scholarly journals Responses of the molluscan fauna to environmental variations in a Halodule wrightii Ascherson ecosystem from Northeastern Brazil

2013 ◽  
Vol 85 (4) ◽  
pp. 1397-1410 ◽  
Author(s):  
KCRISHNA V.S. BARROS ◽  
CRISTINA A. ROCHA-BARREIRA
Keyword(s):  
Seasonal Changes ◽  
Common Species ◽  
Temporal Variations ◽  
Northeastern Brazil ◽  
Halodule Wrightii ◽  
Hypnea Musciformis ◽  
Spatial And Temporal Distributions ◽  
Environmental Variations ◽  
Vertical Variations ◽  
Molluscan Fauna

ABSTRACT This study observed the spatial and temporal distributions of molluscs in a Halodule wrightii meadow, verifying if they respond satisfactorily to seasonal changes in this seagrass ecosystem. Twenty-four species were identified. Chitons were rare, bivalves had greater number of species (11), followed by gastropods (9) which were also the most abundant class (73%). All classes were more abundant in the belowground. The most common species was Tricolia affinis, especially in aboveground. The occurrence of some species in both strata or out of the expected stratum may have been influenced by shallow layer of the sediment considered in this study, hydrodynamic, and low biomass of the studied meadow. According to univariate and multivariate analyses, despite of molluscan descriptors had been related to variables associated with rainfall, the seagrasses had an important role on the seasonal and vertical variations of the molluscan fauna. The biomass of the epiphyte Hypnea musciformis was correlated to temporal variations of the species from aboveground, indicating its secondary role for this community. The molluscs were sensible to environmental variations, and also reflected seasonal changes of the seagrass, showing that damages on these meadows reflect even at lower levels of the marine food web.

scholarly journals Structure of three subtropical bat assemblages (Chiroptera) in the Andean rainforests of Argentina

Mammalia ◽  
2016 ◽  
Vol 80 (1) ◽  
Author(s):  
Mariano S. Sánchez
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Seasonal Changes ◽  
Common Species ◽  
Guild Structure ◽  
Trophic Guild ◽  
Long Tail ◽  
Mist Net ◽  
Yungas Forests

AbstractI evaluated bat assemblages in terms of species richness, relative abundance, trophic guild structure, and seasonal changes at three sites along of the Southern Yungas forests. A total of 854 individuals were captured, representing 25 species of three families, with an effort of 27,138 m of mist net opened per hour. Subtropical assemblages showed a similar structure to those from tropical landmark, with a dominance of frugivorous Phyllostomid; in addition, a few species were abundant, followed by a long tail of less common species. However, subtropical sites differed due to the dominance of the genus

Integrative assessment of the floristic diversity of Gentianaceae in an area of campo rupestre of the Espinhaço Range in the state of Bahia, northeastern Brazil

Phytotaxa ◽  
2021 ◽  
Vol 500 (2) ◽  
pp. 61-94
Author(s):  
JÉSSICA LEÃO BARBOSA TANAJURA ◽  
CAROLINA SANTOS PINHO ◽  
RILQUER MASCARENHAS DA SILVA ◽  
MARIA LUIZA SILVEIRA DE CARVALHO
Keyword(s):  
Field Work ◽  
Common Species ◽  
Predictive Distribution ◽  
Northeastern Brazil ◽  
Campo Rupestre ◽  
Conservation Unit ◽  
Habitat Specificity ◽  
Floristic Similarity ◽  
Espinhaço Range ◽  
Integrative Assessment

This study aimed to assess the diversity of species in the Espinhaço Range (ER), eastern Brazil, using as a model the diverse plant family Gentianaceae and focusing on the Parque Municipal de Mucugê—Projeto Sempre Viva (PMM), a conservation unit with predominance of  “campo rupestre”. For this purpose, fieldwork expeditions were carried out between the years 2016–2018 along with a survey of species of this family recorded for this conservation unit in public databases. For comparative purposes, the listing of species from other five areas of the ER were also surveyed and we modeled the distribution of species endemic to these mountains, taking into account that they have their restrict distribution, high habitat specificity and importance to the ecosystem. The results indicated the presence of 33 species of Gentianaceae for the ER, eight of them occurring in the PMM. Comparatively, the results pointed to a greater floristic similarity between the PMM, Pico das Almas and Catolés, due to the presence of seven common species. Predictive distribution modeling supports high endemicity of the analyzed species, given their low environmental suitability outside the ER. The models also allowed us to identify possible areas showing high Wallacean shortfall for these species. Thus, the results reinforce the importance of field work, access to physical and digital botanical collections and the integrated use of tools for a more reliable survey of biodiversity.

scholarly journals Diel and seasonal changes in the macrozooplankton community of a tropical estuary in Northeastern Brazil

2003 ◽  
Vol 20 (3) ◽  
pp. 439-446 ◽  
Author(s):  
Tâmara de Almeida e Silva ◽  
Sigrid Neumann-Leitão ◽  
Ralf Schwamborn ◽  
Lúcia Maria de Oliveira Gusmão ◽  
Dilma Aguiar do Nascimento-Vieira
Keyword(s):  
Seasonal Changes ◽  
Northeastern Brazil ◽  
Tropical Estuary

Temporal variations of Halodule wrightii meadows and associated fauna near their southern distribution limit in the southwestern Atlantic

2020 ◽  
Vol 63 (3) ◽  
pp. 215-228
Author(s):  
Laura Sordo ◽  
Paulo Lana
Keyword(s):  
Temporal Variations ◽  
Halodule Wrightii ◽  
Associated Fauna ◽  
Benthic Species ◽  
Southern Limit ◽  
Distribution Limit ◽  
Seagrass Biomass ◽  
Sw Atlantic ◽  
Number Of Leaves ◽  
Ecosystem Changes

AbstractHalodule wrightii meadows in Southern Brazil have been regressing in an unsheltered area of the subtropical Paranaguá Bay, near their southern limit in the SW Atlantic, since 2006. To identify early indicators of regression events, we assessed variations in plant and macrobenthic structure in two local meadows under unsheltered and protected conditions. Differences between sites increased after an epiphytic overgrowth of the alga Hincksia mitchelliae at the unsheltered site. Seagrass growth was suppressed and the numbers of burrowing and opportunistic benthic species increased with the increase of algal biomass. In the protected meadow, seagrass biomass and number of leaves changed seasonally, but macrobenthic abundance and species richness remained stable. Ecosystem changes were evident when the unsheltered meadow was already collapsing. The number of leaves per shoot, the horizontal internode length, the abundance and structure of the macrofaunal associations, and the host-epiphyte surface interactions, were the first variables to reflect the early stages of seagrass regression. Our results suggest that the persistence of H. wrightii meadows at their southern distribution limit in the SW Atlantic will be affected by local hydrodynamics and their ability to compete with ephemeral macroalgal species under stress conditions.

Seasonal changes in the chemical composision of the red alga Hypnea musciformis

1973 ◽  
Vol 24 (3) ◽  
pp. 275
Author(s):  
AF Abdel ◽  
NM Abed ◽  
M Edrees
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Chemical Composition ◽  
Seasonal Changes ◽  
Free Amino ◽  
Glucuronic Acid ◽  
Red Alga ◽  
Low Molecular Weight ◽  
Hypnea Musciformis ◽  
Algal Material

Seasonal changes were observed in the chemical composition of the marine red alga Hypnea musciformis. Lipids, cholesterol, and lanosterol were found as constituents of the algal material. No low-molecular weight carbohydrates were found except small amounts of mannitol. The algal hydrolysate was shown to contain galactose, glucose, and xylose in all seasons and was characterized by a high content of glucuronic acid and its lactone in February. Definite seasonal variations were found in the patterns of free amino acids and of amino acid compositions of proteins.

Records of the crangonid shrimp genus Pontocaris Bate, 1888 (Crustacea: Decapoda: Caridea) from Chinese waters, with notes on biology of P. pennata Bate, 1888

Zootaxa ◽  
2008 ◽  
Vol 1807 (1) ◽  
pp. 47
Author(s):  
QINGXI HAN ◽  
XINZHENG LI
Keyword(s):  
Coastal Waters ◽  
Seasonal Changes ◽  
Common Species ◽  
Beibu Gulf ◽  
Chinese Waters ◽  
Océanographic Survey ◽  
Gulf Of Tonkin ◽  
The Mainland Of China ◽  
De Man ◽  
First Time

Based on the material collected mainly by the National Comprehensive Oceanography Survey (1959) and the ChinaVietnam Comprehensive Oceanographic Survey to Beibu Gulf (Gulf of Tonkin) (1959–1960, 1962) from coastal waters of the mainland of China, four Pontocaris species, P. hilarula (De Man, 1918), P. major Chan, 1996, P. pennata Bate, 1888 and P. sibogae (De Man, 1918), are reported in the present paper, of which the former two are reported for the first time from Chinese waters. The seasonal changes of the population of the most common species, P. pennata, are discussed.

scholarly journals Temporal variations of Collembola (Arthropoda: Hexapoda) in the semiarid Caatinga in northeastern Brazil

2013 ◽  
Vol 30 (6) ◽  
pp. 639-644 ◽  
Author(s):  
Aila Soares Ferreira ◽  
Bruno Cavalcante Bellini ◽  
Alexandre Vasconcellos
Keyword(s):  
Temporal Variations ◽  
Northeastern Brazil

scholarly journals Hydroclimatic Controls on the Means and Variability of Vegetation Phenology and Carbon Uptake

2014 ◽  
Vol 27 (14) ◽  
pp. 5632-5652 ◽  
Author(s):  
R. D. Koster ◽  
G. K. Walker ◽  
G. J. Collatz ◽  
P. E. Thornton
Keyword(s):  
Spatial Variation ◽  
Primary Productivity ◽  
Vegetation Type ◽  
Temporal Variations ◽  
Carbon Uptake ◽  
Type Ii ◽  
Vegetation Phenology ◽  
Spatial And Temporal Distributions ◽  
Phenology Model

Abstract Long-term, global offline (land only) simulations with a dynamic vegetation phenology model are used to examine the control of hydroclimate over vegetation-related quantities. First, with a control simulation, the model is shown to capture successfully (though with some bias) key observed relationships between hydroclimate and the spatial and temporal variations of phenological expression. In subsequent simulations, the model shows that (i) the global spatial variation of seasonal phenological maxima is controlled mostly by hydroclimate, irrespective of distributions in vegetation type; (ii) the occurrence of high interannual moisture-related phenological variability in grassland areas is determined by hydroclimate rather than by the specific properties of grassland; and (iii) hydroclimatic means and variability have a corresponding impact on the spatial and temporal distributions of gross primary productivity (GPP).

scholarly journals Anhanguera taxonomy revisited: is our understanding of Santana Group pterosaur diversity biased by poor biological and stratigraphic control?

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3285 ◽  
Author(s):  
Felipe L. Pinheiro ◽  
Taissa Rodrigues
Keyword(s):  
Temporal Variations ◽  
Northeastern Brazil ◽  
Shape Variation ◽  
Ontogenetic Changes ◽  
Geometric Morphometric ◽  
Considerable Difficulty ◽  
Faunal Turnover ◽  
Definition Of ◽  
Almost All ◽  
New Diagnosis

Background Anhanguerids comprise an important clade of pterosaurs, mostly known from dozens of three-dimensionally preserved specimens recovered from the Lower Cretaceous Romualdo Formation (northeastern Brazil). They are remarkably diverse in this sedimentary unit, with eight named species, six of them belonging to the genus Anhanguera. However, such diversity is likely overestimated, as these species have been historically diagnosed based on subtle differences, mainly based on the shape and position of the cranial crest. In spite of that, recently discovered pterosaur taxa represented by large numbers of individuals, including juveniles and adults, as well as presumed males and females, have crests of sizes and shapes that are either ontogenetically variable or sexually dimorphic. Methods We describe in detail the skull of one of the most complete specimens referred to Anhanguera, AMNH 22555, and use it as a case study to review the diversity of anhanguerids from the Romualdo Formation. In order to accomplish that, a geometric morphometric analysis was performed to assess size-dependent characters with respect to the premaxillary crest in the 12 most complete skulls bearing crests that are referred in, or related to, this clade, almost all of them analyzed first hand. Results Geometric morphometric regression of shape on centroid size was highly statistically significant (p = 0.0091) and showed that allometry accounts for 25.7% of total shape variation between skulls of different centroid sizes. Premaxillary crests are both taller and anteroposteriorly longer in larger skulls, a feature consistent with ontogenetic growth. A new diagnosis is proposed for Anhanguera, including traits that are nowadays known to be widespread within the genus, as well as ontogenetic changes. AMNH 22555 cannot be referred to “Anhanguera santanae” and, in fact, “Anhanguera santanae”, “Anhanguera araripensis”, and “Anhanguera robustus” are here considered nomina dubia. Discussion Historically, minor differences in crest morphology have been used in the definition of new anhanguerid species. Nowadays, this practice resulted in a considerable difficulty in referring well-preserved skulls into known taxa. When several specimens are analyzed, morphologies previously believed to be disparate are, in fact, separated by a continuum, and are thus better explained as individual or temporal variations. Stratigraphically controlled excavations on the Romualdo Formation have showed evidence for faunal turnover regarding fish communities. It is thus possible that some of the pterosaurs from this unit were not coeval, and might even represent anagenetic morphotypes. Unfortunately, amateur collecting of Romualdo Formation fossils, aimed especially at commerce, resulted in the lack of stratigraphic data of virtually all its pterosaurs and precludes testing of these further hypotheses.

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