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Mark G. Meekan - One of the best experts on this subject based on the ideXlab platform.
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small scale spatial variation in the elemental composition of otoliths of Stegastes nigricans pomacentridae in french polynesia
Coral Reefs, 2005Co-Authors: Mark G. Meekan, Niels C. Munksgaard, David L. Parry, Serge Planes, Marten Wolter, Alain Loyat, J. H. CarletonAbstract:Solution-based inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine if Stegastes nigricans collected from 15 sites in French Polynesia could be distinguished by the trace element composition of their otoliths. A total of 293 adults were collected by spearing and their otoliths were analysed. We found that elemental signatures differed significantly among sites within and between the islands of Tahiti and Moorea (p<0.001), primarily due to variation in concentrations of the elements Ba, Ca, Li, Mg, Mn, Na, Sr and Y. The otoliths of fish collected within Papeete Harbour in Tahiti had distinctive elemental signatures characterised by relatively high concentrations of Mn. Otoliths of these fish could be distinguished from others that were collected only a small distance (200 m) from the harbour. This is the first time that differences in chemical composition of otoliths have been reported at such small spatial scales and this trait may prove useful for the studies of connectivity of populations at within reef scales.
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Small-scale spatial variation in the elemental composition of otoliths of Stegastes nigricans (Pomacentridae) in French Polynesia
Coral Reefs, 2005Co-Authors: Mark G. Meekan, Niels C. Munksgaard, David L. Parry, Serge Planes, Marten Wolter, J. H. CarletonAbstract:Solution-based inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine if Stegastes nigricans collected from 15 sites in French Polynesia could be distinguished by the trace element composition of their otoliths. A total of 293 adults were collected by spearing and their otoliths were analysed. We found that elemental signatures differed significantly among sites within and between the islands of Tahiti and Moorea (p
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growth related advantages for survival to the point of replenishment in the coral reef fish Stegastes partitus pomacentridae
Marine Ecology Progress Series, 2002Co-Authors: David T. Wilson, Mark G. MeekanAbstract:ABSTRACT: Records of age and growth stored within otoliths were used to compare early life history traits with patterns of light trap catches for the damselfish Stegastes partitus (Poey). Otoliths provided strong evidence that fast growing cohorts of S. partitus larvae had higher survivorship than slow growing cohorts. Average growth rates during the larval phase accounted for 83% of the variability in the magnitude of catches in light traps on a monthly basis. This result suggests that fast growing cohorts of larvae contribute more to the replenishment of benthic populations than slow growing cohorts of this species. Multiple regression identified water temperature, rainfall and wind component as important determinants of larval growth, age at capture and monthly catches of this species. These variables accounted for 7 to 36% of the variance in growth rates, while water temperature was moderately correlated (r2 = 0.48) with catches. If such correlations between larval growth rates and replenishment are a general phenomenon, then this may provide a simple means of predicting year-class success in a range of reef fishes.
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Environmental influences on patterns of larval replenishment in coral reef fishes
Marine Ecology Progress Series, 2001Co-Authors: David T. Wilson, Mark G. MeekanAbstract:Spatial and temporal patterns of larval replenishment to the San Blas Archipelago were measured using 3 light traps in each of 3 habitats (exposed, lagoon and back-reef) over 18 lunar months from December 1996 to June 1998. Traps were sampled for 19 consecutive nights centred on the new moon in each month. The effects of environmental variables (wind speed and wind direction, tidal range, rainfall, solar radiation and water temperature) on catches were examined both in the days immediately prior to settlement and during the entire larval phase using 2 approaches. Firstly, time-series analyses were used to compare night-to-night patterns in light trap catches of 11 species (Astrapogon puncticulatus, Eucinostomus melanopterus, Lutjanus apodus, L. mahogani, Ophioblen- nius atlanticus, Stegastes dorsopunicans, S. partitus, S. planifrons Synodontidae spp., Thalassoma bifasciatum and an unidentified blenny) with environmental variables. Secondly, modified correla- tion analysis was used to examine the relationships between environmental variables, averaged over larval durations, and light trap catches of 6 of these species. Time-series analysis detected significant correlations between catches of 8 species and wind direction; however, correlations were often weak and variable in direction. Similarly, there were weak correlations between day-to-day catches of all but 3 species and water temperature. Modified correlation analysis also found that water temperature was correlated with catches of 4 species (Lutjanus mahogani, Stegastes dorsopunicans, S. partitus and S. planifrons). Catches of the remaining species, Ophioblennius atlanticus and Thalassoma bifas- ciatum, were not correlated with environmental variables in these analyses. Multiple-regression analysis could not detect any combined effects of environmental variables on patterns of light trap catches, although this analysis also identified weak correlations (R 2 = 0.08 to 0.29) between catches of Lutjanus mahogani, Ophioblennius atlanticus, Stegastes dorsopunicans, S. partitus, S. planifrons and Thalassoma bifasciatum and water temperature.
J. M. Lacson - One of the best experts on this subject based on the ideXlab platform.
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Genetic divergence of Maldivian and Micronesian demes of the damselfishes Stegastes nigricans, Chrysiptera biocellata, C. glauca and C. leucopoma (Pomacentridae)
Marine Biology, 1995Co-Authors: J. M. Lacson, S. ClarkAbstract:Samples representing the damselfishes (Perciformes: Pomacentridae) Stegastes nigricans, Chrysiptera biocellata, C. glauca , and C. leucopoma from North Male Atoll, Republic of Maldives, and Guam, Southern Marianas, were surveyed electrophoretically. A sample representing C. leucopoma from Ngemelis Island, Republic of Palau, was included in the analysis to provide a within-Micronesia comparison. On average, products of 23 presumptive protein-coding loci were examined in each sample. In comparisons of Maldivian and Guamanian samples, absolute or virtually fixed allelic differences were detected at: (1) ADA ^* and PEPS ^* for Stegastes nigricans ; (2) ADA ^*, AAT-1 ^*, AAT-2 ^*, and mMDH ^* for C. biocellata , and; (3) ADA ^*, AAT-1 ^*, and AAT-2 ^* for C. glauca . At three polymorphic loci, ADA ^*, sMDH-1 ^*, and sMDH-2 ^*, similar allele frequencies were found in Palauan and Guamanian samples representing C. leucopoma , suggesting that these samples share a gene pool. Significantly different allele frequencies at ADA ^* and sMDH-1 ^* and a virtually fixed allelic difference at sMDH-2 ^* were detected between the Maldivian samples and each of the Micronesian samples representing C. leucopoma . The observed patterns of allele frequency differentiation suggest that Maldivian and Micronesian samples of each of the four study species represent separate demes.
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biochemical systematics of fishes of the genus Stegastes pomacentridae from the southern marianas
Marine Biology, 1992Co-Authors: J. M. Lacson, C P BasslerAbstract:The biochemical systematics of the subset of species of Stegastes (Pisces: Pomacentridae) available from coral reefs surrounding Guam, USA, was studied using three species of Pomacentrus as the outgroup. Analyses of allozymic variation at 14 presumptive loci (10 of which were polymorphic) using various evolutionary tree-construction techniques identified S. fasciolatus as the sister species of an assemblage comprised of S. albifasciatus, S. nigricans, and S. lividus: within this assemblage, S. lividus is the sister species of S. albifasciatus and S. nigricans, the pair of species which shared the most synapomorphic alleles and consistently exhibited the lowest degree of genetic distance relative to estimates for the other pairs of species studied. The consistency of ingroup topologies produced by parsimony analyses using “Manhattan” rectilinear distances computed from allele frequencies with those produced using the distance Wagner procedure and UPGMA (unweighted pair-group method of arithmetic averages) clustering, substantiates strongly the proposed phylogeny. The systematic scheme inferred from molecular data is concordant with predictions based on morphologic differences, i.e., differences in numbers of dorsal spines, that have been used as evidence in support of the proposal to partition Stegastes into at least two subgenera.
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temporal genetic variation in subpopulations of bicolor damselfish Stegastes partitus inhabiting coral reefs in the florida keys
Marine Biology, 1991Co-Authors: J. M. Lacson, D C MorizotAbstract:In 1986 we observed significant genetic heterogeneity among samples of bicolor damselfish (Stegastes partitus) from geographically proximate coral reefs in the Florida Keys. This result was in contrast to results of virtually all previous studies of coral reef fishes. To assess temporal stability of localized genetic differentiation, we resampled reefs in 1989. Within approximately two generations, allele frequencies at the most differentiated locus,ACO-1*, had changed by as much as 0.65, resulting in almost complete homogeneity between previously differentiated subpopulations. Estimates of 10.78 migrants per generation suggested that high gene flow is the most likely factor responsible for the significant change in allele frequencies. We attribute the original genetic differentiation to a population bottleneck, possibly caused by environmental perturbations such as hurricanes and consequent genetic drift. For reef fishes with pelagic egg and/or larval stages, a growing body of data suggests that: (1) populations are geographically extensive gene pools, and (2) rates of dispersal appear to be high enough to allow for continual repopulation of isolated and/or perturbed coral reef communities.
Guy A Hoelzer - One of the best experts on this subject based on the ideXlab platform.
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male male competition and female choice in the cortez damselfish Stegastes rectifraenum
Animal Behaviour, 1990Co-Authors: Guy A HoelzerAbstract:Abstract Male-male competition and female mate choice were investigated in a field population of the Cortez damselfish, Stegastes rectifraenum . Theoretical considerations suggest that female choice should be important when: female mobility is high; breeding is not restricted to a brief, explosive period; and females are capable of rejecting mates despite persistent male mating efforts. Stegastes rectifraenum clearly meets all of these criteria. Focal observations indicated that male body size was significantly positively correlated with male reproductive success, whereas behavioural traits, such as aggressiveness and courtship vigour, were not. An experiment in which successful males were removed from their territories and recolonization monitored indicated that males compete for high-quality territories. In a second experiment, standardizing the quality of male nest sites caused the relationship between male body size and reproductive success to disappear. Contrary to expectations based on current theoretical developments, these results suggest that the single most important correlation with male reproductive success (body size) is produced indirectly by female choice of nest-site quality in combination with male-male competition for high-quality territories.
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Male−male competition and female choice in the Cortez damselfish, Stegastes rectifraenum
Animal Behaviour, 1990Co-Authors: Guy A HoelzerAbstract:Abstract Male-male competition and female mate choice were investigated in a field population of the Cortez damselfish, Stegastes rectifraenum . Theoretical considerations suggest that female choice should be important when: female mobility is high; breeding is not restricted to a brief, explosive period; and females are capable of rejecting mates despite persistent male mating efforts. Stegastes rectifraenum clearly meets all of these criteria. Focal observations indicated that male body size was significantly positively correlated with male reproductive success, whereas behavioural traits, such as aggressiveness and courtship vigour, were not. An experiment in which successful males were removed from their territories and recolonization monitored indicated that males compete for high-quality territories. In a second experiment, standardizing the quality of male nest sites caused the relationship between male body size and reproductive success to disappear. Contrary to expectations based on current theoretical developments, these results suggest that the single most important correlation with male reproductive success (body size) is produced indirectly by female choice of nest-site quality in combination with male-male competition for high-quality territories.
Beatrice Padovani Ferreira - One of the best experts on this subject based on the ideXlab platform.
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food resource use by two territorial damselfish pomacentridae Stegastes on south western atlantic algal dominated reefs
Journal of Sea Research, 2012Co-Authors: Joao Lucas Leao Feitosa, Adilma M Concentino, Simone Ferreira Teixeira, Beatrice Padovani FerreiraAbstract:Abstract Damselfishes are a highly abundant group of reef fishes that are considered keystone species for structuring benthic communities on coral-dominated reefs. To assess how food is utilized by the damselfish species Stegastes fuscus and Stegastes variabilis living on algae-dominated coastal reefs, we evaluated the compositions of algal communities inside their territories and investigated their diets by analyzing their stomach contents. Jointed-calcareous algae were the most abundant morphological group inside the territories of both damselfish species (> 80%), and the biomass of these algae showed a positive linear relationship to all the other non-calcareous algae when grouped together (R² = 0.674; p Stegastes spp. consisted of algal material (> 70%), but they also fed on invertebrates and detritus as accessory items (~ 15%). Algal material composed a consistent proportion of the items ingested by adults and juveniles of both damselfish species with diatoms being the most frequent item, followed by filamentous algae. A positive food selection for all macroalgae morphological groups was observed, except for jointed-calcareous algae (Ivlev's index). The most preferred macroalgae types were filamentous, with values close to + 1 for both damselfish species. Pianka's food overlap index was extremely high regardless of the damselfish species or their life phase and ANOSIM analyses also confirmed that there were essentially no differences between their diets. The present work is the first indication that damselfish may maintain territories dominated by highly unpalatable calcareous macroalgae that have herbivore-deterrent life strategies, although the complex branching structures of these macroalgae create suitable microhabitats for the growth of epiphytic species consumed by the damselfish.
Francisco Gerson Araújo - One of the best experts on this subject based on the ideXlab platform.
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effects of a nuclear power plant thermal discharge on habitat complexity and fish community structure in ilha grande bay brazil
Marine Environmental Research, 2009Co-Authors: Tatiana Pires Teixeira, Leonardo Mitrano Neves, Francisco Gerson AraújoAbstract:Fish communities and habitat structures were evaluated by underwater visual censuses a rocky location impacted by thermal discharge (I) and at two control locations, one in a Sargassum bed (C1) and the other in a rocky shore with higher structural complexity (C2). Habitat indicators and fish communities exhibited significant differences between the impacted and control locations, with the impacted one showing a significant decrease in fish species richness and diversity, as well as a decrease in benthic cover. At the I location, only 13 fish species were described, and the average water temperature was 32 ± 0.4 °C, compared with 44 species at C1 (25.9 ± 0.3 °C) and 33 species at C2 (24.6 ± 0.2 °C). Significant differences in fish communities among locations were found by ANOSIM with Eucinostomus argenteus, Mugil sp. and Haemulon steindachneri typical of location I, while Abudefduf saxatilis, Stegastes fuscus and Malacoctenus delalandi were typical of the control locations. Our study shows that thermal pollution alters benthic cover and influences fish assemblages by altering composition and decreasing richness.
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Effects of a nuclear power plant thermal discharge on habitat complexity and fish community structure in Ilha Grande Bay, Brazil
Marine Environmental Research, 2009Co-Authors: Tatiana Pires Teixeira, Leonardo Mitrano Neves, Francisco Gerson AraújoAbstract:Fish communities and habitat structures were evaluated by underwater visual censuses a rocky location impacted by thermal discharge (I) and at two control locations, one in a Sargassum bed (C1) and the other in a rocky shore with higher structural complexity (C2). Habitat indicators and fish communities exhibited significant differences between the impacted and control locations, with the impacted one showing a significant decrease in fish species richness and diversity, as well as a decrease in benthic cover. At the I location, only 13 fish species were described, and the average water temperature was 32 ± 0.4 °C, compared with 44 species at C1 (25.9 ± 0.3 °C) and 33 species at C2 (24.6 ± 0.2 °C). Significant differences in fish communities among locations were found by ANOSIM with Eucinostomus argenteus, Mugil sp. and Haemulon steindachneri typical of location I, while Abudefduf saxatilis, Stegastes fuscus and Malacoctenus delalandi were typical of the control locations. Our study shows that thermal pollution alters benthic cover and influences fish assemblages by altering composition and decreasing richness. © 2009 Elsevier Ltd. All rights reserved.
