Fishes of a shallow tropical mangrove estuary, Gazi, Kenya

1996 ◽  
Vol 47 (7) ◽  
pp. 857 ◽  
Author(s):  
EN Kimani ◽  
GK Mwatha ◽  
EO Wakwabi ◽  
JM Ntiba ◽  
BK Okoth
Keyword(s):  
Diversity Indices ◽  
Ecological Diversity ◽  
Muddy Sand ◽  
Beach Seine ◽  
Commercial Fish ◽  
Mangrove Estuary ◽  
Fish Juveniles ◽  
The Mean ◽  
Sandy Substratum ◽  
Density And Biomass

The composition and abundance of teleosts in an estuarine mangrove bay, sampled with a beach seine-net, are described. Site 1, at the mouth of a small river, was fringed by mangroves and had a silty substratum; Site 2 was also mangrove-fringed but had a sandy substratum and seagrass patches; Site 3 had a muddy sand substratum and also supported seagrasses. In total, 128 teleost species belonging to 50 families were identified in samples collected over 12 months. Gerreidae, Atherinidae and Clupeidae accounted for 78.5% of the total number of fish. Juveniles were found for 63% of the species. Of the fish species found, 44% were species associated with coral reefs. The mean numbers of species were similar at all sites, despite the differences in substratum type. Ecological diversity indices were higher, and fish density and biomass were lower, in the mangrove-fringed silt site than in the seagrass sites. Mean number of species was highest in February and June. Most families of commercial fish sought by fishers in the area were represented in the samples.

THE NUMBER AND QUALITATIVE CHARACTERISTICS OF FRY FISH IN SHALLOW COASTAL WATERS OF THE VOLGA IN THE SUMMER-AUTUMN PERIOD OF 2012

2017 ◽  
pp. 65-73
Author(s):  
Edward Vladimirovich Nikitin
Keyword(s):  
Fish Species ◽  
Coastal Waters ◽  
Caspian Sea ◽  
The Caspian Sea ◽  
Volga River ◽  
Commercial Fish ◽  
Autumn Period ◽  
Fish Juveniles ◽  
Qualitative Characteristics ◽  
Shallow Coastal Waters

Shallow coastal waters of the Volga river is a flooded feeding area for fish juveniles of nonmigratory fish species. There takes place annual downstream migration of fluvial anadromous fish species from spawning grounds of the Volga river to the Northern Caspian Sea. The most important factors determining the number and qualitative characteristics of fry fishes are the level of the Caspian Sea (currently having a tendency to the lowering), hydrological and thermal regimes of the Volga river. Researches were carried out in definite periods of time. In the summer-autumn period of 2012 fry fishes were presented by 19 species (13 of them were commercial species), which belonged to 9 families. The article gives data on all the commercial fish species. In the first decade of July the maximum number of fry fish was registered in the western part of the Volga outfall offshore - in box 247 (19.86 mln specimens/km2), in the eastern part - in box 142 (20.4 mln specimens/km2). The most populous were roach, red-eye, silver bream and bream; size-weight characteristics were better in the areas remoted from the Volga delta. In the third decade of July the quantitative indicators of fry fish on these areas decreased, size-weight characteristics greatly increased. In the second decade of October in the western part of the seaside there were registered increased pre-wintering concentrations of fish juveniles, their qualitative indicators increased, which is evidence to favorable feeding conditions in 2012.

Suppression of Weed Occurrence in a Five-year Corn-earthworm Coculture System

Weed Science ◽  
2020 ◽  
pp. 1-23
Author(s):  
Tao Li ◽  
Jiequn Fan ◽  
Zhenguan Qian ◽  
Guohui Yuan ◽  
Dandan Meng ◽  
...  
Keyword(s):  
Weed Species ◽  
Ecological Benefits ◽  
Economic Output ◽  
Green Foxtail ◽  
Weed Diversity ◽  
The Mean ◽  
Common Purslane ◽  
Species Specific ◽  
Density And Biomass ◽  
Successive Experiment

Abstract The use of a corn-earthworm coculture (CE) system is an eco-agricultural technology that has been gradually extended due to its high economic output and diverse ecological benefits for urban agriculture in China. However, the effect of CE on weed occurrence has received little attention. A five-year successive experiment (2015 to 2019) was conducted to compare weed occurrence in CE and a corn (Zea mays L.) monoculture (CM). The results show that CE significantly decreased weed diversity, the dominance index, total weed density and biomass, but increased the weed evenness index. The five-year mean number of weed species per plot was 8.4 in CE and 10.7 in CM. Compared to those in CM, the five-year mean density and biomass of total weeds in CE decreased by 59.2% and 66.6%, respectively. The effect of CE on weed occurrence was species specific. The mean density of large crabgrass [Digitaria sanguinalis (L.) Scop.], green foxtail [Setaria viridis (L.) Beauv.], goosegrass [Eleusine indica (L.) Gaertn.], and common purslane (Portulaca oleracea L.) in CE decreased by 94.5, 78.1, 75.0, and 45.8%, whereas the mean biomass decreased by 96.2, 80.8, 76.9, and 41.4%, respectively. Our study suggests that the use of CE could suppress weed occurrence and reduce herbicide inputs in agriculture.

A link between ecological diversity indices and measures of biodiversity

2000 ◽  
Vol 130 (1-3) ◽  
pp. 151-156 ◽  
Author(s):  
János Izsák ◽  
László Papp
Keyword(s):  
Diversity Indices ◽  
Ecological Diversity

scholarly journals Occurrence of nematodes of the genus Anisakis in Mediterranean and Atlantic fish marketed in Sardinia

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Daniele Casti ◽  
Christian Scarano ◽  
Maria Cristina Piras ◽  
Paolo Merella ◽  
Sonia Muglia ◽  
...  
Keyword(s):  
Visual Inspection ◽  
Sensu Stricto ◽  
Body Cavity ◽  
The Body ◽  
Type I ◽  
Merluccius Merluccius ◽  
Commercial Fish ◽  
Scomber Colias ◽  
Third Stage ◽  
The Mean

Anisakiasis is a gastrointestinal fishborne zoonosis caused by the ingestion of third stage larvae of the genus <em>Anisakis</em>. Between January and December 2013, 1112 specimens of four commercial fish species (<em>Engraulis encrasicolus, Merluccius merluccius, Scomber colias</em> and <em>Trachurus mediterraneus</em>) marketed in Sardinia (Italy) were examined for <em>Anisakis</em> sp. The overall prevalence of <em>Anisakis</em> spp larvae was 39.9%, all morphologically identified as Type I. <em>Scomber colias</em> showed the highest prevalence (100%), followed by <em>M. merluccius</em> (Atlantic 91.0%, Mediterranean 71.2%), <em>T. mediterraneus</em> (32.7%) and <em>E. encrasicolus</em> (25.9%). All the larvae found in Mediterranean hosts were genetically identified as <em>Anisakis pegreffii</em>, whereas 90.0% of the larvae found in the Atlantic <em>M. merluccius</em> belonged to <em>Anisakis simplex sensu stricto</em> and 10.0% to <em>A. pegreffii</em>. The mean abundance of <em>Anisakis</em> sp. larvae was positively correlated with fish size in <em>E. encrasicolus</em>, Atlantic <em>M. merluccius</em> and local <em>M. merluccius</em>. The prevalence of infection was greater in the body cavity (37.9%) than in the edible muscle (9.4%). However, 1.8% of the examined fish were infected exclusively in the muscle. Therefore, the risk associated to the consumption of raw or undercooked fishery products poses the need of measures such as visual inspection and preventive treatments to guarantee consumers’ health.

scholarly journals COMMUNITY STRUCTURE AND TROPHIC STATUS OF REEF FISH IN NATUNA WATERS

2020 ◽  
Vol 26 (2) ◽  
pp. 69
Author(s):  
Isa Nagib Edrus ◽  
Pratiwi Lestari
Keyword(s):  
Reef Fish ◽  
Fish Community ◽  
Field Research ◽  
Reef Fishes ◽  
Species Number ◽  
Community Structures ◽  
Underwater Visual Census ◽  
The Mean ◽  
Coral Health ◽  
Density And Biomass

A field research on reef fish-community structures in Natuna waters was carried out in November 2015. This research aimed to obtain the trophic composition of reef fishes and its correlation to diversity, density, and biomass. Underwater visual census on several transect areas was used to collect data. Results show that the identified reef fishes were about 100 species of target-reef fish belonging to 18 families and 23 species of indicator-reef fish of the Chaetodontidae family. The mean species number of target reef fish and indicator reef fish were 42 and 7 species, respectively. The  mean density of the target reef fish and indicator reef fish were 0.4 and 0.05 individual per m2, respectively. The mean of the reef fish relative stock was 0.6 ton/ha. The composition of the herbivores mostly found in the resilient coral reefs r was 46.45 % and the omnivores and planktivores as marketable targeted fishes were 18.64 % and 14.28 %, respectively. The most predominant or major families were from herbivorous, carnivorous, planktivorous, and corallivorous fishes, including Scaridae (i.e. Scarus spp), Lutjanidae (i.e. Lutjanus spp.), Caesionidae (i,e. Caesio cuning and Pterocaesio caerulaurea), and Chaetodontidae (i.e. Chaetodon baronessa and Chaetodon octofasciatus). The results suggested that the community structures were quite prospectively implemented for fisheries; however, it may not be promising for coral resilience. Furthermore, the coral health status was at moderate level in regard to the high numbers of corallivorous butterflyfishes.

Do Dietary Diversity Indices Reflect the Nutritional Status of School Aged Children?

2016 ◽  
Vol 53 (4) ◽  
pp. 405 ◽  
Author(s):  
D. J. Nithya ◽  
R. V. Bhavani
Keyword(s):  
Nutritional Status ◽  
School Children ◽  
Dietary Diversity ◽  
Good Health ◽  
Diversity Indices ◽  
Food Groups ◽  
Anthropometric Indices ◽  
Nutrient Adequacy ◽  
School Aged Children ◽  
The Mean

Dietary Diversity, with foods from all food groups is necessary to meet the requirements for essential nutrients which lead to good health. This study examines whether different dietary diversity indices have relationship with the nutritional status of school children aged 6 to 12 years, in two different regions of India: Wardha district, Maharashtra and Koraput district, Odisha. Dietary diversity was calculated using three methods: Individual food scores calculated using 24 hour diet recall (FS<sub>24hr</sub>) data; household dietary diversity using Berry's index (DDI) and food scores calculated using food frequency data (FS<sub>FFQ</sub>). Anthropometric indices were used to assess the nutritional status of school aged children. The Nutrient Adequacy Ratio (NAR) and the Mean Adequacy Ratio (MAR) were calculated as indicators of nutrient adequacy. The relationship between NAR, MAR and three different diversity indices, dietary diversity and anthropometric indices were analyzed. Overall, 38% of 6 to 12 year school aged children were found to be undernourished. The NAR was &lt;70% for all nutrients except protein, energy, thiamine and niacin and MAR was found to be &lt;70% of requirement with mean of 60.5% in both locations. The dietary diversity was found to be relatively better in Wardha when compared with Koraput. The mean diversity indices in both the locations were FS<sub>24hr</sub> 7.56, DDI 89 and FS<sub>FFQ</sub> 62.9. Overall most of the nutrient adequacy and mean adequacy were correlated with all three dietary diversity indices when both locations were studied together. However all three dietary diversity indices failed to show any relationship with nutritional status of school children aged 6-12 years from both locations taken together.

Moon and tide effects on fish capture in a tropical tidal flat

2010 ◽  
Vol 91 (3) ◽  
pp. 735-743 ◽  
Author(s):  
José Amorim Reis-Filho ◽  
Francisco Barros ◽  
José De Anchieta Cintra Da Costa Nunes ◽  
Cláudio Luis Santos Sampaio ◽  
Gabriel Barros Gonçalves De Souza
Keyword(s):  
Tidal Flat ◽  
Dominant Species ◽  
Full Moon ◽  
Diversity Indices ◽  
Tidal Range ◽  
Species Number ◽  
Trophic Groups ◽  
Significant Difference ◽  
The Mean ◽  
Tropical Tidal Flat

The influence of the lunar phases and tidal range on the fish capture was analysed in a tidal flat in Barra do Paraguaçu (Baía de Todos os Santos). The sampling was realized in the flood tide and ebb tide of the spring (full moon) and neap (waning moon) tides, between June 2007 and May 2008. At all sampling occasions, two parallel drags were accomplished to the tidal flat, in the same direction of the current, in a 100 m long area marked on the beach beforehand, using a seine net of 15 m × 2.0 m with a mesh of 12 mm between adjacent knots. A total of 2312 fish specimens were captured (26.5 kg), belonging to 75 species from 45 families. The mean number of captured fish was significantly larger in full moon at ebb tides, while the mean weight in the captures was larger in ebb tides. There was significant difference in number of species, number of fish, richness and diversity between full and waning moons. The number of fish and biomass were significantly different between tides. Significant differences were found in community structure regarding trophic groups in relation to tide and moon, although the classic diversity indices did not capture this effect between tides. Furthermore, it was possible to identify preferences of occurrence related to the change of tide in dominant species.

Total Organochlorine Content of Fish from the Great Lakes

1993 ◽  
Vol 76 (4) ◽  
pp. 703-706 ◽  
Author(s):  
W Harvey Newsome ◽  
Paul Andrews ◽  
Henry B S Conacher ◽  
R R Rao ◽  
A Chatt
Keyword(s):  
Molecular Weight ◽  
Neutron Activation Analysis ◽  
Great Lakes ◽  
Organochlorine Pesticides ◽  
Lipid Fraction ◽  
Gel Permeation Chromatography ◽  
Commercial Fish ◽  
Gel Permeation ◽  
Organic Chlorine ◽  
The Mean

Abstract Residues of polychlorinated biphenyls (PCBs) and organochlorine pesticides were determined in several species of commercial fish from the Great Lakes and compared to the total organic chlorine determined by neutron activation analysis. The mean organochlorine contents ranged from 44 to 138 ppm (lipid basis) and were 5 to 72 times higher than the contents of PCBs and organochlorine pesticides. Marine fish also contained a large proportion of unidentified organic chlorine. The unknown material in the Great Lakes fish was found to chromatograph with the high molecular weight lipid fraction by gel permeation chromatography.

scholarly journals Discrimination of Picea chihuahuana Martinez populations on the basis of numerous dendrometric, climatic and edaphic traits and genetic diversity

2017 ◽  
Author(s):  
Iliana Karina Dominguez-Guerrero ◽  
Samantha Mariscal-Lucero ◽  
José Ciro Hernández-Díaz ◽  
Berthold Heinze ◽  
José Ángel Prieto-Ruiz ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Discriminant Analysis ◽  
Population Size ◽  
Environmental Conditions ◽  
Diversity Indices ◽  
Ex Situ ◽  
Assisted Migration ◽  
Tree Community ◽  
Southern Central ◽  
The Mean

Background. Picea chihuahuana, which is endemic to Mexico, is currently listed as “Endangered” on the Red List. Chihuahua spruce is only found in the Sierra Madre Occidental (SMO), Mexico. About 42,600 individuals are distributed in forty populations. The populations are fragmented and can be classified into three distinct clusters in the SMO of the two States (south, center and north), each group separated by a distance of about 300 km. The total area covered P. chihuahuana trees is less than 300 ha. A recent study suggested assisted migration as an alternative to the ex situ conservation of P. chihuahuana, taking into consideration the genetic structure and diversity of the populations and also predictions regarding the future climate of the habitat. However, detailed background information is required to enable development of plans for protecting and conserving species and for successful assisted migration. Thus, it is important to identify differences between populations in relation to environmental conditions. The vitality and genetic diversity of populations, which affect vigour, evolution and adaptability of the species, must also be considered. In this study, we examined the P. chihuahuana tree community growing in fourteen different locations, with the overall aim of discriminating the populations and clusters of this species using 22 climatic, 27 edaphic and 15 dasometric variables and three genetic diversity indices. Methods. Each location was represented by one 50 x 50 m plot established in the center of the location in which was measured the climate, soil, dasometric and genetic variables. The putative neutral and adaptive AFLP were used to calculate genetic diversity. Multivariate discriminant analysis including cross-validation was considered to test for significant differences in variables in the southern, central and northern populations and locations of the P. chihuahuana tree community. Spearman's correlation test was used to analyze the relationships between genetic diversity, population size, and the climatic, soil and dasometric variables. Results. The discriminant analysis revealed 22 highly significant variables, which separated the southern, central and northern populations. The mean genetic diversity of P. chihuahuana was significantly correlated with the mean temperature in the warmest month. Genetic diversity of P. chihuahuana calculated with putative adaptive AFLP was not statistically significantly correlated with any environmental factor. Finally, no significant correlations were observed between any of the three genetic diversity indices and population size. Discussion. At least three different ecotypes of P. chihuahuana probably exist, as local adaptation may take place because of the different environmental conditions. Therefore, future reforestation programs should take into account these different ecotypes and environmental conditions.

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