羊年新春送福特派员招募记

2015年春节即将来临,神州大地到处洋溢着浓郁的年味。演播室也不例外,淘气章鱼一推开大门,就感觉年味扑面而来:传统的大红灯笼、精致的中国结、萌到爆的生肖羊……为了庆祝羊年的到来,淘气章鱼和飘逸水母特地穿上了唐装。淘气章鱼一走进演播室,就笑嘻嘻地行了一礼。"给大家拜年啦,祝愿大家在新一年里生活就像啃着甘蔗上楼梯。"

Reproductive Biology of Yellowfin Tuna T. albacares in the West-Central Indian Ocean

Survey of yellowfin tuna in the west-central Indian Ocean was conducted on board of Chinese longliners during 2003,2004 and 2005,which is a part of Chinese Tuna Fishery Scientific Observer Program(CTFSOP) . The reproductive biology has been investigated. A total of 1 023 samples are collected including 417 ovaries and 606 testes. Spawning activities of yellowfin tuna have been studied for both male and female from January to June. The data showed that the average monthly sex ratio is 0.59,and the minimum length at sexual maturity is 101 cm for female and 110 cm for male respectively. Length at 50% sexual maturity is esti-mated at 113.77 cm for female and 120.20 cm for male,whereas maturation rate is 0.066 cm-1 for female and 0.091 cm-1 for male. Sex ratio by length class indicates that the proportion of male is higher than female's along with size increasing;for instance,in the group of the body length longer than 145 cm,some females have their body length from 145 to 160 cm and males have their body length at 160 cm and even longer. Statistically,yellowfin tuna has a significant seasonal reproduction.

Application of a Delay-Difference Model for the Stock Assessment of Southern Atlantic Albacore(Thunnus alalunga)

Delay-difference models are intermediate between simple surplus-production models and complicated age-structured models. Such intermediate models are more efficient and require less data than age-structured models. In this study, a delay-differ- ence model was applied to fit catch and catch per unit effort （CPUE） data （1975-2011） of the southern Atlantic albacore （Thunnus alalunga） stock. The proposed delay-difference model captures annual fluctuations in predicted CPUE data better than Fox model. In a Monte Carlo simulation, white noises （CVs） were superimposed on the observed CPUE data at four levels. Relative estimate error was then calculated to compare the estimated results with the true values of parameters a and fl in Ricker stock-recruitment model and the catchability coefficient q. a is more sensitive to CV than fl and q. We also calculated an 80% percentile confidence interval of the maximum sustainable yield （MSY, 21756 t to 23408 t; median 22490 t） with the delay-difference model. The yield of the southern Atlantic albacore stock in 2011 was 24122t, and the estimated ratios of catch against MSY for the past seven years were approxi- mately 1.0. We suggest that care should be taken to protect the albacore fishery in the southern Atlantic Ocean. The proposed de- lay-difference model provides a good fit to the data of southern Atlantic albacore stock and may be a useful choice for the assessment of regional albacore stock.

Cloning and Expression Analysis of vasa During the Reproductive Cycle of Korean Rockfish, Sebastes schlegeli

Vasa, which is a conserved member of the DEAD-box protein family, plays an indispensable role in primordial germ cell proliferation. However, the expression ofvasa gene during the reproductive cycle in ovoviviparous fish has not been documented. In this study, the full-length sequence of vasa was obtained from the ovary of Korean rockfish （Sebastes schlegeli） using reverse transcription-PCR and rapid amplification of cDNA ends. The Vasa with a mature protein of 650 amino acids showed greatest homology （84%） with giant gourami （Osphronemus gorarny） and Pacific bluefin tuna （Thunnus orientalis）. The expression of vasa mRNA in Korean rockfish was detected in gonads only, suggesting its specific role in gonadal development. In addition, seasonal changes in the vasa expression levels were examined in gonads by quantitative real-time PCR. The vasa transcript levels in adult testis were found higher during spermatogenesis than during spermiation. The vasa transcript levels remained relatively high at the early ovary stage but declined during ovary maturation in adult female fish. These results suggest that the vasa gene play an important role in spermatogenesis and early oogenesis during the reproductive cycle of Korean rockfish.

Evaluation of Three Harvest Control Rules for Bigeye Tuna(Thunnus obesus) Fisheries in the Indian Ocean

The stock of Bigeye tuna(Thunnus obesus) in the Indian Ocean supports an important international fishery and is considered to be fully exploited. The responsible management agency, the Indian Ocean Tuna Commission(IOTC), does not have an explicit management decision-making framework in place to prevent over-fishing. In this study, we evaluated three harvest control rules, i) constant fishing mortality(CF), from 0.2 to 0.6, ii) constant catch(CC), from 60000 to 140000 t, and iii) constant escapement(CE), from 0.3 to 0.7. The population dynamics simulated by the operating model was based on the most recent stock assessment using Stock Synthesis version Ⅲ(SS3). Three simulation scenarios(low, medium and high productivity) were designed to cover possible uncertainty in the stock assessment and biological parameters. Performances of three harvest control rules were compared on the basis of three management objectives(over 3, 10 and 25 years): i) the probability of maintaining spawning stock biomass above a level that can sustain maximum sustainable yield(MSY) on average, ii) the probability of achieving average catches between 0.8 MSY and 1.0 MSY, and iii) inter-annual variability in catches. The constant escapement strategy(CE=0.5), constant fishing mortality strategy(F=0.4) and constant catch(CC=80000) were the most rational among the respective management scenarios. It is concluded that the short-term annual catch is suggested at 80000 t, and the potential total allowable catch for a stable yield could be set at 120000 t once the stock had recovered successfully. All the strategies considered in this study to achieve a ‘tolerable' balance between resource conservation and utilization have been based around the management objectives of the IOTC.

Maternal Inheritance of Yellowfin Tuna （Thunnus albacares） in Captivity

Mitochondrial DNA introgression has been suggested to be responsible for the maternal consistent implications. Study on mt-DNA （mitochondrial DNA） variation in the yellowfin tuna （Thunnus albacares） using RFLP （restriction fragment length polymorphisms） has provided the evidence of maternal inheritance of yellowfin tuna in captivity. Eggs were collected in every spawning in 2004-2006 season. The mt-DNA genotypes of broodstock were compared with their eggs and the maternal inheritance of these females was determined from genotypes in the eggs. The result showed that six genotypes of female broodstock were observed in eggs and four of them were found to share a single female＇s identity and one type was shared by two females. The same genotype was observed in almost every sampling throughout the year. The female broodstocks spawned almost daily throughout the season.

Evaluation of FAD-associated purse seine fishery reduction strategies for bigeye tuna (Thunnus obesus) in the Indian Ocean

In the Indian Ocean, bigeye tuna supports one of the most important fisheries in the world. This fishery mainly consists of two components: longline and purse seine fisheries. Evidence of overfishing and stock depletion of bigeye tuna calls for an evaluation of alternative management strategies. Using an age-structured operating model, parameterize dwith the results derived in a recent stock assessment,we evaluated the effectiveness of applying constant fishing mortality (CF) and quasi-constant fishing mortality (QCF) strategies to reduce fishing effort of purse seining with fish aggregating devices (FADs) at different rates. Three different levels of productivity accounted for the uncertainty in our understanding of stock productivity. The study shows that the results of CF and QCF are similar. Average SSB and catchduring simulation years would be higher if fishing mortality of FAD-associated purse seiningwas reduced rapidly. The banning or rapid reduction of purse seining with FAD resulted in a mean catch, and catch in the last simulation year, higher than that of the base case in which no change was made to the purse seine fishery. This could be caused by growth overfishing by purse seine fisheries with FADs according to the per-recruit analysis. These differences would be more obvious when stock productivity was low. Transferring efforts of FAD-associated purse seining to longline fisheries is also not feasible.Our study suggests that changes are necessary to improve the performance of the current management strategy.

New Easy Method for the Monitoring of Hg Concentration in Fish, Using a Nanostructured Gold Electrode

The applicability of a gold nanoparticle-modified glassy carbon sensor （AuNPs-GCS） for the determination of inorganic mercury in fresh and canned tuna fish by square wave anodic stripping voltammetry （SW-ASV） is demonstrated. Mercury content in sample Tuna Fish ISPRA T22 was determined to value the accuracy of the determination. The concentration in this sample is not certified, so, the Hg amount was determined also with atomic absorption spectroscopy （AAS）： the results obtained with ASV were in good agreement and confirmed literature value reported for this sample. Then, real samples of tuna fish were analyzed. The voltammetric analyses were performed using previously optimized conditions （deposition potential 0 V, step potential 0.004 V, frequency 150 Hz and amplitude 0.003 V）. Medium exchange technique permitted to eliminate possible matrix effects. The concentrations in the real samples were found to be in agreement with the common Hg levels reported in literature for commercialized tuna fish in different countries.

Comparison of Total Mercury Accommodations between Two Edible Fish Tissues （Tuna and Fitofag）

In this study, total mercury in canned tuna in comparison with Hypophthalmichthys molitrix （fitofag or phytophag） fish samples were determined by flow injection cold vapour generation atomic absorption spectrometry after digestion by the two different methods. The mercury concentration varied from 83 to 290 ng g~ with an average value of 147 ng g-1 in canned tuna, while the concentration varied from 14 to 56 ng g-1 with an average value of 26 ng g-1 for fitofag fish. Recoveries of the total mercury were in the range of 81-107% and 120-160% by method 1 and 2, respectively. The results of this study indicate that tuna and fitofag fish from the Persian Gulf area of Iran have concentrations well below the permissible FAO/WHO levels for total mercury and also the feed regime of fishes can affect the mercury accommodation. Therefore, their contribution to the body burden can be considering negligible and the fish seem to be safe for human consumption.

Utilization of Yellowfin Tuna and Red Snapper Roe Protein Concentrate as Emulsifier in Mayonnaise

Roes of yellowfin tuna （Thunnus albacares） and red snapper （Lutjanus champecanus） are considered as abundant and underutilized by-product in Indonesia. The production of roe protein concentrate （RPC） is expected to increase the economic value and potency of their usage. Tuna and red snapper RPC was defatted using etano195% with one, two, three and four times of repetition. Both RPC made with four times repetition of defatting had the highest protein content （79.90% and 80.72%）, showed high emulsion activity （97.46% and 99.62%） and emulsion stability （97.10% and 99.48%）, and decreased the interfacial tension of 51% and 55.9%, respectively. Mayonnaise was made with 0, 25, 50, 75 and 100% substitution level of each RPC with four times repetition ofdefatting. The physical, chemical and organoleptic properties of mayonnaise were studied. The best mayonnaise formulation was obtained from 50% substitution level of tuna and red snapper RPC. Mayonnaise with tuna and red snapper RPC had good viscosity （5,920 cPs and 5,845 cPs）, high emulsion stability （90.5% and 91.73%） and small fat globule size （±2.5 lam and ± 2.25 lam）, respectively. These mayonnaises also showed high score of spreadability and low intense of fishy odor. However they still had quite strong of fishy flavor based on scoring test.

Persistence of malachite green and leucomalachite green in perch (Lateolabrax japonicus)

The persistence of malachite green (MG), and its metabolite leucomalachite green (LMG), in fish tissues is still unclear, leading to many trade disputes. In this research, we established and evaluated an HPLC method that could detect MG and LMG simultaneously, and then investigated the persistence of these two toxins in the tissues of juvenile perch (Lateolabrax japonicus) post sub-chronic MG exposure at 1.0 mg/L. Exposure lasted for 2 h everyday and was repeated six times. The perch were then placed in MG-free seawater for 100 d to eliminate the toxins. Results show that MG accumulated in the tissues, including the gills, liver, muscle, blood and viscera, and then was metabolized rapidly to LMG. The concentrations of these two toxins increased significantly with the accumulation process. In general, the highest concentrations of MG and LMG in all tissue exceeded 1 000 μg/kg, except for MG in the muscle. The order of accumulation levels (highest to lowest) of MG was gill>blood>liver>viscera>muscle, while that of LMG was liver>blood>gill>viscera>muscle. High levels of MG or LMG could persist for several hours but decreased rapidly during the elimination process. The concentration of LMG was much higher than that of MG during the experiment, especially in the gill, liver and blood. Therefore, the three tissues play important roles in toxin accumulation, biotransformation, and elimination. Although the MG and LMG concentrations in muscle were much lower than in other tissues, the content still exceeded the European minimum required performance limit (MRPL), even after 2 400 h (100 d) of elimination. This demonstrates that it is extremely difficult to eliminate MG and LMG from tissues of perch, and therefore use of these toxins is of concern to public health.

翻江倒海的水下“特工” 水下无人航行器

近年来,无人航行器已经成为日益重要的作战工具。在最近的巴尔干和阿富汗战争中,无人飞机已受到公众的广泛关注。但是,无人航行器在海上所起的作用也同样重要。水下无人航行器能改变未来水下战争的模式。最近十年来,潜艇在水下战争中的任务已经改变。冷战时期深海作战的任务在很大程度上已不复存在,取而代之的是潜艇在沿岸海域作战以支援联合远征军事行动,潜艇的活动范围是更、有效的“准备作战区域”。与此同时,当前的政治环境要求把高价值作战平台及其乘员的危险减到最小程度。这些因素推动了作为潜艇秘密“作战助手”的水下无人航行器的开发。利用水下无人航行器,潜艇能在有障碍且有潜在危险的沿岸海域支援远征部队。美国海军已配备了第一代潜射水下无人航行器,用于执行水雷秘密侦察任务,2005年左右将引入下一代系统。美国海军水下作战中心认为,水下无人航行器为未来海战(特别是网络中心战)展示了巨大的希望。在网络化战斗群中,潜艇能够发射和回收水下无人航行器,极大地扩大艇载传感器和武器的覆盖区。这些秘密的航行器可以在水下或水面活动,收集情报、绘制作战区域地图、识别和跟踪感兴趣的目标并最终发射武器。美国海军海上系统司令部已公布了“海军水下无人航行器总计划”。

我们最后的年轻

一雨将下未下,已经一整个下午了,庸懒的空气中凝结着大量的水气,被风吹散在片片橘林里,之后原路返回,带来了橘林的清香,漂浮在车站的上空。站台上挑着担子的人,裤腿一片洇湿还挂着泥浆,在推推攘攘的手臂之间面色惶恐。