Habitat-specific distributions of some fishes in a tropical estuary

1996 ◽  
Vol 47 (6) ◽  
pp. 827 ◽  
Author(s):  
MJ Sheaves

The species richness of fishes and the distributions of six fish species were compared among four habitat types, snaggy banks, clear banks, mud banks and mid channels, in an estuary in tropical Australia. Both day and night samples were collected in fish traps, on four occasions, three months apart. On each sampling trip the highest number of species was trapped from snaggy habitats, intermediate numbers from clear banks or mud banks, and the fewest species from mid channels. Although more species occurred in night than in day samples, the pattern of difference among habitats was consistent. The probability of capture of the six most abundant species, Acanthopagrus australis, Acanthopagrus berda, Arothron manilensis, Arius argyropleuron, Epinephelus coioides and Lutjanus russelli, was compared among habitat types and between day and night samples. Overall, snag habitats tended to be associated with high probabilities of capture of a number of species, particularly A. berda and L. russelli. At night, mid channels were characterized by high numbers of A. argyropleuron. Clear and mud banks, and day samples from mid channels were associated with low numbers of most species.

2015 ◽  
Vol 7 (15) ◽  
pp. 8272 ◽  
Author(s):  
Girish Gogoi ◽  
Vipin Parkash

<p>Hollongapar Gibbon Wildlife Sanctuary is comprised of five distinct compartments.  A total of 138 species of gilled mushrooms belonging to 48 genera, 23 families, five orders of the class Agaricomycetes, division Basidiomycota, have been collected and analyzed. The order Agaricales was was found with the highest number of species (113), followed by Russulales (14), Polyporales (5), Cantharellales (4) and Boletales (2). The species <em>Coprinellus disseminatus </em>and <em>Megacollybia rodmani</em> have shown the highest (8.26) and the lowest density (0.05), respectively.  A total of 24 species, e.g., <em>Termitomyces albuminosus, Marasmius curreyi, Marasmiellus candidus, Leucocoprinus medioflavus, Mycena leaiana, Hygrocybe miniata, Collybia chrysoropha, Gymnopus confluens</em> were common with frequency percentage of 11.9, whereas <em>Megacollybia rodmani</em> with less frequency percentage (2.4) was found only in few quadrates of the sanctuary.  The highly abundant species were <em>Termitomyces medius</em> (91.7) and <em>Coprinellus disseminatus </em>(86.8), and less abundant species were <em>Psilocybe wayanadensis</em> (1.0) and <em>Lepiota</em> sp. (1.0) in the study site.  The order of the species richness index (<em>R</em>) compartment wise was 2&gt;3&gt;4&gt;5&gt;1. Both the Shannon diversity index and Simpson diversity index of agarics was maximum (1.88, 0.98) in compartment 2, whereas minimum (1.72, 0.95) in compartment 1 and 5, respectively.  Moreover, the compartment 2 was found very much similar with compartment 3 and very less similar with compartment 1.</p><div> </div>


2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Thomas Francis Lado ◽  
David Gwolo Phanuel Mogga ◽  
Richard Angelo Lado Benjamin

The study was carried out to determine patterns of birds’ species richness, alpha and beta diversities; and abundance in Badingilo national park using a 10 m fixed-radius point count method. A total of 2670 individuals were recorded from 182 points in the park. The highest expected number of species (Jack1 estimator) was observed in the Riverine habitat and least was in the Agriculture and Human settlement habitat type. The total number of species observed in the park was 63; however Jack1 estimator indicated that there were 68 species in the park. The majority of the birds observed during the study were resident species, few migratory and Palaearctic bird species. Few birds observed in the park were abundant. The most abundant species was the village weaver (381 individuals), and the rarest species were black-bellied bustard, barn owl, black scimitar bill and tree pipit (one individual each).


Mammalia ◽  
2016 ◽  
Vol 80 (6) ◽  
Author(s):  
Alexander Bruckner

AbstractSurveying and monitoring bat populations by recording their calls with stationary detectors has become increasingly popular. This study tested the hypothesis that placing stationary detectors at water bodies yielded more species than in other habitat types in a temperate landscape (settlement, forest, open land). The number of species was significantly affected by habitat type, and sampling at water bodies yielded approximately 50% more species than in open land, the habitat type which was second in species richness. In contrast, bat calling activity was not significantly related to habitat type. With the exception of the northern bat


Author(s):  
Matias I Dufek ◽  
Miryam P Damborsky ◽  
Pablo R Mulieri

Abstract The seasonal fluctuations of flesh fly (Diptera: Sarcophagidae) assemblages were investigated from March 2015 to February 2016 in five habitat types in the Humid Chaco ecoregion, Chaco Province, Argentina. Three of the habitats were anthropized: an urban area, a cattle farm, and an alfalfa crop; and two were natural: a savanna and a forest. Flesh flies were collected monthly at 25 sampling points, five per habitat. In total, 5,790 male specimens comprising 55 species distributed in 15 genera were collected. The assemblage composition of flesh flies in each habitat and season was analyzed in terms of abundance, species richness, and diversity. In addition, the correlation between these community parameters and climatic factors (precipitation 7 and 14 d before samplings, temperature, and relative humidity) were evaluated in each habitat. The highest abundance and species richness of Sarcophagidae were registered in May (autumn) and June (winter), respectively. The lowest diversity values were observed between August and September (end of winter and early spring) in all habitats. However, flesh flies were present and well represented (in terms of species richness) throughout the year in all habitat types. Fluctuations in the abundance of the most abundant species collected were analyzed. The climatic factors were correlated with diversity and species richness in the urban, cattle farm, and savanna habitats. This study revealed that flesh fly assemblages differed temporally between different types of habitats in accordance with climatic factors and microclimate conditions.


1993 ◽  
Vol 44 (6) ◽  
pp. 867 ◽  
Author(s):  
MJ Sheaves

The movements of fishes marked, released and recaptured during a fish trapping study in the estuary of Alligator Creek in tropical north-eastern Australia were studied over a period of two and a half years. The ability to place fish traps accurately with respect to landmarks enabled movements as short as 40 m to be detected. For each of six species of fish, more than 10 individuals were recaptured in Alligator Creek. Within these species, 258 of 1164 tagged fish were recaptured. Three patterns of movement were apparent. The serranids Epinephelus coioides and E. malabaricus and the lutjanid Lutjanus russelli tended to move little, usually being recaptured within 40 m of the site of release. The sparids Acanthopagrus australis and A. berda moved more extensively but still tended to remain within a few hundred metres for extended periods. All the above species demonstrated a strong tendency to be recaptured on the side of the creek on which they were initially captured. The tetraodontid Arothron manilensis proved to be much more vagile than did the other species, ranging freely over relatively large areas of the estuary and often crossing to the opposite bank of the creek. No species showed any preferred direction of movement or any tendency for increased displacement from the site of release with increased time at liberty.


Author(s):  
M.D. Wildsmith ◽  
I.C. Potter ◽  
F.J. Valesini ◽  
M.E. Platell

Benthic macroinvertebrates were sampled seasonally in the subtidal and upper and lower swash zones at two sites in each of six nearshore habitat types on the lower west coast of Australia. The habitat types, which differed mainly in the extent of their exposure to wave activity and whether sea grass and/or nearshore reefs were present, had been distinguished quantitatively using values for a suite of seven statistically-selected enduring environmental characteristics (Valesini et al., 2003). The core samples yielded 121 species representing eight phyla, among which the Polychaeta, Malacostraca and Bivalvia were the most speciose classes, contributing ∼38, 23 and 10%, respectively, to the total number of individuals. The total number of species and mean density of macroinvertebrates at the most protected habitat type (1), i.e. 70 and 209·2 individuals 0·1 m−2, respectively, were far greater than in any other habitat type. Habitat type influenced species composition to a greater extent than either zone or season. Furthermore, the extents of the differences among the species compositions of the six habitat types statistically matched the extents of the differences among the values for the suite of enduring environmental characteristics that distinguished each of those habitat types. Overall, the species composition at habitat type 1 was the most distinct, containing five abundant species of polychaetes that were adapted to deposit-feeding in calm waters with high levels of organic material and which were rare in all other habitat types. In contrast, the fauna at the most exposed habitat type was characterized by four crustacean species and a species of bivalve and polychaete, whose mobility and tough external surface facilitated their survival and feeding in turbulent waters. The zonal differences in faunal compositions among habitat types were greatest in the case of the subtidal zone. The faunal compositions differed among zones and seasons only at the most protected habitat type.


2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Peter Halvarsson ◽  
Johan Höglund

Abstract Background A novel way to study the species composition and diversity of nematode parasites in livestock is to perform deep sequencing on composite samples containing a mixture of different species. Herein we describe for the first time the nematode community structures (nemabiomes) inhabiting Swedish sheep and how these are/were affected by host age and recent anthelmintic treatments. Methods A total of 158 fecal samples were collected (n = 35 in 2007 and n = 123 in 2013–2016) and cultured from groups of sheep on 61 commercial farms in the south-central part of the country where most animals are grazed. Among the samples, 2 × 44 (56%) were paired collections from the same groups pre- and post-treatment with anthelmintics such as macrocyclic lactones, benzimidazoles or levamisole. Samples were analyzed for their nemabiome using the PacBio platform followed by bioinformatic sequence analysis with SCATA. Species richness and diversity were calculated and analyzed in R. Results Nematode ITS2 sequences were found in all larval culture samples except two, even though the fecal egg counts were below the McMaster threshold in 20 samples. Sequencing yielded, on average, 1008 sequences per sample. In total, 16 operational taxonomical units (OTU), all with ≥ 98 % identity to sequences in the NCBI database, were recognized. The OTUs found represented nematode species of which ten are commonly associated with sheep. Multiple species were identified in all pre-anthelmintic treatment larval culture samples. No effects on nematode diversity were found in relation to host age. On the other hand, recent anthelmintic treatment lowered species richness, especially after use of ivermectin and albendazole. Interestingly, despite zero egg counts after use of levamisole, these samples still contained nematode DNA and especially H. contortus. Conclusions Our findings provide evidence that nemabiome analysis combined with diversity index analysis provides an objective methodology in the study of the efficacy of anthelmintic treatment as both high and low abundant species were detected.


2016 ◽  
Vol 51 (8) ◽  
pp. 958-966 ◽  
Author(s):  
Anderson Pedro Bernardina Batista ◽  
José Márcio de Mello ◽  
Marcel Régis Raimundo ◽  
Henrique Ferraço Scolforo ◽  
Aliny Aparecida dos Reis ◽  
...  

Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species richness and diversity by the Shannon diversity index (<25% spatial dependence degree). Areas of low and high species diversity and richness were found in the shrub savanna fragment. Spatial distribution behavior shows relative stability regarding the number of species and the Shannon diversity index in the evaluated years.


2020 ◽  
Author(s):  
E Sebastián-González ◽  
JM Barbosa ◽  
JM Pérez-García ◽  
Z Morales-Reyes ◽  
F Botella ◽  
...  

© 2019 John Wiley & Sons Ltd Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large-scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion-consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using 2,485 carcasses monitored between 1991 and 2018. First, we evaluated how scavenger richness (number of species) and diversity (Shannon diversity index) varied among seasons (cold vs. warm, wet vs. dry). Then, we studied the potential effects of human impact and a set of macroecological variables related to climatic conditions on the scavenger assemblages. Vertebrate scavenger richness ranged from species-poor to species rich assemblages (4–30 species). Both scavenger richness and diversity also showed some seasonal variation. However, in general, climatic variables did not drive latitudinal patterns, as scavenger richness and diversity were not affected by temperature or rainfall. Rainfall seasonality slightly increased the number of species in the community, but its effect was weak. Instead, the human impact index included in our study was the main predictor of scavenger richness. Scavenger assemblages in highly human-impacted areas sustained the smallest number of scavenger species, suggesting human activity may be overriding other macroecological processes in shaping scavenger communities. Our results highlight the effect of human impact at a global scale. As species-rich assemblages tend to be more functional, we warn about possible reductions in ecosystem functions and the services provided by scavengers in human-dominated landscapes in the Anthropocene.


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