新疆菱形藻属和细齿藻属(硅藻门)中国新记录植物

2001年7月至8月、2007年7月分别两次在新疆各地采集硅藻标本,经显微观察,共鉴定出菱形藻属和细齿藻属(硅藻门)中国新记录植物11种1变种,其中菱形藻属9种:额雷菱形藻(Nitzschia eglei Lange-Bertalot)、弯曲菱形藻(N.flexa Schumann)、多样菱形藻(N.diversa Hustedt)、化石菱形藻[N.fossilis (Grunow) Grunow]、吉斯纳菱形藻(N.gessneri Hustedt)、平庸菱形藻(N.inconspicua Grunow)、辐射菱形藻(N.radicula Hustedt)、常见菱形藻(N.solita Hustedt)和粗肋菱形藻(N.valdecostata Lange-Bertalot & Simonsen);细齿藻属2种1变种:科瑞提细齿藻[Denticula creticola (strup) Lange-Bertalot & Krammer]、库津细齿藻汝牧变种(D.kuetzingii var.rumrichae Krammer)和强壮细齿藻[D.valida (Pedicino) Grunow].并对其12种新记录植物的分类学特征进行了详细的描述.     

大兴安岭达尔滨湖桥弯藻科（硅藻门）中国新记录植物

报道了采自大兴安岭达尔滨湖及其周围沼泽水体的硅藻门桥弯藻科中国新记录植物9种1变种,分别为新箱形桥弯藻新月变种Cymbella neocistulavar.lunataKrammer、近箱形桥弯藻Cymbella subcistulaKrammer、疏纹内丝藻Encyonema paucistriatum(Cleve-Euler)Mann、普通内丝藻Encyonema vulgareKrammer、尖锐弯肋藻Cymbopleuraacuta(Schmidt)Krammer、英吉利弯肋藻Cymbopleura anglica(Lagerstedt)Krammer、线形弯肋藻Cymbopleura linearis(Foged)Krammer、十字形弯肋藻Cymbopleura stauroneiformis(Lagerstedt)Krammer、泰尼弯肋藻Cymbopleura tynnii(Krammer)Krammer、两尖拟内丝藻Encyonopsis amphioxys(K櫣tzing)Liu et Shi。其中两尖拟内丝藻Encyonopsis am-phioxys(K櫣tzing)Liu et Shi为新组合。对这些种类进行了光镜观察,部分种类进行了扫描电镜观察,对其分类学特征进行了详细的描述,并记录了它们的生境特征。     

中国黄藻纲植物新记录属和种

报道了采自中国山西、黑龙江、上海、浙江等地的中国黄藻纲植物新记录14种,隶属于7个属,其中椭球藻(属Ellipsoidion)、拟杆藻属(Bumilleriopsis)、异毛藻属(Heterotrichella)和异丝藻属(Heterothtix)4个属在中国是首次报道。     

四川甘孜曲丝藻科硅藻中国新记录

在四川省甘孜藏族自治州进行硅藻多样性调查时,发现了单壳缝目硅藻中国新记录8种1变种(隶属于4属),分别为:原子曲丝藻Achnanthidium atomus Monnier,Lange-Bertalot&Ector、施特劳宾曲丝藻A.straubianum (Lange-Bertalot) Lange-Bertalot、亚显曲丝藻A. pseudoconspicuum (Foged) Jüttner&Cox、半孔曲丝藻A. semiapertum (Guermeur) Andresen,Stoermer&Kreis、阿雷塔斯真卵形藻Eucocconeis aretassii(Manguin) Lange-Bertalot、披针平面藻微小变种Planothidium lanceolatum var. minor Cleve、厄氏平面藻P.oestrupii (Cleve-Euler) Edlund、球囊沙生藻Psammothidium sacculus (Carter) Bukhtiyarova和双生沙生藻P.didymum (Hustedt) Bukhtiyarova&Round。利用光学显微镜(LM)及扫描电镜(SEM)对8种1变种进行观察,并对其形态特征和生境进行了详细描述。     

中国多辐藻属(Myriactula)三个新记录种

报道中国产粘膜藻科(Leathesiaceae)多辐藻属(Myriactula)三个新记录种:阿拉伯多辐藻(Myriactula arabica)、粗丝多辐藻(M.clavata)和马尾多辐藻(M.sargassi)。     

大兴安岭地区硅藻中国新记录

报道了采自中国大兴安岭地区的中心类及无壳缝类硅藻植物5属9种,其中含3个中国新记录种:正链藻属的角状正链藻Orthoseira roeseana(Rabenhorst)O'Meara、脆杆藻属的古拉德脆杆藻Fragilaria goulardii(Brébisson)Lange-Bertalot和菱形脆杆藻Fragilaria nitzschioides Grunow。对国内文献报道较少的正链藻属、假十字形藻属、类十字形藻属、十字形藻属植物的形态特征进行了描述;对9种硅藻植物的分类特征及生态分布特点进行了描述。     

武汉东湖隐藻门植物的分类学研究

隐藻门植物在各种淡水水体中很常见,其中卵形隐藻、啮蚀隐藻在国内被多次报道过。但是由于缺乏分类学的资料,国内关于隐藻门植物的报告并不完全准确,其类群也常常被忽视。我们在2009年6月到2010年3月间,不定期从武汉东湖的各个区域采集水样,共鉴定隐藻门植物4属8种：卵形隐藻、啮蚀隐藻、蛋白核隐藻、四蛋白核隐藻、马索隐藻、反曲弯隐藻、犀角织隐藻、具尾逗隐藻。其中四蛋白核隐藻和犀角织隐藻为中国新记录。作为具尾逗隐藻的异名,尖尾蓝隐藻此前也曾在国内被报道。     

中国连珠藻属(串珠藻科)的分类研究

记述了中国产连珠藻属Sirodotia Kylin的6个种,即黄山连珠藻S.huangshanensis Z．X．Shi et S．L.Xie,威拉连珠藻S．huillensis(Welwitsch ex W．et G．S．West)Skuja,中华连珠藻S.sinica Jao,纤细连珠藻S.delicatula Skuja,瑞典连珠藻S.suecica Kylin和细连珠藻S．tenuissima(Collins)Skuja ex Flint。其中,黄山连珠藻S．huangshanensis Z．X．Shi et S．L.Xie为新种,威拉连珠藻S.huillensis(Welwitsch ex W．et G．S．West)Skuja,纤细连珠藻S．delicatula Skuja和瑞典连珠藻S.suecica Kylin为中国新记录。     

异极藻属(硅藻门)5种中国新记录

对采自海南省三亚亚龙湾国家森林公园,湖北省神农架大九湖湿地和黑龙江省兴凯湖湿地的硅藻标本进行分类学研究,发现异极藻属植物中国新记录5种,分别是狭状披针异极藻(Gomphonema acidoclinatum LangeBertalotReichardt)、矛形异极藻(Gomphonema hasta D.Metzeltin)、林氏异极藻(Gomphonema kobayashiae MetzeltinLange-Bertalot)、宽缘异极藻(Gomphonema latipes E.Reichardt)和隐形异极藻(Gomphonema occultum ReichardtLange-Bertalot)。对相似种类之间的形态差异进行比较,为中国异极藻属植物的分类学研究提供基本资料。     

中国眼裸藻属(Euglenaria)分类学研究

为对眼裸藻属Euglenaria Karnkowska, Linton&Kwiatowski进行分类学修订,研究以采自中国的12株3种眼裸藻属物种为材料,基于形态学和分子生物学手段对眼裸藻属进行系统发育研究,鉴定了3种眼裸藻属物种,分别是尾眼裸藻Euglenaria caudata (Hubner) Karnkowska et Linton、项圈眼裸藻Euglenaria anabaena(Mainx) Karnkowska et Linton和棒形眼裸藻Euglenaria clavata (Skuja) Karnkowska et Linton,提供了它们的形态特征及分子数据。基于最大似然法和贝叶斯法构建了系统发育树,以亲缘关系较近的双鞭藻科Eutreptiaceae Hollande物种为外类群,其余的裸藻类分为扁裸藻科Phacaceae Kim, Triemer&Shin和裸藻科Euglenaceae Dujardin物种两大支,眼裸藻属位于裸藻科分支(0.84/-),共包含28株眼裸藻属物种,主要分为3个小分支,每个小支的支持率均高达99%以上,项圈眼裸藻和尾...     

RAMET DYNAMICS FOR THE CLONAL SEAWEED PTEROCLADIELLA CAPILLACEA (RHODOPHYTA): A COMPARISON WITH CHONDRUS CRISPUS AND WITH MAZZAELLA CORNUCOPIAE (GIGARTINALES)

Little is known about the dynamics and the ecological interactions among ramets (fronds) from populations of clonal red seaweeds. Small ramets are very difficult to tag, so their growth cannot be monitored directly. The temporal variation of the relationship between stand biomass and ramet density offers information on ramet performance. We calculated this relationship for an intertidal population of Pterocladiella capillacea (Gmelin) Santelices et Hommersand (Gelidiales) from Baja California, Mexico. Biomass and density were positively correlated on an annual basis, indicating that biomass accumulated without involving self-thinning among ramets. This contrasts with nonclonal seaweeds, for which self-thinning among individuals occurs during growth, but agrees with other clonal red seaweeds, such as Chondrus crispus Stackhouse and Mazzaella cornucopiae (Postels et Ruprecht) Hommersand (both Gigartinales). The growth pattern for these members of the Gelidiales and of the Gigartinales holds despite differences in holdfast morphology and ramet branching degree and despite differences in the capacity of coalescence during early stages, known only for the Gigartinales. The positive slope for the dynamic biomass–density relationship, on a bilogarithmic scale, was statistically steeper for M. cornucopiae than for P. capillacea and for C. crispus. This suggests that the addition of new ramets during the growth season may be relatively more beneficial for biomass accumulation rates for M. cornucopiae. This would be expected for high-intertidal species subjected to strong abiotic stress, for which ramet crowding constitutes a key protection. Pterocladiella capillacea occurs at the mid-intertidal zone and C. crispus at the subtidal zone, so ramets would be relatively less important in that respect.     

CONVERGENT BIOLOGICAL PROCESSES IN COALESCING RHODOPHYTA

Sporeling coalescence in Gracilaria chilensis Bird, McLachlan et Oliveira produces genetically polymorphic, chimeric individuals. If this is common in red algae, it may have significant biological consequences. In this study, we evaluate the hypotheses that coalescence is widespread among the Rhodophyta and that specific and convergent morphological and ecological responses characterize this as a unique growth style among marine algae. A literature survey on coalescence was undertaken to assess the distribution of this condition in the Florideophycidae. Sixty-two (54.9%) of 113 species considered germinated to form a disk. Subsequent development in 37 of these species showed crust formation and coalescence during development with other crusts in 31 species (84%). Coalescing red algae were members of the orders Ahnfeltiales, Corallinales, Gigartinales, Gracilariales, Halymeniales, Palmariales, and Rhodymeniales. Ultrastructural studies in species of Ahnfeltiopsis, Chondrus, Gracilaria, Mazzaella, and Sarcothalia suggested a common pattern of early development. Newly released, naked spores may fuse into a single cell, as they do in Chondrus canaliculatus, or they may develop individual cell walls that later are surrounded by a thickened common wall. Ultrastructural studies demonstrated two kinds of immediate development after the first mitotic division: direct development by symmetric divisions resulting in discoid sporelings or an indirect asymmetric arrangement of divisions before a diskoid sporeling was formed. Germination in coalescing species is a linear function of the initial spore density, whereas in noncoalescing species maximum germination occurs at intermediate densities. In the field, coalescing species may recruit either from solitary or aggregated spores. However, survival is significantly higher for plantlets grown from a larger number of coalescing spores. Total number of erect axes formed by the coalesced mass is a logarithmic function of the initial number of spores. Thus, germlings grown from a larger number of coalescing spores exhibited a larger photosynthetic canopy than do plantlets grown from a few spores. Juveniles and mature clumps grown from a coalescing mass may exhibit size inequalities among erect axes, with the larger axes located toward the center of the clump. These larger axes mature first or, in some cases, are the only to produce spores. The widespread occurrence of coalescence inroughly half the number of orders of the Florideophycidae, the similarity of the coalescence process, and the finding of various adaptive traits associated with coalescence characterizes this as a unique growth style, splitting the diversity of species now included in the Florideophycidae into two major groups: coalescing and noncoalescing Rhodophyta.     

Life history,morphology and crossability of Chondrus ocellatus forma ocellatus and C. ocellatus forma crispoides (Gigartinales,Rhodophyta) from the north-western Pacific

The morphology, life histories and crossability in culture are described for the marine red algae Chondrus ocellatus Holmes forma ocellatus from Japan, China and Korea and C. ocellatus f. crispoides Mikami (Gigartinaceae, Rhodophyta) from Japan. In culture, all isolates of both formae showed a Polysiphonia-type life history typical of the family Gigartinaceae. Plants of C. ocellatus f. ocellatus from Korea and China and some strains from Japan formed gametangia under long-day conditions (LD) at 15°C; however, two other Japanese strains required short-day conditions (SD) at 15°C for gametogenesis, indicating a photoperiodic response. Plants of C. ocellatus f. crispoides did not require SD for gamete formation. In all strains, tetrasporophytes of both formae produced tetrasporangia under LD. Isolates of C. ocellatus f. ocellatus from Japan, China and Korea were found to be completely sexually compatible regardless of photoperiodic characteristics, and the responses to daylength shown by progeny of LD and SD strains suggested Mendelian inheritance of a daylength factor. Chondrus ocellatus f. ocellatus was sexually incompatible with C. nipponicus Yendo, a morphologically similar species from Japan, but C. ocellatus f. crispoides was partially interfertile with both C. ocellatus f. ocellatus and C. nipponicus, indicating that the three entities are closely related. In view of the apparently higher breeding compatibility between C. nipponicus and C. ocellatus f. crispoides, and the fact that these two entities are more similar morphologically and reproductively, it is proposed, provisionally, to refer C. ocellatus forma crispoides to C. nipponicus.     

Taxonomic reassessment of Chondrus verrucosus (Rhodophyta,Gigartinales), with a description of Chondrus retortus sp. nov

Phylogenetic and morphological reinvestigation of Chondrus verrucosus Mikami was conducted in the Pacific coast of southeastern Honshu, Japan, including the holotype specimen and samples near the type locality. Two entities were recognized by phylogenetic analyses of plastid rbcL and nuclear EF2 sequences. In morphological analyses, the two entities were distinguished by: (i) thallus size and form, and (ii) cell shape of the medullary layer surrounding young carposporangia: one has larger thalli, is regularly canaliculated, with linear medullary cells (large‐type); the other is smaller, canaliculated with crispation and has roundish medullary cells (small‐type). The large‐type was common in southern to eastern Boso Peninsula including near the type locality; the small‐type was typical in the southwest Boso Peninsula and Sagami Bay. The large‐type was shown to be equivalent to C. verrucosus by examination of the holotype specimen. The small‐type is described as a new species, C. retortus Matsumoto et Shimada.     

TWO MORPHOLOGICALLY SIMILAR BIOLOGICAL SPECIES: CHONDRUS PINNULATUS AND C. ARMATUS (GIGARTINACEAE,RHODOPHYTA)1

The nature of the relationship between Chondrus pinnulatus (Harvey) Okamura f. pinnulatus and C. pinnulatus f. armatus (Harvey) Yamada et Mikami (Gigartinaceae, Rhodophyta) was investigated by comparative analysis of their biogeography, phenologies, life histories, gross and vegetative morphology, crossability, and upper thermal tolerance. The forma pinnulatus has a more northerly distribution in Japan and adjacent waters, exhibiting adaptation to the cooler regions, whereas the forma armatus has a more southerly range. The latter may be the result of a higher thermal tolerance. Both formae have a Polysiphonia-type life history and are similar in their internal vegetative morphology. They can, however, be distinguished by gross morphology: forma pinnulatus has wide, flattened axes, compressed to flattened ultimate segments and proliferations, while forma armatus has narrow, compressed to subterete axes and subterete to terete ultimate segments and proliferations. These differences persist in laboratory culture. All intraformae crosses were positive, with carpospores from the cross developing into fertile F₁ tetrasporophytes releasing tetraspores that developed into dioecious F₁ gametophytes, the female gametophytes of which formed normal cystocarps. This suggests that members of populations of each forma freely interbreed. Among interformae crosses, only some offspring derived from geographically distant strains bore normal cystocarps in the F₁ female gametophytes. Other crosses showed that interbreeding between populations of these two formae was blocked by various isolating mechanisms: incompatibility, hybrid inviability, and hybrid sterility. Reproductive isolation between f. pinnulatus and f. armatus is virtually complete in wild populations, because hybrid populations have not been found in the wild. In addition, these two entities can be considered biological species that are also referred to the taxonomic species, C. armatus and C. pinnulatus, because they do not overlap with regard to the morphology of the ultimate segments and proliferations. Subtle (but significant) gross morphological differences, partial interfertility between the two species, and deleterious hybridization in the area in which they occur sympatrically suggest that their evolutionary divergence was relatively recent.     

中国角叉菜属(Chondrus)的分类研究：形态观察和rbcL序列分析

采用rbcL序列分析结合传统形态观察的方法 ,对我国福建省平潭县和漳浦县、山东省青岛市及辽宁省大连市采集的角叉菜属样品进行了研究。新鲜或硅胶干燥样品被用于总DNA提取并用于PCR反应 ,PCR扩增产物回收后直接用于测序反应 ,序列数据经ClustalX1 .8软件排序后 ,采用MEGA2 .1软件根据Kimura’s双因子法计算遗传距离 ,并应用邻接法 (neighbor - joint ing)和最大简约法 (MaximumParsimony)构建系统树 ,Bootstrap法 (5 0 0次重复 )评估分支可信度。研究表明 :确认中国存在Chondrusocellatus、Chondrusnipponicus和Chondrusarmatus三种角叉菜 ;原报道产于我国东南沿海的角叉菜Chondrusocellatus应为Grateloupiaimbricata ;原报道产于大连小平岛的角叉菜Chondrusyendoi应为Mazzaellajaponica。     

Seasonal and spatial patterns of population density in the marine macroalga Mazzaella splendens (Gigartinales, Rhodophyta)

Insight into demographic processes that operate at larger spatial scales can be achieved through studying local populations when a particular species of interest is examined over time, by many investigators, in a variety of locations. On the west coast of North America, Mazzaella splendens (Setchell et Gardner) Fredericq is such a species of interest. A synthesis of local demographic studies of M. splendens from the late 1960s to the present reveals a pattern that is potentially common to the larger natural populations. This is the pattern: population density is high in summer and low in winter for both alternate free‐living life history phases of M. splendens. The magnitude of this seasonal change decreases in increasingly wave‐exposed habitats. In wave‐sheltered habitats there is a seasonal alternation from summer haploid to winter diploid dominance. This alternation gradually changes to constant diploid dominance as wave exposure in the habitat increases. Changes in population density are primarily a function of appearances and disappearances of perennating basal crusts (genets), as modules are produced or lost, rather than differential module production by genets of one phase over those of the other. To test the generality of this pattern, we examined seasonal changes in density, in local populations of M. splendens, in both a wave‐sheltered and a wave‐exposed habitat at Second Beach, Barkley Sound. Greater seasonal fluctuation in population density at wave‐sheltered, compared to wave‐exposed habitats is supported as a pattern potentially common to the natural populations of M. splendens. A change from summer haploid dominance in wave‐sheltered areas to summer diploid dominance in wave‐exposed areas is similarly supported. All changes in population density were the result of appearances and disappearances of genets rather than differential module production by haploid versus diploid basal crusts, also consistent with previous observations. A seasonal alternation in phase dominance, however, was absent from the wave‐sheltered site at Second Beach, Barkley Sound for 3 consecutive years. Seasonal alternation in phase dominance of M. splendens appears dependent on local conditions and is not common to all natural populations.     

DEMOGRAPHIC CONSEQUENCES OF COALESCENCE IN SPORELING POPULATIONS OF MAZZAELLA LAMINARIOIDES (GIGARTINALES,RHODOPHYTA)1

Coalescing macroalgae are ecologically important members of intertidal and shallow subtidal communities. However, we still lack quantitative information on the demographic consequences of coalescence. Using demographic models developed for modular invertebrates, we studied the demography of settlement and early recruitment in the coalescing macroalga Mazzaella laminarioides (Bory) Fredericq. Permanently marked microscopic fields on laboratory‐incubated and field‐incubated plates were monitored regularly (at 15, 30, 45, and 60 d) using image analysis techniques to evaluate the relative importance of settler abundance, mortality, coalescence (fusion), and fission on the changes in size and numbers of recruits. On the plates, spores settled individually or in groups. Over time, spores in close proximity may coalesce, resulting in a mixture of unisporic and multisporic crusts. When new spores arrive, they may or may not coalesce with previously settled crusts. Coalescence and mortality reduce the number of sporelings, but coalescence increases the size of the sporelings, thereby reducing further probability of sporeling mortality. Crust fissions are negligible in frequency, while the frequency of coalescence increases from ～25% after only 3 d, to ～75% after 60 d. Thus, as a result of variable settlement, mortality, and coalescence, any area colonized by M. laminarioides would contain a mixture of crusts of different sizes, ages, and genetic constitution. The interactions between the above three processes create a more complex survivorship curve than the ones known for unitary organisms.     

INFECTIOUS DISEASES OF MAZZAELLA LAMINARIOIDES (RHODOPHYTA): CHANGES IN INFECTION PREVALENCE AND DISEASE EXPRESSION ASSOCIATED WITH SEASON,LOCALITY, AND WITHIN-SITE LOCATION1

This study addresses the issues of infection prevalence and disease expression in two wild populations of the red algal host Mazzaella laminarioides and their variability associated with locality, season, and spatial location of the host in the intertidal zone. Our results demonstrated that Endophyton ramosum is the most frequent infective pathogen affecting M. laminarioides in Matanzas and Pucatrihue. This situation prevailed through the year and across the high-to-low intertidal gradient. Although there was a general trend for lower levels of infection in late winter and early spring, only in a few, cases was well-defined seasonality detected. Furthermore, clear seasonal patterns, as displayed by deformative disease in the high intertidal zone of Pucatrihue, were attenuated in the middle and lower intertidal zones. Differences in levels of infection in M. laminarioides between the high intertidal zones of Matanzas and Pucatrihue diminished toward the low intertidal zone. Thus, effects of seasonality and locality on infection prevalence may be influenced, at least in part, by the position of the hosts an the intertidal zone. Spatial distribution of the diseased individuals also varied along the beach. This pattern was consistent between the two sites and seemed related to wave exposure and the specific pathogen. Comparisons of the size distribution of noninfected fronds with their infected counterparts showed that infections by Endophyton ramosum and Pleurocapsa sp. more frequently affected medium-and large-sized fronds. This pattern was consistent temporally and similar in the two localities. Finally, a clear association between maturity and prevalence of infection was detected. This association resulted in most fronds of the noninfected segment of the host population being immature, whereas most mature fronds were infected. In conclusion, infectious diseases affecting the red alga Mazzaella laminarioides are a persistent phenomenon in wild populations of the host, although only a small segment of the infected populations displays the full expression of the disease. In spite of the suggested role of factors such as season, latitude, and spatial location of the host on disease prevalence and expression, additional studies are needed to understand fully the dynamics of infectious diseases in wild populations of algal hosts.     

Settlement behavior of cyphonautes larvae of the bryozoan Membranipora membranacea in response to two algal substrata

Abstract. Settlement is an important process in the biphasic life histories of many marine invertebrates. Little is known regarding the fine-scale behavioral mechanisms for finding and attaching to a suitable substratum, particularly under conditions that may impose a potential challenge, such as flow. In this study, we examined the settlement behavior of cyphonautes larvae of the bryozoan, Membranipora membranacea, in response to two different algal substrata. Larvae showed a strong preference for settling on the kelp Nereocystis luetkeana over the red alga Mazzaella splendens. We then tested whether the behavioral mechanisms used by larvae to attach to these algae differed when presented with the challenge of flowing water during settlement. We found that larvae exhibited different behaviors on the two species of algae in flowing water. Larvae were more often observed in direct contact with the preferred alga (N. luetkeana) exhibiting fine-scale active search behaviors. On the less preferred alga (M. splendens), larvae were less frequently observed in direct contact with the alga, and appeared to be exhibiting broad-scale passive search behaviors along the surface of the blade. Our results suggest that cyphonautes larvae alter their behavior in response to their preferred settlement habitat.