P. Jayasankar - Academia.edu (original) (raw)
Papers by P. Jayasankar
The exact number of extant delphinid species from seas around India is still debated and the lack... more The exact number of extant delphinid species from seas around India is still debated and the lack of adequate field keys and reliable inventory has resulted in misidentification of several species. As a part of a project to develop a molecular taxonomy of cetaceans from this region, partial sequences of mtDNA cytochrome b were generated from accidentally caught/stranded delphinids and finless porpoise. Species were identified by phylogenetic reconstruction of sample sequences with the reference sequences available in portals GenBank (NCBI) and the web-based program DNA Surveillance. A comparison was made with the homologous sequences of corresponding species from other seas of the world. Our molecular investigations allowed us to identify five species of cetaceans from Indian coasts, including Delphinus capensis, previously reported as D. delphis. We detected unique haplotypes in Indo pacific humpbacked dolphin (Sousa chinensis; n = 2) and finless porpoise (Neophocaena phocaenoides; n = 12) from Indian coast. On the other hand, some haplotypes were shared with other regional populations in spinner dolphin (Stenella longirostris; n = 16) and bottlenose dolphin (Tursiops aduncus; n = 3). Common dolphins (Delphinus capensis; n = 2) had both unique and shared haplotypes including one highly divergent sequence.
The present study investigates carcass traits of market class Hilsa, Tenualosa ilisha (Hamilton, ... more The present study investigates carcass traits of market class Hilsa, Tenualosa ilisha (Hamilton, 1822) to
calculate meat yield and provide baseline information for manual/machine processing. Specimens of
hilsa fish ranging from 800 to 850 g (820.5±12.1 g) were collected from Howrah, West Bengal fish
market. Carcass yield, offal yield and carcass cutability were assessed. The percentage of head yield was
recorded 16.3%. Gutted yield and final dressed yield of 820 g market class hilsa was recorded to be
77.9% and 61.6%, respectively. The average meat: bone ratio in filleting and deboning was reported to be
7.2:1. The middle cut of hilsa fish exhibit the highest total yield percentage and highest meat yield. The
proximate composition of all three cuts were estimated and found that fore cut of hilsa fish shown highest
dry matter, ether extract and protein percentage followed by hind and middle cut
We characterize thirteen polymorphic microsatellite loci isolated from Naja atra genomic librarie... more We characterize thirteen polymorphic microsatellite loci isolated from Naja atra genomic libraries, which were enriched for AC-motif microsatellites. The thirteen loci were screened on a group of 48 individuals from two populations, one in Yong'an and the other in Ganzhou. These markers revealed a relatively high degree of genetic diversity (4-12 alleles per locus) and heterozygosity (Ho ranged from 0.213-0.854 and He ranged from 0.301-0.838). Tests for departure from Hardy-Weinberg equilibrium and for linkage disequilibrium were conducted for each of the two populations separately. After sequential Bonferroni correction, none of the 13 loci showed significant departures from Hardy-Weinberg equilibrium. Hierarchical analysis of molecular variance indicated that a small but significant (P < 0.001) proportion (16.0%) of the total variation in the microsatellite DNA data were attributable to differences among populations, indicating geographical structuring and restricted gene flow. It could be attributable to the Wuyi mountains in the area having a sufficiently isolating effect to significantly reduce gene flow. Our microsatellite data also showed a low N m (1.31) value in the two populations from mainland China. Thus, the Yong'an and Ganzhou populations could be treated as distinct evolutionarily significant units (ESUs). The high level of polymorphism revealed
Marine Biodiversity Records, 2009
... REFERENCES Anoop, A., Yousuf, KS, Kumaran, PL., Nayak, H., Anoop, B., Afsal, VV &amp;... more ... REFERENCES Anoop, A., Yousuf, KS, Kumaran, PL., Nayak, H., Anoop, B., Afsal, VV &amp; Rajagopalan, M., Vivekanandan, E., Krishnakumar PK and Jayasankar. P., 2008. Stomach ... 18. Thiagarajan, R. &amp; Krishnapillai. S., 2000. ...
Journal of Applied Ichthyology, 2013
ABSTRACT The present study investigates carcass traits of farmed freshwater Catla catla for impor... more ABSTRACT The present study investigates carcass traits of farmed freshwater Catla catla for important information in calculating yield and/or providing data for programming machine/manual handling. For this purpose specimens of C. catla ranging from 1880 to 2150 g were collected from grow‐out culture ponds of the Central Institute of Freshwater Aquaculture, Odisha State, India. Carcass yield, offal yield and carcass cutability were assessed. The percentage of head yield was highest (31.2%) in comparison to other carp species. Gutted yield and final dressed yield of 2 kg market class catla amounted to 85.4 and 54.1%, respectively. The average meat : bone ratio in filleting was reported to be 3 : 9. The middle cut of catla had both the highest total yield percentage and highest meat yield. Dry matter, ether extract and protein percentage was highest in the fore cut followed by the middle and hind cuts.
Journal of Applied Ichthyology, 2013
ABSTRACT The present study was carried out to investigate the carcass traits of farmed freshwater... more ABSTRACT The present study was carried out to investigate the carcass traits of farmed freshwater Labeo rohita in relation to body size as important information to calculate yield and/or support for machine/manual processing. For this purpose ninety specimens were collected for nine weight groups from 600 to 1100 g, each group with a 100 g increment. Specimens were collected from grow-out culture ponds of the Central Institute of Freshwater Aquaculture (CIFA), Bhubaneswar. The carcass evaluation technique was followed to evaluate carcass yield, offal yield and carcass cutability. Head size percentage of rohu increased as the body mass increased, which in turn increased the processing yield. Dry matter and ether extract percentage also increased with the body mass; however, moisture percentage showed a decreasing trend. The fore cut showed a distinctly higher ether extract percentage followed by the middle and posterior cuts. There was a good correlation development to describe the relationship between yield traits and body weight.
Estuarine, Coastal and Shelf Science, 2008
The stomachs of 32 individuals of seven cetacean species incidentally caught in gill net and purs... more The stomachs of 32 individuals of seven cetacean species incidentally caught in gill net and purseseine fisheries along Mangalore and Chennai coasts (India) between 2004 and 2006 were examined. The whole stomach (fore-gut, mid-gut and hind-gut) was examined in all cases. Prey remains (666 prey items comprising six species of teleosts, one crustacean and one squid species) were found in the stomachs of eight individuals (the remaining 24 stomachs were found to be empty). All cetaceans were found to feed mostly on teleosts with wide range of trophic levels. Based on an index that included frequency of occurrence, percentage by number and by weight, the oil sardine Sardinella longiceps was the main prey in the sample. Cetaceans appear to favour both pelagic as well as demersal prey, possibly indicating surface and benthic feeding habits.
Journal of Cetacean …, 2007
... 266 JAYASANKAR et al.: CETACEANS IN THE WESTERN INDIAN SECTOR OF THE SOUTHERN OCEAN ... We ar... more ... 266 JAYASANKAR et al.: CETACEANS IN THE WESTERN INDIAN SECTOR OF THE SOUTHERN OCEAN ... We are thankful to the Chief Scientist at PESO, M. Sudhakar from NCAOR and V. Ravindranathan and VN Sanjeevan from the Ministry of Earth Sciences, Government of ...
Molecular genetics provides a powerful tool for conservation of species protected by internationa... more Molecular genetics provides a powerful tool for conservation of species protected by international regulations or threatened by overexploitation. The present communication is the first report from India on the application of molecular tools for the accurate identification of a stranded whale in putrefied condition as it was impossible to identify the species status using conventional taxonomy and the carcass of an unknown animal devoid of its head and tail, collected from a fish market. Partial sequences of mtDNA control region and cytochrome b gene of the whale were generated and tested with BLAST search and DNA surveillance for molecular identification. It was identified as Bryde's whale (Balaenoptera edeni). Partial sequence of mtDNA cytochrome b gene of the unknown fish from the market was generated, tested with BLAST search and was identified as sword fish Xiphias gladius.
... 4Department of Aquaculture Faculty of Fisheries Bogor Agricultural University, Indonesia ... ... more ... 4Department of Aquaculture Faculty of Fisheries Bogor Agricultural University, Indonesia ... morphological characteristics of different stocks and genetic management practices adopted in Indonesia. The Asian Fisheries Science 13(2000): 139-147 Asian Fisheries Society, Manila ...
Biochemical Systematics and Ecology, 2013
ABSTRACT Direct sequencing of mitochondrial DNA regions such as cytochrome b, ATPase 6/8 and cont... more ABSTRACT Direct sequencing of mitochondrial DNA regions such as cytochrome b, ATPase 6/8 and control region was performed to study comparative and evolutionary status of the three mitochondrial genes in Labeo rohita, Catla catla and Cirrhinus mrigala. DNA sequence alignment among species using specific software revealed comparative rates of divergence with considerably faster and more heterogeneous substitution rate for control region as compared to cytochrome b and ATPase 6/8. Despite the relatively high variability of control region, the overall levels of sequence divergence were low in coding regions. Two protein coding genes and the control region with varying degree of sequence divergence established two distinct groups which are genetically distant from each other exhibiting identical phylogenetic structure in IMCs. Closest relationship was between Labeo rohita and Catla catla indicating that they might have diverged from a common ancestral stock in genealogical lineage whereas Cirrhinus mrigala showed greater divergence with all the three DNA regions studied. Findings of this study will help to understand evolution of mitochondrial DNA genes in carps and facilitate future investigations on phylogeographic structure of Indian carps.
The exact number of extant delphinid species from seas around India is still debated and the lack... more The exact number of extant delphinid species from seas around India is still debated and the lack of adequate field keys and reliable inventory has resulted in misidentification of several species. As a part of a project to develop a molecular taxonomy of cetaceans from this region, partial sequences of mtDNA cytochrome b were generated from accidentally caught/stranded delphinids and finless porpoise. Species were identified by phylogenetic reconstruction of sample sequences with the reference sequences available in portals GenBank (NCBI) and the web-based program DNA Surveillance. A comparison was made with the homologous sequences of corresponding species from other seas of the world. Our molecular investigations allowed us to identify five species of cetaceans from Indian coasts, including Delphinus capensis, previously reported as D. delphis. We detected unique haplotypes in Indo pacific humpbacked dolphin (Sousa chinensis; n = 2) and finless porpoise (Neophocaena phocaenoides; n = 12) from Indian coast. On the other hand, some haplotypes were shared with other regional populations in spinner dolphin (Stenella longirostris; n = 16) and bottlenose dolphin (Tursiops aduncus; n = 3). Common dolphins (Delphinus capensis; n = 2) had both unique and shared haplotypes including one highly divergent sequence.
The present study investigates carcass traits of market class Hilsa, Tenualosa ilisha (Hamilton, ... more The present study investigates carcass traits of market class Hilsa, Tenualosa ilisha (Hamilton, 1822) to
calculate meat yield and provide baseline information for manual/machine processing. Specimens of
hilsa fish ranging from 800 to 850 g (820.5±12.1 g) were collected from Howrah, West Bengal fish
market. Carcass yield, offal yield and carcass cutability were assessed. The percentage of head yield was
recorded 16.3%. Gutted yield and final dressed yield of 820 g market class hilsa was recorded to be
77.9% and 61.6%, respectively. The average meat: bone ratio in filleting and deboning was reported to be
7.2:1. The middle cut of hilsa fish exhibit the highest total yield percentage and highest meat yield. The
proximate composition of all three cuts were estimated and found that fore cut of hilsa fish shown highest
dry matter, ether extract and protein percentage followed by hind and middle cut
We characterize thirteen polymorphic microsatellite loci isolated from Naja atra genomic librarie... more We characterize thirteen polymorphic microsatellite loci isolated from Naja atra genomic libraries, which were enriched for AC-motif microsatellites. The thirteen loci were screened on a group of 48 individuals from two populations, one in Yong'an and the other in Ganzhou. These markers revealed a relatively high degree of genetic diversity (4-12 alleles per locus) and heterozygosity (Ho ranged from 0.213-0.854 and He ranged from 0.301-0.838). Tests for departure from Hardy-Weinberg equilibrium and for linkage disequilibrium were conducted for each of the two populations separately. After sequential Bonferroni correction, none of the 13 loci showed significant departures from Hardy-Weinberg equilibrium. Hierarchical analysis of molecular variance indicated that a small but significant (P < 0.001) proportion (16.0%) of the total variation in the microsatellite DNA data were attributable to differences among populations, indicating geographical structuring and restricted gene flow. It could be attributable to the Wuyi mountains in the area having a sufficiently isolating effect to significantly reduce gene flow. Our microsatellite data also showed a low N m (1.31) value in the two populations from mainland China. Thus, the Yong'an and Ganzhou populations could be treated as distinct evolutionarily significant units (ESUs). The high level of polymorphism revealed
Marine Biodiversity Records, 2009
... REFERENCES Anoop, A., Yousuf, KS, Kumaran, PL., Nayak, H., Anoop, B., Afsal, VV &amp;... more ... REFERENCES Anoop, A., Yousuf, KS, Kumaran, PL., Nayak, H., Anoop, B., Afsal, VV &amp; Rajagopalan, M., Vivekanandan, E., Krishnakumar PK and Jayasankar. P., 2008. Stomach ... 18. Thiagarajan, R. &amp; Krishnapillai. S., 2000. ...
Journal of Applied Ichthyology, 2013
ABSTRACT The present study investigates carcass traits of farmed freshwater Catla catla for impor... more ABSTRACT The present study investigates carcass traits of farmed freshwater Catla catla for important information in calculating yield and/or providing data for programming machine/manual handling. For this purpose specimens of C. catla ranging from 1880 to 2150 g were collected from grow‐out culture ponds of the Central Institute of Freshwater Aquaculture, Odisha State, India. Carcass yield, offal yield and carcass cutability were assessed. The percentage of head yield was highest (31.2%) in comparison to other carp species. Gutted yield and final dressed yield of 2 kg market class catla amounted to 85.4 and 54.1%, respectively. The average meat : bone ratio in filleting was reported to be 3 : 9. The middle cut of catla had both the highest total yield percentage and highest meat yield. Dry matter, ether extract and protein percentage was highest in the fore cut followed by the middle and hind cuts.
Journal of Applied Ichthyology, 2013
ABSTRACT The present study was carried out to investigate the carcass traits of farmed freshwater... more ABSTRACT The present study was carried out to investigate the carcass traits of farmed freshwater Labeo rohita in relation to body size as important information to calculate yield and/or support for machine/manual processing. For this purpose ninety specimens were collected for nine weight groups from 600 to 1100 g, each group with a 100 g increment. Specimens were collected from grow-out culture ponds of the Central Institute of Freshwater Aquaculture (CIFA), Bhubaneswar. The carcass evaluation technique was followed to evaluate carcass yield, offal yield and carcass cutability. Head size percentage of rohu increased as the body mass increased, which in turn increased the processing yield. Dry matter and ether extract percentage also increased with the body mass; however, moisture percentage showed a decreasing trend. The fore cut showed a distinctly higher ether extract percentage followed by the middle and posterior cuts. There was a good correlation development to describe the relationship between yield traits and body weight.
Estuarine, Coastal and Shelf Science, 2008
The stomachs of 32 individuals of seven cetacean species incidentally caught in gill net and purs... more The stomachs of 32 individuals of seven cetacean species incidentally caught in gill net and purseseine fisheries along Mangalore and Chennai coasts (India) between 2004 and 2006 were examined. The whole stomach (fore-gut, mid-gut and hind-gut) was examined in all cases. Prey remains (666 prey items comprising six species of teleosts, one crustacean and one squid species) were found in the stomachs of eight individuals (the remaining 24 stomachs were found to be empty). All cetaceans were found to feed mostly on teleosts with wide range of trophic levels. Based on an index that included frequency of occurrence, percentage by number and by weight, the oil sardine Sardinella longiceps was the main prey in the sample. Cetaceans appear to favour both pelagic as well as demersal prey, possibly indicating surface and benthic feeding habits.
Journal of Cetacean …, 2007
... 266 JAYASANKAR et al.: CETACEANS IN THE WESTERN INDIAN SECTOR OF THE SOUTHERN OCEAN ... We ar... more ... 266 JAYASANKAR et al.: CETACEANS IN THE WESTERN INDIAN SECTOR OF THE SOUTHERN OCEAN ... We are thankful to the Chief Scientist at PESO, M. Sudhakar from NCAOR and V. Ravindranathan and VN Sanjeevan from the Ministry of Earth Sciences, Government of ...
Molecular genetics provides a powerful tool for conservation of species protected by internationa... more Molecular genetics provides a powerful tool for conservation of species protected by international regulations or threatened by overexploitation. The present communication is the first report from India on the application of molecular tools for the accurate identification of a stranded whale in putrefied condition as it was impossible to identify the species status using conventional taxonomy and the carcass of an unknown animal devoid of its head and tail, collected from a fish market. Partial sequences of mtDNA control region and cytochrome b gene of the whale were generated and tested with BLAST search and DNA surveillance for molecular identification. It was identified as Bryde's whale (Balaenoptera edeni). Partial sequence of mtDNA cytochrome b gene of the unknown fish from the market was generated, tested with BLAST search and was identified as sword fish Xiphias gladius.
... 4Department of Aquaculture Faculty of Fisheries Bogor Agricultural University, Indonesia ... ... more ... 4Department of Aquaculture Faculty of Fisheries Bogor Agricultural University, Indonesia ... morphological characteristics of different stocks and genetic management practices adopted in Indonesia. The Asian Fisheries Science 13(2000): 139-147 Asian Fisheries Society, Manila ...
Biochemical Systematics and Ecology, 2013
ABSTRACT Direct sequencing of mitochondrial DNA regions such as cytochrome b, ATPase 6/8 and cont... more ABSTRACT Direct sequencing of mitochondrial DNA regions such as cytochrome b, ATPase 6/8 and control region was performed to study comparative and evolutionary status of the three mitochondrial genes in Labeo rohita, Catla catla and Cirrhinus mrigala. DNA sequence alignment among species using specific software revealed comparative rates of divergence with considerably faster and more heterogeneous substitution rate for control region as compared to cytochrome b and ATPase 6/8. Despite the relatively high variability of control region, the overall levels of sequence divergence were low in coding regions. Two protein coding genes and the control region with varying degree of sequence divergence established two distinct groups which are genetically distant from each other exhibiting identical phylogenetic structure in IMCs. Closest relationship was between Labeo rohita and Catla catla indicating that they might have diverged from a common ancestral stock in genealogical lineage whereas Cirrhinus mrigala showed greater divergence with all the three DNA regions studied. Findings of this study will help to understand evolution of mitochondrial DNA genes in carps and facilitate future investigations on phylogeographic structure of Indian carps.