scholarly journals Seasonal variation in the copepod community structure from a tropical Amazon estuary, Northern Brazil

2009 ◽  
Vol 81 (2) ◽  
pp. 187-197 ◽  
Author(s):  
André Magalhães ◽  
Natália da R. Leite ◽  
João G.S. Silva ◽  
Luci C.C. Pereira ◽  
Rauquírio M. da Costa
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Seasonal Pattern ◽  
Copepod Community ◽  
Water Conductivity ◽  
Species Dominance ◽  
Amazon Estuary ◽  
Density Values ◽  
Clear Seasonal Pattern ◽  
Northern Brazil

The main purpose of this study was to investigate the seasonal variation of copepod community structure during the months of July, September and November 2003 (dry season) and January, March and May 2004 (rainy season) in the Curuçá estuary, northern Brazil. Samples were collected during neap tides via gentle 200µm mesh net tows from a small powerboat. Measurements of surface water conductivity were accomplished in situ using an electronic conductivimeter and salinity was later obtained through the transformation of the conductivity values. Salinity varied seasonally from 7.2 ± 0.1 to 39.2 ± 1.8 (mean ± standard deviation) and was influenced mainly by differences in the amount of rainfall between the studied sampling seasons. In total, 30 Copepoda taxa were identified and Acartia tonsa comprised the most representative species throughout the entire studied period followed by Acartia lilljeborgii, Subeucalanus pileatus and Paracalanus quasimodo. In the present study, the density values, ecological indexes and copepod species dominance presented a clear seasonal pattern, showing that the studied area may be considered seasonally heterogeneous in relation to the investigated parameters.

Seasonal variation in population and community structure of shrews in a tropical forest of Gabon

2005 ◽  
Vol 21 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Violaine Nicolas ◽  
Patrick Barrière ◽  
Marc Colyn
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Dominant Species ◽  
Abundant Species ◽  
Dry Season ◽  
Reproductive Phenology ◽  
Ecological Constraints ◽  
Species Dominance ◽  
Composition Structure ◽  
Over Time

The composition, structure and reproductive phenology of a shrew community were investigated for 1 y at two neighbouring sites in an undisturbed African forest of south-western Gabon. We captured 717 shrews, belonging to four genera and 10 species. The data were analysed to answer three main questions: (1) to what extent does the shrew abundance vary seasonally? (2) is there a shift in species dominance over time? and (3) does the intensity of breeding activity vary seasonally? The number of species captured varied seasonally and tended to be least during the period of minimal trap success. Trap success for the four most abundant species (Sylvisorex johnstoni, Crocidura batesi, Paracrocidura schoutedeni and Sylvisorex ollula) varied seasonally with a minimum around the long dry season. Sylvisorex johnstoni remained the dominant species throughout the year. Seasonal variation in trap success of shrews might be related, at least partly, to their reproductive characteristics. Litter size, based on embryo counts, ranged from 1–4 among the species. Breeding occurred throughout the year, but its intensity was lower during the long dry season corresponding with the period of higher ecological constraints for shrews.

scholarly journals Community Structure of Pomacentridae fish in Coastal Waters on Malalayang Dua Village of Manado Gulf

2013 ◽  
Vol 1 (3) ◽  
pp. 125
Author(s):  
Valdino M E Rungkat ◽  
Jan FWS Tamanampo ◽  
Jhon L Tombokan
Keyword(s):  
Community Structure ◽  
Species Composition ◽  
Relative Density ◽  
Coastal Waters ◽  
Diversity Index ◽  
Species Dominance ◽  
Number Of Species ◽  
Density Values

ABSTRACT This study was conducted to determine the species composition and commu-nity structure of Pomacentridae (relative density, diversity, dominance and even-ness of species). This research was conducted in waters of the Manado Bay, at Kelurahan Malalayang Dua shore, on August 14th, 2012. The studies was conduc-ted on 2 sites, one has 3 meters depth (01o27'40.5" NL 124o47'32.5" EL) and ano-ther at 10 meters depth (01o27'43.6" NL 124o47'27.8" EL). The results and analysis of data, the total number of species found at a depth of 2 points is 15 species, in which was found at a depth of 3 meters at a depth of 10 species and 15 species discovered 10 meters. The species most commonly found is Pomacentrus brachial and Dascyllus reticulatus. The highest relative density values at a depth of 3 meters is Dascyllus reticulatus (22%) and at depth10 meters is Pomacentrus brachialis (18%). Diversity index at 3 meters depth is 1.941 while at 10 meters is 2.326. The result showed that diversity of Pomacentridae is low at 3 meters depth and average at 10 meters depth which means moderate community hability. At both depths, there was no species dominance and the avenness was stable.   Keywords : Community Structure, Pomacentridae, Manado Gulf   ABSTRAK Penelitian ini dilakukan untuk mengetahui komposisi spesies dan struktur komunitas ikan Pomacentridae (kepadatan relatif, keanekaragaman, dominasi dan kemerataan spesies). Lokasi penelitian di Teluk Manado, tepatnya di perairan depan Kelurahan Malalayang Dua. Penelitian dilakukan pada 2 titik kedalaman yaitu kedalaman 3 meter (01o27’40.5” LU 124 o47’32.5” BT) dan kedalaman 10 meter pada koordinat (01o27’43.6” LU 124 o47’27.8” BT). Metode yang digunakan adalah metode sensus visual, dengan penentuan jalur mengunakan penanda me-teran sepanjang 50 meter yang diletakkan di daerah terumbu karang yang sejajar garis pantai. Hasil penelitian dan analisis data, jumlah total spesies yang ditemu-kan pada 2 titik kedalaman adalah 15 spesies, di mana pada kedalaman 3 meter ditemukan 10 spesies dan pada kedalaman 10 meter ditemukan 15 spesies. Spe-sies yang paling banyak ditemukan adalah Pomacentrus brachialis dan Dascyllus reticulatus. Nilai kepadatan relatif tertinggi pada kedalaman 3 meter ada-lah spe-sies Dascyllus reticulatus 22% dan pada kedalaman 10 meter adalah Pomacentrus brachialis 18%. Indeks keanekaragaman pada kedalaman 3 meter adalah 1,941 sedangkan pada kedalaman 10  meter  dengan  nilai 2,326. Hal  ini  menunjukkanbahwa keanekaragaman ikan Pomacentridae pada kedalaman 3 meter adalah rendah dan pada kedalaman 10 meter keanekaragamannya adalah sedang dengan kestabilan komunitas sedang. Pada ke dua kedalaman ini tidak ada spesies dominasi dan kemerataannya adalah stabil. Kata kunci : struktur komunitas, Pomacentridae, Teluk Manado 1Bagian dari skripsi 2Mahasiswa Program Studi Manajemen Sumberdaya Perairan FPIK-UNSRAT

Effects of a La Niña event on hydrological patterns and copepod community structure in a shallow tropical estuary (Taperaçu, Northern Brazil)

2016 ◽  
Vol 164 ◽  
pp. 128-143 ◽  
Author(s):  
Marcela P. Andrade ◽  
André Magalhães ◽  
Luci C.C. Pereira ◽  
Manuel J. Flores-Montes ◽  
Emarielle C. Pardal ◽  
...  
Keyword(s):  
Community Structure ◽  
La Niña ◽  
Tropical Estuary ◽  
Copepod Community ◽  
La Nina ◽  
Northern Brazil ◽  
La Nina Event

scholarly journals Epsodic paroxysmal hemicrania with seasonal variation: case report and the EPH-cluster headache continuum hypothesis

2001 ◽  
Vol 59 (4) ◽  
pp. 944-947 ◽  
Author(s):  
Germany Gonçalves Veloso ◽  
Alexandre Ottoni Kaup ◽  
Mario F Pietro Peres ◽  
Eliova Zukerman
Keyword(s):  
Case Report ◽  
Seasonal Variation ◽  
Cluster Headache ◽  
Continuum Hypothesis ◽  
Seasonal Pattern ◽  
Paroxysmal Hemicrania ◽  
Conjunctival Injection ◽  
Unilateral Headache ◽  
Clear Seasonal Pattern ◽  
New Hypothesis

Episodic paroxysmal hemicrania (EPH) is a rare disorder characterized by frequent, daily attacks of short-lived, unilateral headache with accompanying ipsilateral autonomic features. EPH has attack periods which last weeks to months separated by remission intervals lasting months to years, however, a seasonal variation has never been reported in EPH. We report a new case of EPH with a clear seasonal pattern: a 32-year-old woman with a right-sided headache for 17 years. Pain occurred with a seasonal variation, with bouts lasting one month (usually in the first months of the year) and remission periods lasting around 11 months. During these periods she had headache from three to five times per day, lasting from 15 to 30 minutes, without any particular period preference. There were no precipitating or aggravating factors. Tearing and conjunctival injection accompanied ipsilaterally the pain. Previous treatments provided no pain relief. She completely responded to indomethacin 75 mg daily. After three years, the pain recurred with longer attack duration and was just relieved with prednisone. We also propose a new hypothesis: the EPH-cluster headache continuum.

scholarly journals Scyphomedusae and Ctenophora of the Eastern Adriatic: Historical Overview and New Data

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 186
Author(s):  
Branka Pestorić ◽  
Davor Lučić ◽  
Natalia Bojanić ◽  
Martin Vodopivec ◽  
Tjaša Kogovšek ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Seasonal Pattern ◽  
Geographical Location ◽  
Distribution Patterns ◽  
Mnemiopsis Leidyi ◽  
Future Studies ◽  
Phenological Data ◽  
Pelagia Noctiluca ◽  
Regional Trends ◽  
Clear Seasonal Pattern

One of the obstacles to detecting regional trends in jellyfish populations is the lack of a defined baseline. In the Adriatic Sea, the jellyfish fauna (Scyphozoa and Ctenophora) is poorly studied compared to other taxa. Therefore, our goal was to collect and systematize all available data and provide a baseline for future studies. Here we present phenological data and relative abundances of jellyfish based on 2010–2019 scientific surveys and a “citizen science” sighting program along the eastern Adriatic. Inter-annual variability, seasonality and spatial distribution patterns of Scyphomedusae and Ctenophore species were described and compared with existing historical literature. Mass occurrences with a clear seasonal pattern and related to the geographical location were observed for meroplanktonic Scyphomedusae Aurelia solida, Rhizostoma pulmo, and to a lesser extent Chrysaora hysoscella, Cotylorhiza tuberculata and Discomedusa lobata. Holoplanktonic Pelagia noctiluca also formed large aggregations, which were seasonally less predictable and restricted to the central and southern Adriatic. Four species of Ctenophora produced blooms limited to a few areas: Bolinopsis vitrea, Leucothea multicornis, Cestum veneris and the non-native Mnemiopsis leidyi. However, differences between Adriatic subregions have become less pronounced since 2014. Our results suggest that gelatinous organisms are assuming an increasingly important role in the Adriatic ecosystem, which may alter the balance of the food web and lead to harmful and undesirable effects.

Seasonal variation in births in rural East Pakistan

1972 ◽  
Vol 4 (1) ◽  
pp. 107-116 ◽  
Author(s):  
John Stoeckel ◽  
A. K. M. Alauddin Choudhury
Keyword(s):  
Seasonal Variation ◽  
Social Factors ◽  
Seasonal Pattern ◽  
Seasonal Patterns ◽  
First Order ◽  
Monthly Temperature ◽  
Monthly Distribution ◽  
Number Of Births

SummaryAn analysis of the monthly distribution of births in two areas of Matlab Thana, East Pakistan, indicates that there is a seasonal variation in births different from what would be expected by chance. The highest proportion of births occur in the last three months of a year and the lowest proportion between May and July. Investigation into some of the environmental and social factors which might contribute to the seasonal pattern revealed the following: mean minimum monthly temperature 9 months before birth was inversely related to the number of births; all occupations had seasonal patterns different from what would be expected by chance and the business and mill-and-office occupations had distributions significantly different from each other; the distribution of births for all pregnancy orders was different from chance and the distribution for first order pregnancies was significantly different from those for third and fourth or higher orders.

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