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Median Lethal Salinity (MLS-50 96H ) of certain freshwater aquaculture fish species (Order: Cypriniformes) from coastal mainland of Sundarban, India

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The present study evaluated salinity tolerance of nine commonly cultivated freshwater cyprinids (order: Cypriniformes) from coastal mainland of Sundarban, India, where salinity intrusion is a recurrent phenomenon. After 100% mortality of all the fishes had been obtained from 15 to 20 g l-1 salinity levels in the first phase of range-finding test, the median lethal salinity (MLS-50 96h) was determined for every fishes by direct exposure to various salinities (5-18 g l-1) in laboratory. Among the cyprinid group, the silver barb Barbonymus gonionotus showed greater tolerance to salinity (14.23 g l-1) followed by Cyprinus carpio (13.03 g l-1) and Systomus sarana (12.72 g l-1). Among the Indian major carps, Labeo rohita represented highest salinity tolerance (11.09 g l-1). Among all experimented fishes, Labeo bata exhibited least tolerant to increasing salinity (8.14 g l-1) followed by Catla catla and Hypophthalmichthys molitrix (9.04 and 9.38 g l-1 respectively). The results of the present experiment indicated that salinity plays a significant role in the survival of freshwater stenohaline species and sub-lethal salinities of the most of the species are up to and below 10 g l-1 salinity. Under the changing climate scenario, some freshwater aquaculture species such as Barbonymus gonionotus, Cyprinus carpio, Systomus sarana, Labeo rohita can be encouraged in the Indian Sundarban and other tropical deltas where brackish water intrusion is a frequent phenomenon.
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Median Lethal Salinity (MLS- 50 96H) of certain freshwater
aquaculture fish species (Order: Cypriniformes) from coastal
mainland of Sundarban, India
Received: 29 April 2019 / Accepted: 10 May 2019
© IFSI, Barrackpore, India, 2019
Abstract The present study evaluated salinity
tolerance of nine commonly cultivated freshwater
cyprinids (order: Cypriniformes) from coastal mainland
of Sundarban, India, where salinity intrusion is a
recurrent phenomenon. After 100% mortality of all the
fishes had been obtained from 15 to 20 g l-1 salinity
levels in the first phase of range-finding test, the
median lethal salinity (MLS-50 96h) was determined for
every fishes by direct exposure to various salinities
(5-18 g l-1) in laboratory. Among the cyprinid group, the
silver barb Barbonymus gonionotus showed greater
tolerance to salinity (14.23 g l-1) followed by
Cyprinus carpio (13.03 g l-1) and Systomus sarana
(12.72 g l-1). Among the Indian major carps, Labeo rohita
represented highest salinity tolerance (11.09 g l-1).
Among all experimented fishes, Labeo bata exhibited
least tolerant to increasing salinity (8.14 g l-1) followed
by Catla catla and Hypophthalmichthys molitrix (9.04
and 9.38 g l-1 respectively). The results of the present
experiment indicated that salinity plays a significant role
in the survival of freshwater stenohaline species and
sub-lethal salinities of the most of the species are up to
and below 10 g l-1 salinity. Under the changing climate
scenario, some freshwater aquaculture species such as
Barbonymus gonionotus, Cyprinus carpio, Systomus
sarana, Labeo rohita can be encouraged in the Indian
Sundarban and other tropical deltas where brackish
water intrusion is a frequent phenomenon.
Key words Median lethal salinity (MLS-50 96h);
Cyprinids; Stenohaline fish; Sundarban; Salinity
intrusion
Introduction
Salinity is known to be one of the most important
environmental determinants that influence survival,
growth and distribution of many stenohaline fishes
(Boeuf and Payan, 2001). Changes in ambient salinity
can directly influence fish development at different life
stages (Resley et al., 2006; Zhang et al., 2010), fish
metabolism (Nordlie, 2009) and affect survival, growth
and other physiological functions of freshwater fishes
(Boeuf and Payan, 2001; Luz et al., 2008). During
fluctuation of environmental salinity, freshwater fishes
regulate osmotic pressure by consuming energy (Evans
and Claiborne, 2009), but impulsive changes in salinity
that beyond the tolerance limit cause death of the fish
species (Dubey et al., 2016a).
Increasing inland salinity due to climatic
variability and human activity has major economic,
social and environmental consequences, threatening the
viability of numerous aquaculture dependent rural
communities. Water salinity in aquaculture pond
depends on various natural factors such as rainfall,
evaporation, coastal flooding and storm surges. In
tropical countries, where the climate is characterized by
wet and dry seasons, fluctuations of salinity are very
U. K. Das . S. K. Dubey( ) R. K. Trivedi
Department of Aquatic Environment Management, Faculty of
Fishery Sciences, West Bengal University of Animal and Fishery
Sciences, Kolkata 700094, West Bengal, India
B. K. Chand . M. M. Beg
Directorate of Research, Extension and Farms, West Bengal
University of Animal and Fishery Sciences, Kolkata 700037,
West Bengal, India
e-mail: sourabhkumardb@gmail.com
RESEARCH PAPER JIFSI 2019 51 (1):60-66
Utpal Kumar Das . Sourabh Kumar Dubey . Raman Kumar
Trivedi . Bimal Kinkar Chand . Mirza Masum Beg
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pronounced (Suresh and Lin, 1992; Boyd and Tucker,
1998). It is worth to mention that the occurrence of
accelerated sea level rise and frequent extreme weather
events (coastal flooding, cyclones and storm surges) in
low-lying deltaic regions are responsible for
salinity-mediated water stress on inland freshwater
aquaculture (IPCC, 2007). Due to salinity intrusion in
freshwater aquaculture areas, many freshwater species
were subjected to severe salinity stress and some
species perished due to their inability to cope up with
such extreme conditions (Dubey et al., 2017). Therefore,
it is imperative to find out the salinity tolerance of
freshwater aquaculture species to optimize their basic
conditions for culture.
In the lower part of deltaic West Bengal, India,
many areas in the Sundarban delta .are vulnerable to
saline water inundation during extreme weather events
such as cyclones and storm surges. Earthen
embankments encircling the Sundarban keep the
brackish water away from the island. Saline water
inundation due to the breach of river embankment, sea
level rise and subsequent erosion coupled with frequent
extreme weather events affect freshwater fish culture
inside the coastal mainland, which is basically
freshwater ecosystem (Dubey et al., 2017). It is evident
that the freshwater aquaculture of Sundarban is
dominated by Indian Major Carps (IMCs; Labeo rohita,
Catla catla, and Cirrhinus mrigala) that contribute a
major portions (60%) of the total freshwater fish
production; while combination of other minor carps
(Labeo bata, Barbonymus gonionotus), exotic varieties
and catfishes contribute the rest (Hypophthalmychthys
molitrix, Ctenopharyngodon idella, Cyprinus carpio,
Clarias sp., Pangasius sp) (Dubey et al., 2016b).
The effect of salinity on growth of stenohaline
freshwater species appears to vary among species.
Several researchers have studied the salinity tolerance
of stenohaline freshwater fishes revealing different
results (Kilambi and Zdinak, 1980; Kasim, 1983; Von
Oertzen, 1985; Wang et al., 1997; Pillai et al., 2003; Akther
et al., 2009; Dubey et al., 2015; Dubey et al., 2016a).
Nevertheless, stenohaline freshwater fishes still have
received scant attention particularly in respect of saline
water use for the optimization of aquaculture practices.
This formed the foundation for the current study with
an aim to determine the salinity tolerance of commonly
cultivated freshwater fishes through median lethal
salinity (MLS- 50 96h). The information generated from
the study could be a useful guide for farm site and
species selection and would be of concern in
freshwater environments intruded by saline water in the
coastal West Bengal, especially Indian Sundarban.
Materials and methods
Test animals and acclimation
Nine cultivable freshwater aquaculture species viz.,
Labeo rohita, Catla catla, Cirrhinus mrigala, Cyprinus
carpio, Labeo bata, Systomus sarana,
Hypophthalmichthys molitrix, Ctenopharyngodon
idella and Barbonymus gonionotus were included in
this study. The fish fingerlings were collected from lo-
cal fish seed supplier located at the Basanti block of the
Indian Sundarban (latitude 22°1'13.26"N and longitude
88°41'6.57"E) and transported in oxygenated polythene
bags to the NICRA-climate resilient aquaculture wet
laboratory of West Bengal University of Animal and
Fishery Sciences, India.
At first they were provided with a prophylactic
dip in salt solution (2%) and after that they were stored
in FRP (Fibreglass Reinforced Plastics) tanks (L: W: H =
1.8: 0.8: 0.6 m) filled with fresh water under constant
aeration for one week at the ambient temperature of
27 °C - 30 °C. About 30% of water volume was renewed
at two-day interval period. During this acclimatization
period, fish were offered supplementary pelleted feed
(30% crude protein) ad libitum twice daily (09:00 am and
04:00 pm). The leftover food and faecal matters were
removed by regular siphoning. The fish were starved
for 24 hours (h) before being subjected to salinity
tolerance experiment. fish were weighed (g) and
measured to total length (cm) before commensing the
experiment.
Median lethal salinity (MLS- 50 96h) experiment
The MLS- 50 96h is defined as the salinity at which
survival of test species falls to 50% after 96 h of direct
transfer from fresh water to various test salinities
(Watanabe et al., 1990; Dubey et al., 2016a). In the first
phase, a non-renewal static toxicity bioassay was
carried out to determine the salinity range (Peltier and
Weber, 1985; Reish and Oshida, 1987). The desired
salinities were achieved by mixing brine water (90 g l-1)
with freshwater appropriately and vigorous aeration was
applied to the aquarium for 5 h in order to obtain a
JIFSI 2019 51 (1):60-66 61
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homogeneous salinity concentration. The experiment
was performed in 50-liter glass aquaria (60 cm × 30 cm ×
30 cm: L × W × H) and fingerlings of individual fish were
directly subjected to freshwater followed by 5, 10, 15,
and 20 g l-1 saline water and observed for 96 h. The
aquaria were stocked with ten individuals each with three
replicates per treatment with continuous aeration. After
100% mortality of all the fishes had been obtained from
15 to 20 g l-1 salinity levels in the first phase of the
range-finding test (Fig. 1), a definitive salinity tolerance
test was performed in the second phase to find out the
median lethal salinity concentration.
In the second phase, twelve salinity
concentrations (5, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18 g l-1) each having three replications were applied to
find cumulative mortality percentage (0-100%) followed
by MLS- 50 96h. A freshwater treatment was run
simultaneously as a control. The total length (cm) and
weight (g) of the test species and salinity concentration
used for the MLS- 50 96h experiment is given in Table 1.
Ten individual fish were directly subjected to different
salinity treatments (according to Table 1) and observed
for 4 days. Mortality was recorded at 24, 48, 72 and 96 h
of exposure to each salinity level. The loss of opercular
movement and lack of response to the physical
stimulus were the criteria for the determination of fish
death. Dead fishes were removed at the time of each
observation. During this short-term non-renewal test,
the fish were exposed to a standard photoperiod of 16 h
light: 8 h dark with constant aeration, and their feeding
being stopped before the commencement of the trial
(APHA, 2012). All aquaria were arranged indoors in a
random block design in parallel rows. In order to
prevent fish from jumping out, each aquarium was cov-
ered with a nylon mesh nets.
Water quality
Physico-chemical parameters of water from each
salinity treatments such as temperature (°C), pH,
dissolved oxygen (mg l-1) and salinity (g l-1) were
determined randomly with a digital water analysis
instrument (HANNA, HI 9828, Germany) while
ammonia-nitrogen, NH3-N (mg l-1) and
Table 1 Total length (cm) and weight (g) of experimented fishes and salinities used for median lethal salinity (MLS- 50 96h) experiment
Fish species Total length (cm) Weight (g) Salinity concentration used (g l-1)
Labeo rohita 10.44 ± 0.60 10.31 ± 0.09 5, 8, 9, 10, 11, 12, 13,
Catla catla 6.06 ± 0.24 2.53 ± 0.12 14, 15
Cirrhinus mrigala 9.89 ± 0.10 10.90 ± 0.33
Labeo bata 6.96 ± 0.11 3.81 ± 0.05
Systomus sarana 6.84 ± 0.69 2.77 ± 0.38
Hypophthalmichthys molitrix 9.60 ± 0.30 12.61 ± 0.25
Ctenopharyngodon idella 11.81 ± 0.75 9.67 ± 0.20
Cyprinus carpio 5.94 ± 0.26 2.45 ± 0.06 5, 8, 9, 10, 11, 12, 13,
Barbonymus gonionotus 6.96 ± 0.11 3.81 ± 0.05 14, 15, 16, 17, 18
Table 2 Water quality parameters during median Lethal
Salinity (MLS- 50 96h) experiment
Water quality parameters Unit value
Temperature (°C) 29.91 ± 1.14
pH 8.41 ± 1.26
Dissolved oxygen(mg l-1) 5.50 ± 1.95
Alkalinity (mg l-1) 187.31 ± 10.25
Hardness (mg l-1) 279.59 ± 6.77
Ammonia-nitrogen, NH3-N (mg l-1) 0.22 ± 0.11
Phosphate-phosphorus, PO-
4-P (mg l-1) 0.47 ± 0.12
Note: This is the average value of water quality parameters
recorded from all the species wise salinity treatments
Fig. 1 Cumulative mortality (100%) of different
freshwater aquaculture species in saline water (g l-1) during
range-finding test.
62 JIFSI 2019 51 (1):60-66
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phosphate- phosphorus, PO-
4 -P (mg l-1) were measured
using HACH Spectrophotometer (DR 2800, Germany).
Alkalinity (mg l-1) and hardness (mg l-1) were measured
following APHA (2012). Temperature is an important
factor in limiting the survival and can influence salinity
tolerance of fishes (Gutierre et al., 2013). Temperature
was not controlled during study as the experiment was
performed within indoor laboratory at room
temperature. Ammonia was not controlled in the
experimental tank as no supplementary feed was given
during experiment. However, all the recorded parameters
were found within the acceptable limit and optimum for
fish culture (Boyd and Tucker, 1998) (Table 2).
Data analysis
The MLS- 50 96h was calculated by the probit regression
model by pooling mortality data from replicates within
treatments and was considered to be significantly
different when the corresponding 95% confidence
intervals (CI) did not overlap (Finney, 1971). The probit
regression procedure fits a probit sigmoid dose-response
curve and calculates values (with 95% CI) of the dose
variable that corresponds to a series of probabilities.
All statistical analyses were performed using IBM SPSS
20.0 statistical software.
Results
The estimated MLS- 50 96h and confidence limits
computed using the probit model for nine freshwater
aquaculture fishes is given in Table 3. Survival of fishes
was severely affected only when they were subjected
to salinity of
15 g l-1 and beyond it (Figure 1). In these
cases, 100% mortality was observed within 24 h
exposure.
Among the cyprinid group, the silver barb
Barbonymus gonionotus showed greater tolerance to
salinity (MLS: 14.23 g l-1) followed by Cyprinus carpio
(13.03 g l-1) and Systomus sarana (12.72 g l-1). Among
the IMCs, Labeo rohita represented highest salinity
tolerance (MLS: 11.09 g l-1). Rest of the fishes
demonstrated better survival rate at less than
10 g l-1salinity. Among all experimented fishes,
Labeo bata exhibited least tolerance to higher salinity
(MLS: 8.14 g l-1) followed by Catla catla and
Hypophthalmichthys molitrix. The results indicated
that the sub-lethal salinities of the most of the
freshwater stenohaline fish species are up to and below
10 g l-1 salinity.
Discussions
Decreasing survival rates with increasing salinity is
characteristic of freshwater fishes and was reported by
several authors (Ghosh et al., 1973; Kilambi and Zdinak,
1980; Wang et al., 1997; Pillai et al., 2003; Dubey et al.,
2015; Dubey et al., 2016a). Earlier, Saha et al. (1964)
reported a salinity tolerance limit up to 14 g l-1 for the
IMCs. Ghosh et al. (1973) stated that fingerlings of Catla
catla and Labeo rohita could tolerate salinity up to 12.5
g l-1. The salinity tolerance of Cyprinus carpio reported
by Ghosh and Pandit (1976), Kasim (1983) and Wang et
al. (1997) as 12.6, 8.13 and 10.5 g l-1 salinity respectively.
However, the MLS- 50 96h of Cyprinus carpio obtained
in the present study is higher than the previous reports.
Kasim (1983) showed that the upper incipient lethal
salinity of Cirrhinus mrigala and Labeo fimbriatus 3.54
and 7.07 g l-1 respectively which is lower than the present
study. In consistent to the present investigation, Pillai
et al. (2003) found that beyond 8 g l-1 salinity, Labeo
rohita showed sign of stress and mortality. Kilambi and
Zdinak (1980) observed that Ctenopharyngodon idella
could tolerate up to 16 g l-1 salinity. However, similar to
the study, Von Oertzen (1985) observed that
Hypophthalmichthys molitrix could thrive up to
10 g l-1 salinity. Among the cyprinids, silver barb
Barbonymus gonionotus showed highest tolerance to
salinity that confirmed by the study of Akther et al.
(2009) who have demonstrated that lethal salinity
values of more than 13 g l-1. Optimal salinities for the
survival of freshwater fish appear to vary according to
individual species. The variations in results could be
attributed to the age of the fish, experimental design,
temperature optima and other environmental factors,
genetic stock and genetic differences between distinct
populations (Kefford et al., 2004).
Low survival of freshwater stenohaline fish at
elevated salinity could be due to increasing osmotic
maintenance requirements at higher salinities (Kilambi
and Zdinak, 1980). If environmental salinity changes
suddenly and exceeds the tolerable limit, aquatic life
will die due to an imbalance of osmoregulation (Pfeiler,
1981). Fish exposed to variable salinities, use
approximately 10 - 50% of their available energy to
adjust their homoeostatic balance (Boeuf and Payan,
2001). Most fish species are restricted to freshwater or
the saline medium (stenohaline) but some exhibit
extreme plasticity in their osmoregulatory capacity and
can disperse between the two media (euryhaline)
JIFSI 2019 51 (1):60-66 63
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(Nelson et al., 2016). There are two divisions of
freshwater fish, 'primary' and 'secondary' based on their
presumed evolutionary distributions and their perceived
salinity tolerance. 'Primary freshwater fish' are those
families whose members are very strictly confined to
fresh water based on their perceived physiological
intolerance to salinity and 'secondary freshwater fish'
are those that are generally restricted to fresh water, but
in some cases enter the saline environment for short
periods. The primary freshwater fish such as order:
Cypriniformes which move around wholly in fresh
water are not able to tolerate salinities higher than
9.8 g l-1 (Chervinski, 1984).
Increasing salinity level in freshwater and coastal
mainland caused by climate change induced sea level
rise is now major factor that can influence fish growth
negatively (FAO, 2014). The carp polyculture, the major
counterpart of freshwater aquaculture in the Sundarban
is severely affecting by saline water inundation. It is
worth to mention that in the island of Sundarban, where
the average annual rainfall ranges from 1500 mm to 2000
mm, pond water salinity changes due to high
precipitation during monsoon and high evaporation
during the dry season. Apart from that, breaching of
river embankment due to frequent extreme weather
events and subsequent erosion has been a serious and
emergent problem in the Indian Sundarban region over
the past two decades. As a result, many areas have been
inundated with brackish water, converting fresh water
into the polyhaline zone (Dubey et al., 2017). In this
changed scenario, certain freshwater fish has the wider
potentiality for culture in many brackish water areas of
the Indian Sundarban delta and can be co-cultured with
brackishwater fish.
Conclusions
The results of the present experiment indicated that
salinity plays a significant role in the survival of
freshwater stenohaline fish and sub-lethal salinities of
the most of the species is up to and below 10 g l-1
salinity. In view of the current and future climate
variables, more coastal areas of India are going to
become vulnerable to brackish water inundation. Under
such scenario, some freshwater aquaculture species such
as Barbonymus gonionotus, Cyprinus carpio,
Systomus sarana, Labeo rohita etc can be encouraged
in the Indian Sundarban and other tropical deltas where
brackish water intrusion is a frequent phenomenon. This
study will help farmers to make a decision on species
selection that can facilitate reduction of risks
associated with brackish water inundation.
Understanding the basis of tolerance and adaptation to
increasing environmental salinity conditions can assist
the regional culture industry as well as policymakers to
mitigate predicted impacts of climate change across this
region.
Acknowledgments
The study was supported by the grants from Indian
Council of Agricultural Research (ICAR), Govt. of India
through NICRA (National Innovations on Climate
Resilient Agriculture) project entitled "Development of
Climate Resilient Aquaculture Strategies for Sagar and
Basanti Blocks of Indian Sundarban" implemented by
West Bengal University of Animal and Fishery Sciences
in collaboration with the Sundarban Development Board,
Govt. of West Bengal.
Table 3 Median Lethal Salinity (MLS- 50 96h) of commonly cultivated freshwater fishes in Indian Sundarban region
Scientific name (MLS- 50 96h) Confidence Interval Cox & Nagelkerke R2
(95%) Snell R2
Lower bound Upper bound
Order: Cypriniformes
Labeo rohita 11.09 8.87 11.69 0.37 0.45
Catla catla 9.04 8.27 10.78 0.41 0.55
Cirrhinus mrigala 10.37 8.57 11.83 0.36 0.48
Cyprinus carpio 13.03 11.98 13.81 0.43 0.59
Labeo bata 8.14 7.20 9.89 0.37 0.51
Systomus sarana 12.72 11.38 13.47 0.39 0.55
Hypophthalmichthys molitrix 9.38 8.64 10.01 0.40 0.54
Ctenopharyngodon idella 10.59 8.95 11.15 0.37 0.50
Barbonymus gonionotus 14.23 13.59 14.85 0.65 0.87
64 JIFSI 2019 51 (1):60-66
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References
Akther M, Mollah AR, Kadir M 2009. Laboratory
Investigation on Salinity Tolerance to Barbodes
gonionotus (Bleeker). Progressive Agriculture, 20
(1- 2): 193-200
APHA (American Public Health Association). 2012. Standard
Methods for the Examination of Water and Wastewater
(22nd Ed). American Public Health Association,
American Water Works Association, and Water
Environment Federation, Washington, DC:
Bianco PG, Nordlie F 2008. The salinity tolerance of
Pseudophoxinus stymphalicus (Cyprinidae) and Valencia
letourneuxi (Valenciidae) from western Greece suggests a
revision of the ecological categories of freshwater fishes.
Italian Journal of Zoology, 75 (3): 285-293.
https://doi.org/10.1080/11250000801931753
Bœuf G, Payan P 2001. How should salinity influence fish
growth? Comparative Biochemistry and Physiology Part
C: Toxicology & Pharmacology, 130(4), 411-423.
https://doi.org/10.1016/s1532-0456(01)00268-x
Boyd CE, CS Tucker 1998. Pond aquaculture water quality
management. Kluwer Academic Press, London
Dubey SK, Trivedi RK, Chand BK, Rout SK, Mandal B 2015.
Response of Anabas testudineus (Bloch, 1792) to
salinity for assessing their culture potential in brackish
water inundation prone areas of Indian Sundarbans.
Journal of the Inland Fisheries Society of India, 47 (2):
59-69.
Dubey SK, Trivedi RK, Chand BK, Mandal B, Rout SK 2016a.
The effect of salinity on survival and growth
of the freshwater stenohaline fish spotted snakehead
Channa punctata (Bloch, 1793). Zoology and
Ecology, 26 (4): 282-291.
https://doi.org/10.1080/21658005.2016.1225867
Dubey SK, Chand BK, Trivedi RK, Mandal B, Rout SK 2016b.
Evaluation on the prevailing aquaculture practices in the
Indian Sundarban delta: An insight analysis. Journal of
Food, Agriculture & Environment, 14 (2): 133-141
Dubey SK, Trivedi RK, Chand BK, Mandal B, Rout SK 2017.
Farmers' perceptions of climate change, impacts on
freshwater aquaculture and adaptation strategies in
climatic change hotspots: A case of the Indian Sundarban
delta. Environmental Development, 21: 38-51.
https://doi.org/10.1016/j.envdev.2016.12.002
Evans DH, Claiborne JB 2009. Osmotic and ionic regulation in
fishes, pp. 295-366. In Evans, D. H. (ed), Osmotic and
ionic Regulation: Cells and Animals. CRC Press, Boca
Raton
FAO 2014. The State of World Fisheries and Aquaculture:
Opportunities and Challenges. Food and Agriculture
Organization of the United Nations, Rome
Finney DJ 1971. Probit Analysis. (3rd ed). Cambridge
University Press, Cambridge
Ghosh AN, Pandit PK 1976. A note on the salinity tolerance of
common carp, Cyprinus carpio Linn. under Indian
condition. Journal of the Inland Fisheries Society of
India, 8: 115-116
Ghosh AN, Ghosh SR, Sarkar NN (1973). On the salinity
tolerance of fry and fingerlings of Indian major carps.
Journal of the Inland Fisheries Society of India, 5,
215-217
Kasim MH (1983). Salinity tolerance of certain freshwater fishes.
Indian Journal of Fisheries, 30, 46-54
Kefford BJ, Papas PJ, Metzeling L, Nugegoda D (2004). Do
laboratory salinity tolerances of freshwater animals
correspond with their field salinity? Environmental
Pollution, 129(3), 355-362
https://doi.org/10.1016/j.envpol.2003.12.005
Kilambi RV, Zdinak A (1980). The effects of acclimation on the
salinity tolerance of grass carp, Ctenopharyngodon idella
(Cuv. and Val.). Journal of Fish Biology, 16(2), 171-175
https://doi.org/10.1111/j.1095-8649.1980.tb03696.x
Luz RK, Martínez-Álvarez RM, De Pedro N, Delgado MJ (2008).
Growth, food intake regulation and metabolic
adaptations in goldfish (Carassius auratus) exposed to
different salinities. Aquaculture, 276(1-4), 171-178.
https://doi.org/10.1016/j.aquaculture.2008.01.042
Nelson JS, Grande TC, Wilson MVH (Eds.) (2016). Fishes of
the World, 5th Edition. New Jersey: John Wiley & Sons
Nordlie FG (2009). Environmental influences on regulation of
blood plasma/serum components in teleost fishes: a
review. Reviews in Fish Biology and Fisheries, 19(4),
481-564
Peltier WH, CI Weber (1985). Methods for Measuring the Acute
Toxicity of Effluents to Freshwater and Marine
Organisms. (2nd ed.) EPA 600/4-85/013. Washington,
DC: U.S. Environmental Protection Agency
Pfeiler E (1981). Salinity tolerance of leptocephalous larvae
and juveniles of the bonefish (Albulidae:Albula) from the
Gulf of California. Journal of Experimental Marine
Biology and Ecology, 52(1), 37-45.
https://doi.org/10.1016/0022-0981(81)90169-6
Pillai D, Jose S, Mohan MV, Joseph A (2003). Effect of Salinity
on Growth and Survival of Rohu, Labeo rohita (Ham.)
under Laboratory and Field Conditions. Fishery
Technology, 40(2), 91-94
Reish DL, Oshida PS (1987). Manual of methods in aquatic
environment research, Part 10: short-term static
bioassays. Rome: Food and Agriculture Organization of
the United Nations
Resley MJ, Webb KA, Holt GJ (2006). Growth and survival of
juvenile cobia, Rachycentron canadum, at different
salinities in a recirculating aquaculture system.
Aquaculture, 253(1-4), 398-407.
https://doi.org/10.1016/j.aquaculture.2005.08.023
Saha KC, Chakraborty DN, De BK, Chakraborty SJ Jr (1964).
Studies on the salinity tolerance of Indian Major Carps
in captivity. Indian Journal of Fisheries, 12, 247-248
UNESCO (2009). Case studies on climate change and world
heritage site. UNESCO World Heritage Centre. The
United Nations Educational, Scientific and Cultural
Organization, France
Von Oertzen JA (1985). Resistance and capacity adaptation of
juvenile silver carp, Hypophthalmichthys molitrix (Val.),
to temperature and salinity. Aquaculture, 44(4),321-332.
https://doi.org/10.1016/0044-8486(85)90230-3
Wang J-Q, Lui H, Po H, Fan L (1997). Influence of salinity on
food consumption, growth and energy conversion
efficiency of common carp (Cyprinus carpio)
fingerlings. Aquaculture, 148(2-3), 115-124.
https://doi.org/10.1016/s0044-8486(96)01334-8
JIFSI 2019 51 (1):60-66 65
I F SI
Watanabe WO, Ellingson LJ, Olla BL, Ernst DH, Wicklund RI
(1990). Salinity tolerance and seawater survival vary
ontogenetically in Florida red tilapia. Aquaculture,
87(3-4), 311-321.
https://doi.org/10.1016/0044-8486(90)90068-x
Zhang G, Shi Y, Zhu Y, Liu J, Zang W (2010). Effects of salinity
on embryos and larvae of tawny puffer Takifugu flavidus.
Aquaculture, 302(1-2), 71-75.
https://doi.org/10.1016/j.aquaculture.2010.02.005
66 JIFSI 2019 51 (1):60-66
... In a similar type of study on G. catla, 100% survival rate up to 5 ppt salinity and 100% mortality beyond 8 ppt salinity at 45 days of rearing have been reported (Hoque et al., 2020). However, Das et al. (2019) demonstrated that G. catla fingerlings can tolerate up to 9 ppt salinity without mortality; but survivability gradually decreased with increase in salinity levels. ...
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India is the second largest fish producer in the world and dominates by the production from of West Bengal state. The Sundarban is an UNESCO declared world heritage site, situated at the southern fringes on the West Bengal state of India. Aquaculture plays a vital role in the socio-economic development of the communities living in the Sundarban eco-region. Present study encompasses the prevailing aquaculture practices and socioeconomic profile of the fish farmers of Indian Sundarban based on a multi-layered cross-sectional questionnaire based survey. The majority of fish farmers have medium sized families (60%) and the aquaculture operations are dominated by male workers (98%). The fish farmers belonged to low income group (69%) and their annual income lies within 785.75 US$. Majority of the respondent practices traditional type farming (74%) and polyculture is prevalent. Freshwater aquaculture of Sundarban is dominated by Indian Major Carps (IMCs) in combination with other exotic varieties. Composite fish culture is popular throughout the Sundarban and most preferred stocking combination is carps with tilapia (Oreochromis spp.) followed by IMCs with medium and minor carps. Of Sundarban fish farmers, 19% do not give any kind of supplementary feed. The survey revealed that the government, educational institutions and NGOs are unsuccessful to develop sustainable aquaculture practice and methods in Sundarban. Among the various problems of freshwater aquaculture of Sundarban, saline water inundation through breach of pond dykes (68%), disease outbreaks (61%), cyclones and storm surges due to climate change (53%), poor quality of fish seeds (52%), lack of extension services and technical knowledge (49%), social issues like theft (46%) and poisoning (23%) and erratic natures of rainfall (44%) are major issues. To face these challenges a strong technical, financial and extension services from government organisations and research institutions are urgently needed for sustainable development of aquaculture in Sundarban delta. © 2016, World Food Ltd. and WFL Publishers. All Rights Reserved.
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The present study investigated the effect of salinity on growth and survival of Anabas testudineus for assessing their culture potential in brackish water. The estimated median lethal salinity concentration of 96-hour for A. testudineus (11.74 g) was 18.86 g l-1. Based on median lethal salinity concentration, survival and growth performances were ssessed at three sub-lethal salinity levels. Highest growth performances were obtained in 5 g l-1 salinity followed by 0 g l-1, 10 g l-1 and 15 g l-1 salinity. The survival rate was not hampered up to 10 g l-1 salinity. This study implies that A. testudineus can be cultured up to 15 g l-1 salinity and can be considered as an ideal species to promote in Indian Sundarban delta where brakish water intrusion is frequent phenomenon.
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