Benthos of the Port of Melbourne : The Yarra River and Hobsons Bay, Victoria

1978 ◽  
Vol 29 (2) ◽  
pp. 141 ◽  
Author(s):  
GCB Poore ◽  
JD Kudenov
Keyword(s):  
Species Diversity ◽  
Environmental Variables ◽  
Dominant Species ◽  
Hierarchical Classification ◽  
Soft Bottom ◽  
Diverse Communities ◽  
Low Diversity ◽  
Faunal Diversity ◽  
Abundance And Diversity ◽  
Yarra River

The distribution of soft-bottom macrobenthos in the Yarra River and Hobsons Bay, Vic.,is examined in terms of temporal changes in abundance and diversity, and related to selected environmental variables. Hierarchical classification was used to divide the stations into three zones: upstream river stations; downstream river stations with muddy bay stations; and sandy bay stations. The faunas of the river and the central muddy basin of Port Phillip Bay are similar although several common Bay species were absent in the river, probably as a result of competition and lowered salinity and dissolved oxygen. Faunal diversity of the Yarra River was lower than that of Hobsons Bay and is lower than that of equivalent areas in the northern hemisphere. Seasonality in species composition or diversity was not observed. The dominant river species, Theora fragilis (Bivalvia), was more abundant in the lower river than anywhere in Port Phillip Bay. Its life expectancy and density were lowest at stations further up the river. Species diversity seems more predictable in highly diverse communities lacking dominant species than in communities of low diversity dominated at all times by one or two species.

Diversity and community structure of Ephemeroptera in freshwater stream of Megamalai hills, Tamil Nadu, India

ENTOMON ◽  
2021 ◽  
Vol 46 (4) ◽  
pp. 279-284
Author(s):  
S. Barathy ◽  
T. Sivaruban ◽  
Srinivasan Pandiarajan ◽  
Isack Rajasekaran ◽  
M. Bernath Rosi
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Air Temperature ◽  
Tamil Nadu ◽  
Dominant Species ◽  
Diversity Indices ◽  
Low Diversity ◽  
Freshwater Stream ◽  
Species Diversity Indices ◽  
High Diversity

In the study on the diversity and community structure of Ephemeroptera in the freshwater stream of Chinnasuruli falls on Megamalai hills, a total of 523 specimens belonging to thirteen genera and five families were collected in six month periods. Of the five families, Teloganodidae and Leptophlebiidae exhibited high diversity and Caenidae showed low diversity. Choroterpes alagarensis (Leptophlebiidae) is the most dominant species. Diversity indices such as Shannon and Simpson indices showed that diversity was maximum in November and December and it was minimum in August and January. Canonical Correspondence Analysis revealed that rainfall, water flow, turbidity, and air temperature were the major stressors in affecting the Ephemeropteran community structure.

scholarly journals Species Diversity, Distribution and Abundance of Fishes of Seti Gandaki River Basin, Pokhara, Nepal

2020 ◽  
pp. 5-14
Author(s):  
Kishor K. Pokharel ◽  
Khadga B. Basnet ◽  
Trilok C. Majpuria ◽  
Chitra B. Baniya
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
River Basin ◽  
Environmental Variables ◽  
Diversity Indices ◽  
Urban Site ◽  
Abundance And Diversity ◽  
Study Sites ◽  
Urban Sites ◽  
Tor Tor

Species diversity with indices, distribution and abundance of fishes of Seti Gandaki River Basin, Pokhara, Nepal are described from five study sites, three along the main channel and two in major tributaries. Fishes were sampled using a cast-net following pass-removal method. Environmental variables were determined following the standard methods. In total, 30 species belonging to five orders, nine families and 24 genera with absolute abundance of 10,659 were recorded. A longitudinal pattern of distribution and species richness from upstream to downstream sites (17 to 21 species) was observed. Cyprinids were dominant followed by silurids, balitorids, channids, mastacembelids, belonids and cobitids. Distribution pattern and abundance data showed that the species Tor tor, Tor putitora, Chaguninus chagunio, Barilius barila, Opsarius barna, Danio rerio, Lepidocephalichthys guntea, Parachiloglanis hodgarti and Amblyceps mangois were not common in the study area. The environmental variables such as depth, width, discharge and temperature showed effect upon species richness, abundance, distribution and diversity indices, which had lower values at upstream pre-urban sites than at downstream post-urban sites. A sharp decline in species richness, abundance and diversity indices at urban site (10 species) indicated urban influence.

Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska
Keyword(s):  
Environmental Variables ◽  
Climate Changes ◽  
Biological Significance ◽  
Global Changes ◽  
Factors Affecting ◽  
Low Diversity ◽  
Main Factors ◽  
The Antarctic ◽  
High Diversity ◽  
Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

Dominant species can produce a negative relationship between species diversity and ecosystem function

Oikos ◽  
2009 ◽  
Vol 118 (5) ◽  
pp. 723-732 ◽  
Author(s):  
Robert P. Creed ◽  
Robert P. Cherry ◽  
James R. Pflaum ◽  
Chris J. Wood
Keyword(s):  
Species Diversity ◽  
Ecosystem Function ◽  
Dominant Species ◽  
Negative Relationship

Seasonality in a taxocoenosis of molluscs from soft bottoms in the Bay of Cádiz (southern Spain)

2001 ◽  
Vol 81 (6) ◽  
pp. 903-912 ◽  
Author(s):  
Jose L. Rueda ◽  
Manuel Fernández-Casado ◽  
Carmen Salas ◽  
Serge Gofas
Keyword(s):  
Species Richness ◽  
Correspondence Analysis ◽  
Dominant Species ◽  
Southern Spain ◽  
Soft Bottom ◽  
Soft Bottoms ◽  
High Species Richness ◽  
Bay Of Cadiz ◽  
Bay Of Cádiz ◽  
Autumn And Winter

The macrofauna of molluscs associated with soft bottoms in the Bay of Cádiz (southern Spain) was studied monthly from February 1994 to January 1996. The number of species (63) is high for a soft bottom and is related to environmental characteristics (growth of macrophytes) and the biogeographical setting of the studied area. Corbula gibba (∼90%) was the dominant species in this taxocoenosis together with the gastropod Nassarius pygmaeus and the bivalves Pandora inaequivalvis, Parvicardium exiguum and Macoma melo. The most frequent species during the two years was also the bivalve Corbula gibba (100%) followed by the gastropods Nassarius pygmaeus, Tricolia tenuis, Rissoa membranacea and the bivalve Macoma melo. Total abundance of the taxocoenosis in both years reached higher values in spring. The dynamics of the ecological indices such as diversity or evenness, and the species richness showed a similar pattern in both years, with low values of diversity and evenness together with high species richness in spring and summer months and the reverse in autumn and winter. The qualitative correspondence analysis of monthly samples shows an ordination related to seasonality in both studied years, however the values of Jaccard's coefficient do not indicate significant boundaries among the monthly samples. The quantitative correspondence analysis shows an ordination and grouping of samples related to the biology of species, particularly with the recruitment of C. gibba, the dominant species. The existence of similar trends in the structure of the taxocoenoses over both years, and the seasonality highlighted by the qualitative correspondence analysis, seems to indicate a certain stability of the ecosystem.

scholarly journals Distribution of paracalanidae species (Copepoda, Crustacea) in the continental shelf off Sergipe and Alagoas States, Northeast Brazil

2006 ◽  
Vol 54 (4) ◽  
pp. 173-181 ◽  
Author(s):  
Hortência Maria Pereira Araujo
Keyword(s):  
Continental Shelf ◽  
Rainy Season ◽  
Environmental Variables ◽  
Dominant Species ◽  
Seasonal Distribution ◽  
Northeast Brazil ◽  
Oceanic Water ◽  
Density Values ◽  
Oceanic Species ◽  
Parvocalanus Crassirostris

The spatial and seasonal distribution of the Paracalanidae species were studied in eighteen stations in the continental shelf off Sergipe and Alagoas States, northeast Brazil, in December, 2001 and 2003, and in June, 2002 and 2003. The Paracalanidae family was constituted by coastal and shelf species such as Parvocalanus crassirostris, Paracalanus quasimodo, P. indicus and P. aculeatus and oceanic species, Calocalanus pavo and Acrocalanus longicornis. Density values were higher in stations located at 10 m isobath with respect to those located at 20 and 30 m depths. Paracalanidae abundance presented differences between seasons with values higher in June (2002, 2003) than in December (2001, 2002). All species were more abundant in the rainy season except Parvocalanus crassirostris. Paracalanus quasimodo was the dominant species with average densities of 949, 740 and 41 ind.m-3 in December months and 4231, 2389 and 1185 ind.m-3 in June months, at stations with local depths of 10, 20 and 30 m, respectively. Canonical correspondence analysis showed that salinity and temperature were the environmental variables that presented significant correlation with the distribution of Paracalanidae species, probably because these variables are influenced by the estuarine waters and by the dynamic of oceanic water masses in the continental shelf.

scholarly journals Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

2016 ◽  
Vol 16 (3) ◽  
Author(s):  
Felipe Augusto Trindade Gondim-Silva ◽  
Alessandra Rodrigues Santos Andrade ◽  
Rafael Oliveira Abreu ◽  
Jamile Santos Nascimento ◽  
Geovane Paixão Corrêa ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Species Composition ◽  
Rainy Season ◽  
Dominant Species ◽  
The State ◽  
Northeastern Brazil ◽  
Freshwater Wetland ◽  
Northern Coast ◽  
Anuran Species

Abstract The Conde municipality is located in the northern coast of the state of Bahia (NC), northeastern Brazil, and is part of the Atlantic Tropical domain. The anuran fauna of the northern portion of the NC is still poorly known if compared to the southern portion. The Restinga is one of the predominant environments of the coastal plains of the NC and it is characterized essentially by presenting sandy soil covered by herbaceous and shrubby vegetation. The objective of this study was to determine the anuran species composition and diversity for the Restinga of the Conde municipality. Sampling was carried out at night by active search over four periods of five consecutive days each, two over the 'main rainy season' and two in a 'lesser rainy season', using 14 sample units (SUs) and five extra sample plots (EPs). We calculated dominance and species diversity using the Berger-Parker and Shannon-Wiener H' indices, respectively. We used accumulation curves and the Jackknife 1 estimator to estimate anuran species richness, considering only the data obtained from the SUs. We recorded 713 anuran specimens distributed within 33 species, 13 genera and five families (Bufonidae, Craugastoridae, Hylidae, Leptodactylidae and Microhylidae). The Hylidae and Leptodactylidae families had the highest species richness. Considering only the SUs (Jackknife 1 estimator in brackets), we recorded 28 species in the study area (33.9 ± 2.3), 13 in Shrubby Vegetation Zones - SVZ (20.8 ± 2.9) and 25 in Freshwater Wetland Zones - FWZ (28.9 ± 1.9). The abundance and species diversity of the FWZ (n = 638 specimens; H'= 2.4) were higher than those recorded for the SVZ (n = 52 specimens; H' = 1.9). The SVZ and FWZ showed distinct dominant species, wherein Pristimantis paulodutrai was the dominant species in SVZ and Scinax fuscomarginatus in FWZ. The Restinga of the Conde municipality stands out as the one with the highest anuran species richness already recorded considering only SVZ and FWZ. Moreover, its anuran species composition represented 55% of the anuran species known for the NC and included taxa common to three different morphoclimatic domains (Tropical Atlantic, Cerrado and Caatinga).

scholarly journals The The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia

2020 ◽  
Vol 21 (3) ◽  
Author(s):  
ZAHLUL IKHSAN ◽  
HIDRAYANI ◽  
YAHERWANDI ◽  
HASMIANDY HAMID
Keyword(s):  
Species Diversity ◽  
Rice Field ◽  
Diversity Index ◽  
Human Life ◽  
Similarity Index ◽  
Pitfall Trap ◽  
Vital Role ◽  
Tidal Swamp ◽  
Abundance And Diversity ◽  
Number Of Individuals

Abstract. Ikhsan Z, Hidrayani, Yaherwandi, Hamid H. 2020. The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia. Biodiversitas 21: 1020-1026. Hymenoptera is one of the four largest insect orders and it plays a vital role in human life as pollinators, parasitoids, and predators. Hymenoptera parasitoids are particularly important as agents of biological control of pest. The objective of this research was to study the diversity and abundance of Hymenoptera on tidal swamp rice field in Indragiri Hilir District, Riau Province, Indonesia. Samplings were conducted in 3 sub-districts of rice production centers, namely Batang Tuaka, Keritang and Reteh, using four trapping techniques (i.e. insect net, malaise trap, pitfall trap, and yellow pan trap). Shannon diversity index (H '), Krebs evenness index (E), and Jaccard similarity index (Is) were calculated. We found 4,701 individuals consisting of 39 families and 319 species of Hymenoptera at the three studied areas. Tidal swamp rice in Indragiri Hilir District had a high species diversity of Hymenoptera parasitoids and Hymenoptera predators, but a moderate species diversity of Hymenoptera pollinators. Species diversity and evenness of Hymenoptera parasitoids and predators were higher in Keritang than in Batang Tuaka and Reteh. The families of Formicidae, Braconidae, Ichneumonidae, and Scelionidae had the highest number of species, while Formicidae, Scelionidae, Diapriidae, and Braconidae had the highest number of individuals. Based on these findings, the abundance and diversity of Hymenoptera insects in Indragiri Hilir District have the potentials to be developed as biological agents to control pests on tidal swamp rice in this area.

scholarly journals Seasonal Fluctuations of the Numbers of leaf beetles of the subfamily Alticinae (Coleoptera, Chrysomelidae) in lowland steppe of Tigireksky strict nature Reserve (Northern-Western Altai, Russia)

2018 ◽  
Vol 8 (2) ◽  
pp. 322-325
Author(s):  
T. M. Krugova ◽  
E. V. Guskova
Keyword(s):  
Species Diversity ◽  
Dominant Species ◽  
Nature Reserve ◽  
Meadow Steppe ◽  
Seasonal Fluctuations ◽  
Leaf Beetles ◽  
In The Beginning

<p>Seasonal fluctuations of the numbers of leaf beetles of the subfamily Alticinae (Coleoptera, Chrysomelidae) in lowland steppe of Tigirekskiy reserve in 2012 was studied in stipa and in meadow steppe. The maximal species diversity was noted in the beginning - in the middle of summer. The dominant species is Longitarsus luridus (Scopoli, 1763) with the peak of activity in the end of summer.</p>

Helminth parasitism in raccoons, Procyon lotor hirtus Nelson and Goldman, in Saskatchewan

1982 ◽  
Vol 60 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Eric P. Hoberg ◽  
Steven G. McGee
Keyword(s):  
United States ◽  
Species Diversity ◽  
Procyon Lotor ◽  
Life Cycles ◽  
Intensity Of Infection ◽  
Midwestern United States ◽  
Ecological Conditions ◽  
Low Diversity ◽  
Geographic Regions

Thirty-one raccoons, Procyon lotor hirtus Nelson and Goldman, from southern Saskatchewan, Canada, were examined for helminths. Six species were recovered: Plagiorchis cf. cf. elegans (Rudolphi, 1802); Alaria marcianae (LaRue, 1917); Pharyngostomoides adenocephala Beckerdite, Harkema and Miller, 1971; Microphalus sp.; Atriotaenia procyonis (Chandler, 1942); and Physaloptera sp. Comparisons were made with findings in a series of 25 raccoons from the midwestern United States and with published results and surveys in other regions. Notable variation exists in species diversity and intensity of infection of parasites in raccoons from different geographic regions. This is a consequence of diverse ecological conditions in different geographic regions. Since P. lotor is extending its range in Saskatchewan, it is suggested that the low diversity of its helminthic fauna may be attributable to dispersal of animals into regions where they persist in low numbers and where conditions are not suitable for completion of life cycles of helminths that elsewhere occur commonly in raccoons. The trematodes P. elegans and A. marcianae have not been previously reported from raccoons.

Sign in / Sign up

Export Citation Format

Share Document