The macroinvertebrate fauna of littoral and bottom substrata as a tool for biotypology of Frisian waters

During a biotypological research of surface waters in the province of Friesland, The Netherlands, the macroinvertebrate fauna was sampled, both from the littoral and bottom substrata. Results of this investigation in different types of water on 60 and 55 stations in 1981 and 1982, respectively, are presented. The species richness in the littoral samples exceeded that of the bottom samples, and the samples per station had relatively few species in common. Even in many cases the most abundant taxon was a different one in both samples of the same spot. With multivariate analysis of the data sets from bottom, littoral and total samples a fairly good resemblance was found between these data sets. It is concluded that the semi-quantitative processing of macroinvertebrate fauna data leads to reliable results. One can use one sample per station, wherein different substrata are combined. Distinct clusters were recognized in more extreme environmental conditions such as brackish and acid waters. With the help of the macroinvertebrate fauna the other types of water could not easily be differentiated.     

内蒙古自治区螽亚目(Tettigoniodea,Orthoptera)昆虫区系及地带性分布的研究

内蒙古自治区目前共知螽亚目昆虫5科、26属、58种(表1)。其中螽斯占总种数的74.2％,蟋蟀占17.3％,其余的占7.5％。其区系组成以古北种为主体,特别是东北中国种、东西伯利亚——蒙古种和欧洲——西伯利亚种是区系组成的核心(表2)。特有种占有一定的比例(10.3％),主要分布于该区东北部的森林草原亚带和西部的荒漠带。中部地区有部分华北种的渗入。在本区东部的草原带中,螽斯亚科昆虫最为丰富;西部的荒漠带中,硕螽亚科昆虫是最突出的代表种,并有中亚种的分布(表4)。从总的种类分布来看,东北部的森林带和草原带的昆虫种类明显比西部荒漠带要丰富,中部的干草原亚带则是上述两者的过渡区域。 文中还根据螽亚目昆虫在不同植被地区的分布情况,采用Sφgrensen系数比较了各地带之间昆虫区系的相似性(表3)。用聚类分析的方法将10个植被地带或亚带划分成6个大的地带区:森林区、草原区、荒漠区、暖温型森林草原区、暖温型典型草原区和暖温型荒漠草原区(图2)。作者详细地叙述了各个地带区中昆虫区系的组成特点和分布规律。并就前人对该区昆虫区划工作提出了若干修订意见。     

云南高黎贡山蚤类的生态区系

本文报道了１９８５年以来对我甸横断山南端高黎贡山东、西坡蚤类生态区系的调查及研究结果。共发现蚤类５科２３属４７种（亚种）。文中对该山脉蚤类在不同森林植物带的群落结构、种的多样性及均匀度,各种蚤的栖境幅度、宿主多样性进行了陈述和比较,并对蚤类的区系特征、特有种的区系划分等问题进行了讨论。     

Deep soil heterogeneity and fine root distribution in forests and pastures of eastern Amazonia

Little is known about deep soil heterogeneity, or its relationship with fine root distribution. Beneath a mature, closed-canopy forest of eastern Amazonia, and the pastures and secondary forests that are derived from this forest, soil soft spots and hollow chambers occur to at least 9 meters depth. We measured the vertical distribution of these soil patches, and compared chemical characteristics, mycorrhizal infection, and root density of soil soft spots with the surrounding matrix of more homogeneous soil. Soil soft spots and chambers varied little with depth, but occupied the greatest soil volume (0.8 to 1.2%) from 4 to 6 m depth in the mature forest. Soft spots had lower pH, P availability and arbuscular mycorrhizal infection, and higher K availability than surrounding soil. Root length density was 2 to 15 times higher in soft spots than in surrounding soil. In the pastures, roots were found only in soil soft spots at depths of >3 m. Pastures and secondary forest had more soil chambers in the upper meter of soil than mature forest, but were otherwise indistinguishable in their patterns of deep soil heterogeneity. Soil soft spots may be vestiges of cutter ant nest chambers, while hollow chambers are cutter ant chambers and root channels. Chambers may act as conduits for root penetration and water penetration to deep soil.Abbreviations AM arbuscular mycorrhizae - RLD root length density (root length per unit of soil volume)     

Divergence between the Anoas of Sulawesi and the Asiatic Water buffaloes, inferred from their complete amino acid sequences of hemoglobin ß chains

Four complete amino acid sequences of hemoglobin β chains were determined for the swamp and the river types of the Asiatic water buffalo (Bubalus bubalis) and two species of the subgenus Anoa in Bubalus; B. (A.) depressicornis (H. Smith, 1827), the lowland anoa, and B. (A.) quarlesi (Ouwens, 1910), the mountain anoa. The two types of the bubalis were identical in the 145 amino acid residues of the β chains and, compared to this sequence, the two residues were substituted in the depressicornis (β49Thr → Ser and 134Ala → Thr) and the five were in the quarlesi (β53Val → Ile, 74Met → Ile, 111Val → Ile, 115Arg → His and 134Ala → Thr). While both Anoa species diverged from the bubalis by the β134Ala → Thr, they differed from each other by the five substitutions. The Anoa species are endemic to Sulawesi of Indonesia. Their speciation and the present coexistence were discussed with reference to probable immigrations of two ancestral Anoa species to Sulawesi at so long interval that had caused a reproductive isolation between the two wild animals. The earlier immigrants were postulated to be ancestral to the quarlesi and the later ones to the depressicornis.     

Intertidal interstitial Halicyclops from the Brazilian coast (Copepoda: Cyclopoida)

H. tageae sp. n. and Halicyclops ytororoma sp. n. are described from the intertidal interstitial water of Brazilian beaches. H. tageae is distinguished from all congeneric species by the number of setae on legs 1–4 endopodite 2 (1, 1, 2, 2) and by possessing a reduced inner spine on the leg 5 exopodite. It shares with H. brevispinosus, H. pusillus and H. canui the spine formula 2, 3, 3, 3 on exopodite 3 of swimming legs 1–4. H. ytororoma closely resembles H. gauldi and differs from this species by having 4 setae on leg 1 endopodite 3; H. gauldi has 3 setae on this segment.This is the first record of Halicyclops from marine interstitial water in Brazil.     

底栖生物影响下的潮滩微地貌演化数值模拟

潮滩是海岸带湿地的主要类型之一,其中分布的底栖生物对生态环境具有重要的调节作用。潮滩底栖微藻、泥沙与水动力之间存在相互作用,影响潮滩微地貌形态,明晰底栖生物对潮滩微地貌的演化机制至关重要。以黄河三角洲潮滩湿地为研究区,通过构建潮滩微地貌动力模型,探究底栖生物对微地貌格局演化的作用机制,分析底栖生物对微地貌系统稳定性的影响。结果表明(1)底栖微藻生长与泥沙扩散、水流再分配过程交互作用驱动下,潮滩上可形成底栖微藻覆盖的高丘与积水洼地交替分布的规则性微地貌斑图;(2)微地貌斑图的形成提高了潮滩生态系统初级生产力和泥沙淤积高度;(3)底栖微藻与泥沙、水流的交互作用使得潮滩微地貌系统对侵蚀扰动呈现非线性响应行为,系统存在临界点,且在一定侵蚀率范围内存在双稳态;(4)黄河口泥螺入侵使得微地貌系统抵抗侵蚀扰动能力减小,且系统稳定性随泥螺生物量的增加而降低。     

Biogeography of the octocorallian coelenterate fauna of southern Africa

The geographical and bathymetric distribution of southern African octocorals is analysed. Of the over 200 estimated species of regional octocorals, 81 confirmed and adequately described species are studied using a radial sector method. Two primary faunal components are recognized–endemic (53.3% of the fauna by numbers of species) and Indo-Pacific (39.4%). An Atlantic component contributes only minimally (about 1.7%), while the remaining fauna is made up of cosmopolites (2.8%) and scattered species (2.8%). A subantarctic component is not evident for the present-day, although evidence for previous contact is presented. A sister-group analysis using genera as a guide to sister species, shows the biogeographic affinities for the present-day fauna as a whole to be 45% Indo-Pacific, 31% cosmopolitan, 10% endemic, 10% Atlantic and 4% southern oceans (subantarctic). Applying the same method to only those genera with endemic species shows the affinities of the present-day endemic fauna to be 27.5% Indo-Pacific, 27.5% endemic, 24% cosmopolitan, 14% Atlantic and 7% subantarctic. Clearly defined boundaries for west, south, and east coast faunas (as recognized by previous authors in describing various intertidal faunas) are found not be present with regard to the octocoral fauna (largely due to its overwhelmingly subtidal nature). Instead two primary zoogeographic provinces are recognized–the Cape Endemic Province (extending from Liideritz to Inhaca Island) and the south-western fringe of the Indo-Pacific Province from East London north-eastwards. An overlap zone between these two is recognized between East London and Inhaca Island, with the region in the vicinity of Richards Bay having an essentially evenly mixed fauna (roughly 50% Cape Endemic Province and 50% Indo-Pacific). Of the 84 octocoral genera recorded for the region, seven (or 8.3%) are endemic, and of these, five are monotypic while two are ditypic. The fauna is shown to be predominantly sublittoral (about 95% by numbers of species), the shallow sublittoral (< 100 m in depth) being the region with highest species richness. Pennatulaceans are eurybathic (intertidal to 4756 m) and clearly show a high proportion of cosmopolites (20% of presently identified species). Soft corals are stenobathic and restricted to the intertidal, continental shelf and uppermost portion of the continental slope (<500m), while gorgonians are intermediate in depth distributon (intertidal to 1200 m). No cosmopolitan alcyonaceans are presently recorded. The centre of the Cape Endemic Province is the Agulhas Bank–an extensive region of shallow continential shelf (< 200 m in depth) between Cape Town and East London. Two regions of octocoral radiation for southern Africa are postulated–the Agulhas Bank and the western Indian Ocean.     

Cambrian lobopodians–ancestors of extant onychophorans?

This paper is a review of published information on fossil lobopodians, with addition of observations and ideas based on new material. It is also an analysis of the phytogeny of the group, and presents a new classification. A character shared by three or four families, yet not seen before, is a pair of enlarged sclerites covering the head. This forms an argument for re-orienting Hallucigenia once again. This genus no longer being enigmatic, a corner-stone in Stephen Jay Gould's evidence for extinct phyla is therefore gone. It is suggested that the lobopodians, phylum Lobopodia, are arranged in two classes, the extinct Xenusia for marine forms, and the Onychophora for terrestrial forms. The marine lobopodians are morphologically much more diverse than the extant onychophorans, a condition expressed in the classification. New taxa are: Hallucigenia fortis sp. nov., the families Luolishaniidae, Cardiodictyidae and Onychodictyidae, and the new orders Archonychophora, Scleronychophora and Paronychophora.