Effect of ambient oxygen on growth and reproduction in Nile tilapia (Oreochromis niloticus)

2008 ◽  
Vol 65 (7) ◽  
pp. 1413-1424 ◽  
Author(s):  
Jeppe Kolding ◽  
Lise Haug ◽  
Sigurd Stefansson
Keyword(s):  
Oxygen Concentration ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Gonadosomatic Index ◽  
Size At Maturity ◽  
Low Oxygen ◽  
Asymptotic Size ◽  
Ambient Oxygen ◽  
Nile Tilapia Oreochromis Niloticus ◽  
First Maturity

Growth, size at maturity, gonadosomatic index (GSI), egg size, and absolute fecundity of Nile tilapia ( Oreochromis niloticus ) were significantly affected by oxygen levels (1.5 ± 1.0, 2.8 ± 1.4, and 6.0 ± 1.8 mg·L–1) in a controlled experiment designed to test the hypothesis (D. Pauly. 1984. J. Cons. Int. Explor. Mer, 41: 280–284) that O2 is the controlling factor for the transition from juvenile to adult in fish, in general, in the context of phenotypic life history plasticity and “stunting” in tilapias. Size at maturity and the estimated asymptotic size decreased with decreasing O2 concentration, as predicted by Pauly’s hypothesis. All fish matured at the same age (18 weeks old), which is in contrast to conventional definitions of stunting. This finding challenges the suggested plasticity in age at first maturity for tilapia. The results also challenge the hypothesis that stunting is a unique recruitment mechanism, as the smaller fish in the group with low oxygen concentration produced smaller and fewer eggs than the larger fish in the group with high oxygen concentration.

scholarly journals The ability of probiotics to ameliorate blood and gonad damage caused by copper toxicity in Nile tilapia (Oreochromis niloticus)

2021 ◽  
pp. 2964-2970
Author(s):  
Alfiah Hayati ◽  
Manikya Pramudya ◽  
Hari Soepriandono
Keyword(s):  
Oreochromis Niloticus ◽  
Blood Cells ◽  
Nile Tilapia ◽  
Hematological Parameters ◽  
Gonadosomatic Index ◽  
Negative Control ◽  
Histological Structure ◽  
Fish Feed ◽  
Negative Effects ◽  
Nile Tilapia Oreochromis Niloticus

Background and Aim: Industrial waste, such as heavy metals, is a major source of water pollution; at high levels, such pollution can reduce river water quality to the extent that it becomes unsuitable for aquaculture of freshwater fish. This study aimed to focus on the effects of copper (Cu) exposure in Nile tilapia (Oreochromis niloticus) and specifically the ability of Lactobacillus-based probiotics supplementation in fish feed to ameliorate damage to gonads and negative effects on red blood cells (RBCs), whole blood cells (WBCs), hematocrit (HCT) levels, hemoglobin (HGB) levels, and malondialdehyde (MDA) levels following such exposure. Materials and Methods: Thirty-two Nile tilapia fish were divided into eight groups: A negative control (without probiotics or Cu), a positive control (with probiotics but without Cu), three treatments with probiotics in feed, and one of three Cu concentrations (0.75, 1.50, or 3.00 mg/L), and three treatments with these three Cu concentrations but without probiotics in feed. The probiotics concentration in feed was 25 mL/kg (1×108 CFU/mL). Feeding was for 15 days, after which the hematological parameters, gonadal (testis) structure, and MDA levels of fish were analyzed. Results: Exposure to Cu significantly (p<0.05) affected fish hematology (decreased HGB, HCT, RBC, and WBC levels) and altered the structure of the testes. However, the addition of probiotics to fish feed significantly (p<0.05) ameliorated these effects on hematology and maintained the histological structure of the gonads. Conclusion: Cu exposure at ≥1.5 mg/L affected the hematologic parameters, gonadosomatic index, MDA levels, and testicular cells and tissue of Nile tilapia. However, probiotics supplementation in fish feed helped ameliorate the negative effects of Cu on these parameters. Thus, the Lactobacillus-based probiotics used in this study were apparently able to neutralize Cu toxicity in Nile tilapia.

The effect of vaccination in controling bacterial disease caused by Aeromonas hydrophila in nile tilapia (Oreochromis niloticus)

2014 ◽  
pp. 27
Author(s):  
Arne A Ratulangi ◽  
Reiny Tumbol ◽  
Hengky Manoppo ◽  
Henneke Pangkey
Keyword(s):  
Survival Rate ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Bacterial Disease ◽  
Immersion Method ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Different Ages ◽  
Motile Aeromonas Septicaemia

This study aims to apply vaccination against bacterial disease. The purpose of vaccination is to trigger the immune respone both non-specific and specific of fish against bacteria Motile Aeromonas Septicaemia (MAS) caused by Aeromonas hydrophila. The vaccination for fish with different ages: 2-3 weeks and 5 weeks were done using immersion method. The fish were re-vaccinated (booster) after two weeks of the first vaccination. The survival rate was < 50 % for juveniles 2-3 weeks and > 50% for juveniles 5 weeks. Survival rate for juveniles 5 weeks was higher than juveniles of 2-3 weeks. This shows that organs of juveniles of 5 weeks were more complete than the 2-3 weeks juveniles. The age of fish is one of the important factors for successfully vaccination. Penelitian ini bertujuan untuk melakukan penerapan vaksinasi terhadap penyakit bakterial. Vaksinasi ditujukan untuk merangsang respon kekebalan non- spesifik dan spesifik pada tubuh ikan terhadap penyakit Motile Aeromonas Septicaemia (MAS) yang disebabkan oleh bakteri Aeromonas hydrophila. Vaksin diberikan pada benih ikan nila yang berbeda umur yaitu 2-3 minggu dan 5 minggu dengan menggunakan metode perendaman. Ikan divaksinasi ulang (booster) setelah 2 (dua) minggu dari vaksinasi yang pertama. Prosentase kelangsungan hidup < 50 % untuk benih umur 2-3 minggu dan > 50% untuk benih umur 5 minggu. Jumlah kematian benih umur 2-3 minggu lebih tinggi dari 5 minggu. Hal ini menunjukkan bahwa fungsi organ benih umur 5 minggu telah lebih lengkap dari pada benih umur 2-3 minggu. Umur ikan merupakan salah satu faktor penting penentu keberhasilan suatu kegiatan vaksinasi.

Effect of low temperature on genomic DNA methylation in Nile tilapia (Oreochromis niloticus)

2013 ◽  
Vol 37 (10) ◽  
pp. 1460 ◽  
Author(s):  
Huaping ZHU ◽  
Maixin LU ◽  
Zhanghan HUANG ◽  
Fengying GAO ◽  
Xiaoli KE ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Low Temperature ◽  
Oreochromis Niloticus ◽  
Genomic Dna ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus
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