Quantitative analyses of decapod crustaceans at a rocky intertidal shore in the Gulf of Oman, Iran: diversity, zonation and monsoonal fluctuations

2018 ◽  
Vol 99 (2) ◽  
pp. 445-459
Author(s):  
Saeed Ebrahimnezhad ◽  
Reza Naderloo
Keyword(s):  
Vertical Distribution ◽  
Intertidal Zone ◽  
New Records ◽  
Decapod Crustaceans ◽  
Intertidal Zones ◽  
Gulf Of Oman ◽  
South West ◽  
South West Monsoon ◽  
Significant Difference ◽  
High Intertidal Zone

This paper provides data on diversity, zonation and seasonal fluctuations of decapod crustaceans at the northern Gulf of Oman coast, based on quantitative and qualitative samplings. A total of 75 species belonging to four infraorders, 27 families and 48 genera were identified. These species include 20 new records for the entire Gulf of Oman and 13 new records for its Iranian coast. The mid-intertidal zone showed a higher mean diversity and abundance than high- and low-intertidal zones. The mean diversity and abundance in the high-intertidal zone showed significant differences with the mid- and low-intertidal zones. The indices of species richness (Margalef), diversity (Shannon) and evenness (Pielou) showed significant differences among the intertidal zones. Most of the identified species (>60%) that had high values in their frequency of occurrence and relative abundance showed an overlapping vertical distribution, and were present in all three or just in two of the three defined zones. Other species were found only in one of the three zones (non-overlapping vertical distribution). The decapod community in the mid-intertidal zone showed a higher dissimilarity with the high-intertidal zone than with the low-intertidal. Both abundance and diversity were found to be lowest and highest during south-west and north-east monsoons, respectively. During south-west monsoon, the abundance of decapods declined dramatically, but species diversity and ecological indices did not show any statistically significant difference among the sampling periods.

Diversity and first record of heterobranch gastropods (opisthobranchs) from the Saurashtra coast of Kathiawar Peninsula, India

2015 ◽  
Vol 8 ◽  
Author(s):  
Paresh Poriya ◽  
Bhavik Vakani ◽  
Bhavendra Chaudhari ◽  
Pradip Kachhiya ◽  
Rahul Kundu
Keyword(s):  
West Coast ◽  
Intertidal Zone ◽  
Arabian Sea ◽  
New Records ◽  
First Record ◽  
The South ◽  
Field Surveys ◽  
Intertidal Zones ◽  
West Coast Of India ◽  
Saurashtra Coast

This paper reports seven species of opisthobranchs from the intertidal zone of the south Saurashtra coastline off the Arabian Sea, Kathiawar Peninsula, west coast of India. Field surveys were undertaken along the intertidal zones of south Saurashtra coast during 2012–2014. In this study, seven species belonging to six families were recorded, of whichHaminoea ovalis, Flabellina bicolor, Phidiana militaris, Baeolidia palythoaeandSakuraeolis gujaraticaare new records from this coastline.

scholarly journals Responses of the mussel Brachidontes rodriguezii to aerial exposure: implications on growth and physiological condition

2019 ◽  
Vol 97 (7) ◽  
pp. 612-618 ◽  
Author(s):  
María Eugenia Torroglosa ◽  
Juliana Giménez
Keyword(s):  
Shell Length ◽  
Intertidal Zone ◽  
Physiological Condition ◽  
Physiological Stress ◽  
High Tide ◽  
Aerial Exposure ◽  
Intertidal Zones ◽  
The North ◽  
Calcein Am ◽  
High Intertidal Zone

The length of aerial exposure (i.e., environmental conditions) of an organism, due to daily tides, induces physiological responses. A mark–recapture field experiment was conducted in two intertidal zones (low tide and high tide) using the stain calcein AM to determine growth, as measured by shell length, of the mussel Brachidontes rodriguezii (d’Orbigny, 1842) along its vertical distribution off the north Argentinean coast. In the high intertidal zone, B. rodriguezii exhibited slower growth in shell length because of the physiological stress resulting from aerial exposure during low tides. In the low intertidal zone and during spring, B. rodriguezii exhibited faster growth in shell length. It is suggested that growth of B. rodriguezii relies on several environmental factors (temperature, photoperiod, and aerial exposure) that fluctuate according to tidal height.

Littoral Stratification in Growth form and Fecundity of the Rock Barnacle, Semibalanus Balanoides

1988 ◽  
Vol 68 (4) ◽  
pp. 591-599 ◽  
Author(s):  
R. W. Rangeley ◽  
M. L. H. Thomas
Keyword(s):  
Intertidal Zone ◽  
Growth Form ◽  
Base Length ◽  
Nucella Lapillus ◽  
Semibalanus Balanoides ◽  
Factors Affecting ◽  
Intertidal Zones ◽  
Density Dependent ◽  
Low Incidence ◽  
High Intertidal Zone

The population dynamics of rock barnacles, Semibalanus balanoides (L.), residing in low and high intertidal zones are affected by conspicuously different factors. The barnacle population in the high intertidal zone tends to show longterm stability due to a low incidence of both predation and interspecific competition. Wave exposure, desiccation and intraspecific competition are more important factors affecting abundance and size distribution in this zone (Menge, 1976). In the low intertidal zone, barnacle predation by the dogwhelk, Nucella lapillus (L.) is intense (Menge, 1976) and both the adults and larvae are smaller than in the high intertidal zone (Barnes, 1953). The growth form of S. balanoides is density dependent with taller, more columnar individuals predominating at high densities and short conical barnacles at low densities. Lower fecundity of conical individuals may be due to lower internal shell volume compared with columnar forms (Wethey, 1984). Fecundity increases both with increasing age and base length (Arnold, 1977) and is positively density dependent (Wethey, 1984).

scholarly journals A combined field and modeling study of groundwater flow in a tidal marsh

2011 ◽  
Vol 8 (3) ◽  
pp. 5123-5163
Author(s):  
◽  
Keyword(s):  
Water Table ◽  
Intertidal Zone ◽  
Soil Condition ◽  
Tidal River ◽  
High Permeability ◽  
River Bank ◽  
Intertidal Zones ◽  
Field Investigations ◽  
Groundwater Circulation ◽  
High Intertidal Zone

Abstract. Bald mud beaches were found among the mangrove marshes in Dongzhaigang National Nature Reserve, Hainan, China. To investigate the possible reasons for this phenomenon, the intertidal zones of a mangrove transect and a bald beach transect with similar topography and same tidal actions were selected for comparison study. Along both transects, observed water table variations were significant in the high and low intertidal zones and negligible in the middle intertidal zones. Field investigations and observations invite two speculations: (1) existence of a high-permeability zone on each transect which underlies the low-permeability surface mud sediments and outcrops in the high intertidal zone, and (2) considerable inland freshwater recharge along the mangrove transect but negligible freshwater recharge along the bald beach transect. Two-dimensional numerical simulations based on these speculations gave results in line with the observed water table. The bald beach is most probably due to the lack of enough freshwater for generating a brackish beach soil condition essential to mangrove growth. It is also indicated that seawater infiltrated the high-permeability zone through its outcrop near the high intertidal zone, and discharged from the tidal river bank in the vicinity of the low tide line, thereby forming a tide-induced seawater-groundwater circulation which may provide considerable contribution to the total submarine groundwater discharge.

scholarly journals Filamentous cyanobacteria from western ghats of North Kerala, India

2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
V Geethu ◽  
Mamiyil Shamina
Keyword(s):  
Western Ghats ◽  
New Records ◽  
Filamentous Cyanobacteria ◽  
North East ◽  
South West ◽  
South West Monsoon ◽  
Plant Taxon ◽  
Kerala State ◽  
West Monsoon ◽  
Cyanobacterial Genus

Cyanobacteria are Gram negative, photosynthetic and nitrogen fixing microorganisms which contribute much to our present-day life as medicines, foods, biofuels and biofertilizers. Western Ghats are the hotspots of biodiversity with rich combination of microbial flora including cyanobacteria. Though cosmopolitan in distribution, their abundance in tropical forests are not fully exploited. To fill up this knowledge gap, the present research was carried out on the cyanobacterial flora of Peruvannamuzhi forest and Janaki forests of Western Ghats in Kozhikode District, North Kerala State, India. Extensive specimen collections were conducted during South-West monsoon (June to September) and North-East monsoon (October to December) in the year 2019. The highest diversity of cyanobacteria was found on rock surfaces. A total of 18 cyanobacterial taxa were identified. Among them filamentous heterocystous forms showed maximum diversity with 10 species followed by non- heterocystous forms with 8 species. The highest number of cyanobacteria were identified from Peruvannamuzhi forest with 15 taxa followed by Janaki forest with 3 taxa. The non- heterocystous cyanobacterial genus Oscillatoria Voucher ex Gomont showed maximum abundance with 4 species. In this study we reported Planktothrix planktonica (Elenkin) Agagnostidis & Komárek 1988, Oscillatoria euboeica Anagnostidis 2001 and Nostoc interbryum Sant’Anna et al. 2007 as three new records from India. Bangladesh J. Plant Taxon. 28(1): 83-95, 2021 (June)

Nereididae (Annelida: Phyllodocida) of the Persian Gulf and Gulf of Oman, including description of two new species and 11 new records 

Zootaxa ◽  
2017 ◽  
Vol 4244 (1) ◽  
pp. 91 ◽  
Author(s):  
ALIEH BONYADI-NAEINI ◽  
NASRULLAH RASTEGAR-POUYANI ◽  
ESKANDAR RASTEGAR-POUYANI ◽  
CHRISTOPHER J. GLASBY ◽  
HASSAN RAHIMIAN
Keyword(s):  
New Species ◽  
Persian Gulf ◽  
Species Complex ◽  
New Records ◽  
Water Bodies ◽  
Intertidal Zones ◽  
Gulf Of Oman ◽  
Two New Species ◽  
The Persian Gulf ◽  
Neanthes Glandicincta

Currently, only 31 nereidid species are known from the Persian Gulf and Gulf of Oman. The present study was carried out in order to investigate the poorly known diversity of nereidid polychaetes from seas of the southern coasts of Iran. Specimens were collected from 23 locations along the intertidal zones of the two water bodies. Among the 26 species found: two are new, and are described here, including Simplisetia qeshmensis sp. nov. and Neanthes biparagnatha sp. nov.; 11 are new geographical records. Neanthes biparagnatha sp. nov. is most similar to N. deplanata (Mohammed, 1971), which is also found in the Persian Gulf, but can be most easily distinguished from it by the presence of bars in addition to cones in Area IV of the pharynx. Simplisetia qeshmensis sp. nov. may be distinguished from its closest congener, S. erythraeensis (Fauvel, 1918), also reported from the Persian Gulf, by having a greater number of paragnaths in Area I of the pharynx, an additional type of chaeta (homogomph spinigers) in the ventral neuropodial fascicle and having a reduced notopodial lobe in posterior chaetigers. The list of new records includes: one species from both areas, Neanthes glandicincta (Southern, 1921); eight species from the Persian Gulf, Leonnates decipiens Fauvel, 1929, Neanthes acuminata (Ehlers, 1868), Neanthes sp., Neanthes sp. cf. N. acuminata, Nereis sp. cf. N. pelagica Linnaeus, 1758, Perinereis cultrifera (Grube, 1840) species complex., Pseudonereis trimaculata (Horst, 1924), Pseudonereis sp. cf. P. variegata (Grube, 1857) and two from the Gulf of Oman, Leonnates persicus Wesenberg-Lund, 1949 and Perinereis kuwaitensis Mohammed, 1970. The present study brings to 40 the number of nereidid species currently known from the Persian Gulf and Gulf of Oman. A taxonomic key to nereidid species from the intertidal zones of the Persian Gulf and Gulf of Oman is presented to facilitate future investigations. 

Forecasting of Summer Monsoon Rainfall over Gangetic West Bengal, India Utilising Intrinsic Mode Functions, Linear and Neural Regression

2020 ◽  
Vol 12 (1) ◽  
pp. 60-69 ◽  
Author(s):  
Pijush Basak
Keyword(s):  
Neural Network ◽  
West Bengal ◽  
Monsoon Rainfall ◽  
Linear Part ◽  
Intrinsic Mode Functions ◽  
Quasi Biennial Oscillation ◽  
Nonlinear Part ◽  
South West ◽  
South West Monsoon ◽  
West Monsoon

The South West Monsoon rainfall data of the meteorological subdivision number 6 of India enclosing Gangetic West Bengal is shown to be decomposable into eight empirical time series, namely Intrinsic Mode Functions. This leads one to identify the first empirical mode as a nonlinear part and the remaining modes as the linear part of the data. The nonlinear part is modeled with the technique Neural Network based Generalized Regression Neural Network model technique whereas the linear part is sensibly modeled through simple regression method. The different Intrinsic modes as verified are well connected with relevant atmospheric features, namely, El Nino, Quasi-biennial Oscillation, Sunspot cycle and others. It is observed that the proposed model explains around 75% of inter annual variability (IAV) of the rainfall series of Gangetic West Bengal. The model is efficient in statistical forecasting of South West Monsoon rainfall in the region as verified from independent part of the real data. The statistical forecasts of SWM rainfall for GWB for the years 2012 and 2013 are108.71 cm and 126.21 cm respectively, where as corresponding to the actual rainfall of 93.19 cm 115.20 cm respectively which are within one standard deviation of mean rainfall.

Survey of feral honey bee (Apis mellifera) colonies for Nosema apis in Western Australia

2007 ◽  
Vol 47 (7) ◽  
pp. 883 ◽  
Author(s):  
Rob Manning ◽  
Kate Lancaster ◽  
April Rutkay ◽  
Linda Eaton
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Western Australia ◽  
Honey Bees ◽  
Nosema Apis ◽  
The South ◽  
South West ◽  
Feral Populations ◽  
Significant Difference

The parasite, Nosema apis, was found to be widespread among feral populations of honey bees (Apis mellifera) in the south-west of Western Australia. The location, month of collection and whether the feral colony was enclosed in an object or exposed to the environment, all affected the presence and severity of infection. There was no significant difference in the probability of infection between managed and feral bees. However, when infected by N. apis, managed bees appeared to have a greater severity of the infection.

Recurrent landslides in Southern Western Ghats, India: A changing environmental perspective

2021 ◽  
Author(s):  
Asokan Laila Achu ◽  
Girish Gopinath
Keyword(s):  
Western Ghats ◽  
Hot Spot ◽  
Extreme Rainfall ◽  
Vital Role ◽  
Monsoon Period ◽  
Extreme Rainfall Events ◽  
South West ◽  
South West Monsoon ◽  
West Monsoon ◽  
The Western Ghats

<p>The Western Ghats (WG), an elevated passive continental margin along the southwestern coast of India, is the most widely populated biodiversity hot spot in the world. Monsoon climate is prevalent throughout the length of the Western Ghats. The WG region is prone to the occurrence of various hydro-climatic disasters such as extreme rainfall-driven floods and landslides. During the past 100 years, landslides and floods caused by extreme rainfall events in the WG have occurred in 1924 and 1979; but the most disastrous event, in terms of area of impact, loss of life and economic impact, occurred in August 2018. Generally, the south-west monsoon (Indian summer monsoon) occurs in the first week of June and extends up to September and the Indian Meteorological Department (IMD) predicted above-normal rainfall of 13% during the month of August 2018. But the State received an excess of 96% during the period from 1st to 30th August 2018, and 33% during the entire monsoon period till the end of August. The unprecedented heavy rains, storms, floods and associated thousands of landslides have caused exorbitant losses including 400 life losses, over 2.20 lakh people were displaced, and 20000 homes and 80 dams were damaged or destructed. This study aimed to elucidate the reasons behind the thousands of landslides caused in WG using observed and field evidences. Changes in south-west monsoon pattern and rainfall intensity played a vital role in the occurrence of landslides in WG. Further, the extensive causalities are the result of anthropogenic disturbances including landscape alterations and improper landuse practices in the hilly tracks of WG. The major causative factors for series of landslides in various segments of WG is due to hindrance of lower order streams/springs, vertical cutting, intensive quarrying, unscientific rain pits & man-made structures together with erratic rainfall triggered major and minor landslides in various segments of WG. The present investigation concludes that a scientific landuse policy and geoscientific awareness is essential to mitigate the environment.</p>

First study of the Polycladida (Rhabditophora, Platyhelminthes) from the Pacific Coast of Costa Rica

Zootaxa ◽  
2021 ◽  
Vol 4964 (2) ◽  
pp. 363-381
Author(s):  
PATRICIA SOUTULLO ◽  
DANIEL CUADRADO ◽  
CAROLINA NOREÑA
Keyword(s):  
Costa Rica ◽  
Intertidal Zone ◽  
Pacific Coast ◽  
New Records ◽  
Rocky Intertidal ◽  
Animal Kingdom ◽  
Invertebrate Diversity ◽  
Marine Park ◽  
Rocky Intertidal Zone ◽  
The Pacific

In the present work was carried out in the intertidal zone of Las Baulas de Guanacaste National Marine Park (PNMB) located on the Pacific coast of Costa Rica.                The main objective was to contribute to knowledge about the invertebrate diversity of the park, one of the richest bioregions on the planet, about which little is known. This study assesses the Order Polycladida Lang, 1884, a cornerstone of this ecosystem and one of the most cosmopolitan and plastic invertebrate taxa in the animal kingdom.                In total, 57 individuals were collected in the rocky intertidal zone of Carbón and Langosta beaches. Nine different species were identified, of which four are new for Costa Rica: Semonia bauliensis n. sp.; Cryptostylochus sesei n. sp.; Paraplanocera angeli n. sp., Prostheceraeus fitae n. sp.; and five new records: Paraplanocera oligoglena (Schmarda, 1859); Marcusia ernesti Hyman, 1953; Enchiridium magec Cuadrado, Moro & Noreña, 2017; Pseudobiceros bajae (Hyman, 1953); and the genus Boninia spp. 

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