Guild composition and habitat use by Tetraodontiformes (Teleostei, Acanthopterygii) in a south-western Atlantic tropical estuary

2015 ◽  
Vol 96 (6) ◽  
pp. 1251-1264 ◽  
Author(s):  
Amanda Carvalho De Andrade ◽  
Sérgio Ricardo Santos ◽  
José Roberto Verani ◽  
Marcelo Vianna

Sampling of the demersal ichthyofauna of Guanabara Bay was conducted bimonthly for 2 years at 10 stations distributed along a hydrobiological gradient. A total of 16,081 Tetraodontiformes specimens were collected, representing 10 species distributed among Ostraciidae, Monacanthidae, Tetraodontidae and Diodontidae. Tetraodontiformes appear to be well adapted to hydrological variations and inhospitable conditions prompted by intense eutrophication. However, abiotic factors traditionally considered important in estuarine community structure play a secondary role in the distribution of Tetraodontiformes. The type of sediment appears to be the most important physical factor but acts only as an indicator of ecological domain. The low explanatory power of physicochemical variables, in addition to the relative stability of the bay's ichthyofauna, suggests an influence of biological parameters. The species exhibited wide variation in their use of Guanabara Bay and utilized it as a resting, feeding and growing area. Among the species captured, Stephanolepis hispidus, Lagocephalus laevigatus, Sphoeroides greeleyi, Sphoeroides testudineus, Sphoeroides tyleri, Chilomycterus reticulatus and Chilomycterus spinosus were categorized as marine estuarine opportunists, and Aluterus heudelotii and Aluterus schoepfii were classified as marine stragglers. Acanthostracion sp. could not be categorized. The boom of C. spinosus indicates an ecological misbalance and must be carefully investigated.

2017 ◽  
Vol 144 ◽  
pp. 71-82 ◽  
Author(s):  
T.V. Rehitha ◽  
N. Ullas ◽  
G. Vineetha ◽  
P.Y. Benny ◽  
N.V. Madhu ◽  
...  

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Alexandre Buzzani ◽  
Rodolfo Paranhos ◽  
Marianne P. Mello ◽  
Fernanda Abreu ◽  
Anderson Aquino dos Santos ◽  
...  

Author(s):  
Robert Y. George ◽  
Robert J. Menzies

SynopsisIn this paper the subject of faunal zonation in the ocean floor from the intertidal, and over the continental shelf, slope and rise and to the abyssal plain is examined on the basis of faunal change at the generic and species level. The region investigated over a period of five years aboard R/V Eastward is a Beaufort-Bermuda transect, approximately 75 kilometres wide and 500 kilometres long and bounded between 32° and 36°N latitude and 64° and 79°W longitude. A new method, involving numerical indices reflecting changes in the composition of taxa, endemism and diversity between adjacent depth levels, was developed for defining faunal boundaries. Isotherms and isobaths utilised by earlier authors for characterising deep-sea boundary on a global scale do not coincide with natural faunal boundaries. This study analyses the vertical distribution of 128 species of isopod crustaceans and 28 species of large epibenthic invertebrates. The zonation patterns seem to correspond with correlations in environmental conditions such as currents, topography and sediments.We suggest four major vertical faunal provinces, characterised at the generic level, namely (1) the Intertidal Faunal Province; (2) the Shelf Faunal Province; (3) the Archibenthal Zone of Transition; and (4) the Abyssal Faunal Province and internal zones within these characterised at the species level. The main aspects of interest include the presence of a narrow ‘meso abyssal zone’ with a species maximum, the demonstration of the true transitional nature of the Archibenthal Zone in biotic and abiotic factors and the characteristic low-biomass Red Clay environment showing definite faunal isolation from the continental margin.


Author(s):  
Paloma de Almeida Rodrigues ◽  
Rafaela Gomes Ferrari ◽  
Rachel Ann Hauser-Davis ◽  
Luciano Neves dos Santos ◽  
Carlos Adam Conte-Junior

(1) Although suffers from intense pollution inputs, Guanabara Bay, the most socioeconomically and environmentally important estuary in Rio de Janeiro, Brazil, is still home to a diverse fauna, including several fish and crab species consumed by humans. The bay presents high sedimentation rates and sediment contamination, further aggravated by dredging processes carried out in recent years. In this context, this study aimed to verify the effect of the dredging process on total mercury (THg) concentrations at Guanabara Bay through swimming crab assessments sampled before (2016), during (2017), and after (2018) the dredging process, and mainly, if the detected concentrations can be harmful to consumer health; (2) Methods: Swimming crab samplings were carried out at the same time and sampling points in 2016, 2017 and 2018 and the total Hg was determined using a Direct Mercury Analyzer (DMA-80, Milestone, Bergamo, Italy); (3) Results: Increased Hg concentrations were observed during the dredging process, decreasing to lower values, close to the initial concentrations, at the end of the process. Some of the investigated abiotic factors favor Hg dynamics in the aquatic environment, while others were positively altered at some of the assessed sampling areas at the end of the dredging process; (4) Conclusions: Although crab Hg levels were below maximum permissible limits for human consumption, it is important to note that these animals are significantly consumed around Guanabara Bay, which may lead to public health issues in the long term.


1994 ◽  
Vol 45 (3) ◽  
pp. 375 ◽  
Author(s):  
SJM Blaber ◽  
DT Brewer ◽  
AN Harris

The demersal fish fauna of the Gulf of Carpentaria was surveyed during November and December 1990. Over 300 species from 85 families were caught by trawling a systematic grid of 107 stations. The absolute mean biomass was 124.8 kg ha-1 (s.e. =44.1) for day trawls and 53.7 kg ha-1 (s.e. =6.0) for night trawls. The overall mean catch rates were 421.3 kg h-1 (s.e. = 128.5) for day trawls and 198.6 kg h-1 (s.e. =21.5) for night trawls. Biomasses were twice as high in the prawn-trawling grounds of Albatross Bay, the south-eastern gulf and Groote Eylandt as they were elsewhere in the gulf. Twenty-five species made up 75% of the biomass; the dominant families were Haemulidae, Carangidae, Leiognathidae and Nemipteridae. Community-structure and distribution patterns were analysed by numerical classification techniques and principal-coordinates analysis. These indicated six main site groups and 15 fish community groups, based on fish species occurrences and biomasses. There was a relationship between fish distribution patterns and depth of water but not other abiotic factors recorded (sediment type, salinity, temperature and turbidity).


2021 ◽  
Author(s):  
Sungeun Lee ◽  
Jackson W Sorensen ◽  
Robin L Walker ◽  
Joanne B Emerson ◽  
Graeme W Nicol ◽  
...  

Viruses shape microbial community structures, impacting metabolic pathways and influencing biogeochemical cycles. Despite their importance, the influence of biotic and abiotic factors on viral community structures across environmental gradients in soil is relatively unknown compared to their prokaryotic hosts. While soil pH strongly influences microbial community structure, it is unclear whether there is a similar influence on soil virus communities. In this study, prokaryotic and viral communities were characterized in soils sampled from the extremes of a long-term pH-manipulated soil gradient (pH 4.5 and 7.5), and viral populations were compared to those in a variety of soil ecosystems ranging in pH (4.0 - 7.5). Prokaryotic and viral community structure were significantly influenced by soil pH at the local scale. Of 1,910 viral operational taxonomic units (vOTUs), 99% were restricted to pH 4.5 or 7.5 soil only. These were compared in gene sharing networks of populations from six other European and North American soil systems. A selection of viral clusters from acidic and neutral pH soils were more associated with those from the local gradient pH 4.5 or 7.5 soils, respectively. Results indicate that as with prokaryotes, soil pH is a factor structuring viral communities at the local and global scale.


2017 ◽  
Vol 5 (2) ◽  
pp. 105
Author(s):  
Ruddy D. Moningkey ◽  
Lawrence J. L. Lumingas ◽  
Unstain N. W. J. Rembet

The present paper describes the soft-bottom macrozoobenthic community structure inhabiting Lembeh Island’s waters (North Sulawesi). Material for the study was collected from 5 stations in October 2013 using a La Motte grab (600 cm2) and subsequently sieved through a 1 mm square mesh sieve. A total of 1147 individuals belonging to 78 species (taxa) of macrozoobenthos  and representative of higher taxonomic groups belonging to 12 phyla were recorded and identified. Univariate analysis showed low abundance of individuals and number of species in the Pintu Kota station which has a black sludge of sediment but Shannon index values at this station is the highest. Instead Motto station relatively far from anthropogenic disturbance showed a high abundance of individuals and number of species but Shannon  index values at this station is the lowest. The station is dominated by Tanais sp at a density of 9533 individuals m-2. Shannon index is less sensitive to measure the effect of anthropogenic disturbances compared with the abundance of individuals and number of species. The multivariate analysis (Cluster Analysis and Correspondence Analysis) managed to separate the three groups (essemblage) makrozoobethos: Group A (Posokan), Group B (Motto) and Group C (Pancoran, Mawali and Pintu Kota). Abiotic factors such as granulometri, physicochemical, hydrodynamics and anthropogenic factors believed to be the factors controlling the formation of the ecological group.Keywords: macrozoobenthos, anthropogenic impact, multivariate analysis, Lembeh Island.   ABSTRAKTulisan ini menggambarkan struktur komunitas makrozoobentos substrat lunak yang menghuni perairan Pulau Lembeh (Sulawesi Utara). Materi untuk studi ini dikumpulkan dari 5 stasiun pada Oktober 2013 dengan menggunakan grab La Motte (600 cm2) dan kemudian disaring dengan saringan berukuran 1 mm persegi mata saringan. Sebanyak 1147 individu yang termasuk dalam 78 spesies (taksa) makrozoobentos dan mewakili 12 fila atau grup taksonomi telah dicatat dan diidentifikasi. Analisis univariat menunjukkan rendahnya kelimpahan individu dan jumlah spesies di stasiun Pintu Kota yang memiliki sedimen lumpur berwarna hitam tetapi nilai indeks Shannon di stasiun ini adalah yang tertinggi. Sebaliknya di stasiun Motto yang relatif jauh dari gangguan antropogenik menunjukkan tingginya kelimpahan individu dan jumlah spesies tetapi nilai indeks Shannonnya adalah yang terendah. Stasiun ini didominasi oleh Tanais sp dengan kepadatan 9533 individual m-2. Indeks Shannon kurang peka mengukur pengaruh gangguan antropogenik dibandingkan dengan nilai kelimpahan individual dan jumlah spesies. Analisis multivariat (Analysis Kluster dan Analisis Korespondensi) berhasil memisahkan 3 grup (essemblage) makrozoobetos: Grup A (Posokan), Grup B (Motto) dan Grup C (Pancoran, Mawali dan Pintu Kota). Faktor abiotik seperti granulometri, hidrodinamika dan fisika-kimia perairan serta faktor antropogenik diduga merupakan faktor-faktor pengendali pembentukan grup ekologis tersebut.Kata kunci: makrozoobentos, dampak antropogenik, analisis multivariat, Pulau Lembeh.  


Sign in / Sign up

Export Citation Format

Share Document