Spatial and temporal variation in populations and community of ectoparasites on young snapper, Pagrus auratus (Bloch & Schneider) (Sparidae), from the wild and captivity at Port Hacking, Sydney, Australia

1996 ◽  
Vol 47 (4) ◽  
pp. 585 ◽  
Author(s):  
FR Roubal ◽  
N Quartararo ◽  
A West
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Significant Influence ◽  
Condition Factor ◽  
Stocking Density ◽  
Spatial And Temporal Variation ◽  
Age Classes ◽  
Pagrus Auratus ◽  
Sydney Australia

Snapper in both the estuary (0+, 1+ age classes) and from offshore reefs (1+, 2+, 3+ age classes) at Port Hacking, NSW, were infested with the monogeneans Lamellodiscus pagrosomi, Anoplodiscus cirrusspiralis and Bivagina pagrosomi and the copepods Unicolax chrysophryerzus, Pseudoeucanthus australiensis, Hatschekia pagrosomi, Clavellopsis sargi and Lernanthropus atrox; offshore snapper also had the monogenean Choricotyle australiensis and the copepods Caligus spp. and Lepeophtheirus sekii. Most species had a higher prevalence, but not intensity, on offshore fish. Season was not a significant factor for most infrapopulations. Species richness, number of parasites and diversity were greater on offshore fish and differed among estuary samples but not offshore samples. Estuary infracommunities were dominated by L. pagrosomi (mainly 1+) and B. pagrosomi (mainly 0+); C. sargi and L. atrox dominated when richness was low. Offshore infracommunities were dominated by H. pagrosomi except in winter when L. pagrosomi was dominant, possibly owing to movement of estuary fish to offshore reefs. Captivity in experimental cages in the estuary resulted in transient increases in A. cirrusspiralis, B. pagrosomi and Benedenia sekii. Lamellodiscus pagrosomi increasingly dominated all samples and infracommunities. Neither condition factor nor stocking density had a significant influence on infestation.

scholarly journals Aquatic macrophyte community varies in urban reservoirs with different degrees of eutrophication

2014 ◽  
Vol 26 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Suelen Cristina Alves da Silva ◽  
Armando Carlos Cervi ◽  
Cleusa Bona ◽  
André Andrian Padial
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Indicator Species ◽  
Beta Diversity ◽  
Aquatic Macrophytes ◽  
Aquatic Macrophyte ◽  
Wiener Index ◽  
Spatial And Temporal Variation ◽  
Macrophyte Community ◽  
Aquatic Macrophyte Community

AIM: Investigate spatial and temporal variation in the aquatic macrophyte community in four urban reservoirs located in Curitiba metropolitan region, Brazil. We tested the hypothesis that aquatic macrophyte community differ among reservoirs with different degrees of eutrophication. METHODS: The reservoirs selected ranged from oligotrophic/mesotrophic to eutrophic. Sampling occurred in October 2011, January 2012 and June 2012. Twelve aquatic macrophytes stands were sampled at each reservoir. Species were identified and the relative abundance of aquatic macrophytes was estimated. Differences among reservoirs and over sampling periods were analyzed: i) through two‑way ANOVAs considering the stand extent (m) and the stand biodiversity - species richness, evenness, Shannon-Wiener index and beta diversity (species variation along the aquatic macrophyte stand); and ii) through PERMANOVA considering species composition. Indicator species that were characteristic for each reservoir were also identified. RESULTS: The aquatic macrophyte stand extent varied among reservoirs and over sampling periods. Species richness showed only temporal variation. On the other hand, evenness and Shannon-Wiener index varied only among reservoirs. The beta diversity of macrophyte stands did not vary among reservoirs or over time, meaning that species variability among aquatic macrophyte stands was independent of the stand extent and reservoir eutrophication. Community composition depended on the reservoir and sampling period. CONCLUSIONS: Our results support our initial expectation that reservoirs of different degrees of eutrophication have different aquatic macrophyte communities. As a consequence, each reservoir had particular indicator species. Therefore, monitoring and management efforts must be offered for each reservoir individually.

scholarly journals What drives the spatial distribution and dynamics of local species richness in tropical forest?

2017 ◽  
Vol 284 (1863) ◽  
pp. 20171503 ◽  
Author(s):  
Thorsten Wiegand ◽  
Felix May ◽  
Martin Kazmierczak ◽  
Andreas Huth
Keyword(s):  
Species Richness ◽  
Tropical Forest ◽  
Temporal Variation ◽  
Tropical Forests ◽  
Temporal Variability ◽  
Dynamic Models ◽  
Neutral Theory ◽  
Spatial And Temporal Variation ◽  
Demographic Stochasticity ◽  
Spatio Temporal

Understanding the structure and dynamics of highly diverse tropical forests is challenging. Here we investigate the factors that drive the spatio-temporal variation of local tree numbers and species richness in a tropical forest (including 1250 plots of 20 × 20 m 2 ). To this end, we use a series of dynamic models that are built around the local spatial variation of mortality and recruitment rates, and ask which combination of processes can explain the observed spatial and temporal variation in tree and species numbers. We find that processes not included in classical neutral theory are needed to explain these fundamental patterns of the observed local forest dynamics. We identified a large spatio-temporal variability in the local number of recruits as the main missing mechanism, whereas variability of mortality rates contributed to a lesser extent. We also found that local tree numbers stabilize at typical values which can be explained by a simple analytical model. Our study emphasized the importance of spatio-temporal variability in recruitment beyond demographic stochasticity for explaining the local heterogeneity of tropical forests.

scholarly journals Spatial and temporal variation of fish assemblages in a subtropical small stream of the Huangshan Mountain

2010 ◽  
Vol 56 (6) ◽  
pp. 670-677 ◽  
Author(s):  
Yunzhi Yan ◽  
Shan He ◽  
Ling Chu ◽  
Xiuying Xiang ◽  
Yanju Jia ◽  
...  
Keyword(s):  
Species Richness ◽  
Spatial Variation ◽  
Temporal Variation ◽  
Fish Assemblages ◽  
Spatial And Temporal Variation ◽  
Scaling Analysis ◽  
Small Stream ◽  
Study Sites ◽  
Species Richness And Abundance ◽  
Huangshan Mountain

Abstract Spatial and temporal variation of fish assemblages were investigated seasonally from May 2007 to February 2008 across 11 study sites in a subtropical small stream, the Puxi Stream, of the Huangshan Mountain. Along the longitudinal gradient from headwater to downstream, fish species richness and abundance increased gradually, but then decreased significantly at the lower reaches. The highest species richness and abundance were observed in August and the lowest in February. Based on analysis of similarities (ANOSIM), fish assemblages were significantly different in spatial variation but not in temporal variation. Although differences were observed both among sites and among stream orders, the lower R value in order-variation suggested stream order was not the optimal factor explaining the spatial variation of fish assemblages. In addition, dam construction did not significantly alter fish assemblages in the sites adjacent to and immediately downstream to dams. Using cluster analysis and non-metric Multi Dimensional Scaling analysis (NMS), assemblages were separated into three groups at a Bray-Curtis similarity value of 42%: the upper, middle and lower groups. Following analysis of similarity percentages of species contributions (SIMPER), shifts in occurrence or abundance of S. curriculus, Z. platypus, R. bitterling and A. fasciatus contributed most to the differences amongst the three groups. Standard Deviation Redundancy Analysis (RDA) suggested that habitat structure (such as elevation, substrate, and flow velocity) contributed to the spatial and temporal pattern of fish assemblages in the Puxi Stream. In conclusion, the fish assemblages in Puxi Stream presented significant spatial but not temporal variation. Human disturbance has perhaps induced the decrease in species diversity in the lower reaches. However, no significant change was observed for fish assemblages in sites far from and immediately downstream from low-head dams.

High levels of spatial and temporal recruitment variability in the temperate sparid Pagrus auratus

2004 ◽  
Vol 55 (7) ◽  
pp. 663 ◽  
Author(s):  
Paul A. Hamer ◽  
Gregory P. Jenkins
Keyword(s):  
Temporal Variation ◽  
Larval Settlement ◽  
Spatial And Temporal Variation ◽  
Size Distributions ◽  
Early Life Stages ◽  
Nursery Areas ◽  
Eastern Australia ◽  
Pagrus Auratus ◽  
Class Strength ◽  
Average Water

Knowledge of spatial and temporal variation in the abundance of early life stages is important to developing an understanding of juvenile recruitment processes and, ultimately, the dynamics and demographics of fish populations. In Victoria, south-eastern Australia, snapper, Pagrus auratus, supports an important fishery characterised by high variability in year-class strength. We investigated spatial and temporal variation in the recruitment of small juvenile (0+) snapper by monitoring their abundance in four bay and inlet nursery areas during four consecutive summer/autumn recruitment periods (2000–2003). We found considerable spatial variability in the abundance of recruits, both within and among inlets. Interannual recruitment variation, however, differed among inlets. Recruitment into the largest nursery area and most important fishery, Port Phillip Bay, varied by ~10-fold across years, whereas variation for the other inlets was low or not significant. There were also clear differences in size distributions of recruits among both inlets and years. Strong recruitment in Port Phillip Bay during 2001 was related to a longer period of spawning and successful larval settlement and was associated with above average water temperatures. Future monitoring of 0+ recruitment in Victoria and studies of the recruitment processes should be specific to individual nursery areas.

scholarly journals Spatial and temporal variation in community composition of herbivorous insects on Neoboutonia macrocalyx in a primary tropical rain forest

2013 ◽  
Vol 29 (3) ◽  
pp. 229-241 ◽  
Author(s):  
Kaisa Heimonen ◽  
Jeremiah S. Lwanga ◽  
Marko Mutanen ◽  
Tommi Nyman ◽  
Heikki Roininen
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Community Composition ◽  
Rain Forest ◽  
Tropical Rain Forest ◽  
Spatial And Temporal Variation ◽  
Herbivorous Insects ◽  
Herbivorous Insect ◽  
Insect Communities ◽  
Study Sites

Abstract:Spatial and temporal variation of tropical insect communities has rarely been studied, although such variation influences estimates of global species richness. Therefore, we compared spatial and temporal variation of herbivorous insect communities on Neoboutonia macrocalyx trees among seven sites over 1 y in a primary tropical rain forest in Kibale National Park, Uganda. The distance between the study sites varied from 4.8 to 31.2 km and altitudinal differences ranged from 20 to 242 m. Permutational multivariate analysis of variance (PERMANOVA) revealed significant spatial changes in community composition of the herbivorous insects and study sites differed also in insect abundance (6.9–26.2 individuals m−2 of leaf area). This is likely to be caused by differences in vegetation, altitude and microclimate among the study sites. The similarity of insect species composition was negatively correlated with geographic and altitudinal distances among sites and positively correlated with the similarity of tree community composition. Species richness varied significantly between sampling dates, ranging from 33 to 41 species. Also community compositions changed between sampling dates, which likely follows from marked seasonal changes in climate and the phenology of other host plants used by the generalist insect species also living on Neoboutonia macrocalyx. In general our study supports the idea of high variability of herbivorous insect communities in primary rain forests even at a small spatial scale. This should be considered when estimations of insect biodiversity are made.

DIVERSIDAD DE REPTILES DE LA LAGUNA EL QUELELE EN NAYARIT, MÉXICO

2015 ◽  
Vol 8 ◽  
Author(s):  
Juana Naggai Fuentes-Castrejón ◽  
Adrián Maldonado-Gasca
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Water Availability ◽  
Abundant Species ◽  
Spatial And Temporal Variation ◽  
Ecological Indices ◽  
Biological Value ◽  
Different Types ◽  
Total Species ◽  
Risk Categories

<p>Mexico is considered a megadiverse country, ranking second worldwide in reptile diversity. To determine the spatial and temporal variation of the reptile assemblage in El Quelele lagoon in Bahía de Banderas, Nayarit (20°43’N and 105° 17’W), we realized transects of 500 m<sup>2</sup> for three different types of vegetation (mangrove, marshes and thorn forest) during two seasons (Dry and Rainy), We calculate the ecological indices (Shannon, Simpson and Pielou) and the biological value index. We report 19 species, representing 21.5% of the total species reported in Nayarit. The most abundant species were <em>Anolis nebulosus</em>, <em>Holcosus undulata</em> and <em>Iguana iguana</em>. Four species (21%) are endemic to Mexico, and nine species (47%) are registered within at-risk categories. Mangroves had the highest species richness (13 spp.), followed by marshes (9 spp.) and finally the thorn forest (5 spp.). Diversity was highest during the dry season within mangroves (H’=2.93) and in the marshes (1-D=0.93), which may be related to water availability. This study provides a foundation for reptile conservation in this area.</p>

Effect of morphodynamics on the spatial and temporal variation of macrofauna on three sandy beaches, Rio de Janeiro State, Brazil

2001 ◽  
Vol 81 (3) ◽  
pp. 369-375 ◽  
Author(s):  
Valéria Gomes Veloso ◽  
Ricardo Silva Cardoso
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Temporal Variation ◽  
Abundant Species ◽  
Temporal Variations ◽  
Sandy Beaches ◽  
Spatial And Temporal Variation ◽  
Total Density ◽  
Beach Width ◽  
Slope Beach

Three exposed sandy beaches were selected to compare fluctuations in density of the most abundant species, and to verify the influence of spatial and temporal variations on the community structure. Sampling was carried out every three months, from June 1993 to May 1995, on Fora, Prainha, and Boqueirão Beaches. The first two beaches were classified by Dean's morphodynamic index (Ω) as intermediate, and the last as reflective. Slope, beach width and median grain size were significantly different among the beaches. Two-way analysis of variance revealed significant differences in species richness only among the beaches. No significant differences in density of the macrofauna between beaches and season were observed. However, Prainha Beach showed a higher temporal variation of the density of the macrofauna (and higher standard deviation) than the other two beaches. Emerita brasiliensis (Crustacea: Decapoda), Excirolana braziliensis (Crustacea: Isopoda), and Pseudorchestoidea brasiliensis (Crustacea: Amphipoda) were the most abundant species. Canonical correspondence analysis calculated the influence of the temporal variation as 27·5%; the influence of the environmental variation on community structure was 20·9%. The results suggest that in spite of the long-term fluctuations in species density, the beaches did not have temporal differences in the species richness and total density macrofauna during the study period.

scholarly journals Spatial and temporal variation of benthic fish assemblages during the extreme drought of 1997-98 (El Niño) in the middle rio Negro, Amazonia, Brazil

2004 ◽  
Vol 2 (3) ◽  
pp. 127-136 ◽  
Author(s):  
Mario J. F. Thomé-Souza ◽  
Ning Labbish Chao
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Fish Assemblages ◽  
Dry Season ◽  
Spatial And Temporal Variation ◽  
Otter Trawl ◽  
Total Biomass ◽  
Benthic Fish ◽  
Rio Negro ◽  
Density And Biomass

Spatial and temporal variation in the benthic fish composition, species richness, density and biomass were studied in the lower rio Branco and its confluence with the rio Negro during the 1997-98 dry season (September to February). Samples were taken with a 5.28 m (16-ft) otter trawl in three expeditions and at two depth strata (<7m and >7m). Five to seven trawl hauls were made randomly in each sample site per expedition. A total of 58 trawls yielded 134 species, 5,657 individuals and 22 kg total biomass. Fishes were distributed in 25 families and seven orders. Siluriformes was the most specious with 59 species, followed by Gymnotiformes (30), Characiformes (30), Perciformes (9), Clupeiformes (4), Pleuronectiformes (1) and Tetraodontiformes (1). The variation on composition, richness of species, density and biomass occurred during the dry season, from September 1997 to February 1998. Differences between depth strata were observed. Siluriformes and Gymnotiformes were more abundant at the beginning of the dry season (September) but diminished toward the end of dry season (February), whereas the Perciformes and Characiformes (mainly post-larvae and juveniles) became more abundant at the end of the dry season. The diminishing density of benthic fish communities during this extremely dry season may have been caused by predation or migration.

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