scholarly journals Species composition and diversity of cast net fisheries in New Calabar River, Niger Delta, Nigeria

2018 ◽  
Vol 4 (1) ◽  
pp. 19-26 ◽  
Author(s):  
HE Dienye ◽  
OA Olopade ◽  
SA Toby
Keyword(s):  
Decapod Crustacean ◽  
Abundant Species ◽  
Diversity Indices ◽  
Fish Stock ◽  
Base Line ◽  
Fisheries Resources ◽  
Fish Samples ◽  
Catch Composition ◽  
Rivers State ◽  
Management And Conservation

A study on the catch composition and diversity of cast net fisheries was conducted between May and August, 2017 in the New Calabar River, Rivers state, using cast net of varying mesh sizes (1.5mm and 2.5mm). Fish samples were collected from three sampling stations, viz. Station1- Aluu, Station 2- Choba and Station 3- Iwofe. The fish species recorded comprised of 26 species under 11 families, and one decapod crustacean. The three most abundant species were; Coptodon guineensis (25.11%), Coptodon zilli (18.56%) both from the Cichlidae family, and Penaeus nitialis (10.90%) from the Penaeidae family, while the least abundant species was Liza grandisquamis (0.13%) from the Mugilidae family. The diversity indices showed that station 2 recorded the highest number of species (21) while station 1 recorded the lowest with (12) species. Simpson’s indexes of diversity, Simpson’s reciprocal index, Shannon- weiner index, and Pielou’s evenness index, were estimated. This study serves as a base line data which will assist relevant bodies in the management and conservation of fisheries resources in the New Calabar River. It is therefore recommended that for an improved and sustainable exploitation and management of fisheries resources of the New Calabar River, proper monitoring and management for fish stock must be done.J. Biodivers. Conserv. Bioresour. Manag. 2018, 4(1): 19-26

scholarly journals Catch composition of deep-sea resources of commercial importance in the Colombian Caribbean

2019 ◽  
Vol 54 (2) ◽  
pp. 194 ◽  
Author(s):  
Marcela Grijalba-Bendeck ◽  
Jorge Paramo ◽  
Matthias Wolff
Keyword(s):  
Deep Sea ◽  
Unit Area ◽  
Base Line ◽  
Total Biomass ◽  
Sustainable Utilization ◽  
Depth Stratum ◽  
Important Species ◽  
Management Plans ◽  
Catch Composition ◽  
Management And Conservation

Recent studies in the Colombian Caribbean Sea describe the potential for a new deep-sea crustacean fishery between 200 a 550-m depth. In order to support appropriate management plans for their sustainable utilization, the goal of the present study was to identify the catch composition and to detect general trends in the bathymetric distribution of the main four biological categories (crustaceans, teleostean, chondrichthyes and molluscs), in relation to depth strata. A total catch per unit area of 8,759 ind. km-2 and 226 kg km-2 was reported and the major contribution was supported by teleostean fish (89 species; 62% abundance and 73% of total biomass), dominating the depth stratum 200-300 m, followed by crustaceans (36% and 22%, respectively) for deeper waters (> 500 m). Most important species were the fish Coelorinchus caelorhincus (20.2 ind. km-2; 16.7 kg km-2) and the crustaceans Penaeopsis serrata (579 ind. km-2, 7% of the total abundance) and Pleoticus robustus (12.6 kg km-2, 6% of the total biomass). The information obtained is part of a base line required to describing the potential effects of deep-sea fisheries on the ecosystem and supporting future decisions about use, management and conservation of deep resources for this region.

scholarly journals Characterisation of artisanal catches in selected fishing areas of the Lower Tana Delta and Malindi-Ungwana Bay, Kenya

2020 ◽  
Vol 19 (1) ◽  
pp. 45-53
Author(s):  
Mumini Dzoga ◽  
Danny Simatele ◽  
Cosmas Munga
Keyword(s):  
Clarias Gariepinus ◽  
Abundant Species ◽  
Fishing Effort ◽  
North Coast ◽  
Marine Habitat ◽  
North East ◽  
Fisheries Resources ◽  
The North ◽  
Scomberomorus Commerson ◽  
Catch Composition

Shore-based assessment of fisheries resources in Ngomeni, Kipini and Ozi fishing areas of Malindi-Ungwana Bay and the Lower Tana Delta on the north coast of Kenya was conducted from January to December 2017 to establish catch composition, species richness, and fishing effort (catch-rate, number and types of fishing gears and crafts) in the marine, estuarine and riverine habitats. Distinct catch composition (R = 0.27, P < 0.05) was observed across the three habitats. Catch composition differed significantly spatially and seasonally across the three fishing areas, and between the north east (NE) and south east (SE) monsoon seasons (R = 0.332, P < 0.05). The wolf herring, Chirocentrus dorab, was the most abundant fish species in Ngomeni, centrally located in Malindi-Ungwana Bay, while the catfishes, Arius africanus and Clarias gariepinus, were the most abundant species in Kipini and Ozi, respectively. Gillnets operated from dhows (mashua) and fibre-reinforced plastic (FRP) boats in Ngomeni (marine), and canoes using-basket traps in Ozi (riverine), landed significantly larger Spanish mackerel, Scomberomorus commerson, and sea catfish, Arius africanus (Kruskal Wallis test: Df = 2; F = 197.141; p < 0.001; Df = 2, F = 490, p < 0.001), respectively. Species diversity by area in combination with habitat and type of fishing craft showed higher diversity for Ngomeni in the marine habitat with mashua fishing crafts than in Kipini. Significantly different catch rates (Df = 2, F = 10.43, p<0.001; Df = 1, F = 5.897, p < 0.021) were observed in the three (3) fishing areas and during the NE monsoon and the SE monsoon, respectively. Canoes were the most common fishing craft used, especially in Ngomeni, accounting for 37.1%, and 97.5% in Ozi, while mashua crafts accounted for 44.5% of the total fishing craft in Kipini. Monofilament nets were most common in Ngomeni (34.0%) while basket traps dominated the Ozi site at 63.6%. The Kipini area was dominated by handlines (28.8%). It is therefore evident that the three (3) fishing areas of the Malindi-Ungwana Bay and Lower Tana Delta showed significant differences in catch composition and size of fish caught, attributed partly to the variation in habitat types and fishing methods between the sites. Overall, the Ngomeni area was characterized by more advanced fishing craft with the majority powered by engines, including mashua and FRP boats, compared to Kipini and Ozi fishing areas where canoes were dominant.

scholarly journals Strategies of the small-scale fisheries on the Central Amazon floodplain

2002 ◽  
Vol 32 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Carlos Edwar de Carvalho FREITAS ◽  
Vandick da Silva BATISTA ◽  
Antonio José INHAMUNS
Keyword(s):  
Hydrological Cycle ◽  
Small Scale ◽  
Good Tool ◽  
Central Amazon ◽  
Small Scale Fisheries ◽  
Fisheries Resources ◽  
Patterns Of Use ◽  
Target Fish ◽  
Catch Composition ◽  
High Level

A multivariate approach was applied to data of small-scale fisheries developed in Central Amazon, using information about catch composition, environment, fishing gear and season of the hydrological cycle. The correspondence analysis demonstrated to be a good tool for the analysis related multispecies fisheries. The analysis identified patterns of use of fisheries resources by the riverine communities, showing the correlation between the environmental factors and the fishing strategy for the capture of target fish species, indicating the high level of empiric knowledge about the environment and fisheries.

Cyprinid Fishes: An Overview on the Present Status in Meghalaya, India

2020 ◽  
Vol 7 (1) ◽  
pp. 13-22
Author(s):  
Rupak Nath ◽  
◽  
S M Kharbuli
Keyword(s):  
Drainage Basin ◽  
Diversity Indices ◽  
Drainage Basins ◽  
Lower Elevation ◽  
Occasional Occurrence ◽  
Elevation Zone ◽  
Commercially Important ◽  
Cyprinid Fishes ◽  
Catch Composition ◽  
Rivers And Reservoirs

Cyprinid fishes of Meghalaya were investigated from twin drainage basins Brahmaputra and Barak-Surma-Meghna. 27 cyprinid fishes under 14 genus and 7 sub families were recorded from rivers and reservoirs of four different gradient zones. The diversity of Cyprinid fishes was highest with 49% representation of Cyprinids at lower elevation Zone IV below 500 m above MSL and bio diversity indices estimated as H: 3.05, 1-D: 0.10. In contrary lowest diversity with 7% representation of fishes was observed at elevation 1501 to 2000 m above MSL in Zone I with bio diversity indices H: 0.25, 1-D: 0.57. Distribution of commercially important cyprinids under genus Labeo, Systomus and Cirrhinus were found to be restricted to rivers of Barak-Surma-Meghna drainage basin. Catch percentage of cyprinids indicates that 70% of fishes exhibit occasional occurrence and 30% as common occurrence. High percentage of occasional occurrence, low catch composition percentage and with restricted distribution of commercially important fishes to only certain rivers of Barak-Surma-Meghna drainage is an indication of depletion of cyprinid resources in the state and requires taking multi prong conservation measures to protect cyprinid fishes in Meghalaya.

Arthropod community structures of rice ecosystems in the Philippines

1991 ◽  
Vol 81 (4) ◽  
pp. 407-416 ◽  
Author(s):  
K.L. Heong ◽  
G.B. Aquino ◽  
A.T. Barrion
Keyword(s):  
Abundant Species ◽  
Diversity Indices ◽  
Nilaparvata Lugens ◽  
The Philippines ◽  
Arthropod Community ◽  
Dominant Group ◽  
Cropping Patterns ◽  
Cyrtorhinus Lividipennis ◽  
Positive Correlations ◽  
Relative Differences

AbstractThe arthropod community associated with irrigated rice grown in five sites in Luzon Island, Philippines, was analysed using guild categories. Phytophages and predators were predominant in all sites. The phytophage species were mainly Homoptera and dominated by Nephotettix virescens (Distant), N. nigropictus (Stål) (Cicadellidae), and Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth) (Delphacidae). Predators were mainly Heteroptera with Microvelia douglasi atrolineata Bergoth (Veliidae), Mesovelia vittigera (Horváth) (Mesoveliidae), and Cyrtorhinus lividipennis Reuter (Miridae) as the most abundant species. Spiders were the next dominant group with Pardosa pseudoannulata (Böesenberg & Strand) and three species of Tetragnatha the most common. Differences in species diversity between the sites were easily differentiated using diversity indices. The relative differences in arthropod abundance, species richness and diversity may be attributed to the median temperatures, cropping patterns, and diversity in crop stages and germplasm in the sites. Predator-Homoptera correlations were significant in all cases. High positive correlations were obtained for veliids, spiders and Cyrtorhinus lividipennis, in most sites.

scholarly journals I Macroeteroceri della Riserva Naturale Orientata “Laghetti di Marinello” (Sicilia nord-orientale) (Lepidoptera Heterocera)

2012 ◽  
pp. 31-43
Author(s):  
Marco Infusino ◽  
Concetta Calabrò ◽  
Salvatore Saitta ◽  
Stefano Scalercio
Keyword(s):  
Light Source ◽  
Sono State ◽  
Abundant Species ◽  
Diversity Indices ◽  
Climatic Conditions ◽  
Number Of Species ◽  
Sono Stati ◽  
Natural Reserve ◽  
North Eastern ◽  
First Time

Riassunto - Gli scopi di questa ricerca sono quelli di contribuire alla conoscenza della macrolepidotterofauna della Sicilia nord-orientale e di caratterizzare la comunità presente nella Riserva Naturale Orientata “Laghetti di Marinello”. Sono stati effettuati 23 campionamenti tra dicembre 2007 e dicembre 2008 col metodo della caccia al lume. Sono stati catturati 2.537 individui appartenenti a 160 specie, tra cui Chloroclystis v-ata e Laelia coenosa, segnalate per la prima volta in Sicilia; importanti anche le segnalazioni di Calamodes subscudularia, Mythimna languida e M. joannisi, specie piuttosto rare e localizzate. Le specie più abbondanti sono state: Eilema caniola, Eublemma viridula, Idaea filicata, Dysauxes famula e Idaea seriata, che da sole rappresentano il 42% di tutta la comunità, favorite dalla presenza delle rispettive piante nutrici e dall’elevato adattamento alle condizioni climatiche del sito. Il numero di specie e i valori degli indici di diversità indicano un basso livello di biodiversità ospitata, ma la fenologia, le analisi corologica e autoecologica delle specie, insieme ai confronti effettuati con altre faune, indicano una comunità ben caratterizzata e peculiare, diretta espressione delle condizioni abiotiche e biotiche della Riserva.Abstract - Macroheterocera of the Oriented Natural Reserve “Laghetti di Marinello” (north-eastern Sicily) (Lepidoptera: Heterocera). The aim of this research is to contribute to the knowledge of the fauna of macrolepidoptera of north-eastern Sicily and to describe the community present in the Oriented Natural Reserve “Laghetti di Marinello”. 23 samples were carried out from December 2007 to December 2008 using a white vertical sheet reflecting a light source. 2.537 specimens belonging to 160 species were captured. Chloroclystis v-ata and Laelia coenosa were reported for the first time in Sicily, Calamodes subscudularia, Mythimna languida and M. joannisi, very rare and localized species, were also reported. The most abundant species were: Eilema caniola, Eublemma viridula, Idaea filicata, Dysauxes famula and Idaea seriata, which represent the 42% of the whole community and are favoured by the presence of their feeding plants and by their high adaptability to the climatic conditions of the place. The number of species and the values of the diversity indices show a low level of biodiversity, but phenology, chorological and autoecological analysis of the species, with comparisons made with other faunae, show a well characterized and peculiar community, direct expression of the abiotic and biotic conditions of the Reserve.

Spatial patterns of meiofauna and diversity of nematode species assemblages in the Uvea lagoon (Loyalty Islands, South Pacific)

2008 ◽  
Vol 88 (5) ◽  
pp. 931-940 ◽  
Author(s):  
Y. Guo ◽  
M.-N. Helleouet ◽  
G. Boucher
Keyword(s):  
Species Richness ◽  
Spatial Patterns ◽  
Environmental Parameters ◽  
Nematode Species ◽  
Abundant Species ◽  
Diversity Indices ◽  
Species Assemblages ◽  
Leeward Side ◽  
Local Composition ◽  
Total Species Richness

Meiofauna assemblages were investigated at 15 stations on triplicated samples in the Uvea Atoll (Loyalty Islands) in relation to 9 selected environmental parameters. Spatial patterns and variability of meiofauna density were quantified according to location, macrofauna and nematode species assemblages. Meiofauna was dominated by ciliates and nematodes. Densities of total meiofauna and of most of the meiofauna taxa were significantly higher in the back reef North Pléiades stations than the leeward side of the Island. The highest correlation between biotic patterns and environmental parameters that best explains the pattern was with sediment thickness and to a lesser extent organic matter, C/N ratio and depth. One hundred and thirty-four nematode species were identified with four dominant species Chromadora macrolaimoides, an undescribed species of Bolbonema, Daptonema svalbardense and Prochromadorella septempapillata. Three significantly different nematode species assemblages were detected in two of the previously described macrofauna assemblages by cluster analysis and multidimensional scaling methods suggesting that nematodes are more sensible ecological indicators than macrofauna. Diversity indices based on dominance were not significantly different among the three nematode species assemblages but indices based on species richness and rarefaction were significantly higher leeward of Uvea Island. Estimates of total species richness showed no sign of stabilizing with sample size. However, rare species stabilized very quickly, whereas abundant species were added with increasing sampling coverage, indicating a high spatial variability of the local composition of nematodes.

scholarly journals Seasonal variations of the ichthyoplankton assemblage in the Yangtze Estuary and its relationship with environmental factors

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6482 ◽  
Author(s):  
Hui Zhang ◽  
Weiwei Xian ◽  
Shude Liu
Keyword(s):  
Seasonal Variations ◽  
Historical Data ◽  
Wiener Index ◽  
Abundant Species ◽  
Diversity Indices ◽  
Yangtze Estuary ◽  
The Yangtze Estuary ◽  
Factors Affecting ◽  
Annual Variations ◽  
Major Factors

Seasonal variations of the ichthyoplankton assemblage and its relationship with the environment were analyzed based on four seasonal surveys during 2012. Historical data was collected to be compared with results from previous years in order to indicate the seasonal and inter-annual variation of the ichthyoplankton assemblage in the Yangtze Estuary and the adjacent waters. A total of 3,688 individuals belonging to 5 orders, 9 families, and 15 species were collected. No samples were collected in the winter cruise. In 2012, all samples were separated into four ecotypes, which is comparable with the historical data from previous years. The Engraulis japonicus was the most abundant species of all teleost fishes. The E. japonicus was captured in every season and contributed the most to the abundance of ichthyoplankton, which was greater than that of previous years. This result may be due to the periodic fluctuations of E. japonicus or from the displacement of spawning grounds offshore for environmental reasons. The diversity indices of the assemblage were significantly different among seasons, with the number and abundance of the species peaking in the spring, while richness, evenness and diversity indices peaked in the autumn. The species richness of the ichthyoplankton varied from 0.74 to 1.62, the Pielou evenness index varied from 0.10 to 0.49 and the Shannon–Wiener index varied from 0.19 to 1.04. The results of CCA analysis showed that the major factors affecting the ichthyoplankton assemblage differed throughout the seasons. Chla was the key factor affecting the ichthyoplankton in 2012. These seasonal and inter-annual variations likely resulted from migrations associated with fish spawning as well as the environment. Compared with data from previous studies, the relationship between the assemblage structure of ichthyoplankton and corresponding environmental variables have undergone a decline.

scholarly journals GENETIC CHARACTERIZATION OF KISSING GOURAMI (Helostoma temminckii Cuvier, 1829) IN OGAN RIVER, SOUTH SUMATRA INFERRED FROM 16S rRNA AND COI MITOCHONDRIAL GENES

2019 ◽  
Vol 25 (1) ◽  
pp. 37
Author(s):  
Tuty Arisuryanti ◽  
Gregorius Altius Pratama ◽  
Lukman Hakim ◽  
Johan Putra Koentjana ◽  
Fitria Kurnia Nazira
Keyword(s):  
16S Rrna ◽  
Genetic Divergence ◽  
Nucleotide Diversity ◽  
Genetic Characterization ◽  
Haplotype Diversity ◽  
Mitochondrial Genes ◽  
Coi Gene ◽  
Fish Stock ◽  
Fish Samples

Genetic characterization data of kissing gourami are important to understand historical lineage thus enhancing sustainability of the species and to establish regulation for sustainable management of the fish stock in their habitat. However, investigation of genetic characterization of kissing gourami, one of native Indonesian freshwater fishes has poorly understood. Therefore, the aim of this study was to examine genetic characterization of the fish species collected from Ogan River, South Sumatra using partial sequences of two mitochondrial genes, 16S rRNA and COI. The results revealed that for the 621 bp determined in 16S rRNA gene of the samples, five sites were variable, of which one was parsimony informative. Concatenate data revealed three haplotypes with an overall haplotype diversity of 0.833±0.222 and nucleotide diversity of 0.003±0.001. The genetic divergence varied from 0-0.49%. Next, sequence analysis of COI gene exhibited 609 bp which can be translated into 203 amino acids. For the 609 bp sequence determined in the fish samples, three haplotypes were revealed with nine variable sites and two parsimony informatives. Haplotype diversity and nucleotide diversity of the fish samples were 0.833±0.22 and 0.00794±0.0025, respectively. The haplotype divergence between the fish samples was also supported by three nonsynonymous codons. In addition, the genetic divergence varied from 0 % to 1.16 %. The results suggest that genetic variation of the kissing gourami has to be monitored and further studies are needed to compare the same species from different location to know the historical lineage and demography.

scholarly journals Diversity and density of Collembola as influenced by soil physico-chemical properties in fallow land ecosystem of Assam, India

2020 ◽  
Vol 41 (6) ◽  
pp. 1626-1631
Author(s):  
S. Bhagawati ◽  
◽  
B. Bhattacharyya ◽  
B.K. Medhi ◽  
S. Bhattacharjee ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Population Analysis ◽  
Chemical Properties ◽  
Abundant Species ◽  
Diversity Indices ◽  
Organic Carbon Content ◽  
Fallow Land ◽  
Physico Chemical ◽  
Variation Patterns

Aim: To investigate the influence of soil physico-chemical properties on diversity and density of Collembola in an undisturbed fallow land ecosystem. Methodology: Soil sampling was done at monthly intervals to explore the diversity, density and seasonal variation patterns of collembolan population in a fallow land ecosystem during March, 2015 to February, 2016. Collembolans were sampled using Tullgren funnel and identified by standard taxonomic keys. Finally, correlation studies were conducted to assess the influence of different soil physico-chemical properties on diversity and density of collembolans. Results: Five species of Collembola (Cyphoderus sp., Entomobrya sp., Isotoma sp., Folsomia sp. and Hypogastrura sp.) belonging to 4 families (Cyphoderidae, Entomobryidae, Isotomidae and Hypogastruridae) were identified. Cyphoderus sp. was recorded to be the most abundant species contributing 44.29 percent of population. Analysis of different diversity indices revealed higher diversity of collembolans during summer, indicating the presence of relatively stable habitats as compared to other seasons. Summer season also recorded highest density of Collembola. During all the seasons studied, a strong significant positive correlation (P<0.05 and P<0.01) of collembolan population was registered with soil moisture and organic carbon, respectively, however, remaining edaphic factors registered non-significant relationship with the collembolan density and diversity Interpretation: The study clearly indicated that the soil moisture and organic carbon content had a positive relationship with collembolan population and provides a relatively favourable ecological niche for their assemblages.

Sign in / Sign up

Export Citation Format

Share Document