four clones that were common in both macrophyte zones. The reaction norms of these clones were flat across habitats, suggesting little phenotypic plasticity for morphology or life-history traits. Flat reaction norms, high among-clone variation, and low coefficients of variation (relative to the sexual population) are in accordance with the FPV model for the origin of clonal lineages. We also measured the prevalence of infection by trematode larvae to determine whether clones are inherently more or less infectable, or whether they are freezing phenotypic variation for resistance from the sexual population. We did this in the deep habitats of the lake where recycling of the parasite by the vertebrate host is unlikely, thereby reducing the complications raised by frequency-dependent responses of parasites to host genotypes. We found no indication that clones are either more or less infectable than the resident sexual population. Taken together, our results suggest that phenotypic variation for both life-history traits and resistance to parasites is frozen by clones from the local sexual population.     

Artificial nest predation rates vary among habitats in the Australian monsoon tropics

Rates of nest predation have frequently been shown to differ between fragmented and unfragmented habitats, but have rarely been compared among natural habitats in the same geographic region. In this study, artificial nests of two types (open cup and domed) were placed in four habitats (mangroves, monsoon rainforests, eucalypt woodlands and paperbark swamps) over 12 months in three localities near Darwin in the Australian monsoon tropics to determine the effects of habitat, season and nest type on the rate of nest predation. A quail egg and a similarly coloured plasticine egg were placed in each nest. Habitat had a strong effect on nest predation rates, with nests in mangroves experiencing predation rates more than four times higher than those in eucalypt woodlands and paperbark swamps. Despite the strong rainfall seasonality of the region, there was no consistent seasonal variation in nest predation rates. Nest type also had little influence on predation rates, except in paperbark swamps where open cup nests suffered a higher predation rate than domed nests. The study indicates that generalised nest predation rates for tropical regions, even for small areas (e.g. <17 km radius), might overlook substantial variation between habitats. Such variation confounds purported differences in nest predation rates between tropical and temperate regions.     

Ecological factors influencing disease risk in Eagle Owls Bubo bubo

In this study we assessed whether local habitat features and host population density influenced disease risk in Eagle Owl Bubo bubo fledglings. Measures of immune defence (concentrations of circulating white blood cells), prevalence of three parasite types (a blood parasite Leucocytozoon ziemanni , an insect Carnus haemapterus , and a tick Rhipicephalus sp.) and total number of parasite species were used to quantify disease risk. We tested the hypotheses that disease risk in fledglings was higher in nests located in areas with higher length of and proximity to watercourses (as a higher abundance and viability of parasites and vectors occur in wetter areas), higher cover of forest (as forest moistness and humidity can favour higher vector and parasite proliferation), higher habitat diversity (as environmental heterogeneity increases the pool of potential vectors and parasites) and higher local owl population density (as disease transmission might be density-dependent). The clearest relationship was with the proximity of freshwater, although the other hypotheses were also partially supported. Concentrations of white blood cells, the number of parasite species and, weakly, the prevalence of Carnus haemapterus were all higher in nests closer to watercourses. The prevalence of blood parasites increased with the cover of forested areas. Fledglings from nests located in more diverse habitats had higher white blood cell concentrations and showed higher prevalence of blood parasites. Finally, local host population density was positively correlated with the prevalence of blood parasites. The results suggest the existence of complex and interrelated links between ecological parameters and three different measures of disease risk, and highlight the importance of immunological approaches to assess disease risk at an intraspecific level.     

Faster clonal turnover in high‐infection habitats provides evidence for parasite‐mediated selection

According to the Red Queen hypothesis for sex, parasite‐mediated selection against common clones counterbalances the reproductive advantage of asexual lineages, which would otherwise outcompete sexual conspecifics. Such selection on the clonal population is expected to lead to a faster clonal turnover in habitats where selection by parasites is stronger. We tested this prediction by comparing the genetic structure of clonal and sexual populations of freshwater snail Potamopyrgus antipodarum between years 2003 and 2007 in three depth‐specific habitats in Lake Alexandrina (South Island, New Zealand). These habitats differ in the risk of infection by castrating trematodes and in the relative proportion of sexual individuals. As predicted, we found that the clonal structure changed significantly in shallow and mid‐water habitats, where prevalence of infection was high, but not in the deep habitat, where parasite prevalence was low. Additionally, we found that both clonal diversity and evenness of the asexual population declined in the shallow habitat. In contrast, the genetic structure (based on F–statistics) of the coexisting sexual population did not change, which suggests that the change in the clonal structure cannot be related to genetic changes in the sexual population. Finally, the frequency of sexuals had no effect on the diversity of the sympatric clonal population. Taken together, our results show a more rapid clonal turnover in high‐infection habitats, which gives support for the Red Queen hypothesis for sex.     

Parasitism and breeding system variation in North American populations of Daphnia pulex

The Red Queen hypothesis proposes that frequency-dependent selection by parasites may be responsible for the evolutionary maintenance of sexual reproduction. We sought to determine whether parasites could be responsible for variation in the occurrence of sexual reproduction in 21 populations of Daphnia pulex (Crustacea; Cladocera) that previous studies have shown to consist of either cyclical parthenogens, obligate parthenogens, or a mixture of both. We measured parasite prevalence over a four-week period (which essentially encompasses an entire season for the temporary snow-melt habitats we sampled) and regressed three different measures of sexuality against mean levels of parasite prevalence. Levels of parasitism were low and we found no relationship between levels of sexuality and mean parasite prevalence. Genetic variation with infection level was detected in 2 of the 21 populations, with several different clones showing signs of overparasitism or underparasitism. Overall, however, our results suggest that parasites are not a major source of selection in these populations and it thus seems unlikely they are responsible for maintaining breeding system variation across the study region.     

Exploring the Diversity and Distribution of Neotropical Avian Malaria Parasites – A Molecular Survey from Southeast Brazil

Southeast Brazil is a neotropical region composed of a mosaic of different tropical habitats and mountain chains, which allowed for the formation of bird-rich communities with distinct ecological niches. Although this region has the potential to harbor a remarkable variety of avian parasites, there is a lack of information about the diversity of malarial parasites. We used molecular approaches to characterize the lineage diversity of Plasmodium and Haemoproteus in bird communities from three different habitats in southeast Brazil based on the prevalence, richness and composition of lineages. We observed an overall prevalence of 35.3%, with a local prevalence ranging from 17.2% to 54.8%. Moreover, no significant association between prevalence and habitat type could be verified (p>0.05). We identified 89 Plasmodium and 22 Haemoproteus lineages, with 86% of them described for the first time here, including an unusual infection of a non-columbiform host by a Haemoproteus (Haemoproteus) parasite. The composition analyses of the parasite communities showed that the lineage composition from Brazilian savannah and tropical dry forest was similar, but it was different from the lineage composition of Atlantic rainforest, reflecting the greater likeness of the former habitats with respect to seasonality and forest density. No significant effects of habitat type on lineage richness were observed based on GLM analyses. We also found that sites whose samples had a greater diversity of bird species showed a greater diversity of parasite lineages, providing evidence that areas with high bird richness also have high parasite richness. Our findings point to the importance of the neotropical region (southeast Brazil) as a major reservoir of new haemosporidian lineages.     

Spatial and temporal variation in fish community structure of a marine embayment in Zanzibar,Tanzania

Spatial and temporal variation in the fish community structure were studied in a tropical non-estuarine embayment in Chwaka Bay, Zanzibar (Tanzania). Fish samples were collected bi-monthly (at each spring low tide) for 1 year (November 2001–October 2002) from a range of bay habitats ranging from mangroves deep inside the bay to seagrass beds close to the mouth of the bay. Additionally, environmental variables were examined to determine their relationship with the fish community structure. Being a non-estuarine embayment, the environmental variables as well as the fish community structure in each habitat remained relatively constant for most part of the year; however, a marked decline was observed during the rainy period (April–May). Significant variations in fish community variables (density, biomass and species richness) and in water temperature and salinity were observed during the rainy season in all habitats, with larger changes in the mangrove and mud/sand flats habitats than in the seagrass beds. Seasonal variations in water clarity and dissolved oxygen were not significant, though. Many species disappeared from the mangrove and mud/sand flats habitats during the rainy season and those which persisted showed a remarkable decrease in density. Moreover, the results indicate that mangroves were the preferred settling habitats for Gerres filamentosus, Gerres oyena, Lethrinus lentjan and Monodactylus argenteus, especially during the dry period (December–February) before the rainy season. This observation is contrary to what has been reported from some other tropical regions where greater abundance and species richness was observed during the rainy season. A significant relationship was found between density of fish and temperature, salinity and turbidity. Since salinity was the most conspicuously changing environmental variable with seasons, we propose that salinity, alone or in combination with low visibility and temperature, was probably the most important environmental factor structuring the fish assemblage in the mangrove and mud/sand flats habitats, particularly during the rainy season. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Handling editor: J. A. Cambray     

A newHalophytophthora species,H. porrigovesica, from subtropical and tropical mangroves

A new oomycete was found from intertidal fallen leaves of mangroves in Japan and Thailand and is described here asHalophytophthora porrigovesica. This species is characterized by having an epapillate, ovate zoosporangium with a lens-shaped dehiscence plug-like material at the apex, and by forming an expanding long cylindrical vesicle prior to zoospore release. A key to 14 species and 2 varieties ofHalophytophthora including the new species is proposed. The subtropical (Iriomote is., Japan) strains and tropical (Thailand) strains were different in physiological properties and especially in the asexual reproduction. The subtropical strains showed a lower optimal temperature and wider range of suitable temperature and salinity for zoosporangium formation, whereas the tropical strains showed a higher optimal temperature and narrower range of temperature and salinity. These differences are explained as adaptations of the strains to the environmental conditions of their respective habitats. From the subtropical mangroves, six strains of the new species have been isolated only from submerged leaves ofSonneratia alba, while several strains have been isolated from tropical mangroves from the leaves of three species of mangrove trees,S. alba, Bruguiera gymnorrhiza andAvicennia alba. This indicates a change of taxon selectivity (host specificity) with the geographical distribution.     

Density,parasitism, and sexual reproduction are strongly correlated in lake Daphnia populations

Many organisms can reproduce both asexually and sexually. For cyclical parthenogens, periods of asexual reproduction are punctuated by bouts of sexual reproduction, and the shift from asexual to sexual reproduction has large impacts on fitness and population dynamics. We studied populations of Daphnia dentifera to determine the amount of investment in sexual reproduction as well as the factors associated with variation in investment in sex. To do so, we tracked host density, infections by nine different parasites, and sexual reproduction in 15 lake populations of D. dentifera for 3 years. Sexual reproduction was seasonal, with male and ephippial female production beginning as early as late September and generally increasing through November. However, there was substantial variation in the prevalence of sexual individuals across populations, with some populations remaining entirely asexual throughout the study period and others shifting almost entirely to sexual females and males. We found strong relationships between density, prevalence of infection, parasite species richness, and sexual reproduction in these populations. However, strong collinearity between density, parasitism, and sexual reproduction means that further work will be required to disentangle the causal mechanisms underlying these relationships.     

Thresholds in seascape connectivity: the spatial arrangement of nursery habitats structure fish communities on nearby reefs

Ecosystems are linked by the movement of organisms across habitat boundaries and the arrangement of habitat patches can affect species abundance and composition. In tropical seascapes many coral reef fishes settle in adjacent habitats and undergo ontogenetic habitat shifts to coral reefs as they grow. Few studies have attempted to measure at what distances from nursery habitats these fish migrations (connectivity) cease to exist and how the abundance, biomass and proportion of nursery species change on coral reefs along distance gradients away from nursery areas. The present study examines seascape spatial arrangement, including distances between habitats, and its consequences on connectivity within a tropical seascape in Mozambique using a seascape ecology approach. Fish and habitat surveys were undertaken in 2016/2017 and a thematic habitat map was created in ArcGIS, where cover and distances between habitat patches were calculated. Distance to mangroves and seagrasses were significant predictors for abundance and biomass of most nursery species. The proportions of nursery species were highest in the south of the archipelago, where mangroves were present and decreased with distance to nurseries (mangroves and seagrasses). Some nursery species were absent on reef sites farthest from nursery habitats, at 80 km from mangroves and at 12 km from seagrass habitats. The proportion of nursery/non-nursery snapper and parrotfish species, as well as abundance and biomass of seagrass nursery species abruptly declined at 8 km from seagrass habitats, indicating a threshold distance at which migrations may cease. Additionally, reefs isolated by large stretches of sand and deep water had very low abundances of several nursery species despite being within moderate distances from nursery habitats. This highlights the importance of considering the matrix (sand and deep water) as barriers for fish migration.     

Australian Tropical and Subtropical Rain Forest Community Assembly: Phylogeny,Functional Biogeography,and Environmental Gradients

To compare community assemblage patterns in tropical northeastern and subtropical central eastern Australia across selected gradients and scales, we tested the relationship of species traits with phylogenetic structure, and niche breadth. We considered phylogenetic relationships across current‐day species in assemblages in relation to rain forest species pool sizes, and trait values along gradients including elevation and latitude. Trait values were quantified across scales for seed size, leaf area, wood density and maximum height at maturity for 1137 species and 596 assemblages using trait gradient analysis (TGA). Local assemblages of subtropical species had narrower trait ranges, and higher niche breadth values than corresponding assemblages of tropical species. Leaf size and seed size increased at low latitudes, and community phylogenetic structure was most strongly correlated with seed traits in the subtropics, reflecting dispersal and re‐colonization processes. Elevation accounted for little of the variance in community phylogenetic structure or trait variation across local and regional scales. Stable moist forest areas retained many species from ancestral rain forest lineages across a range of temporally conserved habitats; species within assemblages were less related; and rain forest assemblages had higher functional diversity, but lower niche breadth. This suggests that on average, assemblages of species in stable areas had greater trait variation and narrower distributions. Historic and recent rain forest contraction and re‐expansion can result in recolonized areas that are dominated by species that are more related (phylogenetically) than by chance, have smaller, widely dispersed seeds, and greater niche breadth (broader distributions).     

Clinal life-history variation in the river-sculpin,Cottus hangiongensis: an example of phenotypic plasticity

An amphidromous sculpin,Cottus hangiongensis, distributed freely in a natural river system, exhibited clinal differences in population density, sex ratio, age composition and life-history. In a second river, in which the distribution was restricted to a narrow area in the lower reaches by a notched weir, the species was characterized by high population density and a similar population structure in two different habitats. Little life-history variation was evident. Field observations suggested that clinal life-history variations inC. hangiongensis were not genotypic, but environmentally-induced, phenotypic responses. Rearing experiments demonstrated that the maturity of one-year old males was delayed under low density conditions, and that no relationship existed between the timing of maturity and the sex ratio. This suggests that phenotypic life-history variation inC. hangiongensis is induced primarily in response to population density. Such phenotypic plasticity in life-histories of individualC. hangiongensis populations may be an adaptation for exploitation of broad and heterogenous river habitats.     

Rats,pigs and men: disturbance and diversity in the New Guinea highlands

A trapping study of four species of Rattus and three of Melomys in rainforest and grassland habitats revealed differences in altitudinal distribution and in both gross and subtle habitat selection between species. The species are ranked on a scale of increasing opportunism on the basis of various demographic characteristics (e.g. reproductive rate, life span and population density). Species judged to be more opportunistic occur in habitats subject to more intense disturbance from pigs and humans. It is argued that changes in the pattern of species coexistence have followed overt human impact in the New Guinea highlands.     

Can rodents enhance germination rates in rainforest seeds?

The decline of large coevolved frugivorous species within fragmented habitats can have an effect on ecological processes, for example, seed dispersal and germination. It is therefore necessary for more resilient species to ensure essential processes are maintained within the system. This study investigates the influence of two rodent species, Melomys cervinipes (Fawn‐footed Melomys) and Rattus fuscipes (Bush Rat), on the germination process of rainforest fruits. Both species are endemic to north Queensland rainforest and commonly found in fragmented habitats in high densities. We found in 85% of fruit species tested, rodent feeding increased seed germination rate by a factor of 3.5. Our results suggest that rodents can play a significant role in enhancing germination rates of fruits in the tropical rainforest of far north Queensland.     

Growth differences in males of the river-sculpin Cottus hangiongensis along a river course,a correlate of life-history variation

Synopsis Growth patterns of the 1982 year-class, individual growth patterns, age at sexual maturity and longevity in the river-sculpin, Cottus hangiongensis (Cottidae), were investigated along the course of the Daitobetsu River of southern Hokkaido, Japan. Slow growth occurred in males from the lower reaches, while more rapid growth was found in males from upstream areas. Age at first sexual maturity in males generally increased from 2 or 3 years in downstream areas to 4–6 years in upstream sites. Longevity was estimated as 7 years throughout the river course except in the uppermost site where it was 6 years. The growth differences evident in male C. hangiongensis are likely a result of differences in sculpin population density and/or food abundance along the river course, and are apparently reflected in variation in their life-history as well.     

Environmentally induced clonal reproduction and life history traits of the liana Machaerium cuspidatum in an Amazonian rain forest,Ecuador

The population structure of the canopy liana Machaerium cuspidatum Kuhlm. & Hoehne (Fabaceae) was studied in ten transects covering a total of 2.5 ha of tropical rain forest in Yasuní National Park, eastern Ecuador. The aim was to investigate how trellis availability, topographic position and light availability affected the population density and structure of the most abundant liana species in the area. The environmental variation affected plants in different size classes differently. Large plants (diameter 1 cm) were almost exclusively found in areas with low canopy and dense undergrowth. These areas had the highest density of suitable host plants. Seedling-sized plants (height < 30 cm) and saplings (height 30 cm but diameter < 1 cm) occurred more frequently and withhigher density in steep upland areas than in the floodplains, presumably due to elevated seedling mortality in the periodically flooded areas. Seedling-sized plants and saplings did not grow in areas with elevated light levels, and although plants of all sizes were highly clumped, this clumping rarely coincided with patches with abundant canopy gaps. Machaerium cuspidatum reproduces clonally when branches re-root and break off from the parentplant. The density of clonally produced plants was high in areas where the density of sexually produced plants was low, whereas the total density varied little among habitat types. A higher proportion of the seedling-sized plants were of sexual origin in the upland areas. An environmentally induced increase in the production of independent ramets enables M. cuspidatum to persist in the floodplains. This shows that plants may expand theirrealised niches to habitats with a low potential for seedling survival if high seedling mortality can be compensated for by increased clonal reproduction.     

Parasitism by helminths in the grey-sided vole (Clethrionomys rufocanus) in northern Finland: influence of density, habitat and sex of the host

We have studied helminths from 532 grey-sided voles (Clethrionomys rufocanus) in two localities in northern Finland, representing different biogeographic zones, during 1978-1983. The helminth communities in the two study areas were similar, characterized by a small number of species (eight) compared to eastern Siberia and Japan, and by the dominance of a single anoplocephalid cestode Andrya kalelai. The prevalence of this helminth varied significantly among habitats, possibly because of differences in the distribution and abundance of the intermediate hosts, oribatid mites. Vole density did not explain the habitat differences in A. kalelai, nor did the prevalence of A. kalelai increase between 2 yr of sustained high density in the host population. A between-year increase in the prevalence of the larval cestode Taenia tenuicollis at Kilpisj?rvi was probably due to a simultaneous increase in the abundance of its definitive hosts, mustelids. The prevalence of A. kalelai was always higher in males; no sexual differences were detected in the larval T. tenuicollis.     

Variation in infection parameters among populations within parasite species: intrinsic properties versus local factors

Within any parasite species, variation among populations in standard infection parameters (prevalence, intensity and abundance) is an accepted fact. The proportion of hosts infected and the mean number of parasites per host are not fixed values across the entire geographic range of any parasite species. The question is whether this inter-population variation occurs within a narrow, species-specific range and is thus driven mainly by the biological features of the parasite, or whether it is substantial and unpredictable, leaving population parameters at the mercy of local conditions. Here, the repeatability of estimates of prevalence, intensity and abundance of infection was assessed across populations of the same parasite species, for 77 metazoan parasite species of Canadian freshwater fishes. Overall, parameter values from different populations of the same parasite species were more similar to each other and more different from those of other species, than expected by chance alone. Much of the variation in parameter values in the dataset was associated with differences between parasite species, rather than with differences among populations within species. This was particularly true for intensity and abundance of infection; in contrast, prevalence values, while somewhat repeatable among populations of the same species, still showed considerable variation. Among the higher taxa investigated (monogeneans, trematodes, cestodes, nematodes, acanthocephalans, copepods), there was no evidence that species of one taxon display intrinsically greater variation in population parameters than species of other taxa. Overall, the results suggest that intensity and abundance of infection are real species characters, though somewhat variable. This conclusion supports the view that the biological features of parasite species can potentially override local environmental conditions in driving parasite population dynamics.     

Parasites, democratization, and the liberalization of values across contemporary countries

The countries of the world vary in their position along the autocracy–democracy continuum of values. Traditionally, scholars explain this variation as based on resource distribution and disparity among nations. We provide a different framework for understanding the autocracy–democracy dimension and related value dimensions, one that is complementary (not alternative) to the research tradition, but more encompassing, involving both evolutionary (ultimate) and proximate causation of the values. We hypothesize that the variation in values pertaining to autocracy–democracy arises fundamentally out of human (Homo sapiens) species‐typical psychological adaptation that manifests contingently, producing values and associated behaviours that functioned adaptively in human evolutionary history to cope with local levels of infectious diseases. We test this parasite hypothesis of democratization using publicly available data measuring democratization, collectivism–individualism, gender egalitarianism, property rights, sexual restrictiveness, and parasite prevalence across many countries of the world. Parasite prevalence across countries is based on a validated index of the severity of 22 important human diseases. We show that, as the hypothesis predicts, collectivism (hence, conservatism), autocracy, women’s subordination relative to men’s status, and women’s sexual restrictiveness are values that positively covary, and that correspond with high prevalence of infectious disease. Apparently, the psychology of xenophobia and ethnocentrism links these values to avoidance and management of parasites. Also as predicted, we show that the antipoles of each of the above values—individualism (hence, liberalism), democracy, and women’s rights, freedom and increased participation in casual sex—are a positively covarying set of values in countries with relatively low parasite stress. Beyond the cross‐national support for the parasite hypothesis of democratization, it is consistent with the geographic location at high latitudes (and hence reduced parasite stress) of the early democratic transitions in Britain, France and the U.S.A. It, too, is consistent with the marked increase in the liberalization of social values in the West in the 1950s and 1960s (in part, the sexual revolution), regions that, a generation or two earlier, experienced dramatically reduced infectious diseases as a result of antibiotics, vaccinations, food‐ and water‐safety practices, and increased sanitation. Moreover, we hypothesize that the generation and diffusion of innovations (in thought, action and technology) within and among regions, which is associated positively with democratization, is causally related to parasite stress. Finally, we hypothesize that past selection in the context of morbidity and mortality resulting from parasitic disease crafted many of the aspects of social psychology unique to humans.     

Habitat Use by Fishes in Coral Reefs,Seagrass Beds and Mangrove Habitats in the Philippines

Understanding the interconnectivity of organisms among different habitats is a key requirement for generating effective management plans in coastal ecosystems, particularly when determining component habitat structures in marine protected areas. To elucidate the patterns of habitat use by fishes among coral, seagrass, and mangrove habitats, and between natural and transplanted mangroves, visual censuses were conducted semiannually at two sites in the Philippines during September and March 2010–2012. In total, 265 species and 15,930 individuals were recorded. Species richness and abundance of fishes were significantly higher in coral reefs (234 species, 12,306 individuals) than in seagrass (38 species, 1,198 individuals) and mangrove (47 species, 2,426 individuals) habitats. Similarity tests revealed a highly significant difference among the three habitats. Fishes exhibited two different strategies for habitat use, inhabiting either a single (85.6% of recorded species) or several habitats (14.4%). Some fish that utilized multiple habitats, such as Lutjanus monostigma and Parupeneus barberinus, showed possible ontogenetic habitat shifts from mangroves and/or seagrass habitats to coral reefs. Moreover, over 20% of commercial fish species used multiple habitats, highlighting the importance of including different habitat types within marine protected areas to achieve efficient and effective resource management. Neither species richness nor abundance of fishes significantly differed between natural and transplanted mangroves. In addition, 14 fish species were recorded in a 20-year-old transplanted mangrove area, and over 90% of these species used multiple habitats, further demonstrating the key role of transplanted mangroves as a reef fish habitat in this region.