Trachypenaeus Curvirostris Research Articles

Improving the size selectivity and exploitation pattern of cocktail shrimp (Trachypenaeus curvirostris) in shrimp trawl fishery of the South China Sea.

In order to improve the size selectivity and exploitation pattern for cocktail shrimp (Trachypenaeus curvirostris) in shrimp trawl fishery of the South China Sea (SCS), selective properties of four codends were tested and compared. These experimental codends involved two mesh sizes, 30 and 35 mm, and two mesh shapes, diamond-mesh (T0) and diamond-mesh turned by 90 degree (T90), respectively. Our results demonstrated that increasing the mesh sizes in T0 codends or/and applying T90 codends would improve the selective properties for cocktail shrimp in the SCS. By comparing selectivity parameters, delta selectivity and exploitation pattern indicators, the T90 codend with 35-mm mesh size (T90_35) presented the best selective properties for cocktail shrimp in the studied areas. It will be a potential choice to substitute the currently legal codend in fisheries management to mitigate the bycatch of undersized cocktail shrimp in shrimp trawl fisheries of the SCS.

Comparative investigation of various modification methods on Trachypenaeus Curvirostris surimi gel: Gelling properties, rheological behaviors and structure characteristics.

The aim of this study was to compare the investigations of various contents of egg white protein (2.0%-8.0%, EWP), microbial transglutaminase (0.1%-0.4%, MTGase), and konjac glucomannan (0.5%-2.0%, KGM) on the gelling properties and rheological behavior of Trachypenaeus Curvirostris shrimp surimi gel (SSG), and assessed the modification mechanisms through the analysis of structure characteristics. The findings suggested that all modified SSG samples (expect SSG-KGM2.0% ) had the higher gelling properties and the denser network structure than those of unmodified SSG. Meanwhile, EWP could give SSG a better appearance than MTGase and KGM. Rheological results showed that SSG-EWP6% and SSG-KGM1.0% had the highest G' and G″, demonstrating that the formation of higher levels of elasticity and hardness. All modifications could increase gelation rates of SSG along with the reduction of G″ during the degeneration of protein. According to the FTIR results, three modification methods changed SSG protein conformation with the increasing α-helix and β-sheet contents and the decreasing of random coil content. LF-NMR results indicated that more free water could be transformed into immobilized water in the modified SSG gels, which contributed to improve the gelling properties. Furthermore, molecular forces showed that EWP and KGM could further increase the hydrogen bonds and hydrophobic interaction in SSG gels, while MTGase could induce the formation of more disulfide bonds. Thus, compared with another two modifications, EWP modified SSG gels showed the highest gelling properties.

Shrimp community structure and influence of environmental variables in the East China Sea and Yellow Sea in spring.

Based on data collected from research vessel cruises performed in May 2020 off the East China Sea (ECS) and the southern Yellow Sea (YS) (26°30'-35°00' N, 120°30'-127°00' E), we analyzed the shrimp community and its relationships with environmental variables by using index of relative importance, biodiversity indices, and multivariate techniques. A total of 29 species were recorded, belonging to 11 families and 19 genera. The dominant species were Metapenaeopsis longirostris, Leptochela gracilis, Solenocera melantho, Crangon hakodatei, Parapenaeus fissuroides, Plesionika izumiae, and Trachypenaeus curvirostris, which together accounted for 82.9% of the total biomass and 90.8% of the total abundance of shrimps. Results of Cluster and NMDS analyses showed that three groups were identified for the shrimp community in the ECS and YS in spring, including group A (inshore of northern ECS and YS group), group B (offshore of northern ECS group) and group C (southern ECS group). ANOSIM and SIMPER analysis showed significant differences between group A and B, gourp A and C, and group B and C, with the dissimilarity of 92.2%, 95.8% and 91.6%, respectively. The typical species were T. curvirostris, C. hakodatei, L. gracilis and Palaemon gravieri in group A, and S. melantho in group B, and M. longirostris, P. fissuroides, P. izumiae and Solenocera alticarinata in group C. Significant differences were also detected in biomass, diversity index, species richness index and evenness index among groups, with significantly greater values in group C than those in A and B. Environmental variables and the substrate also displayed significant differences among groups. Results of canonical correspondence analysis showed that bottom temperature, bottom salinity, depth, and the substrate were the main environmental variables affecting spatial structure of shrimp community. Water mass characteristics and substrate type had important influences on the distribution of shrimp community in the ECS and YS in spring.

Effect of codend mesh sizes on the size selectivity and exploitation pattern of cocktail shrimp (Trachypenaeus curvirostris) in shrimp trawl fishery of the South China Sea

This study aims at improving fishery management by testing and comparing the size selectivity and exploitation pattern of diamond-mesh codends, with mesh sizes ranging from 25 to 54 mm, for cocktail shrimp (Trachypenaeus curvirostris) in the South China Sea (SCS). Beginning from 25 mm, the minimum mesh size regulated by the shrimp trawl fishery industry, we investigated how the mesh sizes of the codends would affect the size selectivity and exploitation pattern in reference to the minimum conservation reference size (MCRS, 7.0 cm total length) of cocktail shrimp in the SCS. According to our results, the selective properties of the codend mesh sized at 25 mm in line with the regulation failed to protect the undersized individuals of cocktail shrimp because of its 50% retention length of 5.85 cm (confidence interval, CI: 5.16–6.18 cm), far less than the MCRS of cocktail shrimp. As the retention probability of a shrimp with a MCRS length was as high as 97.45 % (CI: 86.86–100.00%), more than 40% of the undersized shrimp was retained. It was proved that increasing the codend mesh size did not significantly improve the size selectivity and exploitation pattern which might be improved by other gear modifications.

Astaxanthin Extract from Shrimp (Trachypenaeus curvirostris) By-Products Improves Quality of Ready-to-Cook Shrimp Surimi Products during Frozen Storage at -18 °C.

The effects of astaxanthin extract (AE) from shrimp by-products on the quality and sensory properties of ready-to-cook shrimp surimi products (RC-SSP) during frozen storage at −18 °C were investigated. Changes in 2-thiobarbituric acid reactive substances (TBARS) value, sulfhydryl groups, carbonyls, salt-soluble protein content, textural properties, color, and sensory quality over specific storage days were evaluated. The AE from shrimp by-products contained 4.49 μg/g tocopherol and 23.23 μg/g astaxanthin. The shrimp surimi products supplemented with 30 g/kg AE had higher redness values and greater overall acceptability and texture properties after cooking (p < 0.05). AE showed higher oxidative stability in RC-SSP than the control, as evidenced by lower TBARS and carbonyl content, and higher sulfhydryl and salt-soluble protein content. AE from shrimp by-products had positive effects on the antioxidant activity and color difference of RC-SSP, and could be used as a potential multifunctional additive for the development of shrimp surimi products.

Evaluating the impacts of fishing and migratory species in a temperate bay of China using the ecosystem model OSMOSE-JZB

Small-scale fisheries (SSFs) play a vital role in the sustainability of local economies. Migratory species moving into and out of an ecosystem may influence the dynamics of local fish communities and SSFs. We used the end-to-end model, OSMOSE-JZB (Object-oriented Simulator of Marine ecOSystEms), to evaluate the impacts of fishing and a migratory shrimp (Trachypenaeus curvirostris) on the ecosystem of Jiaozhou Bay, China. Increased fishing intensity (i.e., annual fishing effort) resulted in the decline of four ecological indicators, including the total biomass of the community, mean trophic level of the community, inverse fishing pressure, and large fish index. Compared to managing fish stocks under uniform fishing mortality over the fishing season, landings and community biomass were higher when a “race to fish” (i.e., large catches in a short period) occurred. The results suggested that managing fishing seasonality (i.e., temporal allocation of fishing effort) could mitigate the negative impact of fishing intensity. Two resident high-trophic-level fishes were sensitive to changes in fishing intensity and fishing seasonality. The changes in trophic interactions had larger impacts on species at low trophic levels than fishing. Pearson's correlation analysis showed that T. curvirostris biomass was negatively correlated with the biomass of resident species and positively correlated with the biomass of other migratory species. We also found that fishing changed the impact of varying T. curvirostris migratory biomass on other species. Resident species were more sensitive to changes in fishing and T. curvirostris migratory biomass than other migratory species. We argue that SSFs management can benefit from the development of temporal fishing strategies and consideration of trophic interactions stemming from migratory species dynamics.

Trachysalambria aspera (Alcock, 1905) (Crustacea, Decapoda, Penaeidae) from the southeastern Arabian Sea, India.

Trachysalambria aspera (Alcock, 1905) was first reported and described in detail by Alcock (1905) as Trachypeaneus asper Alcock, 1905, from the Ganjam coast (Odisha, India) and Andaman Sea. Chan et al. (2016) revised the species under the genus Trachysalambria based on molecular genetic data and resolved the confusion in their taxonomy in literature. However, they could not examine the types of T. aspera due to their non-availability (Chan et al. 2016). So we discuss the characters of the species based on the photograph of the type specimen from the Zoological Survey of India, Kolkata with that of Chan et al. (2016) and also with the specimens collected from southwest coast of India where the species has not been reported earlier, but only Trachysalambria curvirostris (George, 1967). Earlier, among Trachysalambria species, T. curvirostris was reported from both the east (Bay of Bengal) and west coasts (Arabian Sea) of Indian waters (Kunju, 1960; George, 1967; Muthu, 1971; Thomas, 1976). Chan et al. (2016) states that T. curvirostris may have a restricted distribution to northern Pacific Ocean.

White spot syndrome virus (WSSV) prevalence in wild crustaceans in the Bohai Sea

The impacts of mariculture on coastal ecosystems are increasingly raising attention recently. To study the prevalence of white spot syndrome virus (WSSV) in wild crustaceans, a pathogenic agent of cultured shrimps, continuous and large-scale surveys in the Bohai Sea were firstly conducted from 2016 to 2018. A total of 820 samples were collected from 59 sampling sites. The results of loop-mediated isothermal amplification (LAMP) assay showed that 11 of the 19 wild species were identified to be WSSV positive. Among them, Alpheus distinguendus had the highest WSSV-positive rate at 21.9%. The percentage of WSSV positive sampling sites was 76.7%, 55.0%, 43.7% in 2016, 2017, 2018, respectively. The percentage of WSSV positive samples was 17.4%, 12.2% and 7.8%, respectively. The multiple sequence alignment and phylogenetic tree analysis showed that the WSSV VP26 gene cloned from the wild crustaceans was consistent with those from WSSV strains previously reported in India, China, Brazil, Thailand, as well as Mexico, which was clustered tightly into one branch. The presence of WSSV virions in the epithelial cells of wild southern rough shrimp Trachypenaeus curvirostris was confirmed by TEM assay, which further verifying the occurrence of WSSV infection in wild crustaceans. The results of present study demonstrated that WSSV had colonized in the populations of offshore wild crustaceans in the Bohai Sea, and the potential negative impact of WSSV prevalence on the wild crustacean populations together with marine ecosystem deserved close attention and further investigation.

闽南渔场游泳动物优势种种群聚集特性

基于2016年4月和10月闽南渔场渔业资源的专项调查数据，运用相对性重要指数、平均拥挤度指数、聚块指数、Cassie指标、Mrisita指数等方法分析闽南渔场游泳动物优势种组成及其种群聚集特性，比较不同的季节、类群和种类及其相互间的聚集状态，探究种群聚集驱动因子，旨在发现闽南渔场游泳动物优势种种群聚集的特征、内在规律和形成机制。结果表明，闽南渔场游泳动物优势种共17种，其中鱼类6种、虾类3种、蟹类4种、头足类4种；鱼类中六指马鲅（Polydactylus se-xfilis）聚集强度最强，头足类中火枪乌贼（Loligo beka）聚集强度最强；虾类和蟹类中春季以哈氏仿对虾（Parapenaeopsis hardwickii）和拥剑梭子蟹（Portunus gladiator）的聚集强度最强，而秋季以鹰爪虾（Trachypenaeus curvirostris）和日本蟳（Charybdis japonica）的聚集强度最强；鱼类、虾类、蟹类和头足类中春季分别以二长棘犁齿鲷（Evynnis cardinali）、鹰爪虾、三疣梭子蟹（P. trituberculatus）和火枪乌贼的平均拥挤度最高，而秋季分别以带鱼（Trichiurus lepturus）、鹰爪虾、拥剑梭子蟹和杜氏枪乌贼（Loligo duvaucelii）的平均拥挤度最高；闽南渔场游泳动物优势种的平均拥挤度呈现出秋季高于春季，虾类、蟹类种群聚集强度大于鱼类、头足类的特点。;The relative importance index, mean crowding index, patchiness index, Cassie index and Mrisita index were used to analyze the composition and aggregation characteristics of the dominant species of nekton in Minnan Fishing Ground using the special investigation data of fishery resources in Minnan Fishing Ground in April and October 2016. The results showed that there were 17 dominant species of nektons in Minnan Fishing Ground, including 6 species of fish, 3 species of shrimp, 4 species of crab and 4 species of cephalopod. Polydactylus se-xfilis had the strongest aggregation intensity among fishes, and Loligo beka had the strongest aggregation intensity among cephalopods in spring and autumn. Parapenaeopsis hardwickii had the largest aggregation intensity among shrimps, and Portunus gladiator had the largest aggregation intensity among crabs in spring. Trachypenaeus curvirostris had the largest aggregation intensity among shrimps, and Charybdis japonica had the largest aggregation intensity among crabs in autumn. In spring, Evynnis cardinali, Trachypenaeus curvirostris, Portunus trituberculatus, Loligo beka had the highest mean crowding among fishes, shrimps, crabs and cephalopods, respectively. In autumn, Trichiurus lepturus, Trachypenaeus curvirostris, P. gladiator and Loligo duvaucelii had the highest mean crowding among fishes, shrimps, crabs and cephalopods, respectively. The average crowding of main dominant species of nekton in autumn was higher than that in spring, and the aggregation intensity of shrimp and crab was higher than that of fish and cephalopod in the Minnan Fishing Ground.

Separation and determination of bromophenols in Trachypenaeus curvirostris and Lepidotrigla microptera by capillary zone electrophoresis

Bromophenols have been identified as key off-flavor compounds found in seafood. In this report, a new method of capillary zone electrophoresis (CZE) was established for simultaneous assay of five bromophenols, 4-bromophenol (4-BP), 2,4,6-tribromophenol (2,4,6-TBP), 2,4-dibromophenol (2,4-DBP), 2-bromophenol (2-BP) and 2,6-dibromophenol (2,6-DBP), in seafood. The optimum buffer system was 20 mM borate-NaOH buffer (pH 10.00). Voltage was +30 kV and the ultraviolet absorbance detection at 280 nm. The column was an uncoated 50 μm ID fused-silica capillary. Regression equations revealed linear relationships (correlation coefficients: 0.9990, 0.9998, 0.9997, 0.9999 and 0.9989) between the peak area of each compound and its concentration. Calibration curves were constructed in the range of 18.8-1200, 15-960, 9.4-600, 10.6-680 and 3.0-370 mg/mL for 4-BP, 2,4,6-TBP, 2,4-DBP, 2-BP and 2,6-DBP, respectively. The relative standard deviations of migration times and peak areas were < 2.1% and 4.9% within one day, respectively. The recoveries of bromophenols were 91.5-103.4%. The detection limits (S/N = 3) of 4-BP, 2,4,6-TBP, 2,4-DBP, 2-BP and 2,6-DBP were 1.6, 1.9, 1.2, 0.9 and 1.4 mg/mL, respectively. The effects of several CE parameters on the resolution were studied systematically. Compared with liquid chromatography, the method described here is relatively rapid and can give symmetrical peaks. The contents of 5 bromophenols in seafood (Trachypenaeus curvirostris and Lepidotrigla microptera) were determined with satisfactory repeatability and recovery. The contents of 4-BP, 2,4,6-TBP, 2,4-DBP and 2,6-DBP in T. curvirostris were 3.9, 2.5, 7.3 and 0.6 ng/g, respectively. The feasibility of this method for the determination of bromophenols in freshwater fish and crustaceans (Macrobrachium nipponense and Carassius auratus var. Pengzesis) also tested. The result indicated that these flavor compounds in freshwater fish and crustaceans were lower than the detection limits mentioned above.

Spatial pattern of benthic macroinvertebrate communities and their relationship with environmental variables on the East China Sea shelf

To detect the large-scale spatial pattern of the benthic macroinvertebrate communities and the relationship with their environment on the East China Sea shelf, forty sites were sampled for benthic macroinvertebrates and environmental variables during August and September 2015. A total of 12529 benthic macroinvertebrate individuals and 274 species were collected, with crustaceans being predominant, followed by mollusks. Four communities were identified by hierarchical agglomerative cluster (HAC) analysis and cross-verified by non-metric multidimensional scaling (NMDS) ordination: an Inshore community (IC); a Transitional community (TC); a Northern offshore community (NOC); and a Southern offshore community (SOC). Significant differences in their community structure were found by permutational multivariate analysis of variance (PERMANOVA). The indicator species varied among the four communities, with Solenocera crassicornis, Sternaspis scutata and Virgularia sp. dominating IC, Solenocera koelbeli, Trachysalambria curvirostris and Nitidotellina valtonis dominating TC, Parapenaeus fissuroides, Onustus exutus and Drachiella morum dominating NOC, and Heikeopsis japonica, Solenocera pectinulata and Actiniaria dominating SOC. Significant differences among communities were detected for species number (S), Margalef's index (d), Pielou's index (J′), Hill's number (N∞), total taxonomic distinctness (SΔ+), average phylogenetic diversity (Φ+), total phylogenetic diversity (SΦ+) and abundance through statistical analyses. The redundancy analysis (RDA) model revealed that turbidity, silicate and depth were significant environmental variables influencing the benthic macroinvertebrates. Variation partitioning (VPA) showed that water characteristics had a greater impact than sediment conditions on the distribution of benthic macroinvertebrates in the East China Sea.

The complete mitochondrial genome of Trachypenaeus curvirostris (Stimpson, 1860)

Trachypenaeus curvirostris is a common and important shrimp species in the shallow waters of Indo-West Pacific. In this study, the mitochondrial genome of T. curvirostris was determined for the first time using next-generation sequencing; the overall base components of mitogenome consisting of 15968 bp was 35.16% (5614 bp) for A, 33.51% (5351 bp) for T, 11.54% (1842 bp) for G, 19.80% (3161 bp) for C, and its GC content was 31.34%. The mitochondrial circular genome was composed of 13 protein-coding genes, 22 transfer RNAs, 1 D-loop and 2 ribosomal RNAs. Polygenetic analysis showed that the T. curvirostris was more closed to Parapenaeopsis hardwickii.

The carotenoid characteristics of the important wild shrimp Trachysalambria curvirostris (Stimpson, 1860) in China

Trachysalambria curvirostris is an economically important shrimp in the coastal waters of the Western Indo-Pacific. However, there is no information about its carotenoid composition and distribution. The carotenoid profiles including concentration, composition, molecular forms (free or esterified) and configuration (geometrical and optical isomers) of raw and dried Trachysalambria curvirostris (Stimpson, 1860) were qualitatively and quantitatively assessed. In the raw shrimp, astaxanthin and β-carotene were the two dominant carotenoids, which contributed 75.18%–88.86% and 2.86%–16.83% of the total carotenoid content. Traces of echinenone, canthaxanthin and astacene were also detected. The carotenoid content in the waste (80.28 mg/kg dry weight) was nearly two-fold higher than that in the meat (49.69 mg/kg dry weight). Of the total astaxanthin in these shrimp, 85.18%–90.59% was esterified. All- trans astaxanthin was the predominant geometrical isomer followed by 13- cis, 9- cis, di- cis and 15- cis isomers. A mix of three stereoisomers was found in all parts and the percentages of meso (3 S, 3’ R ) and (3 S, 3’ S ) forms were significantly higher than the (3 R, 3’ R ) isomer. Compared to the carotenoid content of the raw shrimp, only 26.17 mg/kg remained in the dried shrimp. Nearly half of the carotenoids were lost during the drying process. Substantial hydrolysis and isomerization also occurred.

Feeding ecology of Conger myriaster and structure of the food webs in artificial reef zone, Laoshan Bay, China

Based on cage net and longline fishing surveys in Laoshan Bay, China, from April 2015 to January 2017, a total of 279 Conger myriaster stomach samples were analyzed to study their feeding ecology, including diet composition, feeding type, feeding grade, feeding intensity, trophic niche, and trophic level. The stomach content analysis of nine key fish species (including Sebastes schlegelii, Hexagrammos otakii, Hexagrammos agrammus, Sebastiscus mamoratus, Lateolabrax maculatus, etc.), were conducted to examine the food webs in artificial reef zone. The results showed that the diet of C. myriaster consisted of more than 30 species belonging to seven orders, in which shrimps were the most dominant prey species, followed by fishes and cephalopods. The dominant species in the diet of C. myriaster were H.otakii, Enedrias fangi, Trachypenaeus curvirostris, Ammodytes personatus and Alpheus japonicas. The diet composition of C. myriaster varied with season and anal length. Fishes and shrimps were the two important groups throughout the years. Cephalopods were predominant in spring. Cephalopods and crabs were predominant in Autumn. Fish eggs were eaten mostly during winter. Fish eggs and T. curvirostris were the dominant prey groups of the C. myriaster with anal length ≤120 mm, whereas A. personatus and A. japonicas were the dominant prey groups of the C. myriaster with anal length 120-130 mm, H.otakii and E.fangi were the dominant prey of the C. myriaster with anal length ＞130 mm. The percentage of empty stomach of C. myriaster varied significantly with season, but the mean stomach fullness index did not. The percentage of empty stomach and mean stomach fullness index did not differ significantly among different anal length groups. The trophic levels of the key fish species were higher than level 3, with C. myriaster at the top of food webs (with a trophic level of 4.636). Decapoda, crabs, amphipoda and molluscs were the main prey of key fish species, while Crustaceans, E. fangi, H. otakii and A. personatus were the main preys of L. maculatus and C. myriaster.

Length-weight relationships of thirteen penaeoid shrimps in the East China Sea

Abstract Length-weight relationships of various shrimp species were examined based on data from bottom trawl surveys from May 2014 to April 2015 in the East China Sea. A total of 2335 individuals belonging to Penaeidae and Solenoceridae were measured and weighed. Significant length-weight relationships were found for all species. The b-values of the length-weight relationships ranged from 2.0855 (Trachysalambria curvirostris) to 3.4808 (Metapenaeopsis barbata) with a mean value of 3.10 (±0.05). The differences in b-values between sexes and seasons were also examined. Whenever possible, b-values were compared for the species obtained both in this study and some of the species previously reported in other studies. Differences in the b-values for the same species in different areas suggest the influence of differences in environmental or habitat factors, including temperature and depth.

Sexual Size Dimorphism On Some Penaeid Shrimp In Sudanese Red Sea

في البحر الأحمر السوداني ، أجريت العلاقات الشكلية للروبيان على بعض أنواع Penaeid: Penaeus monodon ، Penaeus indicus ، Penaeus semisulcatus ، Metapenaeus monoceros ، Trachypenaeus curvirostris و Metapenaeus stebbingi. كانت الإناث أكبر من الذكور في جميع الأنواع المدروسة ، وكان أكبر الأنواع P. semisulcatus وأصغرها هو Trachypenaeus curvirostris والذي كان وزنه 6 جرام كحد أقصى خلال الدراسة. الجدول 1. تم الحصول على بعض قياسات الجسم تشوه الشكل الجنسي في جميع القياسات الشكلية لكل من P. semisulcatus و T. curvirostris. ومع ذلك ، لا يوجد تشوه جنسي في القياسات الشكلية لـ P. monodons ، في تشوه الشكل الجنسي M. monoceros في قياسات الطول وفي P. indicus فقط في الطول الإجمالي. تختلف علاقة الطول والوزن بالجمبري المدروس حسب الجنس. يظهر كلا الجنسين من T. curvirostris و P. semisulcatus ازدواج الشكل الجنسي في الطول الكلي وطول الدرع ووزن الجسم ، في P. monodon لم يكن ازدواج الشكل الجنسي ، وكان مثنوية الشكل الجنسي P. indicus في قياسات الطول وفي M. monoceros فقط في وزن الجسم .

Descriptive analysis, DNA barcoding and condition index of Penaeids (Crustacea: Decapoda) from the Egyptian Mediterranean coast

Penaeid shrimps represent the most economically important decapod group in the Egyptian capture fisheries. Up till now, the absence of proper morphological and genetic tools for species identification is negatively affecting the proper management of fisheries, especially when associated with the scarcity of data about fisheries of such species that have high economic value or the ones suffering from overfishing. In the present study, we sampled three penaeid species that prevail the Egyptian capture fisheries of the Mediterranean; Penaeus semisulcatus, Metapenaeus monoceros and Trachypenaeus curvirostris. Morphological clues for the identification of these species were thoroughly recorded. Furthermore, the DNA was extracted from these species and partial fragments of the cytochrome oxidase subunit 1 (CO1) and 16S rRNA genes were amplified using polymerase chain reaction (PCR) and sequenced. New barcodes of these species were added to the GenBank database as confirmed by the thorough morphological identification. Some discrepancies were detected between our samples and those in the Genbank database (whenever available). Hence, phylogenetic analyses ensued for proper placement of our samples with their closest relatives that were previously submitted to GenBank. Moreover, morphometric studies were conducted to provide the fundamental parameters which are important for fisheries management of the currently studied shrimp species. Through these parameters tested, the study provided a tool to select the appropriate stocks for successful hatcheries, and added more value to the growing sector of shrimp aquaculture in Egypt. This study is the first of its kind in Egypt as it provides both morphological and genetic clues for identifying such species, and also in assessing their fisheries in the Mediterranean supreme fishery in Egypt.

서해 군산 연안에서 새우조망으로 어획된 저서생물의 종조성 및 군집구조

Abstract Species composition of aquatic organism in the marine ranching area of Gunsan, Korea were investigated using shrimp beam trawl from May to December in 2010. A total of 91 species, 98,127 ind./ ㎢ and 877.6 ㎏/㎢ of aquatic organism were collected. Among them, species were included 60 species in Pisces, 21 in Crustacea and 10 in Mollusca. The individual dominant species, occupying over 10% of total individuals, were Latreutes anoplonyx(47,327 ind/㎢, 48.23%), Crangon hakodatei(11,578 ind./㎢, 11.80%) and Trachysalambria curvirostris(10,237 ind./㎢, 10.40%). And the biomass dominant species, occupying over 9% of total biomass, were Paralichthys olivaceus(135 ㎏/㎢, 15.4%), Okamejei kenojei(98.2 ㎏/㎢, 11.2%) and Portunus tribuberculatus(84.8 ㎏/㎢, 9.6%). From the cluster and MDS analysis based on Bray-Curtis similarity matrix of fourth root transformed data of number of species and individuals per unit area collected more than two times during this survey by each month and station was divided into three different groups. Group A showed seasonal similarity of characteristic of distribution in August and November, Group B in December and Group C in May. Key words : Species composition, Community structure, Dermersal organisms, Gunsan, Shrimp beam trawlCorresponding author : 051-626-9895, bluejuve@gmail.com 2016 (R2016051) .

Headspace In-Tube Microextraction Coupled with Capillary Electrophoresis for Detection of Bromophenols in Water and Trachypenaeus curvirostris

A rapid, simple, and sensitive method has been developed for the analysis of bromophenols in tap water and Trachypenaeus curvirostris by using headspace in-tube microextraction (HS-ITME) coupled with capillary electrophoresis (CE). In the newly developed method, simply by placing a capillary filled with a basic run buffer in the HS above an acidic donor solution, volatile acidic analytes were extracted into the acceptor phase in the capillary. After extraction, electrophoresis of the extracts in the capillary was carried out. Extraction parameters such as the extraction temperature, extraction time, pH of the sample solution, ionic strength, and volume of the sample solution were systematically investigated. Under the optimized conditions, enrichment factors for three bromophenols were 812, 685, and 568, respectively. The proposed method provided a good linearity, low limits of detection (below 5.25 ng/mL), and good repeatability of the extractions (RSDs below 7.8 %, n = 6). The tap water and T. curvirostris samples were analyzed by the proposed method, and the obtained results indicated that the proposed method provides acceptable recoveries and precisions.

Significant genetic differentiation between the Yellow Sea and East China Sea populations of cocktail shrimp Trachypenaeus curvirostris revealed by the mitochondrial DNA COI gene

The cocktail shrimp Trachypenaeus curvirostris is an ecologically and economically important shrimp species in the Yellow Sea and East China Sea. However, there is no information about its population genetic structure. The population genetic structure and level of gene flow of T. curvirostris from the Yellow Sea and the East China Sea were studied with a 658-bp segment of mtDNA COI gene. In total, 85 individuals were collected from five locations and 13 haplotypes were obtained. The genetic variation of COI gene in five populations was moderate, giving an overall haplotype diversity of 0.6888 ± 0.0432 and nucleotide diversity of 0.0069 ± 0.0038. Conflicting to our expectation, significant genetic differentiation was detected in this species. The result revealed two genetically divergent lineages, displaying clear different geographical distributions in the studied area. The significant genetic differentiation between the Yellow Sea and East China Sea populations might be caused by the Yangtze River outflow. Mismatch distribution revealed that T. curvirostris had undergone population range expansion, possibly before 103,400–109,700 years ago in the last interglaciation, rejecting the sudden demographic expansion.