scholarly journals Free living nematode communities as fundamental food for shrimps in the ecological - model of mangrove - shrimp farming ponds, Nam Can district, Ca Mau province

2018 ◽  
Vol 16 (3) ◽  
pp. 581-588
Author(s):  
Nguyen Thi My Yen ◽  
Tran Thanh Thai ◽  
Nguyen Tan Duc ◽  
Ngo Xuan Quang
Keyword(s):  
Seasonal Changes ◽  
Food Source ◽  
Ecological Model ◽  
Shrimp Farming ◽  
Natural Food ◽  
Free Living ◽  
Shrimp Ponds ◽  
Nematode Communities ◽  
Free Living Nematode ◽  
Sampling Times

Free-living nematodes were investigated in order to understand as the natural food for shirmp in the model of ecological mangrove – shirmp farm in mangroves forest according to their composition and densities by seasonal changes. Twenty – four samples of free living nematodes were collected in 8 ecological shrimp ponds (three replicate per pond) in 4 hamlets of Tam Giang commune, Nam Can district, Ca Mau province. Three sampling campaigns were carried out during dry, transitional and rainy seasons in year 2015. In total of 111 nematode genera, 32 families, 10 orders belong to 2 classes of free living nematodes were identified in these mangrove shrimp ponds. Nematode genera richness were quite high, and significant different among three sampling times while their density in the rainy season was considerably higher than such of the dry season. Some genera Pseudolella, Dichronema, Gomphionema, Ponponema, Halalaimus, Sphaerotheristus, Eumorpholaimus, Euleutherolaimus, Parodontophora, Ptycholaimellus, and Sabatieria were typical in these mangrove areas. Especially, two genera Daptonema and Terschellingia develop dominantly in 3 sampling campaigns. Additionally, a significant number of nematode genera were found in all sampling times whereas some other genera only represent in one season. Desities of nematode communities were recognised rather high. Average densities and standard deviation in each mangrove shrimp ponds ranged from 222 ± 122 (individual / 10 cm2) to 7255 ± 5454 (individual / 10 cm2). These characteristic of free living nematode communities in the ecological model of mangrove - shirmp ponds might provide suitable natural food source for shirmps and enrich the benthic foodweb.

Nutrient potential of various Xenorhabdus and Photorhabdus bacteria for a free-living nematode Panagrellus redivivus

Nematology ◽  
2008 ◽  
Vol 10 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Li Cao ◽  
Xuehong Qiu ◽  
Xiaofen Liu ◽  
Xiuling Liu ◽  
Richou Han
Keyword(s):  
Mass Production ◽  
Entomopathogenic Nematodes ◽  
Food Source ◽  
Bacterial Isolates ◽  
Nutrient Source ◽  
Free Living ◽  
First Feeding ◽  
Yeast Strains ◽  
Panagrellus Redivivus ◽  
Free Living Nematode

Abstract Xenorhabdus and Photorhabdus bacteria are symbionts of entomopathogenic nematodes of the genera Steinernema and Heterorhabditis, respectively. To determine the nutrient potential of these bacteria for a free-living nematode, Panagrellus redivivus, a promising food source for first-feeding fish and crustacean, sterile first-stage juveniles (J1) of P. redivivus were fed on various isolates of Xenorhabdus and Photorhabdus bacteria in liquid cultures. Most of the tested bacterial isolates did not support the growth of P. redivivus. However, four of the Xenorhabdus isolates (X. nematophila All, X. bovienii T319, X. beddingii X-7 and X. poinarii KG) provided nutrients for the production of these nematodes in a liquid medium. Two Xenorhabdus isolates (X. beddingii X-7 and X. poinarii KG) even supported mass production of the nematode in a sponge medium, with yields comparable to those with yeast strains. This is the first report that Xenorhabdus bacteria can function as a nutrient source for mass production of nematodes other than their usual symbiotic partners.

Orchard floor management effect on soil free-living nematode communities

Soil Research ◽  
2021 ◽  
Author(s):  
Gil Eshel ◽  
Adrian Unc ◽  
Roey Egozi ◽  
Efrat Shakartchy ◽  
Tirza Doniger ◽  
...  
Keyword(s):  
Free Living ◽  
Nematode Communities ◽  
Orchard Floor Management ◽  
Free Living Nematode ◽  
Management Effect

scholarly journals Multi-correlation between nematode communities and environmental variables in mangrove-shrimp ponds, Ca Mau Province, Southern Vietnam

2020 ◽  
Vol 42 (3) ◽  
Author(s):  
Tran Thanh Thai ◽  
Nguyen Thi My Yen ◽  
Hoang Nghia Son ◽  
Ngo Xuan Quang
Keyword(s):  
Species Richness ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Environmental Variables ◽  
Diversity Index ◽  
Shrimp Farming ◽  
Natural Food ◽  
Nematode Communities ◽  
Correlation Analyses ◽  
The Impact

Multi-correlation between bio-indices of nematode communities and ecological parameters in mangrove-shrimp farming ponds in Tam Giang commune, Nam Can District, Ca Mau Province, Vietnam were investigated. In which, diversities of nematode communities and several environmental variables in eight ponds were considered to process. Our findings underlined the high diversity of nematode communities in mangrove-shrimp farming ponds compared to other mangrove habitats. Nematode diversities provided more oppotunity in natural food for shrimp. Single correlation analyses showed that the species richness index correlated significantly to three variables (salinity, total organic carbon, and total nitrogen), the Margalef diversity index correlated to two variables (salinity, total organic carbon), and the expected number of species for 50 individuals index correlated with one variable (salinity). Results of multi-correlation analyses between the nematode bio-indices and the environmental variables were completely different from those of single-correlation analyses. In multi-correlation analyses, the species richness and the Margalef diversity index correlated to two variables (salinity, total organic carbon), Pielou’s evenness index and Hill indices correlated with dissolved oxygen, also the Hurlbert index correlated to total organic carbon. Hence, it is necessary to pay attention to the impact of complex interactions between the multi-environmental variables and nematode communities. This research aims to explain the differences between single- and multi-correlation for evaluation of the effects of environmental factors on nematodes as well as aquatic organisms. 

scholarly journals Distribution pattern of free living nematode communities in the eight Mekong estuaries by seasonal factor

2013 ◽  
Vol 4 (1) ◽  
pp. 28-33
Author(s):  
Quang Xuan Ngo ◽  
Ngoc Chau Nguyen ◽  
Dinh Tu Nguyen ◽  
Van Lam Pham ◽  
Ann Vanreusel
Keyword(s):  
Distribution Pattern ◽  
River System ◽  
Multivariate Techniques ◽  
Wet Season ◽  
Free Living ◽  
Estuarine Area ◽  
Nematode Communities ◽  
Seasonal Factors ◽  
Free Living Nematode ◽  
Seasonal Factor

The temporal variation of nematode communities in eight mouth stations of the Mekong River system was investigated in order to compare the change between the dry and the wet season. The nematode data was analysed by multivariate techniques such as SIMPROF, MDS, ANOSIM and SIMPER in the software PRIMER v.6 – PERMANOVA.  Our results showed that average dissimilarity between seasons of the nematode communities in each station was high. Seasonal factor did not affect strongly their distribution pattern. Dominant genera Desmodora and Oncholaimellus usually occurred in the sand stations and Parodontophora and Halalaimus were characteristic for the silty group in both seasons. The spatial variations in this estuarine area have an influence that is larger than seasonal factors. Sự phân bố theo thời gian của quần xã tuyến trùng sống tự do vùng cửa sông Mekong được nghiên cứu nhằm đánh giá sự khác biệt của chúng trong mùa mưa và mùa khô. Dữ liệu của tuyến trùng được xử lý và phân tích đa biến như SIMPROF, MDS, ANOSIM và SIMPER bằng phần mềm PRIMER v.6 – PERMANOVA. Kết quả nghiên cứu cho thấy sự khác biệt theo mùa trong quần xã tuyến trùng tại mỗi điểm là khá lớn nhưng yếu tố mùa không ảnh hưởng gì tới mô hình phân bố của chúng. Một số giống ưu thế trong nền đáy cát như Desmodora and Oncholaimellus trong khi đó Parodontophora và Halalaimus thích nghi nền bùn sét phù sa vẫn hiễn diện trong cả 2 mùa. Kết quả nghiên cứu cũng cho thấy sự biến động trong không gian ở đây lớn hơn sự biến động về mùa vụ.

scholarly journals Effect of heavy metals on soil nematode communities in the vicinity of a metallurgical plant in North Slovakia

2015 ◽  
Vol 52 (3) ◽  
pp. 252-260 ◽  
Author(s):  
P. Šalamún ◽  
V. Hanzelová ◽  
D. Miklisová ◽  
T. Brázová
Keyword(s):  
Stress Responses ◽  
Industrial Pollution ◽  
Pollution Source ◽  
Soil Nematode ◽  
Free Living ◽  
Nematode Communities ◽  
Generic Composition ◽  
Free Living Nematode ◽  
Nematode Diversity ◽  
Remote Sites

Abstract The effect of industrial pollution from chromium ferroalloys production on soil free-living nematode assemblages, c-p groups and generic composition was investigated along 7-km transect. From trace elements (Cr, Cu, Ni and Pb), only chromium exceeded the thresholds for uncontaminated soils (10 mg.kg-1) near the pollution source. In contrast mobilizable fraction of Cr has increased with the distance from the pollution source and was found to be positively correlated with Cox, soil pH, and moisture. Generic richness (nematode diversity) was also higher at remote sites. The low contamination has no significant impact on the nematode communities as illustrated by the c-p groups composition and balanced community structure. Widely applied ecological indices SI and EI also proved maturing ecosystem without any significant stress responses

Effects of increasing levels of pharmaceutical penicillin G contamination on structure of free living nematode communities in experimental microcosms

2015 ◽  
Vol 40 (1) ◽  
pp. 215-219 ◽  
Author(s):  
Ahmed Nasri ◽  
Soufiane Jouili ◽  
Fehmi Boufahja ◽  
Amor Hedfi ◽  
Ezzeddine Mahmoudi ◽  
...  
Keyword(s):  
Penicillin G ◽  
Free Living ◽  
Nematode Communities ◽  
Free Living Nematode
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