黄海纤毛虫的丰度和生物量

海洋浮游纤毛虫是在海洋中浮游生活的一类单细胞原生动物，主要是指寡毛类纤毛虫(Oligotrich ciliates)，隶属原生动物界(Protozoa)、纤毛门(Ciliophora)、寡毛纲(Oligotrichea)，分属于Oligotrichina 和Tintinnina两个亚纲。它们个体微小，粒径在5-200 µm之间，是微型浮游动物和海洋微食物环(Marine Microbial Food Web)的重要组成部分。 2006年4月至2007年12月，在黄海(包括胶州湾)采样分析海洋浮游纤毛虫的种类组成(砂壳纤毛虫)、丰度和生物量，分析纤毛虫在这一海区的季节变化和空间变化。 纤毛虫丰度和生物量的研究方法为：Rosette采水器(胶州湾用Niskin采水器)采集水样，取1 L水样，加Lugol’s试剂固定(终浓度1%)，Utermöhl方法100倍镜检。测量虫体的体长、体宽，按最接近的几何形状(圆柱体、球体和圆锥体)计算体积。生物量由体积乘转换系数(0.19 pgC/µm3)得到，砂壳纤毛虫的肉体体积按照壳体积的1/3近似。 本文的结果表明，胶州湾各站纤毛虫平均丰度于6月达到全年最高值6065 ind./L，12月为全年丰度最低值843 ind./L。平均生物量8月达全年最高值(18.5 µg C/L)，6月为全年最低值(0.6 µg C/L)。砂壳纤毛虫种丰富度于8月达到最高值，共发现25种砂壳纤毛虫，1月种类最少(6种)。湾内站位的纤毛虫平均丰度比湾外的高(6月和8月除外)。砂壳纤毛虫在纤毛虫总丰度中的比例较小，平均为25%，范围为8-57%，分别于1月和8月达到最低和最高值。 两次冷水团大面调查结果表明，4月表层纤毛虫平均丰度(1490 ind./L)要高于10月(972 ind./L)。10月表层纤毛虫生物量0.14-5.33 µg C/L，14194站、15694站和15894站生物量较高，为4.08-5.33 µg C/L。无壳纤毛虫优势种Laboea strobila在两个航次中均呈现斑块分布，4月航次丰度0-10000 ind./L，10月航次丰度11-350 ind./L；砂壳纤毛虫优势种Ptychocylis obtusa仅在4月航次发现，最大丰度2895 ind./L，10月航次未发现。4月航次砂壳纤毛虫有百乐拟铃虫(Tintinnopsis beroidea)，丰度为0-1920 ind./L；卡拉直克拟铃虫(Tintinnopsis karajacensis)，丰度很小(10-93 ind./L)。10月航次砂壳纤毛虫优势种Tintinnidium primitivum，丰度为35-700 ind./L；也出现了尖底类瓮虫(Amphorellopsis acuta)和网纹虫(Favella spp.)，但丰度不大(0-210 ind./L)；运动类铃虫(Codonellopsis mobilis)、筒状拟铃虫(Tintinnopsis tubulosoides)和Eutintinnus sp.丰度也较低(35-105 ind./L)；Craterella torulata丰度为0-120 ind./L，主要分布于15694站。10月航次已经出现了温跃层，位于30 m左右水层，纤毛虫主要分布于温跃层之上。 六次黄海断面航次表明：温跃层在5月已经出现，到12月消失。在有温跃层的5月、6月、8月、9月，纤毛虫主要分布于温跃层(30 m左右)之上。其中8月份航次纤毛虫丰度最高，表层平均丰度3103 ind./L。12月份纤毛虫丰度最低，表层平均丰度406 ind./L。纤毛虫生物量春夏季为0.02-5.5 µg C/L，冬季为0.04-1.99 µg C/L。小型无壳纤毛虫占优势，砂壳纤毛虫东方拟铃虫(Tintinnopsis orientalis)、筒状拟铃虫、运动类铃虫、Craterella torulata和Tintinnidium primitivum几乎在各个航次均有分布。

Spatial distribution of ciliates, copepod nauplii and eggs, Engraulis japonicus post-larvae and microzooplankton herbivorous activity in the Yellow Sea, China

The abundance of anchovy Engraulis japonicus larvae, >20 mum ciliates, copepod eggs and nauplii, and microzooplankton herbivorous activity were studied in the Yellow Sea in June 2000. Anchovy juveniles and larvae were found in only 6 of the 19 stations sampled. The ciliate communities were dominated by 2 species: Laboea strobila and Strombidium compressum. In the surface waters, the abundance of L. strobila ranged between 0 and 560 ind. l(-1). S. compressum only appeared at Stns 15 to 18 (20 to 3300 ind. l(-1)). L. strobila was found mainly in the top 20 m. The abundance of L. strobila was less than 50 ind, l(-1) in waters deeper than 25 m. S, compressum showed subsurface abundance peaks at the salinity abnormality. Tintinnids occurred occasionally with abundance lower than 100 ind. l(-1), The total ciliate abundance fell in the range of 40 to 3420 ind. l(-1). The ciliate biomass in the surface water and the water column ranged between 0,15 and 6.76 mug C l(-1) and 0.4 and 134.4 mg C m(-2), respectively, In the surface waters, the abundance of copepod eggs and nauplii ranged from 0,3 to 3.1 and 1,1 to 15.6 ind, l(-1), respectively. The average abundance of copepod eggs and nauplii in 4 depth (0, 5, 10 and 20 m) fell in the range of 0.2 to 2.8 and 1.0 to 29.4 ind. l(-1), respectively. As a food item of the E. japonicus post-larvae, the abundance of copepod nauplii and eggs appeared to be low. The abundance peaks of ciliate and E, japonicus post-larvae coincided. Although not found in the gut of E, japonicus post-larvae, aloricate ciliates might be ingested by first-feeding anchovy larvae, preventing initial starvation and prolonging the time to irreversible starvation. On the basis of dilution experiments with positive microzooplankton grazing rates, microzooplankton grazed at rates of 0 to 0.61 d(-1). Grazing pressure of microzooplankton on chlorophyll a standing stock (P-i) and potential chlorophyll a primary production (P-p) were 17 to 46% and 35 to 109% d(-1), respectively.

THE CHOLINERGIC, SEROTONINERGIC AND PEPTIDERGIC COMPONENTS OF THE NERVOUS-SYSTEM OF MONIEZIA-EXPANSA (CESTODA, CYCLOPHYLLIDEA)

The central (CNS) and peripheral (PNS) nervous systems of the cyclophyllidean tapeworm, Moniezia expansa, were examined for the presence of cholinergic, serotoninergic and peptidergic elements using enzyme cytochemical and immunocytochemical techniques in conjunction with light and confocal scanning laser microscopy. Cholinesterase activity and 5-hydroxytryptamine- and regulatory peptide-immunoreactivities (IRs) were localized to the nerve fibres and cell bodies of all of the major neuronal components in the CNS of the worm, including the cerebral ganglia and connecting commissure, the 10 longitudinal nerve cords and associated transverse ring commissures. Although each of the 3 systems appeared well developed and comprised a significant portion of the nervous system, the serotoninergic constituent was the most highly developed, consisting of a vast array of nerve fibres and cell bodies distributed throughout the strobila of the worm. A close association of cholinesterase reactivity and peptide-IRs was evident throughout the CNS, indicating the possible co-localization of acetylcholine and neuropeptides. Within the PNS, cholinergic activity and serotoninergic- and peptidergic-IRs occurred in the subtegumental network of nerve fibres and somatic musculature. Although all 3 neurochemical elements were present in the acetabula, they were found in different nerve fibres; only cholinergic and peptidergic cell bodies were found. The common genital opening, vagina and ootype regions of the reproductive system displayed a rich innervation of all 3 types of neuronal populations. Within the peptidergic system, immunostaining with antisera raised to the C-terminus of the neuropeptide Y superfamily of peptides and the invertebrate peptides, neuropeptide F (M. expansa) and FMRFamide was the most prevalent. Limited positive-IR for substance P and neurokinin A were also recorded in the CNS of the worm.

Characterizations of juvenile stages of some semaeostome Scyphozoa (Cnidaria), with recognition of a new family (Phacellophoridae)

Phacellophora camtschatica has long been assigned to the semaeostome scyphozoan family Ulmaridae. Early stages (scyphistomae, strobilae, ephyrae, postephyrae, and young medusae) of the species were compared with those of several other semaeostomes currently assigned to Ulmaridae, Pelagiidae, and Cyaneidae. Juveniles of P. camtschatica did not strictly conform with characters of those of any of these families, and appeared intermediate between Cyaneidae and Ulmaridae. A new family, Phacellophoridae, is proposed to accommodate P. camtschatica.

A new species of Potamotrygonocestus Brooks & Thorson, 1976 (Eucestoda : Tetraphyllidea) from Plesiotrygon iwamae Rosa, Castello & Thorson (Mylliobatoidea : Potamotrygonidae) and a redescription of Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003

Potamotrygonocestus Brooks & Thorson, 1976 is currently represented by six recognised species of tetraphyllidean cestodes inhabiting Neotropical freshwater stingrays. Potamotrygonid stingrays examined to date have included only a single specimen of Plesiotrygon iwamae. Only one species of tetraphyllidean, Potamotrygonocestus chaoi Marques, Brooks & Araujo, 2003, has been described from this host, and this description was based on limited material. New efforts to document the diversity in this host species resulted in the collection of eight additional specimens of P. iwamae, one of these from the upper Rio Solimoes, at Sao Paulo de Olivenca Amazonas during September, 2003, and seven from the Baia do Marajo, Para, during November, 2003. The specimen from the upper Solimoees was found to be infected with P. chaoi. Voucher material from this stingray was used for the redescription of this cestode, which is characterized by strobila 8.78-22.83 mm long and a great number of proglottides, 58-93; the new material provided strobilar length and proglottis counts for complete worms. Potamotrygonocestus marajoara n. sp. is the second species of this genus reported from Plesiotrygon iwamae, although it appears to be restricted to the lower Amazon. This new species resembles P. chaoi in possessing filitriches and blade-like spinitriches on the scolex, cephalic peduncle and cirrus, but differs from other species of the genus in the number of testes, which is 44 on average per proglottis, and by having apical sucker measuring 95-175 mu m in length. Additional data on the distribution and morphology of the microtriches and a detailed description of the female reproductive system are also provided in this study.

Análise taxonômica e molecular de Cestoda nematotaeniidae parasito de intestino delgado de Rhinella marina (Linnaeus, 1758) (Amphibia: Bufonidae) de Belém-Pa

Os anfíbios da espécie Rhinella marina também conhecidos como Sapo-Cururu e possuem distribuição mundial. Possuem hábitos noturnos, e devido a sua alimentação bem diversificada vivem em diferentes habitats. Assim podem estar parasitados com uma variedade de helmintos. Dentre os helmintos, os cestodas são o objeto de estudo deste trabalho. Os membros da Família Nematotaennidae são comumente encontrados parasitando o intestino delgado de anfíbios e répteis. O presente trabalho tem como objetivo identificar e caracterizar morfologicamente e molecularmente um cestoda parasito de R. marina da cidade de Belém-PA. Para isso vinte hospedeiros foram capturados em domicílios da região metropolitana de Belém-PA e, após necropsia, os cestoda foram retirados do intestino delgado, alguns exemplares foram fixados em A.F.A, alguns fixados em Glutaraldeído a 2% em tampão cacodilato, e outros em álcool absoluto para serem processados para diferentes técnicas. Parte da amostra foi desidratada em uma série etanólica, corados com Carmin®, clarificados com Salicilato de Metila®. Alguns exemplares foram desidratados e incluídos em parafina para realização de cortes transversais e longitudinais. Os exemplares fixados em glutaraldeído foram desidratados e incluídos em Historesina®. Os cestoda também foram processados para microscopia Eletrônica de Varredura. A identificação foi realizada por meio de desenhos realizados no microscópio Olympus BX 41 com câmara clara, fotografias feitas em microscópio MEDILUX, com sistema de captura de imagem e MEV. Os Cortes histológicos longitudinais foram fotografados e com o Software RECONSTRUCTTM foi realizada a reconstrução tridimensional do corpo do parasito. Helmintos fixados em álcool absoluto foram submetidos a extração de DNA, amplificação gênica pela técnica de PCR e seqüenciamento de nucleotídeos. Os cestoda possuem um corpo cilíndrico, filiforme e indistintamente segmentado, exceto na porção posterior. Escólice com quatro ventosas sem rostéolo ou órgão apical, os proglotes grávidos apresentam duas cápsulas piriformes, que se fundem na base, contendo os ovos. A partir das observações por microscopia eletrônica e luz dos cestoda encontrados no intestino delgado de R. marina, observou-se que estes cestoda pertencem à Família Nematotaeniidae, no entanto os outros caracteres morfológicos e moleculares por nós encontrados não encaixam este cestóide em nenhum gênero desta Família.

Cathetocephalus thatcheri gen. et sp. n. (Tetraphyllidea: Cathetocephalidae) fam. n. from the Bull Shark

Cathetocephalus thatcheri gen. et sp. n. is described from the spiral valve of the bull shark, Carcharhinus leucas (Valenciennes), taken in the Gulf of Mexico and the Atlantic coast of Florida. A new family is erected for the new genus. The species most closely resembles Pillersium owenium Southwell, 1927, in that both possess a scolex which is perpendicular to the long axis of the strobila. It differs, however, in having a single neck and holdfast organ rather than a bifurcate neck with two bothridia. Also, the surfaces of the scolex differ from those of P. owenium by possessing fleshy papilliform structures on the leading and trailing edges rather than leaflike folds. Specimens with several strobilae are figured and discussed.

Chlorophyll a content, protist biomass and experimental plankton growth and mortality in West Greenland water samples

We evaluated the role of microzooplankton (sensu latto, grazers <500 µm) in determining the fate of phytoplankton production (PP) along a glacier-to-open sea transect in the Greenland subarctic fjord, Godthabfjord. Based on the distribution of size fractionated chlorophyll a (chl a) concentrations we established 4 zones: (1) Fyllas Bank, characterized by deep chl a maxima (ca. 30 to 40 m) consisting of large cells, (2) the mouth and main branch of the fjord, where phytoplankton was relatively homogeneously distributed in the upper 30 m layer, (3) inner waters influenced by glacial melt water and upwelling, with high chl a concentrations (up to 12 µg/l) in the >10 µm fraction within a narrow (2 m) subsurface layer, and (4) the Kapisigdlit branch of the fjord, ice-free, and characterized with a thick and deep chl a maximum layer. Overall, microzooplankton grazing impact on primary production was variable and seldom significant in the Fyllas Bank and mouth of the fjord, quite intensive (up to >100% potential PP consumed daily) in the middle part of the main and Kapisigdlit branches of the fjord, and rather low and unable to control the fast growing phytoplankton population inhabiting the nutrient rich waters in the upwelling area in the vicinity of the glacier. Most of the grazing impact was on the <10 µm phytoplankton fraction, and the major grazers of the system seem to be >20 µm microzooplankton, as deducted from additional dilution experiments removing this size fraction. Overall, little or no export of phytoplankton out of the fjord to the Fyllas Bank can be determined from our data.

Abundance and biomass of dinoflagellates and ciliates at time series station Helgoland Roads, North Sea, 2007-2009

A monitoring programme for microzooplankton was started at the long-term sampling station ''Kabeltonne'' at Helgoland Roads (54°11.30' N; 7°54.00' E) in January 2007 in order to provide more detailed knowledge on microzooplankton occurrence, composition and seasonality patterns at this site and to complement the existing plankton data series. Ciliate and dinoflagellate cell concentration and carbon biomass were recorded on a weekly basis. Heterotrophic dinoflagellates were considerably more important in terms of biomass than ciliates, especially during the summer months. However, in early spring, ciliates were the major group of microzooplankton grazers as they responded more quickly to phytoplankton food availability. Mixotrophic dinoflagellates played a secondary role in terms of biomass when compared to heterotrophic species; nevertheless, they made up an intense late summer bloom in 2007. The photosynthetic ciliate Myrionecta rubra bloomed at the end of the sampling period. Due to its high biomass when compared to crustacean plankton especially during the spring bloom, microzooplankton should be regarded as the more important phytoplankton grazer group at Helgoland Roads. Based on these results, analyses of biotic and abiotic factors driving microzooplankton composition and abundance are necessary for a full understanding of this important component of the plankton.