火腿伪镖水蚤对抑食金球藻中国株的摄食行为及摄食后的表现

全球河口海域屡屡爆发褐潮,但我们对致因种抑食金球藻和浮游桡足类之间的营养关系还不甚清楚。我们就浮游桡足类火腿伪镖水蚤摄食抑食金球藻中国株的单种或混合饵料时的摄食行为和生长、发育等表现进行了研究。研究发现：火腿伪镖水蚤的无节幼体、桡足幼体和成体摄食单种抑食金球藻饵料时,摄食率和食物浓度之间的关系符合米氏方程。较之桡足类幼体和成体,无节幼体摄食抑食金球藻时的I_max（最大摄食率）值最大,同时大于其摄食中肋骨条藻的I_max值。通常情况下,火腿伪镖水蚤在摄食抑食金球藻和中肋骨条藻的混合饵料时避食抑食金球藻,但于无节幼体,这种情况并不明显。无节幼体摄食单种抑食金球藻饵料在无节幼体期末期死亡,无法进入桡足类幼体期,与饥饿状态下的个体相似。但是,饵料中抑食金球藻的存在对桡足幼体的生长无明显效应,但却极大地减少了成体的生殖率。我们的研究表明火腿伪镖水蚤无节幼体,在褐潮的控制中有潜在作用,然而,这种潜在控制作用由于桡足类种群的衰落难以持续。     

Dietary separation between co-occurring copepods in a food-limited tropical coral reef of the Sanya Bay

Food differentiation among coexistent species in the field is important strategy for copepods to acquire materials and maintain population stabilization.In situ diet analysis of co-occurring six copepod species in coral waters of the Sanya Bay was conducted using a PCR protocol based on 18 S ribosomal gene.Various prey organisms were uncovered,including dinoflagellate,diatom,green algae and plant,protozoa and metazoan.All these spatially coexisting six species showed different dietary diversity,with the food niche breadth(B)ranging from 1.00(Temora turbinate in morning)to 10.68(Calanopia elliptica in night).While food overlap between all these copepods were low,with the average value of the diet niche overlap index being approximately 0.09.Even temporally co-existing species sampled from the same time point fed on different groups of prey items with the food overlap index of 0.04 to 0.07 in midday and night but 0 in morning.As the most important dominant copepod in the Sanya Bay,Subeucalanus subcrassus seems to be capable to regulate its feeding,by exhibiting a rhythm of herbivorous feeding in midday and carnivorous feeding in morning and night,to better coordinate with other competitors for utilization of food resources.For most copepods,none of the prey items belonged to the dominant phytoplankton in the ambient water,indicating that copepod can better their survival by widening the choice of potential food resources in food limited environment.The dietary separation observed here might be important strategy for copepod to maintain population stabilization and thriving in the Sanya coastal waters.     

First distribution record of the invasive copepod Oithona davisae Ferrari and Orsi, 1984, in the coastal waters of the Aegean Sea

The occurrence of the invasive nonindigenous copepod Oithona davisae Ferrari and Orsi, 1984, is reported for the first time in the Aegean Sea. The data we collected in August 2017 from 14 stations along the Turkish coast of the Aegean Sea reveal the spatial distribution of O. davisae between the openning of the Dardanelles Strait in the north and the Izmir Bay in the south. The O. davisae individuals, in seven mesozooplankton samples collected from a single station, were consistently found in the inner part of the Izmir Bay from April 2015‐October 2016. The abundance of female O. davisae ranged from 4 ind./m³ in April 2015 to 31,524 ind./m³ in July 2016 and contributed to the total oithonid female population by 10.8% in April 2015 and 92.8% in September 2016. Our results show that this species is well established in the inner part of Izmir Bay and that it has become a permanent component of the copepod community in the area.     

Protoraphis Simonsen,a newly recorded marine epizoic diatom genus for China

Epizoic diatoms on marine copepods are common in nature and may have a special ecological relationship with their hosts.However,this special ecological group is not well known,and it has only rarely been studied in the China seas.To address this knowledge gap,the species diversity and classification of epizoic diatoms on planktonic copepods were studied with samples collected from the East China Sea.In the present study,a marine araphid diatom genus Protoraphis and its type species,Pr.hustedtiana,were observed and identified by light and electron microscopy,thus representing the first record of this genus and its type species in China.This genus is characterized by a median sternum strongly bent to opposite sides and terminate in two transapical grooves at the valve ends.Protoraphis hustedtiana was found to be epizoic on the posterior body appendages and segments of the marine calanoid copepod Candacia bradyi.An internal view shows a complex,ear-shaped process that is close to the apical slit field.The ecological habitats and geographical distributions of Protoraphis were also discussed,and,together with complementary morphological studies,our results have increased the number of records for marine epizoic diatoms to three genera with three species in China,including Pseudohimantidium and Pseudofalcula.     

黄渤海双壳类的寄生剑水蚤类研究

本文对黄渤海双壳类的寄生桡足类进行了调查。共检查双壳类32种8628个体,从9种双壳类中发现了1126个寄生剑水蚤类标本。基于形态学研究鉴定出剑水蚤类8种,隶属于4科8属。分别为负羽壳蚤(Conchyliurus quintus Tanaka)、竹蛏赫尔曼蚤(Herrmannella soleni Kim&Ho)、拟舐皮蚤(Lichomolgus similis Ho&Kim)、二分偏顶蛤蚤(Modiolicola bifida Tanaka)、高氏牡蛎蚤(Ostrincola koe Tanaka)、多刺伪海螂蚤(Pseudomyicola spinosus(Raffaele&Monticelli))、东方贻贝蚤(Mytilicola orientalis Mori)和日本蹄螺蚤(Trochicola japonica Shimura&Kuwabara)。其中,高氏牡蛎蚤在中国黄海曾有报道,其余7种为中国新记录种。依据黄渤海的标本对上述物种的形态进行了简要描述和讨论,并对其宿主、感染率、感染强度、地理分布等进行了报道。     

中国海洋吸虫纲物种多样性的研究

在国家908专项调查和成果集成工作的基础上,结合对海洋吸虫文献资料的收集,分析研究了中国海洋吸虫的物种多样性.其结果表明中国海洋吸虫有1 184种,其中单殖目吸虫410种,复殖目吸虫774种.单殖目的宿主都是硬骨鱼.复殖目物种成虫的宿主主要是鱼,也有爬行纲和兽纲.吸虫感染宿主有些具有专一性,但也有些具有普遍性.宿主的食性、地理分布和季节分布与吸虫感染密切相关.不同于以往70多年来主要进行的分类研究,本文主要探讨海洋吸虫的生活史及与其宿主的关系,这将为水生生物病虫害的防治和海洋物种多样性的研究提供基础资料,具有重要生物学和生态学的意义.     

Seasonal Variations in Abundance and Size Composition of the Lobate Ctenophore Bolinopsis Mikado (Moser) in Tokyo Bay, Central Japan

Surveys of the abundance and size composition of the ctenophore Bolinopsis mikado were conducted in Tokyo Bay over a 5-year period from 1990 to 1994. B. mikado appeared throughout the year, and its mass occurrence was observed between August and November; annual maximum abundance ranged from 19 to 91 ind. m^–2. Water temperature seems to influence the seasonal variation of B. mikado abundance. Environmental conditions (e.g. rough waters due to a typhoon) and predation by the beroid ctenophore Beroe cucumis appear to affect annual variations of B. mikado abundance. Size frequency distributions of B. mikado indicated that its reproduction was most active in summer and fall but occurred throughout the year in Tokyo Bay. A sharp decline of the copepod population in August 1990 was probably due to predation by B. mikado which was very abundant at that time; its predatory impact was estimated to be 24 % day^–1.