Types of cladoceran species described by Sven Ekman in the Swedish Museum of Natural History,with redescription of Daphnia cavicervix Ekman, 1900 (Daphniidae,Anomopoda, Cladocera)

In the course of our examination of samples of Cladocera from South America and subantarctic islands in the collection of the Swedish Museum of Natural History, Stockholm, we found some type material of Sven Ekman, unrecognized earlier, as well as other samples described in his publications (Ekman 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar], 1905 Ekman, S. 1905. Cladoceren und Copepoden aus antarktischen und subantarktishen Binnengewässern.. Wissendchaftliche Ergebnisse der Schwedischen Südpolar‐Expedition 1901–1903, Zoologie, 5: 1–40.  [Google Scholar]). A single specimen of Pleuroxus scopuliferus Ekman, 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar], apparently seen by its author, is re‐deposited as the lectotype, while the neotype of this taxon earlier selected by Frey (1993 Frey, D. G. 1993. Species of Pleuroxus (Anomopoda, Chydoridae) from the subantarctic islands and southernmost South America: a partial unravelling of the Pleuroxus aduncus problem.. Hydrobiologia, 262: 145–188.  [Google Scholar]) must be rejected according to ICZN (2000 ICZN. 2000. International code of zoological nomenclature , 4, 306London: International Trust for Zoological Nomenclature.  [Google Scholar]). Daphnia cavicervix Ekman, 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar] is redescribed based on numerous parthenogenetic, ephippial females and males, and lectotype and paralectotypes are selected. Some recent problems of systematics of Daphnia in South America are discussed.     

The non-marine Crustacea of Antarctica and the Islands of the Southern Ocean: biodiversity and biogeography

A total of 101 verified species and eight ordinal taxa represent the non-marine Crustacea on Antarctica and the islands of the Southern Ocean. The largely terrestrial Isopoda and Amphipoda are confined to some sub-Antarctic and cool temperate islands while the predominantly freshwater Anostraca, Anomopoda, Copepoda (=Calanoida, Cyclopoida, Harpacticoida) and Ostracoda (Podocopida) occur throughout the region. Holocene sea-level rises fragmented freshwater and terrestrial species ranges on New Zealand, Auckland, Campbell, and possibly other South Pacific islands, leaving a legacy of vicariant taxa. Tertiary species probably survived Pleistocene glaciation in aquatic refugia on the New Zealand/South Pacific, Falkland, Crozet and Kerguelen archipelagoes, but there are no valid records of Tertiary Antarctic Crustacea. All 40 Continental and Maritime Antarctic freshwater records can be ascribed to the historic introduction of anthropogenic aliens, Holocene immigration of colonists, returning re-colonists and marine species 'marooned' in epishelf and other coastal lakes.     

Redescription of Alona macracantha Smirnov and Timms, 1983 and its assignment to Maraura gen. nov. (Cladocera: Anomopoda: Chydoridae)

Three new species of the harpacticoid family Ameiridae are described from clean sand at high water neap tide on St Martin's Flat, Isles of Scilly. Ameiropsis martinis sp. nov. appears most closely related to A. australis Kunz, 1975 Kunz, H. 1975. Copepoda Harpacticoidea aus dem litoral des sudlichen Afrika. 1 Teil. Kiel Meeresforsch., 31(2): 179–212.  [Google Scholar] but can be distinguished from it by the shape of the rostrum and the armature of the operculum, female genital field and the male P5 baseoendopodal lobe. Sarsameira parexilis sp. nov. was originally identified as S. exilis T. and A. Scott, 1894 Scott, T. 1894. Additions to the fauna of the Firth of Forth. Part IV. 12th Annual Report of the Fisheries Board for Scotland, : 231–270.  [Google Scholar] but the females can be distinguished from S. exilis by their smaller body size and shape of the caudal ramus whilst the males can be distinguished by the 12-segmented antennule and four setae on the P5 baseoendopodal lobe. Ameira longispina sp. nov. is unique within the “Ameira” complex of genera and species because of the marked elongation of the inner spine on the basis of the male P1. This species is tentatively placed in Ameira Boeck, 1865, but has features which indicate that it probably occupies an intermediate position between this genus and Psammameira Noodt, 1952. The previously unknown males of Sarsameira perezi Bodin, 1970 Bodin, P. 1970. Copépodes Harpacticoides marins des environs de La Rochelle 1. Especes de la vase intertidale de Chatelaillon. Tethys, 2(2): 385–436.  [Google Scholar] and Nitocra elegans (T. Scott, 1905 Scott, T. 1905. On some new and rare Crustacea from the Scottish seas. 23rd Annual Report of the Fisheries Board for Scotland, : 141–153.  [Google Scholar]) are also described.     

Redescription of Leydigia parva Daday, 1905 and assignment to Parvalona gen. nov. (Cladocera: Anomopoda: Chydoridae)

A morphological investigation of Leydigia parva Daday, (Chydoridae: Anomopoda: Cladocera), based on specimens from Paraguay (type specimens) and Brazil, clarifies its position in the subfamily and prompts its assignment to a new genus, Parvalona. The affinity of this rare benthic chydorid with Leydigia Kurz, 1875 and Alona Baird, 1843, in which this taxon was placed earlier, is discussed.     

Comparative investigation of the late embryogenesis of Leptodora kindtii (Focke, 1844) (Crustacea: Branchiopoda), with notes on types of embryonic development and larvae in Cladocera

The embryonic development of the parthenogenetic eggs of Leptodora kindtii has been investigated by observing living embryos removed from the female brood pouch. The sequence of morphological changes was analysed, as was the time at which the activity of certain organs began. The timing of these events at 20–22°C is documented. These data were compared with similar information obtained for some representatives of Ctenopoda and Anomopoda. The sequence of appearance of rudiments of organs on the ventral side of the embryos is similar in all these groups but the timing of shedding of the embryonic membranes differs. Hatching from the inner egg membranes takes place at the late metanauplius stage in Leptodora as in Ctenopoda and Cyclestherida, while in Anomopoda this stage is embryonized. The development of Leptodora is more like that of Ctenopoda than of Anomopoda. The embryos of all the above‐mentioned groups begin to grow at approximately the same morphological stage. A new scheme for the periodization of the embryogenesis of L. kindtii is proposed, which includes four well‐separated stages. Previously, the same number of developmental stages has been reported for Ctenopoda and Anomopoda. In Leptodora, as well as in Ctenopoda, the first two of these occur within the egg membranes. Cyclestheria has at least one embryonic moult and one embryonic stage more than Leptodora and other cladocerans. Embryonic stages 3 and 4 of the parthenogenetic eggs of L. kindtii represent a peculiar type of secondary larvae developing inside the female's brood pouch. The appearance of a free‐living nauplius in L. kindtii arises from its mode of hatching from the gamogenetic egg.     

An ecological study of Cueva de los Roques lava tube (Tenerife,Canary Islands)

Several aspects of the ecology of Cueva de los Roques were studied: the survey initiated by other speleologists was completed; the flora at the entrance to the cave was studied; and the fauna of the whole cave was analysed by sampling on two occasions three months apart, using a combination of visual searching and baited trapping. The most striking result was the difference in both physical conditions and biology between the two branches of the cave. Branch A has several entrances and thus appreciable air movements, with the result that it is inhabited only by trogloxenes and a few troglophiles. In contrast, branch B is a blind tube with constant high humidity and stable temperature, here there is a community of troglobites. We have found a total of 27 species of invertebrates; these include nine troglobites, of which seven are already known from other lava tubes on Tenerife. This suggests the occurrence of dispersal through a network of cracks in the subsoil, as in other volcanic and karst regions.     

Revision of the hirsuticornis‐like species of Macrothrix Baird, 1843 (Cladocera: Anomopoda: Macrothricidae) from Subantarctic and temperate regions of the southern hemisphere

The aim of this paper is to revise populations of Macrothrix cf. hirsuticornis (Cladocera: Anomopoda: Macrothricidae) from different regions of the southern hemisphere. It is demonstrated that M. hirsuticornis Norman and Brady, 1867 Norman, A. M. and Brady, G. S. 1867. A monograph of the British Entomostraca belonging to the families Bosminidae, Macrothricidae and Lynceidae.. Natural History Transactions of Northumberland and Durham, 1: 354–408.  [Google Scholar] s. str. is absent there, and five related species occupy different Subantarctic islands and the southernmost portions of South America, and Africa. Macrothrix boergeni Studer, 1878 Studer, T. 1878. Beiträge zur Naturgeschichte wirbelloser Tiere von Kerguelensland.. Archiv für Naturgeschichte, 44: 102–121.  [Google Scholar] from the Kerguelen Archipelago is redescribed and a neotype is selected. All populations in the southernmost portion of continental South America, Tierra del Fuego, Falklands, South Georgia, South Orkney Islands, and on the Antarctic Peninsula belong to M. oviformis Ekman, 1900 Ekman, S. 1900. Cladoceren aus Patagonien, gesammelt von der schwedischen Expedition nach Patagonien 1899.. Zoologische Jahrbücher, Abteilung für Systematik, Geographie und Biologie der Tiere, 14: 62–84.  [Google Scholar]. All the taxa described from this region—M. ciliata Vávra, 1900 Vávra, W. 1900. “Süsswasser‐Cladoceren. Ergebnisse der Hamburger magalhaensische Sammelreise 1892/93. II Band. Arthropoden.”. In Hamburg 1–25.  [Google Scholar], M. odontocephala Daday, 1902 Daday, E. 1902. Mikroskopische Süsswasserthiere aus Patagonien, gesammelt von Dr. Filippo Sylvestri.. Természetrajzi Füzetek, Budapest, 25: 201–310.  [Google Scholar], M. propinqua Sars, 1909 Sars, G. O. 1909. Fresh‐water Entomostraca from South Georgia.. Archiv for Mathematik og Naturvidenskab, 30: 1–35.  [Google Scholar], and, probably, M. inflata Daday, 1902 Daday, E. 1902. Mikroskopische Süsswasserthiere aus Patagonien, gesammelt von Dr. Filippo Sylvestri.. Természetrajzi Füzetek, Budapest, 25: 201–310.  [Google Scholar]—are junior synonyms of M. oviformis. Two new species are established: M. sarsi sp. nov. from the Cape region of South Africa and M. ruehei sp. nov. from Crozet, Marion islands, and Île Amsterdam. Macrothrix cf. flagellata Smirnov and Timms, 1983 Smirnov, N. N. and Timms, B. V. 1983. A revision of the Australian Cladocera (Crustacea).. Records of the Australian Museum, Supplement, 1: 1–132. [Crossref] , [Google Scholar], previously known only from Tasmania, is found on Macquarie Island too. Differences between species from the southern hemisphere and Palaearctic M. hirsuticornis are summarized. It is demonstrated that characters of the general body shape (i.e. presence of a hood or a tooth on posterior head border) have a limited value for the systematics of Macrothrix. In contrast, some fine details, mostly missed by previous authors, are valuable for species discrimination. The present study increases the number of species recorded from the Antarctic‐Subantarctic region. Probably, the current pattern of Macrothrix distribution results from a disruption of a pan‐continental (early Mesozoic?) species complex.     

生物操控技术在景观水体生态修复中的应用

城市景观水体通常与外源水体隔绝;因缺乏流动性以及外源污染物的不断积累,导致水体生态系统失去平衡,逐渐散失景观价值.本试验应用循环增氧技术加速水体的混合,促进浮游藻类的生长及其对水体污染物的吸收,有望成为景观水体生态修复提供了一个新的组合手段.     

New finding of Mesozoic ephippia of the Anomopoda (Crustacea: Cladocera)

Fossil Mesozoic anomopods (Crustacea: Cladocera) have only been found twice previously, although this group apparently differentiated in the Palaeozoic. This paper describes the finding of anomopod ephippia of three different types in the locality Khutel‐Khara, Mongolia (Lower Cretaceous, 129±9 Mya). This discovery demonstrates once more that the idea of rarity of cladocerans in Mesozoic fossils was motivated by insufficient attention of carcinologists to such fossils.     

中国枝角类（甲壳纲：双甲目）新记录种和亚种

中国枝角类（甲壳纲：双甲目）新记录种和亚种陈受忠，陈文静（中国科学院水生生物研究所，武汉４３００７２）【关键词】枝角类，盘肠科，新记录从采自江西省的浮游生物标本中，镜检得枝角类的一个种及一个亚种是我国的首次发现，故予报道。１圆唇盘肠Ｃｈｙｄｏｒｕｓｋ...