Daphnia (water fleas) belong to the zooplankton group called Cladocerans have sexual reproduction when conditions less favorable that produce diapausing eggs are enclosed in the ephippium. Hatching ephippial eggs in the laboratory is important in ecological, toxicology, genetical, and evolutionary studies. This study aims to improve the current methods of egg hatching from ephippium. Each of 50 ephippium were treated together by placing them in a glass jar and adding 50 mL bleach solution (sodium hypochlorite). Concentrations of sodium hypochlorite used in this experiment were 0%, 0.5%, 1%, 2%, 4% and 8%. These concentration treatments were crossed with the following exposure times (1, 2, 4, 8, 16, and 32 minutes). Culturing was done in 80 mL of artificial Daphnia medium, incubated in constant light and temperatures 20°C for 25 days. There were two repetitions in this experiment that were run at the same time. Result of this experiment showed that pretreatment with 0.5-8% bleach solution significantly increases the yield of total hatch rate of Daphnia magna resting eggs by about 21% over unbleached control. However, there was no significant difference among the bleach treatments. Concentration of bleach solution 0.5%, 1% and 4% significantly accelerated the time period until the first hatching (first day hatching). Difference of exposure time (1-32 minutes) at each concentration treatments were not influence the yield of total hatch and the time period until first hatching.
The research aimed to monitor surface water quality by using water quality index NSF-WQI and accurate biotic index of benthic macroinvertebrate. This study was conducted in September to November 2012 in some water tourism destinations in three regencies, i.e. Jember (three sites), Pasuruan (one site), and Malang (one site), East Java, Indonesia. Each site consisted of three stations (upstream, middlestream and downstream). Reference upstream and middlestream were located in the Meru Betiri National Park (MBNP) Jember. Water quality and benthic macroinvertebrates sampling were conducted in each site. While physical-chemical data consisted of TDS, DO, pH, NO 3 -N, TP and temperature were analyzed to determine the NSF-WQI index. Macrozoobenthic data were analyzed to determine three diversity indices and 11 biotic indices. Results showed that based on parameter of DO, TP, NO 3 -N, TDS and pH, water quality in downstreams were generally lower than upstreams. Upstream to middlestreams of two sites in Jember were good to excellent based on NSF-WQI water quality and biotic indices. Therefore, the water were qualified as drinking water resources and also served as safe recreational water. The accurate biotic indices to surface water quality in this study were % EPT, ASPT, HBI, FBI and % Gastropodes.
This research aimed to determine spore of vesicular-arbuscular mycorrhizae collected from acid dry land of Central Lampung. The character of research was descriptive-explorative. Soil samples were collected by stratified random sampling method. The results indicated that amount of spore at rizospher area reached 33-311 spores/g of soil. There were 8 forms of mycorrhizae spores. The species of mycorrhizae found were Gigaspora margarita, Glomus moseae, Glomus versiforme, Acaulospora sp., Endogone piriformis, Smilacina racemosa, Entrophospora sp. and Scutellospora sp. Further research is needed for the exploitation land improvement of the effectiveness of natural mycorrhizae on acid dry land at Central Lampung.
The objective of this study was to analyze the dynamics and community structure of Cyanobacteria, and trophic status of intensive shrimp culture (Litopenaeus vannamei) ponds in Situbondo based on Trophic Diatom Index (TDI). The ex post facto research was conducted in situ in the hamlet of Pond Mutiara Mas III Klatakan Situbondo, East Java Indonesia. The observation of Cyanobacteria and diatom community structure were conducted weekly during four cycles of shrimp farming ponds. Cycle of shrimp farming ponds is a cultivation period of the shrimps from seed to mature which ranges from 90-120 days. The dependent variables were the density of Cyanobacteria and diatom community, as well as chemical parameters, namely nitrite and orthophosphate. Trophic status was determined using TDI counted from diatom density. All of the data were then classified using cluster and biplot analysis program PAST ver. 3.11 to describe the profile of ecosystem quality. The research results showed that four Genera of Cyanobacteria were identified as Oscillatoria, Anabaena, Microcystis, and Merismopedia during the farming cycles with Oscillatoria was the highest density. Based on the TDI values, the trophic status of the waters in the shrimp ponds was eutrophic until hyper-eutrophic. The water quality decreased along with the length of incubation time.
The purpose of this study was to determine the hydroseeding mulch optimum compositions for germination and productivity of a few species of local plants pioneer in the post-mining land of coal from South Kalimantan. The method used in this research was by hydroseeding technique. The species observed were Crotalaria pallida, Cajanus cajan, Kyllinga monocephala, Paspalum conjugatum, Digitaria sanguinalis and Eleusine indica. Seven variations of mulch were added to the post-mining soil. Planting seeds carried out were monoculture and polyculture. Each composition of mulch was replicated three times resulting in 147 pots. Seed germination was observed for 15 days. The results showed that all species were able to germinate and and grow well in the mulch that was added to the post-mining soil, except Kyllinga monocephala on mulch two, four and five and Digitaria sanguinalis on mulch four. The best mulch for plant growth was characterized by pH of 6.8-7.0, 47-59% organic matter, and energy ranging from 2,337.68 to 3,792.68 Kcal/kg. The highest percentage of germination was observed for Cajanus cajan (56.7%) and Crotalaria pallida (39.4%) on mulch two with germination time of eight and three days after planting. The lowest germination percentage was shown by Kyllinga monocephala at all mulch treatments (up to 30 days after planting). The optimum composition of mulch that could be recommended to accelerate the revegetation was mulch two (pH 7.06 and 59% organic matter), especially for Leguminosae, and mulch seven (pH 6.8 and 47% organic matter), especially for Poaceae and polyculture.
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