Life history and production of Capitella capitata (Polychaeta: Capitellidae) in Río de la Plata Estuary (Argentina)

A benthic survey was carried out from November 1998 to December 1999 in the tidal flats of Bahía Samborombón (Río de la Plata estuary, Argentina), in order to study the population structure, reproductive aspects, growth and secondary production of Capitella capitata (Fabricius, 1780). Growth was analyzed using ELEFAN routine, and the secondary production was estimated by Hynes and Coleman's method (1968). C. capitata did not present periods of very important recruitments throughout the year; however, the abundance of smallest size classes was higher during summer and autumn. The summer cohort showed a growth rate (K) of 2.05 and a seasonal growth oscillation (C) of 0.6, pointing out that worms grew very slowly during winter months. The life span of this cohort was 13 months. The autumn cohort showed a lower growth rate (K= 1.5) and its growth was lowest during winter. The life span was 15 months for this cohort. C. capitata in Punta Rasa presented an extended reproductive period, with absence of activity during winter months. The type of eggs and larvae suggest that C. capitata has benthic larval development in the study area, destining its reproductive effort to the production of a low number of eggs, and assuring larvae survival through incubation in brooding tubes. The annual mean biomass in Punta Rasa was 0.117 g m-2 (AFDW), with a mean secondary production of 0.23 g m-2 y-1 and a P/B ratio of 1.96 y-1. The relatively low density, biomass production and P/B ratio of C. capitata in Punta Rasa can be considered as reference values for this species inhabiting undisturbed or moderately disturbed areas.

Studies on freezing and storage of Psenopsis cyanea

The freezing and storage characteristics of Psenopsis cyanea caught on board FORV Sagar Sampada from a depth of 350 m off Cochin are reported. The fat content of the fish was high (15.58% on the weight of whole fish) and the meat was white in colour. Peroxide value, free fatty acids and thiobarbituric acid values increased during frozen storage and organoleptically the fish was acceptable up to 32 weeks at -22 ± 1°C.

Studies on canning Psenopsis cyanea

Suitability of Psenopsis cyanea, a deep sea fish caught on board FORV Sagar Sampada from a depth of 350m off Cochin for processing into canned product was studied. The fish having high fat content around 52% (DWB) and white attractive meat renders itself well for canning yielding a product good in organoleptic characteristics. However to have a presentable appearance to the product the fish has to be skinned prior to canning. Gentle agitation of P. cyanea in 0.25% aqueous solution of lactic acid at ambient temperature for 15 min followed by thorough washing yields skinless fish. Fish suffers around 8% (DWB) fat loss during skinning. Fish canned in natural style and in brine have better organoleptic characteristics initially. On storage they develop slight rancidity. Fish canned in oil maintains the characteristics over a longer period.

Partial characterization of the hemolytic activity of the nematocyst venom from the jellyfish Cyanea nozakii Kishinouye

Using a recently developed technique to extract jellyfish venom from nematocysts, the present study investigated the hemolytic activity of Cyanea nozakii Kishinouye nematocyst venom on chicken erythrocytes. Venom extract caused a significant concentration-dependent hemolytic effect. The extract could retain its activity at -80 degrees C but was unstable when kept at 4 degrees C and -20 degrees C for 2 days. The hemolytic activity was inhibited by heating within the range of 37-100 degrees C. The extract was active over a pH range of 5.0-8.63 and the pH optima for the extract was 7.8. Incubation of the venom with sphingomyelin specially inhibited hemolytic activity by up to 70%. Cu2+ and Mn2+ greatly reduced the hemolytic activity while Mg2+, Sr2+ and Ba2+ produced a relatively low inhibiting effect on the hemolytic activity. Treatment with Ca2+ induced a concentration-dependent increase in the hemolytic activity. In the presence of 5 mM EDTA, all the hemolytic activity was lost, however, the venom containing 1.5 mM EDTA was stable in the long-term storage. PLA(2) activity was also found in the nematocyst venom of C. nozakii. These characteristics provide us a fundamental knowledge in the C. nozakii nematocyst venom which would benefit future research. (C) 2010 Published by Elsevier Ltd.

Joint effects of population density and toxicant exposure on population dynamics of Capitella sp I

Very few studies have analyzed the dependence of population growth rate on population density, and even fewer have considered interaction effects of density and other stresses, such as exposure to toxic chemicals. Yet without such studies we cannot know whether chemicals harmful at low density have effects on carrying capacity or, conversely, whether chemicals reducing carrying capacity are also harmful at low density, impeding a population's capacity to recover from disturbance. This study examines the combined effects of population density and a toxicant (fluoranthene) on population growth rate (pgr) and carrying capacity using the deposit-feeding polychaete Capitella sp. I as a test organism. Populations were initiated with a stable age distribution, and population density and age/size distribution were followed during a period of 28 wk. Fluoranthene (FLU), population density, and their interaction influenced population growth rate. Population growth rate declined linearly with the logarithm of population biomass, but the slope of the relationship was steeper for the control populations than for populations exposed to 50 mug FLU/(g sediment dry mass). Populations exposed to 150 mug FLU/(g sediment dry mass) went extinct after 8 wk of exposure. Despite concerns that toxicant effects would be exacerbated at high density, we found the reverse to be the case, and effects of fluoranthene on population growth rate were much reduced in the region of carrying capacity. Fluoranthene did. reduce carrying capacity by 46%, and this could haven important implications for interacting species and/or sediment biogeochemical processes.

Morphological and physiological caste differences in Synoeca cyanea (Hymenoptera, Vespidae, Epiponini) according to the ontogenetic development of the colonies

Morphological caste differences in different stages of the biological cycle in Synoeca cyanea were not distinct. Females presented a gradual sequence in ovarian development from filamentous ovarioles to well developed ones with the presence of intermediates, with shorter ovaries than queens, which can be present or not according to the stage of colonial development. Such data suggest that access to the reproductive status would only be possible in some intervals of colonial development.

Temporal trends in reef fish assemblages inside Virgin Islands National Park and around St. John, U.S. Virgin Islands, 1988-2006

This report is a result of long-term fish monitoring studies supported by the National Park Service (NPS) at the Virgin Islands National Park since 1988 and is now a joint NPS and NOAA collaboration. Reef fish monitoring data collected from 1988 to 2006 within Virgin Islands National Park (VINP) and adjacent reefs around St. John, U.S. Virgin Islands (USVI) were analyzed to provide information on the status of reef fishes during the monitoring period. Monitoring projects were initiated by the National Park Service (NPS) in the 1980s to provide useful data for evaluation of resources and for development of a long-term monitoring program. Monthly monitoring was conducted at two reef sites (Yawzi Point and Cocoloba Cay) starting in November 1988 for 2.5 years to document the monthly/seasonal variability in reef fish assemblages. Hurricane Hugo (a powerful Category 4 storm) struck the USVI in September 1989 resulting in considerable damage to the reefs around St. John. Abundance of fishes was lower at both sites following the storm, however, a greater effect was observed at Yawzi Point, which experienced a more direct impact from the hurricane. The storm affected species differently, with some showing only small, short-term declines in abundance, and others, such as the numerically abundant blue chromis (Chromis cyanea), a planktivorous damselfish, exhibiting a larger and longer recovery period. This report provides: 1) an evaluation of sampling methods, sample size, and methods used during the sampling period, 2) an evaluation of the spatial and temporal variability in reef fish assemblages at selected reef sites inside and outside of VINP, and 3) an evaluation of trends over 17 years of monitoring at the four reference sites. Comparisons of methods were conducted to standardize assessments among years. Several methods were used to evaluate sample size requirements for reef fish monitoring and the results provided a statistically robust justification for sample allocation.

Diversity, abundance distribution and secondary production of intertidal and subtidal benthic macrofauna of Bushehr Province with emphasis on annelida groups

The present investigation was undertaken to establish a reference situation for future use, to identify temporal and spatial composition of macrofauna and estimate some ecological indices in the sub tidal waters along the Bushehr coastal waters in Persian Gulf. Six transects were selected including Genaveh, Farakeh, Shif, Bandargah, Rostami and Asalouyeh, at each transect 3 station were sampled in depths of zero, 5 and 10 metres. Sampling was seasonally carried out by a VAN VEEN grab 0.0225 m2, during summer 2008 until spring 2009. Samples were wet sieved immediately using 0.5 mm mesh size sieves and sediment retained in the sieve was preserved in 4% buffered formalin solution. Macrofauna specimen were separated from the sediments using decantation and elutriation methods, enumerated and identified up to the Genus level. Environmental factors such as temperature. pH, and salinity were recorded in field using sensitive probs and refractometer (for salinity) and also sediment samples were taken for TOM and grain size analysis in all the stations. 5611 specimens belonging to 66 genera were collected during the present study. Polychaetes were dominant both in terms of genus number (31) and relative abundance (74 % of total macrofaunal abundance). The other dominant groups were Artheropoda, (16.1%), Molusca (2.8%), Echinodermata (1.29%) and others including Nematoda, Nemertina, Echiura and Turbellaria (5.8%). Thirty one Genera belong of 27 families of polychaeta, one genus and family of Subphylum Chlicerata,19 genera belong to 14 families of Crustacea, 8 genera belong to 6 families of Molusca, were indentified in the studied region. 1 family (Polygordidae) and 3 genera (Flabeligera, Pilargis and Polygordius) of Polychaeta, 1 family (Nymphonidae) and genus (Nymphon) of Chelicerata, 1 Family (Nematoplanidae) and genus (Nematoplana) of Turbellaria, were identified for the first time in Persian Gulf area. The result indicated that macrofauna organism have strong relationship with the grain size characteristics of the sediments they inhabit. The most surface deposit feeder specimens such as Prionospio and Cossura were found in zero meters depth of Genaveh, Farakeh, Bandargah, Rostami and Asalouyeh stations with sandy substratum, however the most burrowing deposit feeder and scavenger specimens such as Capitella and Petaloproctus were collected in 5 and 10 meter depths of stations with silty–clay substratum. The annual mean abundance, Shanon- weiner diversity and evenness of macrofauna were estimated1152.73 N/ m² , 2.72 and 0.792 respectively .The annual average biomass and secondary production were computed 1.797 gDW m² and 3.594 gDW m² y-1 .The average of water temperature, salinity, pH and oxygen concentration were recorded between 16.37-36.05 °C, 38-42 g/l, 7.89-8.76 and 4.23-8.23 mg/l, respectively during this study in 6 studied region. Among of investigated stations Asalouyeh adjacent of effluent canal of Gas and petrochemical industry sewage and Farakeh regions adjacent the Helleh estuary had the lowets and the highest community indices. The average of diversity and density in 5 meters depth stations with moderate of sand, silt and clay were slightly more than 2 other depths stations, it seems that 5 meters stations are made a transition habitats between 2 sandy and clay habitats, that can be used by 2 groups of surface and borrowing deposit feeders. Based on the data provided in this survey, the temperature variation, sediment texture, TOM, type habitat and manmade factors of Gas and petrochemical industries have had the most effect on the macrofauna community structure in the studied region during sampling periods.

Six new records of intertidal polychaetes from Pakistan

This paper describes six species of polychaete worms, which are new records from Pakistan. The species are: Arabella iricolor (Montagu), Capitella capitata (Fabricius), Mesochaetopterus sagittarius (Claparede), Phyllochaetopterus herdmani Willey, Lysidice natalensis Kinberg and Marphysa depressa (Schmarda).

黄东海胶质浮游动物水母类研究

近年来，胶质类浮游动物尤其是水母类在近岸高生产力的海洋生态系统中的作用越来越受到全球科学家们的关注。这种关注很大程度上是由于近年来很多海域或海湾出现水母类大量繁殖的现象而引起的，这种现象与过度捕捞、气候变化、富营养化以及生物入侵等因素有着内在的联系，给人们带来经济，社会和生态等各方面的损失。这种损失包括：当水母大量出现时，由于它们与鱼类存在食物和捕食竞争，使渔业资源和渔业生产锐减；由于它们会堵塞和撕破渔业生产网，干扰了人们的渔业生产活动；另外水母增多增加了海滨游泳爱好者被蛰伤甚至死亡事件发生的频率，对旅游者们的娱乐行为造成不便。到目前为止全球范围内报道了许多水母大量繁殖并对经济社会或海洋生态系统造成负面影响的事件。在北海水母数量爆发的频率与气候相关的事实表明了该海域将要面临一个更多的胶质类浮游动物的未来。所有这些都表明海洋中水母的生态学问题仍旧是全球的一个研究热点。到目前为止，在世界上许多海湾和海区有关水母生态学问题的研究上，均已取得方方面面有意义的进展。但在我国，由于对水母功能群的研究缺乏足够的重视，对于大型水母来讲它们被认为是渔业生产的副产品或者‘垃圾’，在渔业拖网捕获后把它们直接扔入海中并不去研究；对于小型水母来讲，因为它们为非饵料生物，并且有易碎，粘糊糊等难操作的特点，对浮游生物网同步采集到的水母的研究力度远不如对其他浮游动物类群的研究力度，因此我国对水母功能群生态学的研究基础相当薄弱。 本论文基于以上背景对黄东海大型和小型水母类的生物地理分布格局进行了研究，对其生物量或丰度等生态学指标进行了定量研究。（1）利用浮游生物网样品对黄海小型水母类的种类组成及其丰度的时空变化进行了研究，表明黄海测区内小型水母整体丰度很低，且主要分布在50 m等深线以浅海域，各水母类群以及优势种类的季节更替非常明显。比较不同海区的小型水母的丰度水平及其占浮游动物丰度的比例，发现黄海的小型水母丰度水平最低，为0.8（0.04–1.3）ind. m-3，只占浮游动物丰度的 < 0.5 %，表明小型水母在黄海海域并非占优势的功能群。（2）在中国黄东海采集的沙海蜇和在日本采集的越前水母的COI基因序列差异（0.2%）处于种内水平，从分子水平上证明两者为同一个种类，基于形态学和分子生物学的证据，我国大型水母沙海蜇的分类地位可初步订正为：Nemopilema nomurai Kishinouye, 1922（Scyphozoa：Rhizostomeae：Rhizostomatidae）。（3）利用渔业底层拖网的方法对黄东海大型水母的种类组成，总生物量及各优势种类生物量的时空分布进行了半定量研究。结果共鉴定到11个种（类），其中沙海蜇（Nemopilema nomurai），洋须水母（Ulmaridae genus sp.）以及多管水母（Aequorea spp.）为黄海的优势种（类），沙海蜇（只在东海北部）和霞水母（Cyanea spp.）为东海的优势种（类）；这四个种（类）的湿重随着伞径的增大成冪增长的方式。大型水母平均总生物量的季节变化模式为：3月份水母总生物量最低，为4.6 ± 9.4 kg km–2，春夏季随着海水表层温度的升高，大型水母的生物量逐渐增加，9月初水母的总生物量达到最高值，为22891 ± 25888 kg km–2，随后随着海水的温度下降，生物量也逐渐下降。洋须水母的生物量在10月份达到最高值（2780 ind. km–2，1807 kg km–2），主要在黄海中部出现。多管水母在5月份丰度最高，为8262 kg km–2，且主要分布在30N以北海域。 聚焦大量爆发的水母种（类）沙海蜇和霞水母，基于实测的拖网资料，提供了该种可见的浮游阶段1周年的地理发生和生物量数据；结果表明，这两个种（类）表现了不同的季节出现和生物量格局：首先是黄海出现的沙海蜇（5–12月在黄海出现），5月份少量幼水母体在黄东海的交界处出现，6月它们的分布范围在南黄海扩大，到8月末及9月初沙海蜇几乎遍布黄海，其生物量和丰度以压倒其他大型水母类的优势形成“bloom”（生物量占所有大型水母的96.7%，丰度占93%，在南黄海平均生物量20446 kg km-2，平均占渔获物生物量的86.1 %），10月份至12月，沙海蜇的生物量逐渐减少甚至为零，其分布区域也向北回缩。其次为东海出现的霞水母（5月–10月）：霞水母在5月初达到生物量的高值（平均生物量为380 kg km-2），其伞径随纬度的升高而变小，8月至10月其生物量骤然下降。这两个种类的生物量高值分布在温度或潮汐锋区。结合水文条件及沙海蜇和霞水母关键的生活史策略推测了黄东海该种浮游阶段的生活史模型。 最后，通过对黄海8、9月份沙海蜇生物量的最高峰或暴发时期的呼吸率，摄食率进行估算，获得其每天对浮游动物现存量及生产力的潜在摄食压力，结果表明2006年9月在对沙海蜇最大捕获率的情况下，沙海蜇的摄食率为8.37（0.12–37.83）mg C m-2d-1，假设都以浮游动物为食，这时每天对浮游动物现存量及生产力的摄食压力分别为11.2%（0.17–50.6%），134.1%（1.98–605.7%）。因此在沙海蜇暴发期间对浮游动物的潜在的消耗非常大，甚至为毁灭性的。

两种大型水母毒素的分离纯化及其蛋白酶活性和抗氧化活性的研究

水母在我国分布广，种类多，数量大，是一种丰富的海洋生物资源。已研究的水母毒素主要分布于触角和刺丝囊中，是一类结构新颖独特的肽类毒素。水母种类的不同，其毒素的结构、生物活性往往不同。本文首次报道了海蜇（Rhopilema esculentum Kishinouye）毒素 和白色霞水母（Cyanea nozakii Kishinouye）毒素的提取、纯化、理化性质及蛋白酶和抗氧化方面的生物学活性，主要结果如下： 1.用DEAE Sepharose Fast Flow分离海蜇毒素，用含0.4 mol/L NaCl 的PBS (0.02 M，pH 8.0) 进行阶段洗脱时，得到的组分是组蛋白H4。 2.水母毒素的蛋白酶活性实验结果为：海蜇毒素和白色霞水母毒素都有蛋白酶活性。该两种毒素的蛋白酶活性都受理化因素的影响，其中0.5%甘油和1%邻菲罗啉可以有效的抑制海蜇毒素的蛋白酶活性。 3.对海蜇毒素蛋白的体外抗氧化活性研究表明：蛋白样品均具有抗氧化性，它们对超氧阴离子和羟自由基具有显著的清除作用。对白色霞水母毒素蛋白的体外抗氧化活性研究表明：白色霞水母蛋白具有较高的清除羟自由基的能力，白色霞水母蛋白对超氧阴离子的清除作用较弱。白色霞水母蛋白有较强的还原能力，但没有螯合能力。 通过本文的研究表明水母毒素具有蛋白酶活性和抗氧化活性，能够清除氧自由基。这些研究结果为开发利用水母资源和毒素的合理、综合利用打下了坚实的基础。

The broad-scale distribution and abundance of Scyphomedusae in Irish waters

Scyphomedusae are receiving increasing recognition as key components of marine ecosystems. However, information on their distribution and abundance beyond coastal waters is generally lacking. Organising access to such data is critical to effectively transpose findings from laboratory, mesocosm and small scale studies to the scale of ecological processes. These data are also required to identify the risks of detrimental impacts of jellyfish blooms on human activities. In Ireland, such risks raise concerns among the public, but foremost amongst the professionals of the aquaculture and fishing sectors. The present work looked at the opportunity to get access to new information on the distribution of jellyfish around Ireland mostly by using existing infrastructures and programmes. The analysis of bycatch data collected during the Irish groundfish surveys provided new insights into the distribution of Pelagia noctiluca over an area >160 000 km2, a scale never reached before in a region of the Northeast Atlantic (140 sampling stations). Similarly, 4 years of data collected during the Irish Sea juvenile gadoid fish survey provided the first spatially, explicit, information on the abundance of Aurelia aurita and Cyanea spp. (Cyanea capillata and Cyanea lamarckii) throughout the Irish Sea (> 200 sampling events). In addition, the use of ships of opportunity allowed repeated samplings (N = 37) of an >100 km long transect between Dublin (Ireland) and Holyhead (Wales, UK), therefore providing two years of seasonal monitoring of the occurrence of scyphomedusae in that region. Finally, in order to inform the movements of C. capillata in an area where many negative interactions with bathers occur, the horizontal and vertical movements of 5 individual C. capillata were investigated through acoustic tracking.