scholarly journals Molluscan Diversity Influenced by Mangrove Habitat in the Khors of Qatar

Wetlands ◽  
2021 ◽  
Vol 41 (4) ◽  
Author(s):  
Jassim A. Al-Khayat ◽  
P. Vethamony ◽  
Mandar Nanajkar
Keyword(s):  
Species Richness ◽  
Arabian Gulf ◽  
Species Number ◽  
Mangrove Habitat ◽  
Developing Region ◽  
Tidal Area ◽  
Mollusc Species ◽  
Molluscan Diversity ◽  
Molluscan Species ◽  
Mangrove Conservation

AbstractThe Exclusive Economic Zone (EEZ) of Qatar is a rapidly developing region within the Arabian Gulf, where monitoring of changes in benthic biodiversity and its functioning is needed. The influence of mangroves and seasonality on the nearshore subtidal molluscan diversity at three distinct khors (nearshore tidal bays) – natural mangroves (Al Dhakhira), planted mangroves (Al Mafyar) and no-mangroves (Dawhat Zekreet) – are investigated in this study. This study concludes that even the sub-tidal area is influenced by mangroves, and mangroves increase the diversity of molluscs compared to the site that lacks mangroves. The maximum salinity (59.8 psu) was observed at Dawhat Zekreet during summer, and the minimum (41.44 psu) at Al Dhakhira in winter. Chlorophyll a level was low for all the khors, and rarely exceeded 1 μg/L, depicting oligotrophic waters. Al Dhakhira demonstrated the highest molluscan species richness (32), and shared 28 species in common with Al Mafyar. Dawhat Zekreet had the fewest mollusc species number and no mangroves. When cumulative diversity over all seasons was considered, Dawhat Zekreet exhibited the lowest species richness; Al Dhakhira, the highest. Some mangrove regions have been already utilized for developmental activities, and Qatar needs to continue the program of mangrove conservation as a vital habitat for molluscs.

scholarly journals The improvement of molluscs population: as a parameter of success of local scale mangrove conservation on the south coast of Lombok

2021 ◽  
Vol 913 (1) ◽  
pp. 012047
Author(s):  
Agil Al Idrus ◽  
Baiq Nunung Hidayati ◽  
Erna Ajizah ◽  
Wahyu Bintang Ilahi ◽  
Abdul Syukur
Keyword(s):  
Species Richness ◽  
Research Method ◽  
Wealth Index ◽  
Local Scale ◽  
Marine Biota ◽  
Ecological Data ◽  
Observation Methods ◽  
Mollusc Species ◽  
Main Factor ◽  
Mangrove Conservation

Abstract Mangroves are known by local people as mangrove plants that contribute to the sustainability of the diversity of marine biota species, such as molluscs. At the study site, mangrove conservation activities have been carried out by the community and are thought to influence the development of molluscs populations significantly. The study aims to assess the results of local-scale mangrove conservation with the development of molluscs populations. The research method uses observation methods with transect methods for ecological data. Ecological data analysis uses the index of evenness, richness, and diversity. The analysis found 27 species of molluscs consisting of 21 species of gastropods and 6 species of bivalves. The highest evenness and diversity was found at 2.4 in Gerupuk, while the highest wealth index was 16.8 in Poton Bakau. Furthermore, the molluscs species found consists of two classes, namely bivalves and gastropods. The main factor in determining species richness, is more determined by the condition of the substrate. In this case, the presence of mangroves is very important in creating the substrate conditions needed by the diversity of mollusc species. Therefore, mangrove conservation is very important for the protection and preservation and diversity of molluscs species. Information on the ecological potential of mangroves on fauna diversity, especially molluscs, can be a major source of ecosystem-based marine resource management, such as at the study site.

Molluscan biostratigraphy of the lower River Bend Formation at the Martin Marietta Quarry, New Bern, North Carolina

1991 ◽  
Vol 65 (1) ◽  
pp. 80-118 ◽  
Author(s):  
Thomas J. Rossbach ◽  
Joseph G. Carter
Keyword(s):  
North Carolina ◽  
Coastal Plain ◽  
Warm Water ◽  
Gulf Coastal Plain ◽  
Generic Level ◽  
Evolutionary Transitions ◽  
Molluscan Fauna ◽  
Molluscan Diversity ◽  
Molluscan Species ◽  
River Bend

The lower River Bend Formation at the Martin Marietta New Bern quarry in Craven County, North Carolina, contains a diverse and abundant moldic molluscan fauna. This fauna, reconstructed by latex casts, suggests a Vicksburgian or a post-Vicksburgian, pre-Chickasawhayan age for the New Bern exposure. Forty-one molluscan species and subspecies are presently identified from the lower River Bend Formation, 11 of which are new: Turritella caelatura alani, Turritella neusensis, Galeodaria britti, Phalium newbernensis, Cymatium planinodum, Oocorys vadosus, Ecphora wheeleri, Lyria concinna, Scaphella saintjeani, Turricula (Orthosurcula) aequa, and Lucina (Stewartia) micraulax. This fauna is virtually identical at the generic level and similar at the species level to the Vicksburgian faunas of the Gulf Coastal Plain. About 37 percent of the New Bern species also occur in the Vicksburgian of Mississippi, although many of these species reach considerably larger sizes at New Bern. Apparent evolutionary transitions between previously known Vicksburgian and Chickasawhayan mollusks suggest a time of deposition intermediate between these two Oligocene stages.Moderately high molluscan diversity, the abundance of characteristically warm-water genera, and associated carbonate-rich sediments suggest that the lower River Bend Formation represents a subtropical, open-marine, predominantly carbonate environment immediately seaward of a nearshore lagoonal or barrier island complex.The lower River Bend Formation at New Bern differs faunally, climatically, and sedimentologically from the upper River Bend Formation in quarry exposures near Belgrade, North Carolina. The upper River Bend Formation contains a lower diversity molluscan fauna with marked dominance diversity and few warm-water taxa. It represents a slightly cooler nearshore, open-marine environment in a transitional siliciclastic-carbonate sedimentary regime. The considerable taxonomic and sedimentologic differences between the lower and upper parts of the River Bend Formation corroborate microfossil evidence suggesting that they represent temporally distinct depositional cycles.

scholarly journals Anurans of the Parque Estadual do Mirador, a remnant of Cerrado in the state of Maranhão, Northeastern Brazil

2017 ◽  
Vol 17 (4) ◽  
Author(s):  
Etielle Barroso de Andrade ◽  
Luiz Norberto Weber ◽  
José Roberto de Souza Almeida Leite
Keyword(s):  
Species Richness ◽  
Central Region ◽  
Wide Distribution ◽  
The State ◽  
Northeastern Brazil ◽  
Species Number ◽  
Sampling Effort ◽  
The South ◽  
Cerrado Biome ◽  
South Central

Abstract The Cerrado is one of the most threatened biomes in Brazil. It is estimated that much of its original vegetation has been replaced by some type of human use. This is quite worrying, mainly in the northern part where the number of wildlife inventories is insufficient and creates the false impression of low diversity in the region. The Parque Estadual do Mirador-PEM, located in the south-central region of the state of Maranhão, presents vegetation typical of the Cerrado biome and corresponds to one of 46 priority areas for conservation in the state. Herein, we describe the species richness and composition of the anurofauna from the PEM and analyze the influence of different types of vegetation in its formation. Our inventory was conducted from December 2013 to February 2015, using the active search and auditory census methods on breeding sites in different water bodies of the park. We recorded 31 anuran species belonging to five families (species number in parentheses): Leptodactylidae (14), Hylidae (12), Bufonidae (3), Microhylidae (1) and Phyllomedusidae (1). The rarefaction curve and species richness estimators indicated that the sampling effort was enough to record most of the species in the region. The richness of anurans in the PEM was higher than reported by other authors for several areas of Cerrado. Most species have a wide distribution in Brazil or are strongly associated with the Caatinga or Amazon biomes. Only about 19% are endemic to the Cerrado biome. This study is the first to inventory the anurans species of the south-central region of state of Maranhão and provides important data on amphibian communities from the northern part of the Brazilian Cerrado.

scholarly journals Superhost Plants Alter the Structure of Plant–Galling Insect Networks in Neotropical Savannas

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 369 ◽  
Author(s):  
Araújo ◽  
Moreira ◽  
Falcão ◽  
Borges ◽  
Fagundes ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Plant Diversity ◽  
Host Plants ◽  
Plant Species Richness ◽  
Variable Number ◽  
Insect Species ◽  
Species Number ◽  
Neotropical Savannas ◽  
Galling Insects

Host plants may harbor a variable number of galling insect species, with some species being able to harbor a high diversity of these insects, being therefore called superhost plants. In the present study, we tested the hypothesis that the occurrence of superhost plant species of genus Qualea (Vochysiaceae) affects the structure of plant–galling insect ecological networks in Brazilian Cerrado. We sampled a total of 1882 plants grouped in 131 species and 43 families, of which 64 species and 31 families of host plants hosted 112 galling insect species. Our results showed that occurrence of superhosts of genus Qualea increased the linkage density of plant species, number of observed interactions, and the size of plant–galling insect networks and negatively affected the network connectance (but had no effect on the residual connectance). Although the occurrence of Qualea species did not affect the plant species richness, these superhosts increased the species richness and the number of interactions of galling insects. Our study represents a step forward in relation to previous studies that investigated the effects of plant diversity on the plant–insect networks, showing that few superhost plant species alter the structure of plant–herbivore networks, even without having a significant effect on plant diversity.

scholarly journals Stability in the plant communities of the Park Grass Experiment: the relationships between species richness, soil pH and biomass variability

1994 ◽  
Vol 346 (1316) ◽  
pp. 185-193 ◽  
Keyword(s):  
Species Richness ◽  
Plant Communities ◽  
Climatic Conditions ◽  
Species Number ◽  
Soil Reaction ◽  
Moisture Deficit ◽  
Rothamsted Experimental Station ◽  
Park Grass Experiment ◽  
The Relationship ◽  
Biomass Variability

The Park Grass Experiment (PGE), begun at Rothamsted Experimental Station in 1856 and still running, affords a unique opportunity to test for the influence of species number and soil reaction on biomass variability in a suite of comparable plant communities. Biomass variability was measured by calculating the coefficient of variation ( CV ) over time of annual hay yield in an eleven-year moving window. CV and species number were both strongly negatively correlated with biomass; both relations were affected by time and pH. Multiple regression of CV on species number and mean biomass for nonacidified plots in 42 years between 1862 and 1991 showed a relationship between biomass and CV which was negative in most years and significantly so in nearly three quarters of them (30/42). We are unable to tell how much of this effect is intrinsic to the statistical relation between the mean and CV of biomass. Species number was negatively correlated with CV in 29/42 years, but this was statistically significant on only three occasions. Because this relation was highly significant in the year (1991) for which we have the largest sample size (34 plots), we tentatively conclude that biomass variability may be lower in more species-rich communities, although the effect is possibly a weak one. We suggest that physiological stresses imposed by low pH may explain the greater variability of plots with acidified soil. An increase in the variability of biomass that occurred across plots with time may be due in part to acidification across the whole experiment. Three hypotheses are proposed to explain the relationship between species richness and biomass variability: (i) biomass variability on more species-rich plots is better buffered against climatic variation because species differ in their response to climatic conditions: (ii) there are fewer species on plots with greater biomass variability because species have been lost by competitive exclusion in years when biomass reaches high values; (iii) species richness and variability are both correlated with a third variable, for example soil moisture deficit within a plot. All three hypotheses are susceptible to testing within the PGE.

Distribution of Epibenthic Mollusca on a Transect Through the Beagle Channel (Southern Chile)

1998 ◽  
Vol 78 (3) ◽  
pp. 875-889 ◽  
Author(s):  
Katrin Linse ◽  
Angelika Brandt
Keyword(s):  
Boundary Layer ◽  
Species Richness ◽  
Shallow Water ◽  
Benthic Boundary Layer ◽  
Southern Chile ◽  
Beagle Channel ◽  
Epibenthic Sledge ◽  
Molluscan Species

During the Joint Chilean–German–Italian Magellan ‘Victor Hensen’ Campaign in 1994 an epibenthic sledge (EBS) was used to catch the epibenthic and benthic-boundary-layer macrofauna.Eighteen EBS samples were taken at 12 locations on a transect through the Beagle Channel. The aims of the study were to describe the epibenthic molluscan species, to quantify their abundances and to describe their distribution. In total 35,087 specimens were collected, yielding 107,223 ind 1000 nr−2. Bivalvia were most abundant 78,615 individuals (52 spp.) followed by Gastropoda (17,289, 52spp.), Aplacophora (4745, 9 spp.), Polyplacophora (4665) and Scaphopoda (1909,5 spp.). The molluscan abundance of the hauls were strikingly different, between 3 and 37,927 ind 1000 m−2 haul. Only stations off the eastern entrance showed high abundances, which was represented at all depths and sediments. Elsewhere the abundances were low. Species richness was highest in shallow water (< 100 m) with 69 species and decreased with depth. But at the deepest station 37 species were found.

Maximum local helminth parasite community richness in British freshwater fish: a test of the colonization time hypothesis

Parasitology ◽  
1993 ◽  
Vol 106 (1) ◽  
pp. 91-100 ◽  
Author(s):  
J.-F. Guégan ◽  
C. R. Kennedy
Keyword(s):  
Species Richness ◽  
Host Range ◽  
Freshwater Fish ◽  
Host Species ◽  
Fish Host ◽  
Helminth Species ◽  
Species Number ◽  
Sampling Effort ◽  
Component Community ◽  
Colonization Time

SUMMARYThe investigation of Price & Clancy (1983), which demonstrated a significant positive correlation between total helminth species number per host species and geographical range of freshwater fish host species in Britain, was re-examined using a different measure of parasite species richness. Re-calculation of the correlations between the two parameters after controlling for the effect of the composition of the list of fish by excluding, on biological and distributional grounds, 2 species of agnathans and 7 species of introduced teleosts, and for the effect of sampling effort by using helminth richness in the richest component community of each fish species rather than check-list data, reveals no significant relationship between helminth species richness and host range. Habitat and an omnivorous host diet now appear more significant determinants of helminth richness than the accumulation of parasites by predation. The findings provide little support for the interpretation of the relationship between helminth species richness and host range in terms of island biogeographic theory, but do support an alternative explanation in terms of the colonization time hypothesis, i.e. that helminth species richness is related to the time since the fish host arrived in Britain.

scholarly journals Edge effects and landscape matrix use by a small mammal community in fragments of semideciduous submontane forest in Mato Grosso, Brazil

2008 ◽  
Vol 68 (4) ◽  
pp. 703-710 ◽  
Author(s):  
M. Santos-Filho ◽  
DJ. da Silva ◽  
TM. Sanaiotti
Keyword(s):  
Species Richness ◽  
Small Mammal ◽  
Species Number ◽  
Sampling Effort ◽  
Similar Species ◽  
Species Accumulation Curves ◽  
Mammal Species ◽  
Mato Grosso ◽  
Species Accumulation ◽  
Species Richness And Abundance

A community of small mammals was studied in seasonal semideciduous submontane forest in the state of Mato Grosso, Brazil. This study evaluated the use of edge and matrix pasture, by different small mammal species. Overall, 31 areas were studied, with a total sampling effort of 33,800 trap x nights. Only seven of the 25 species captured in the study sites were able to use the pasture matrix; we classified these species as generalists. Fourteen species were found to be intermediate in habits, being able to use forest edges. We found only four species habitat specialists, occurring only on transect lines in the interior of the fragment, at least 150 m from the edge. Transects located in the pasture matrix and 50 m from the edge had significantly lower species richness and abundance than transects located in the fragment edge or in the interior of the fragment. All transects located within the fragment had similar species richness and abundance, but transects located 50 m from the edge had slightly lower, but non-significant, species richness than transects located 100 m apart from edges. Rarefaction curves demonstrated that only medium-sized fragments (100 300 ha) reached an asymptote of species accumulation. The other areas require further sampling, or more sampling transect, before species accumulation curves stabilize, due to a continued increase in species number.

scholarly journals Preliminary data on the Posidonia meadows and associated macrozoobenthic community of Sazani island (Albania)

2015 ◽  
Author(s):  
Jula Selmani ◽  
Stela Ruci ◽  
Denada Kasemi ◽  
Sajmir Beqiraj ◽  
Lefter Kashta
Keyword(s):  
Species Richness ◽  
Marine Protected Area ◽  
Rapid Assessment ◽  
Posidonia Oceanica ◽  
The State ◽  
Macroinvertebrate Community ◽  
Eastern Coast ◽  
Benthic Macroinvertebrate ◽  
Species Number ◽  
Species Richness And Abundance

The seagrass Posidonia oceanica meadows are scarcely studied in the Albanian coast. Data presented in this work have been collected during an assessment of benthic communities of Sazani Island, Albania, in May 2013. The P. oceanica meadow has a limited distribution around this island, covering a relatively small area on its eastern coast. Although this meadow seems to be under degradation, it is still a good shelter for high species number and high abundance of benthic macroinvertebrates. The highest species richness and abundance has been recorded for sponges, hydrozoans, gastropods, bivalves, polychaetes, echinoderms, bryozoans and ascidians. The sciaphilic and photophilic communities were clearly evident, associated respectively to the P. oceanica rhizomes and leaves. Referring to the species richness and abundance, a rapid assessment of ecological and environmental state of benthic macroinvertebrate community has been done. Other parameters used for the assessment of the state of P. oceanica meadow have also been recorded, and possible reasons for the degradation of the meadow have been highlighted. These assessments of the benthic macroinvertebrate community and the state of seagrass meadow are also important within the framework of monitoring, conservation and management of the only Marine Protected Area of Albania, where Sazani Island is a core area.

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