Effects of Saline Water on Growth and Survival of Mottled Duck Ducklings in Louisiana

1991 ◽  
Vol 55 (3) ◽  
pp. 471 ◽  
Author(s):  
Anne M. Moorman ◽  
Thomas E. Moorman ◽  
Guy A. Baldassarre ◽  
David M. Richard
2020 ◽  
Vol 48 (1) ◽  
pp. 141-149
Author(s):  
Shankar Chandra Mandal ◽  
Shahin Kadir ◽  
Anwar Hossain

Climate change induced salinity intrusion has a global and local effect on the aquaculture production. Thai-Pangas (Pangasius hypophthalmus) has become one of the cheapest protein sources in Bangladesh because of its wide range of environment tolerance, excellent growth and survival rate. Present study was thus conducted to measure the effects of salinity on the growth performance and survival of pangas. For the determination of the effect of salinity on growth and survival, 15-day old fingerlings were reared in 0, 2, 4, 6, 8, 10, 12, 14 and 20‰ for 60 day at laboratory condition. All fish fingerlings in treatment with 20‰ salinity died within 6 hours of stocking while 62.5% mortality was found within 6 hours at 14‰ salinity. No mortality was detected in other treatment groups. Significantly higher specific growth rate was detected at 0, 2 and 4‰ salinity than that of 12 and 14‰ salinity. No significant change in food conversation ratio was found among treatments. No significant difference was observed on proximate composition between and within treatments. Water quality parameters include temperature, dissolved oxygen and pH were 27.23 ± 0.02 °C, 8.33 ± 0.05 mg/L and 8.05 ± 0.03, respectively throughout the experimental period. Thus, the present study suggests the suitability of pangas fingerlings at up to 4‰ saline water with desirable growth rate. Bangladesh J. Zool. 48(1): 141-149, 2020


2017 ◽  
Vol 44 (8) ◽  
pp. 648 ◽  
Author(s):  
Kaya L. Klop-Toker ◽  
Jose W. Valdez ◽  
Michelle P. Stockwell ◽  
Matthew E. Edgar ◽  
Loren Fardell ◽  
...  

Context The severity and prevalence of the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd) is correlated with several environmental variables, including salinity, temperature, and moisture content, which influence the pathogen’s growth and survival. Habitats that contain these environmental variables at levels outside of those optimal for Bd growth and survival may facilitate the survival of susceptible host species. Therefore, manipulation of environmental salinity is a potential management strategy to help conserve Bd-susceptible species. However, host behaviour also influences disease dynamics, and the success of habitat manipulation programs depends on how hosts use this altered habitat. Aims To assess if the Bd-susceptible green and golden bell frog, Litoria aurea, will select waterbodies with a salinity increased to S=3; if this selection is affected by infection; and if a frog’s time in a waterbody of this salinity affects infection load or blood physiology. Methods We conducted a filmed choice experiment and a 3-year field study where infected and uninfected frogs could choose between fresh or saline waterbodies. Key results In both the laboratory experiment and field study, Bd-infected L. aurea spent a significantly greater amount of time in or closer to a waterbody than uninfected frogs. Experimentally infected frogs tended to prefer the saline water over fresh, but their choice of water usage did not differ statistically from uninfected frogs. In the field, frogs began to avoid ponds when salinities rose above S=5. Conclusions Because both wild and captive, and infected and uninfected L. aurea readily selected waterbodies with a salinity of S=3, this salinity could potentially be used as a passive method for reducing the severity of Bd when managing this species. However, further testing is needed to understand the efficacy of this treatment, and care must be taken to prevent salinities rising above S=5, because this level seems to produce an avoidance response and therefore may not be suitable in every location. Implications Manipulation of aquatic habitats may be a worthwhile focus for Bd management in habitats where water level fluctuations are minimal.


2015 ◽  
Vol 7 (2) ◽  
pp. 885-888 ◽  
Author(s):  
M. Ayaz ◽  
K. Sumara ◽  
Kailash H. Vadher ◽  
Ajaj H. Ishakani

The growth and survival of Litopenaeus vannamei post larvae was measured in controlled different salinities condition 35ppt (T1), 40ppt (T2), 45ppt (T3) and 50ppt (T4) were maintained. Group of Shrimp post larvae (weight 0.032 g ± 0.002) were stocked at a density of 35 nos. /aquarium in above salinity ranges. Animals were fed with commercial feed (35% Crude Protein) @ 5% of body weight four times a day. The results indicate that higher SGR was observed in T2 (1.99±0.08) followed by T1 (1.75±0.07), T3 (1.54±0.06) and T4 (1.49±0.17). Highest survival (100 %) was recorded in T1 followed by T2 (96.42%), T3 (94.99%) and T4 (74.21%). From the results of the present study it could be seen that higher salinity significantly reduced the growth and survival of L. vannamei but will also open study area of physiological adaption of animal at higher saline water in performance of organisms.


Author(s):  
Roberto González-De Zayas ◽  
Liosban Lantigua Ponce de León ◽  
Liezel Guerra Rodríguez ◽  
Felipe Matos Pupo ◽  
Leslie Hernández-Fernández

The Cenote Jennifer is an important and unique aquatic sinkhole in Cayo Coco (Jardines del Rey Tourist Destination) that has brackish to saline water. Two samplings were made in 1998 and 2009, and 4 metabolism community experiments in 2009. Some limnological parameters were measured in both samplings (temperature, salinity, pH, dissolved oxygen major ions, hydrogen sulfide, nutrients and others). Community metabolism was measured through incubated oxygen concentration in clear and dark oxygen bottles. Results showed that the sinkhole limnology depends on rainfall and light incidence year, with some stratification episodes, due to halocline or oxycline presence, rather than thermocline. The sinkhole water was oligotrophic (total nitrogen of 41.5 ± 22.2 μmol l−1 and total phosphorus of 0.3 ± 0.2 μmol l−1) and with low productivity (gross primary productivity of 63.0 mg C m−2 d−1). Anoxia and hypoxia were present at the bottom with higher levels of hydrogen sulfide, lower pH and restricted influence of the adjacent sea (2 km away). To protect the Cenote Jennifer, tourist exploitation should be avoided and more resources to ecological and morphological studies should be allocated, and eventually use this aquatic system only for specialized diving. For conservation purposes, illegal garbage disposal in the surrounding forest should end.


2017 ◽  
Vol 11 (3) ◽  
pp. 249
Author(s):  
Lisa Fajar Indriana ◽  
Yuli Afrianti ◽  
Sitti Hilyana ◽  
Muhammad Firdaus Firdaus

Teripang pasir, Holothuria scabra merupakan komoditas hasil laut yang bernilai ekonomis tinggi. Penangkapan berlebihan stok di alam mendorong berkembangnya kegiatan budidaya. Penempelan merupakan fase kritis pada larva teripang karena terjadi peralihan sifat planktonis ke bentik yang memerlukan substrat. Penelitian ini bertujuan untuk mengetahui preferensi penempelan, pertumbuhan, dan sintasan larva H. scabra fase penempelan pada substrat lamun yang berbeda. Penelitian menggunakan metode rancangan acak lengkap dengan perlakuan empat jenis daun lamun berbeda dan lima ulangan. Perlakuan terdiri atas Enhalus acoroides (L-1), Syringodium isoetifolium (L-2), Cymodocea serrulata (L-3), dan Cymodocea rotundata (L-4). Jumlah awal larva sebanyak 1.000 individu dan substrat dirangkai dengan luasan yang sama sebesar 12 cm x 17 cm untuk setiap unit penelitian. Hasil penelitian menunjukkan jenis lamun yang digunakan sebagai substrat berpengaruh secara nyata terhadap preferensi penempelan dan sintasan larva teripang pasir, namun tidak berpengaruh terhadap pertumbuhan. E. acoroides menunjukkan hasil terbaik dengan preferensi penempelan 0,26 ind. cm-2 dan sintasan 10,66%; sehingga layak digunakan sebagai substrat penempelan dalam pembenihan teripang pasir, H. scabra.Holothuria scabra larvae on different seagrass substrates. By: Lisa Fajar Indriana, Yuli Afrianti, Sitti Hilyana, and Muhammad FirdausSandfish Holothuria scabra is marine commodities with a high economic value. Overfishing of natural stocks has compelled an interest to begin aquaculture practice. Settlement is a critical phase for the planktonic larvae as they will transform to benthic form in the presence of substrate. This study aims to evaluate the settlement preferences, growth, and survival rate of H. scabra larvae settled on different seagrass leaves. The research was conducted using the Completely randomized design with four different species of seagrass leaves and five replications. The treatments consist of Enhalus acoroides (L-1), Syringodium isoetifolium (L-2), Cymodocea serrulata (L-3), and Cymodocea rotundata (L-4). Initial number of larvae was 1,000 individuals and the substrate was set with same widthof 12 cm x 17 cm for each unit. Results of the experiment indicated that settlement preference and survival rate of H. scabra larvae was significantly affected by seagrass used as substrate while no significantly differences was observed for growth of larvae. E. acoroides showed the best result with 0.26 ind. cm-2 settelement preference and 10.66% survival rate, so that suitable to be used as settlement substrate in H. scabra hatchery.


2019 ◽  
Vol 118 (8) ◽  
pp. 172-189
Author(s):  
Magreth B Tjizumaue ◽  
Krishna Govender

Due to the absence of appropriate Consumer Protection legislation in Namibia, there seems to be a lack of consumer protection, which may result in consumers being exploited. Since the literature reveals that Consumer Awareness, Consumer Protection, Service Quality and Customer Satisfaction influence Customer Loyalty, the aforementioned relationship was explored among consumers of long-term insurance products in Namibia. The researcher embedded the study in the Services Marketing and User’s Satisfaction/Dissatisfaction theory and developed a framework for creating a more aware consumer and thus contribute to the growth and survival of the long-term insurance industry in Namibia.  A survey was conducted using a questionnaire, among a judgmental sample of 407 long-term insurance consumers in Namibia and Structural Equation Modelling was used to analyse (eight) hypothesized relationships among the research constructs alluded to in the title of this study. In summary, it was ascertained that if the customers are fully aware (have sufficient knowledge of the products and their consumer rights), they will feel protected against unfair business practices. Furthermore, if they perceive having received quality services, they are more likely to be satisfied with the service provider and will therefore, remain loyal.


Sign in / Sign up

Export Citation Format

Share Document