Effects of adding EM bacteria and mechanical aeration on water quality, growth and antioxidant status of Meretrix meretrix and Exopalaemon carinicauda farmed in the clam–shrimp polyculture system

2021 ◽  
Author(s):  
Zhidong Zhang ◽  
Yangping Wu ◽  
Yu Zhang ◽  
Yi Cao ◽  
Suhua Chen ◽  
...  
Keyword(s):  
Water Quality ◽  
Antioxidant Status ◽  
Meretrix Meretrix ◽  
Exopalaemon Carinicauda ◽  
Clam Shrimp ◽  
Mechanical Aeration

scholarly journals Association between nocturnal and diurnal aeration in Nile tilapia rearing tanks

2018 ◽  
Vol 40 (1) ◽  
pp. 31176
Author(s):  
Francisco Roberto dos Santos Lima ◽  
Davi De Holanda Cavalcante ◽  
Vanessa Tomaz Rebouças ◽  
Marcelo Vinícius do Carmo e Sá
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Growth Performance ◽  
Soil Quality ◽  
Nile Tilapia ◽  
Water Quality Management ◽  
Fish Growth ◽  
Clear Advantage ◽  
Mechanical Aeration

The present study has assessed the benefits of the association between nocturnal and diurnal aeration of water on Nile tilapia’s culture tanks’ water and soil quality, as well as to fish growth performance. There were control tanks without mechanical aeration. In the nocturnal tanks, the aeration was provided daily from 22:00 h up to 06:00 h. The diurnal tanks were provided with aeration daily from 10:00 h up to 18:00 h. In the nocturnal and diurnal tanks, the culture water was aerated from 10:00 h up to 06:00 h. The concentration of NH3 was significantly lower in the diurnal aerated, and nocturnal + diurnal aerated tanks when compared to the non-aerated tanks. The best water quality management to attain simultaneously high DO2 and low NH3 concentration was the nocturnal + diurnal aeration of water. The nocturnal + diurnal aeration of water has not shown any clear advantage on fish growth performance after 10 weeks when compared to the nocturnal aeration of water. It was concluded that the nocturnal + diurnal aeration of water is a water quality management superior to the nocturnal aeration because it achieves a better water quality 

scholarly journals Effects of C/N Ratio on Water Quality, Growth Performance, Digestive Enzyme Activity and Antioxidant Status of Nile tilapia Oreochromis niloticus (Linnaeus, 1758) in Biofloc Based Culture System

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ammar Dilmi ◽  
Wahid Refes ◽  
Abdellah Meknachi
Keyword(s):  
Water Quality ◽  
Growth Performance ◽  
Culture System ◽  
Antioxidant Status ◽  
Digestive Enzyme ◽  
Quality Parameters ◽  
Clear Water ◽  
Feed Conversion ◽  
Low Weight ◽  
Nile Tilapia Oreochromis Niloticus

A 62-d trial was conducted to evaluate the effects of different C/N ratios on water quality, growth performance, digestives activity, and antioxidant indicators of tilapia fingerlings in BFT systems. Three biofloc treatments (added molasses) with a C/N ratio of 14 (BFT14), 17 (BFT17), and 20 (BFT20) were tested against control in clear-water, each treatment in triplicate. Four hundred twenty tilapias (24.2±0.1 g) were distributed on 12 tanks of 350 L. The dynamics of water quality parameters showed a shift from a predominantly autotrophic to a predominantly heterotrophic biofloc with an increase in the C/N ratio from 14 to 20. The growth and Feed conversion of tilapia were not significantly different between the control, BFT14, and BFT17 groups. A low weight gain and high FCR were found in the BFT20 treatment (0.61±0.07 and 1.11±0.12 g/d) compared to the control (0.84±0.05 and 1±0.07 g/d). Activities of proteases and alpha-amylase in the liver and digestive tract were similar in all treatments. As a measure of stress, CAT and SOD activities did not differ significantly among the four groups. Overall, it was possible to reduce the C/N ratio to14, without negatively affecting the biofloc development, growth performance, and physiological parameters of juvenile tilapia.

Fine structural morphology of immunocytes of some molluscs and insects

1990 ◽  
Vol 48 (3) ◽  
pp. 386-387
Author(s):  
S.G. Pal ◽  
G. Baur ◽  
B. Ghosh ◽  
S. Palit ◽  
S. Modak ◽  
...  
Keyword(s):  
Blood Cells ◽  
Phosphate Buffer ◽  
Room Temperature ◽  
Structural Information ◽  
Uranyl Acetate ◽  
Meretrix Meretrix ◽  
Lead Citrate ◽  
Bivalve Molluscs ◽  
Structural Morphology ◽  
Ultrathin Sections

In recent years some of the blood cells of several molluscs and insects are characterised as immunocytes. Similar cells from a few invertebrates from India have been looked into under conventional TEM to register the ultrastructural features. This type of study is first of its kind in the subcontinent. Immunocytes from bivalve molluscs Meretrix meretrix, Laroellidens marqinalis and two insect species, apterygote Ctenolepism a longicaudata and pterygote Gesonula punctifrons provide a new set of fine structural information which forms a basis of comparison with those studied earlier.Immunocytes have been collected from the fresh live species of bivalve molluscs and insects obtained locally at Calcutta. These were fixed in icecold 2% glutaraldehyde in 0.1M phosphate buffer (pH 7.2-7.4) for 1-2 hours at 4-5°C. Subseguently pellets were post-osmicated in 1% OsO4 at room temperature for 1-2 hours. Following dehydration these were embedded in Araldite mixture in plastic capsules and polymerization was effected for 2 days at 60°C. Ultrathin sections were cut in a ultrotome and sections were double stained with Uranyl acetate and lead citrate. These were viewed in a TEM.

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