Etroplus Suratensis Research Articles

Genome size estimation of brackishwater fishes and penaeid shrimps by flow cytometry.

Flow cytometry was used for estimating the genome size of five brackishwater finfish and four shrimp species. The genome size for Lutjanus argentimaculatus was 0.95 ± 0.10 and 0.79 ± 0.01pg for Scatophagus argus. The genome sizes for Chanos chanos (0.72 ± 0.01pg), Etroplus suratensis (1.71 ± 0.16pg) and Liza macrolepis (0.87 ± 0.02pg) which are important aquaculture species are reported for the first time in this study. The phylogenetic tree constructed using sixty-seven sequence accessions of cytochrome c oxidase subunit 1 (COI) gene of Lates calcarifer revealed two separate clades. The Indian Lates calcarifer species with estimated genome size of 0.44 ± 0.02pg belonged to a clade different than that of South East Asia and Australia reported to have larger genome size. The genome size for the four major species of genus Penaeus (Penaeus monodon, Penaeus indicus, Penaeus vannamei and Penaeus japonicus) were found in similar range. The genome size of female shrimps ranged from 2.91 ± 0.03pg (P. monodon) to 2.14 ± 0.02pg (P. japonicus). In male shrimps, the genome size ranged from 2.86 ± 0.06pg (P. monodon) to 2.19 ± 0.02pg (P. indicus). Significant difference was observed in the genome size between male and female shrimp of all species except in P. monodon. The highest relative difference of 12.78% was observed in the genome size between the either sex in P. indicus. The interspecific relative difference of 30.59% in genome size was highest between the male shrimps of P. monodon and P. indicus and 35.98% between the female shrimps of P. monodon and P. japonicus. The stored gills and pleopod tissues could be successfully used up to 3 weeks to estimate the genome size in shrimps.

Development of integrated multi-trophic aquaculture (IMTA) for tropical brackishwater species in Sindhudurg District, Maharashtra, west coast of India

Integrated multi-trophic aquaculture (IMTA), farming of species from different trophic levels and with complimentary ecosystem function, is regarded as a suitable approach to develop a sustainable aquaculture system. In order to establish an IMTA system, a study was carried out in Sindhudurg District, Maharashtra, India for selected tropical brackish-water species. Two equal sized pens (250 m2) were constructed for IMTA and control respectively in each land based system and open water cages were set in the estuary. Different combinations of fed species (Chanos chanos, Etroplus suratensis, Mugil cephalus, Penaeus indicus) and an extractive crop (Crassostrea madrasensis) were stocked in IMTA experimental system whereas monoculture of P. indicus served as control. Water quality characteristics were found to be within the admissible limits. Soil organic carbon was found to be lesser in the IMTA system compared to control. The productivity of IMTA system was higher than control: 3250 kg h-1 vs 2000 kg ha-1. Further, income and benefit-cost ratio was found to be higher in IMTA pens. The present study concludes that IMTA is a possible option for system diversification as well as species diversification without compromising economic profitability of culture.

Heavy metal contamination status in seven fish species from reservoirs of Polonnaruwa district, Sri Lanka

Heavy metal contamination in aquatic ecosystems has become an emerging environmental issue. The stable physico-chemical properties of heavy metals could result in bioconcentration and bioaccumulation in different organs of freshwater fishes. The present study records the accumulation of Lead (Pb), Cadmium (Cd), Chromium (Cr), Copper (Cu) and Zinc (Zn) in the head, muscle and skin regions of seven fish species namely, Labeo rohita , Oreochromis mossambicus, Oreochromis niloticus, Etroplus suratensis , Heteropneustes fossilis , Oligolepsis acutipennis and Puntius dorsalis collected from Minnerya, Parakrama Samudraya and Kaudulla reservoirs in Polonnaruwa district, Sri Lanka. The results showed that both Pb and Cd accumulated in high concentrations in the head region compared to the skin and muscles of the fish samples. The highest amounts of Pb (22.44±5.48 mg/Kg) and Cd (4.98±0.86mg/Kg) were recorded from the head parts of the H. fossilis in Minneriya and O. niloticus in Kaudulla respectively, whereas the highest amount of Cr (30.87±4.51mg/Kg) was detected in head part of the O. acutipennis in Minneriya. The Cu concentration was the highest (2.92±0.001 mg/Kg) in head regions of H. fossilis from Minneriya. Zn was the most abundant heavy metal detected in the head, muscle and skin regions of fish in all three reservoirs. The highest amount of Zn (118.93±10.55mg/Kg) was detected in the head part of O . acutipennis from Minneriya. The Pb, Cd, Cr, Cu and Zn concentrations detected in the head part of popular edible freshwater species, O. mossambicus, O. niloticus and E. suratensis were higher than the provisional tolerable weekly intake (PTWI) of Pb (0.025 mg/Kg), Cd (0.007 mg/Kg), Cr (0.1 mg/Kg), Cu (3.5 mg/Kg) and Zn (7 mg/Kg) specified by the FAO/WHO. Therefore, long-term consumption of these fish species especially the head parts may lead to accumulation of these heavy metals in tissues and lead to chronic diseases which may risk the health of consumers especially in the north-central province of Sri Lanka.

Cage Farming Headed For Equal Opportunity In Aquaculture Development In Kerala, India

With the involvement of women in cage farming activities, the village may have opened up a better avenue for the development of aquaculture as well as social upliftment and equal opportunity. In nearby areas to this activity, empowerment of women through cage culture with pearl spot, GIFT tilapia (Oreochromis niloticus (Linnaeus, 1758)) and red snapper (Lutjanus argentimaculatus (Forsskal 1775)) was earlier reported by Joseph et al. (2016), and for pearl spot cage culture by Kappen et al. (2016).

Oxidative stress and antioxidant defense responses of Etroplus suratensis to acute temperature fluctuations

Fishes are always exposed to various environmental stresses and the chances of succumbing to such stresses are of great physiological concern. Any change in temperature from the ambient condition can induce various metabolic and physiological changes in the body. The present study evaluates the effects of temperature induced stress on the antioxidant profile of Etroplus suratensis such as superoxide dismutase, catalase, glutathione peroxidase and lipid peroxidation. Fishes of same size were kept in a thermostatized bath at three different temperature regimes viz 16°C, 27°C (ambient temperature) and 38°C for 72h. These temperatures were selected based on the CT Max (Critical Thermal Maximum) and CT Min (Critical Thermal Minimum) exhibited by E. suratensis. Superoxide dismutase and catalase activity was found maximum in brain and muscle respectively during the 48th hour of exposure in fishes kept at 38°C. At 16°C the antioxidant response of glutathione peroxidase was maximum in muscles, whereas the lipid peroxidation rate was found to be high in gills compared to other tissues. The profound increase in the levels of oxidative stress related biomarkers indicate that the thermal stressors severely affected oxidative state of E. suratensis by the second day of experiment. Such down-regulation of redox state accompanied with the induction of oxidative stress cascade may lead to physiological damage in various tissues in fishes, in vivo. However current data indicate that a transition to low and high temperature environment from ambient condition severely affected the levels and profile of the antioxidant markers overtime in E. suratensis.

Haematological Variations of Etroplus Suratensis with Respect to Heavy Metal Contamination in Two Distinct Regions of Vembanadu Estuary, South-West Coast of India.

Haematological Variations of Etroplus Suratensis with Respect to Heavy Metal Contamination in Two Distinct Regions of Vembanadu Estuary, South-West Coast of India.

Isolation and Determination of Protease Enzyme Synthesized by Pseudomonas Sp . from the Gut of Estuarine Fish Etroplus suratensis

Isolation and Determination of Protease Enzyme Synthesized by Pseudomonas Sp . from the Gut of Estuarine Fish Etroplus suratensis

Deviation of habitat salinity during seasonal gonad recrudescence affects plasma sex steroid levels and suppresses gonadal maturation in an euryhaline fishEtroplus suratensis

Impact of osmoregulation on plasma sex steroid levels and gonadal histo-architecture was monitored to elucidate the effects of deviation from habitat salinity on gonadal recrudescence in an active reproductive season of an euryhaline fish Etroplus suratensis (pearlspot). Fish were maintained in three different salinities of 0 ppt Fresh Water (FW), 15 ppt Brackish Water (BW) and 30 ppt Sea Water (SW) for a period of 60 days. Plasma osmolality values were found to be significantly highest in SW-acclimated fish accompanied by highest levels of plasma K⁺ and Cl¯ ions. The progress of gonadal recrudescence was higher in BW followed by FW and SW as evident from the cellular features of gonads and increased level of plasma sex steroids, such as, in case of female and 11-keto Testosterone and Testosterone in case of males. Plasma cortisol levels were comparatively higher in fish of both sexes in SW group. Significantly high levels of cortisol in SW suggest its role in hypo-osmoregulation and associated stress. This study clearly reveals that salinity changes during the active reproductive phase can suppress the steroid-mediated gonad recrudescence maximally under hypo-osmoregulation in an euryhaline fish.

Enhancement of breeding frequency and reproductive performance of pearlspot Etroplus suratensis by curtailing parental care

Increasing the breeding frequency and reproductive performance of pearlspot, Etroplus suratensis in small tank system by manipulating parental care and salinity is reported. A total of 3 experiments were carried out to evaluate the reproductive performance of pearlspot. In the first experiment on breeding of pearlspot involving parental care (without larval separation), production of a single batch of offspring per pair of parent fish (294 larvae, 24–43 fry) was observed after 90days. Whereas the second experiment on pearlspot breeding by curtailing parental care (with larval separation) demonstrated a higher breeding frequency; 6 in 120days. The average inter-spawning interval and larval production were 17.6±1.12days and 1333.3±143.0 respectively. The third experiment was to evaluate the breeding frequency of pearlspot at low (5.40±0.75‰) and high salinity (27.20±0.80‰) by curtailing parental care. The average inter-spawning interval was found to be significantly (p<0.05) lower (32.14±4.38days) at low salinity when compared to high salinity (64.37±12.95days). Similarly, the breeding frequency was also higher at lower salinity in 215days (5.66±0.66 at low compared to 3.67±0.67 at high salinity). The present study demonstrated that i) curtailing parental care through larval separation can be used to improve the breeding frequency and reproductive performance of pearlspot in captivity ii) relatively lower salinity reduced the inter-spawning interval of pearlspot iii) feasibility of breeding pearlspot in small tank system (1000L).

Application of fish cell lines for evaluating the chromium induced cytotoxicity, genotoxicity and oxidative stress

In the present study, we hypothesize that cytotoxicity, genotoxicity and oxidative stress play a key role in chromium induced toxicity in SISS, SISK, IEE, IEK, IEG, SICH and ICG cell lines after 24 h exposure. Three fish species namely Lates calcarifer, Etroplus suratensis and Catla catla were exposed to the concentrations of 0, 10, 20, 30, 40 and 50 mg/L of chromium for 96 h under static conditions for conducting acute toxicity tests. LC50 was then calculated. The percentage cell survival was assessed by multiple endpoints such as MTT, NR, AB and CB assays in the seven fish cell lines exposed to different concentrations of chromium and EC50 values of all the four endpoints were calculated. High significances were noted in the correlations between each in vitro cytotoxicity assays and in vivo mortality data. Cell shrinkage, cell detachment, vacuolations and cell swelling at the highest concentration of chromium (50 mg/L) were seen on microscopic examination of cell morphology. Comet assay and Hoechst staining were carried out to assess DNA damage and nuclear fragmentation in the seven fish lines exposed to chromium. The results of antioxidant parameters obtained indicate a significant reduction in the level of catalase, superoxide dismutase, glutathione S-transferase and Glutathione peroxidase, and increased level of lipid peroxidation in all the cell lines exposed to chromium. These results confirm that fish cell lines could be used as an alternative to whole fish for cytotoxicity, genotoxicity and oxidative stress assessment in chromium toxicity studies.

Trace metal concentrations in euryhaline fish species from Chilika lagoon: human health risk assessment

Five trace metals, viz. copper (Cu), chromium (Cr), iron (Fe), mercury (Hg) and zinc (Zn), in three organs (muscle, gills and liver) of four selected fish species (Mugil cephalus, Eleutheronema tetradactylum, Etroplus suratensis and Daysciaena albida) from Chilika lagoon were studied monthly to assess the concentration level and human health risk via consumption. The average and range of metal concentrations (μg g−1) in flesh of the fish species were found to be: Cu (4.15, 3.47–5.03), Cr (0.25, 0.04–0.63), Fe (19.72, 14.51–27.30), Hg (0.07, 0.05–0.08) and Zn (8.09, 4.41–11.36). The metal concentrations measured in the edible muscles of all fish species were found lower as compared to the contents in liver and gill. Analysis of variance revealed a significant difference in trace metal accumulation among the organs (p 0.05), with the exception of Zn accumulation (p < 0.05). The estimated daily intake (EDI) of the trace metals through the consumption of fish as a dietary component varied widely from 0.48 to 21.33% with respect to the corresponding permissible tolerable daily intake (PTDI). The target hazard quotients (THQs) calculated considering these EDIs for individual metals indicated that the Cr and Cu metals dominantly contributed (avg. THQ = 0.198) to represent the hazard index (HI) than other metals (avg. THQ = 0.029). The average HI determined for all the species was <1 (0.484, ranged 0.255–0.605), indicating that these fish species of Chilika are safe for human consumption.

Role of Synthetic Hormones on Reproductive Performance in Etroplussuratensis

The present study was conducted to experiment the role of synthetic hormones on reproductive performance in Etroplus suratensis. The performance of these hormones were assessed by studying the fecundity, egg size, percentage of egg fertilization, percentage of deformed larvae development, percentage of hatching, milt collection, sperm motility and time of sperm survival. The observation from this showed that the above said reproductive parameters were found to be maximum in the HCG+LHRH administration followed by ovaprim administration. The findings of this study state that the combination of HCG+LHRH is advisable for the induced maturation for E. suratensis than individual hormone treatment.

Effect of Herbal Maturation Diets on Biochemical Composition ofDifferent Organs of Etroplus suratensis

The study was conducted to document the biochemical changes in the different body parts of Etroplus suratensis when feeding them with herbal maturation diets. Three different herbal maturation diets, such as Mucuna pruriens: Withania somnifera:Moringa oleifera (MP:WS:MO) in 1:1:1 ratio (Experimental Diet-1 - EXD1), MP:WS:MO in 2:1:2 ratio (Experimental Diet-2 - EXD2), MP:WS:MO in 1:2:1 ratio (Experimental Diet-3 - EXD3) and a control diet(without herbal extracts) were prepared by mixing the said proportions of the herbal extract with other feed ingredients and fed to the adult female animals. The effects of herbal maturation diet on biochemical parameters such as level of triglyceride, total protein, cholesterol and carbohydrate in blood, liver, gonad and body tissue were analyzed in the experimental fish. The results showed that the level of triglyceride, total protein, cholesterol and carbohydrate were significantly increased in EXD3 herbal maturation diets fed fishes than the other experimental and control diet fed animals. The results proved that the administration of the herbal maturation diet EXD3 enhanced the level of the triglyceride, total protein, cholesterol and carbohydrate which can in turn leads to quick maturation and reproductive success in E. suratensis.

Arsenic and Cadmium Contamination in Water, Sediments and Fish is a Consequence of Paddy Cultivation: Evidence of River Pollution in Sri Lanka

The upper Malwathu Oya is a seasonal river. The main livelihood of people living in the immediate vicinity of the river is paddy cultivation, and chronic kidney disease is reported among them. Farmers utilize different types of agricultural chemicals in their fields expecting bumper harvests. Several agricultural chemicals have been reported to contain toxic trace elements in Sri Lanka. Therefore, arsenic and cadmium might end up in the river water. The presence of these trace elements in the river water and sediments can result in their bioaccumulation in fish tissues. The main purpose of this study was to investigate the presence of two trace elements in water and sediments, as well as in fish tissues (gills, kidney, liver and muscle) of three food fish species, Etroplus suratensis, Anabas testudineus and Channa striata during cultivating and non-cultivating seasons of the year. Further, the level of bioaccumulation of two trace elements in fish tissues in relation to the contamination level of water and sediments was assessed. Data were gathered for 43months. Arsenic and cadmium concentration in water showed a significant (P<0.05) seasonal variation. Generally, the two trace elements in the river water were highest during the cultivating seasons than in other seasons. In all species, both trace elements in the gills highly depended on the concentration in the water. In all species, two trace elements in water and sediment did not significantly affect the levels in muscle tissue. Therefore, the trace element levels in the edible parts of these three fish were well below the maximum permissible levels of international institutions.

Length-weight relationships of six tropical fish species from Chilika Lagoon, India

Summary The length weight relationships (LWRs) of six tropical fish species from Chilika Lagoon, India were studied. Specimens were caught using a wide range of fishing gear operated in the lagoon from January to December 2014. The fresh specimens were measured for total length and weight, then dissected and the sex confirmed. Previously unavailable in FishBase, the detailed LWRs of Daysciaena albida, Eleutheronema tetradactylum, Etroplus suratensis and Mystus gulio are reported for the first time. Maximum total lengths reported for Nematalosa nasus and Osteogeneiosus militaris in this study are new records for these species. The existence of a differential growth between male and female O. militaris was confirmed, which was not known earlier.

Length-weight relationship of two cichlid fish species, Etroplus suratensis (Bloch, 1790) and Etroplus maculatus (Bloch, 1795) from Lake Vembanad, Kerala, India

The present study describes the length–weight relationships (LWRs) of two cichlid fish species, Etroplus suratensis (Bloch, 1790) and Etroplus maculatus (Bloch, 1795) collected from Vembanad Lake, Kerala, India during the period June 2012 to May 2013 using gill nets with various mesh sizes (3.5–9 cm) and cast nets with a 1.5 cm mesh size. The values of parameters b in the LWR equation were estimated as 2.67 for E. suratensis and 2.72 for E. maculatus, respectively.

Effect of probiotics on digestive enzyme activities and growth of cichlids,Etroplus suratensis(Pearl spot) andOreochromis mossambicus(Tilapia)

In aquaculture, exposure to stressful conditions and problems related to diseases often occur resulting in serious economic loss. The use of probiotics that control pathogens through different mechanisms, aiding digestion by exoenzyme supply and establishment of beneficial microflora in the digestive tract has got increased attention recently. Two different bacterial species Micrococcus MCCB 104 and Bacillus MCCB 101 were tested as probiotics for two cichlid species Etroplus suratensis and Oreochromis mossambicus. The strains were administered separately and together, at a rate of 103 CFU animal−1 day−1 for 28 days. The effects on digestive enzyme activity and growth were compared with those fed on control diet. FCR of E. suratensis was high in case of Bacillus alone as well as the mixed culture (Micrococcus and Bacillus together) than that of control. However, the SGR of E. suratensis was slightly lower than that of control during 14 days trial. SGR of both the treatments (Bacillus alone and mixed culture) was higher than that of the control on 28th day, and this might be due to the reason that specific duration is needed for the assimilation and conversion of nutrients into proteins. The intestinal digestive hydrolases of E. suratensis were profoundly enhanced mainly by Bacillus and mixed cultures. The hepatopancreatic versions of major digestive enzymes in E. suratensis were influenced variously by different probiotic treatments. The alpha-amylase activity of hepatopancreas has been elevated significantly by mixed culture during 14 days experiments while on 28 days trials both Bacillus and mixed culture showed an enhancing effect. During 14 days feeding trials, the intestinal lipase activity has been prominently enhanced by all probiotic treatments. It is found that, in O. mossambicus, both 14 days and 28 days feeding experiments, the pepsin as well as intestinal digestive enzymes such as amylase, total alkaline protease, lipase and their hepatopancreatic counter parts showed a significant elevation in their specific activity. Intestinal alpha-amylase and total alkaline proteases of O. mossambicus showed an increase in specific activities on both 14 days and 28 days feeding experiments with the Bacillus and Micrococcus combination. The hepatopancreatic enzymes were highly influenced by the Bacillus species in O. mossambicus. The results of this study suggest that live probiotic microorganisms such as Micrococcus MCCB 104 and Bacillus MCCB 101 may be incorporated while formulating the cost-effective, nutritionally balanced diet of E. suratensis and O. mossambicus for better growth performance and nutrient utilization.

Assessment of soil and source water characteristics of disused shrimp ponds in selected coastal states of India and their suitability for resuming aquaculture

The key objective of this study was to assess the suitability of soil and source water quality of abandoned shrimp farms in selected coastal states of India, for resuming aquaculture activities. Soil samples along with associated source water were collected from 60 disused shrimp ponds in different districts of Andhra Pradesh, Tamil Nadu, Odisha and Kerala and analysed for basic physico-chemical parameters. Results of the analysis indicated that the reason for disuse might be reduction in price/repeated occurrences of diseases and that the sampled farms are suitable for aquaculture use. Most of the soil in Andhra Pradesh and Tamil Nadu are suitable for aquaculture without any remediation. Few ponds in Jagatsingpur and Puri districts of Odisha and Kerala needs simple remediation measures like application of lime to increase the soil pH. Source water in Tamil Nadu, Andhra Pradesh and Odisha (Harishpur Creek, Budhabalanga Creek and the coastal canal) fall under high saline areas and are suitable for culture of tiger shrimp Penaeus monodon, white shrimp Litopenaeus vannamei and finfishes like Asian seabass Lates calcarifer and mullets whereas, Kerala and northern parts of Chilka Lake of Odisha fall under low saline areas and are suitable for culture of white shrimp L. vannamei and pearlspot Etroplus suratensis.

Assessment of soil and source water characteristics of disused shrimp ponds in selected coastal states of India and their suitability for resuming aquaculture

The key objective of this study was to assess the suitability of soil and source water quality of abandoned shrimp farms in selected coastal states of India, for resuming aquaculture activities. Soil samples along with associated source water were collected from 60 disused shrimp ponds in different districts of Andhra Pradesh, Tamil Nadu, Odisha and Kerala and analysed for basic physico-chemical parameters. Results of the analysis indicated that the reason for disuse might be reduction in price/repeated occurrences of diseases and that the sampled farms are suitable for aquaculture use. Most of the soil in Andhra Pradesh and Tamil Nadu are suitable for aquaculture without any remediation. Few ponds in Jagatsingpur and Puri districts of Odisha and Kerala needs simple remediation measures like application of lime to increase the soil pH. Source water in Tamil Nadu, Andhra Pradesh and Odisha (Harishpur Creek, Budhabalanga Creek and the coastal canal) fall under high saline areas and are suitable for culture of tiger shrimp Penaeus monodon , white shrimp Litopenaeus vannamei and finfishes like Asian seabass Lates calcarifer and mullets whereas, Kerala and northern parts of Chilka Lake of Odisha fall under low saline areas and are suitable for culture of white shrimp L. vannamei and pearlspot Etroplus suratensis .

Complete mitochondrial genome sequence of E. suratensis revealed by next generation sequencing

The complete mitochondrial genome of Etroplus suratensis, the Green chromide cichlid, was determined for the first time through NGS method. The genome is 16,467 bp (Accession no. KU301747) in length and consisted of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. Organization of genes and their order are in accordance with other vertebrates. The overall base composition on plus strand was A: 28.3%, G: 15.2%, C: 30.9%, T: 25.6%, and the A + T content 53.9%. The control region contains a putative termination-associated sequence and three conserved sequence blocks. This mitogenome sequence data would play an important role in population genetics and phylogenetics of cichlid fish of India.