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E V Radhakrishnan - One of the best experts on this subject based on the ideXlab platform.
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Stock and population characteristics of the Indian rock lobster Panulirus Homarus Homarus (Linneaus, 1758) from Kanyakumari, Tamil Nadu, on the southern coast of India
Indian Journal of Fisheries, 2015Co-Authors: R. Thangaraja, E V Radhakrishnan, Rekadevi ChakraborthyAbstract:Stock parameters of the Indian rock lobster, Panulirus Homarus Homarus were estimated from the commercial landing data (2007) collected from Kanyakumari District on the southern coast of penninsular India. The estimated annual average landing of lobsters (2000-2011) in Tamil Nadu was 233.5±77.05 t. P. Homarus Homarus formed 47% of the total average lobster landing in Tamil Nadu. The stock showed two annual cohorts which is evident from two spawning peaks. Mortality parameters Z, M, F and exploitation rate E were estimated as 2.51, 0.67, 1.84 and 0.73, respectively using length converted catch curve method. Probability of capture Lc50 was 46.75 mm CL with Lc/L∞ = 0.39. The estimated Emax was 0.65. Growth parameters L∞ and K were estimated as 119.4 mm CL and 0.30 respectively. The Y/R and B/R were estimated as 0.39 and 2.23. Recruitment pattern for P. Homarus Homarus showed two cohorts which was represented by two recruitment peaks. The study revealed that P. Homarus Homarus from Kanyakumari District is overexploited and the decline in catch over the years suggests adoption of responsible fishing methods to sustain this high value coastal resource.
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Fishery and ecology of the spiny lobster Panulirus Homarus (Linnaeus, 1758) at Khadiyapatanam in the southwest coast of India
2012Co-Authors: R. Thangaraja, E V RadhakrishnanAbstract:Commercial exploitation of palinurid lobsters has been on the increase due to high demand and lucrative price for live lobsters in the international market. The spiny lobster Panulirus Homarus caught generally by traps and bottom-set gillnets support significant commercial catches along the southern Indian coast. Fishery along the southwest coast is seasonal, extending from September to March and peak landings are during October to December. The catch gradually declines from January and the landing is negligible in April and May. The paper presents results of a field study carried out on the ecology of the lobster fishing ground at Khadiyapatanam, on the southwest coast of India. Hydrographical parameters were used to correlate the lobster catch from the coastal fishing grounds during the fishing (October-November) and the non-fishing season (April-May) for which lobster catch and the entangled associated fauna and flora from 8 bottom-set-gillnets operated at different depth zones were monitored. Mean catch in the bottom-set- gillnet varied from 1.6 to 0.68 kg/net/day during October-January and 0.1 kg/net/day during April-May. Negative correlation between bottom sea water temperature and the catch of P. Homarus was observed. The environmental and ecological conditions, widespread beds of the brown mussel Perna indica are likely to be impacting the abundance of P. Homarus at Khadiyapatanam fishing ground. The major groups of organisms in the fishing ground were echinoderms, fishes, sponges, crustaceans and molluscs. The paper discusses the probable influence of environmental and ecological factors that impact the distribution and fishery of P. Homarus in the fishing grounds of
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effect of environmental parameters on immune response of the indian spiny lobster panulirus Homarus linnaeus 1758
Fish & Shellfish Immunology, 2007Co-Authors: Bindhu Verghese, E V Radhakrishnan, Abinash PadhiAbstract:Abstract The high export value of the Indian spiny lobster Panulirus Homarus increasingly attracts the aquaculturists for farming and fattening. However, lack of knowledge on the effect of environmental parameters on the immune system of this animal could result in high mortality, which ultimately may cause major loss to the industry. Here, we report the effect of salinity (20, 25, 35, 40, and 45‰), pH (5.0, 8.0, and 9.5), dissolved oxygen (DO) (1 and 5 mg L−1), and ammonia-N concentration (0, 0.5, 1.5 and 3 mg L−1) on the immune response of P. Homarus measured in the haemolymph in terms of Total Haemocyte Count (THC), phenoloxidase (PO) activity, and NBT-reduction. Our data showed significant reduction (P
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Early Larval Development of the Spiny Lobster Panulirus Homarus (Linnaeus, 1758) Reared in the Laboratory
Crustaceana, 1995Co-Authors: E V Radhakrishnan, M VijayakumaranAbstract:[Phyllosoma larvae of the spiny lobster, Panulirus Homarus were hatched and reared in the laboratory on a diet of Artemia salina nauplii. The larvae were reared in individual as well as in mass culture systems. The temperature of the rearing water ranged from 26 to 29°C and salinity from 34 to 35%o. The larvae reared individually moulted nine times and reached the sixth stage in sixty days. Mean total length of the newly hatched larva was 1.48 mm and stage VI larva measured an average of 4.87 mm. The early stages ofphyllosoma larva of P. Homarus are morphologically similar to those of other tropical species. Larvae infested with sedentary ectoparasites were effectively treated with 10 ppm malachite green. Change in feeding habits resulted in mortality of the larvae in the sixth stage., Phyllosoma larvae of the spiny lobster, Panulirus Homarus were hatched and reared in the laboratory on a diet of Artemia salina nauplii. The larvae were reared in individual as well as in mass culture systems. The temperature of the rearing water ranged from 26 to 29°C and salinity from 34 to 35%o. The larvae reared individually moulted nine times and reached the sixth stage in sixty days. Mean total length of the newly hatched larva was 1.48 mm and stage VI larva measured an average of 4.87 mm. The early stages ofphyllosoma larva of P. Homarus are morphologically similar to those of other tropical species. Larvae infested with sedentary ectoparasites were effectively treated with 10 ppm malachite green. Change in feeding habits resulted in mortality of the larvae in the sixth stage.]
Madjid Delghandi - One of the best experts on this subject based on the ideXlab platform.
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Genome-wide SNP analyses reveal high gene flow and signatures of local adaptation among the scalloped spiny lobster (Panulirus Homarus) along the Omani coastline
BMC Genomics, 2018Co-Authors: Rufaida Dhuhai Al-breiki, Shannon R. Kjeldsen, Hasifa Afzal, Manal Saif Al Hinai, Kyall R. Zenger, Dean R. Jerry, Mohammed Ali Al-abri, Madjid DelghandiAbstract:Background The scalloped spiny lobster ( Panulirus Homarus ) is a popular seafood commodity worldwide and an important export item from Oman. Annual catches in commercial fisheries are in serious decline, which has resulted in calls for the development of an integrated stock management approach. In Oman, the scalloped spiny lobster is currently treated as a single management unit (MU) or stock and there is an absence of information on the genetic population structure of the species that can inform management decisions, particularly at a fine-scale level. This work is the first to identify genome-wide single nucleotide polymorphisms (SNPs) for P. Homarus using Diversity Arrays Technology sequencing (DArT-seq) and to elucidate any stock structure in the species. Results After stringent filtering, 7988 high utility SNPs were discovered and used to assess the genetic diversity, connectivity and structure of P. Homarus populations from Al Ashkharah, Masirah Island, Duqm, Ras Madrakah, Haitam, Ashuwaymiyah, Mirbat and Dhalkut landing sites. Pairwise F _ST estimates revealed low differentiation among populations (pairwise F _ST range = − 0.0008 - 0.0021). Analysis of genetic variation using putatively directional F _ST outliers (504 SNPs) revealed higher and significant pairwise differentiation ( p
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Isolation, characterization, and multiplexing of novel microsatellite markers for the tropical scalloped spiny lobster (Panulirus Homarus).
Genetics and molecular research : GMR, 2015Co-Authors: Madjid Delghandi, Hasifa Afzal, Dean R. Jerry, S. Goddard, Hoc Tan Dao, S.s. Al-jardaniAbstract:Of the various spiny lobster species in the tropical and subtropical Indo-West Pacific region, the tropical scalloped spiny lobster (Panulirus Homarus) supports one of the most commercially valuable fishery resources in many coastal African and Asian countries. The last decade has witnessed a serious decline in the wild populations of this species. Knowledge of the genetic basis of spiny lobster population structure is a prerequisite to achieve a sustainable fisheries management for this species. Here, we describe 13 novel polymorphic microsatellite markers developed for P. Homarus, using a cross-species primer design strategy based on P. ornatus Roche 454 shot-gun generated sequencing. Microsatellite polymorphisms were assessed in 96 unrelated P. Homarus individuals of a natural population, with the number of alleles per locus varying from 2 to 14, the observed and expected heterozygosity from 0.00 to 0.78 and from 0.03 to 0.79, respectively, and with only four loci (Pho-G27, Pho-G32, Pho-G36, and Pho-G58) deviating from Hardy- Weinberg equilibrium. Genetic linkage disequilibrium analysis between all pairs of the loci showed significant departure from the null hypothesis between loci Pho-G22 - Pho-G30, and Pho-G30 - Pho-G35. The successful cross amplification of these microsatellites highlights the potential of the developed microsatellites for future population genetic research within the different Panulirus species.
Yong Chen - One of the best experts on this subject based on the ideXlab platform.
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Mesoscale climatic impacts on the distribution of Homarus americanus in the US inshore Gulf of Maine
Canadian Journal of Fisheries and Aquatic Sciences, 2019Co-Authors: Kisei R. Tanaka, Jui-han Chang, Ying Xue, Larry D. Jacobson, Yong ChenAbstract:American lobster (Homarus americanus) supports one of the most valuable fisheries in the United States. Spatial distributions of H. americanus are hypothesized to be influenced by climate-driven en...
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a simulation study to evaluate impacts of uncertainty on the assessment of american lobster fishery in the gulf of maine
Canadian Journal of Fisheries and Aquatic Sciences, 2002Co-Authors: Yong Chen, Carl WilsonAbstract:The status of the American lobster (Homarus americanus) in the Gulf of Maine (GOM) has been assessed for the last two decades by comparing an estimated current fishing mortality rate for females ( Fcur) with a deterministi- cally estimated biological reference point, F10%. The most recent assessment determined that GOM had exceeded the F10% for every year calculated, although in this time landings and abundance have doubled. The current policy does not consider uncertainty in the assessment. This study evaluates the impacts of uncertainty in F10% and Fcur on the status assessment of lobster fishery. Using a Monte Carlo simulation approach, we found that the status assessment would be influenced by uncertainties in estimating F10% and Fcur, and by the choice of decision confidence level reflecting the level of risk managers would like to take. A large uncertainty in Fcur and F10% and a high decision confidence level re- duce the likelihood of defining the stock as overfished, and vice versa. Our results suggest that the probability of lob - ster overfishing may be less than previously thought, and that uncertainty in Fcur and F10% should be quantified and considered in determining the status of the GOM lobster stock. Resume : Au cours des vingt dernieres annees, la comparaison du taux de mortalite des femelles du a la peche (Fcur )a une valeur de reference biologique (F10%) estimee de facon deterministe a permis d'evaluer l'etat du stock de homards americains (Homarus americanus) du golfe du Maine (GOM). L'evaluation la plus recente indique que la population GOM a depasse F10% pour chacune des annees considerees, bien que durant cette periode les debarquements et l'abondance aient double. La politique actuelle de gestion ne tient pas compte de l'incertitude associee a cette evalua- tion. Notre etude examine les effets de l'incertitude reliee a F10% et a Fcur sur l'evaluation de l'etat de ce stock de homards. Une simulation de type Monte Carlo indique que l'evaluation pourrait etre influencee par les incertitudes dans l'estimation de F10% et de Fcur et par le choix du niveau de confiance des decisions qui reflete le risque que les gestionnaires acceptent d'encourir. Une incertitude importante associee a F10% et a Fcur et un niveau de confiance elevee dans les decisions reduisent la probabilite de definir un stock comme surexploite, et vice versa. Nos resultats laissent croire que la probabilite qu'il y ait une surpeche des homards est moindre qu'on ne le croyait jusqu'a mainte- nant. Il est cependant important de calculer et de prendre en compte l'incertitude associee a F10% et a Fcur dans l'evaluation de l'etat du stock de homards GOM. (Traduit par la Redaction) Chen and Wilson 1403
Marcia Bowen - One of the best experts on this subject based on the ideXlab platform.
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Neustonic postlarval American lobsters, Homarus americanus, in the western Gulf of Maine: spatial and interannual variations
Canadian Journal of Fisheries and Aquatic Sciences, 2000Co-Authors: Lewis S. Incze, Peter Aas, Terri Ainaire, Marcia BowenAbstract:We examined the seasonal abundance of postlarval (PL) (stage IV) American lobsters, Homarus americanus, from neuston samples from 1989 to 1995 at Johns Bay, Maine, and Seabrook, New Hampshire, loca...
Rémy Rochette - One of the best experts on this subject based on the ideXlab platform.
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Role of gamete limitation in the occurrence of ‘abnormal early clutches’ on female American lobster, Homarus americanus, in eastern Canada
Marine Biology, 2019Co-Authors: Feng Tang, Julien Gaudette, Bernard Sainte-marie, Rémy RochetteAbstract:A large-scale survey in 2011–2014 found that ovigerous female American lobsters, Homarus americanus , carrying “abnormal” early clutches (
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The Lobster Node of the CFRN: co-constructed and collaborative research on productivity, stock structure, and connectivity in the American lobster (Homarus americanus)
Canadian Journal of Fisheries and Aquatic Sciences, 2018Co-Authors: Rémy Rochette, Bernard Sainte-marie, Michel Comeau, Marc Allain, Jackie Baker, Louis Bernatchez, Virginia Boudreau, Jean Côté, Gilles Miron, Laura L. RamsayAbstract:In 2010, more than 20 associations representing harvesters from five provinces bordering the range of American lobster (Homarus americanus) in Canada, from the Gulf of Maine to southern Labrador, j...