10. Snow algae of the Windmill Islands region, Antarctica

A list of the 24 species of snow algae identified from the region, a resume of what is currently known about the major species, and avenues for further research are provided. New species discovered include 2 Desmotetra spp., one Chlorosarcina sp., 2 Chloromonas spp. and a Palmellopsis sp. Several of these are from genera whose members have previously been found only in the soil flora. Not only was it necessary to elucidate the life cycle of these species, but it was also essential to examine them ultrastructurally to determine their taxonomic positions.     

中国海域多毛类环节动物物种多样性研究进展

多毛类环节动物是海洋底栖生物群落的重要类群之一, 在海洋生物监测、海水养殖、底栖食物链网、生态评估和生态修复中起着重要的作用。本文根据我国学者首篇记述中国海域多毛类物种文献、首次发表新种文献和首篇博士论文的年份, 将中国海域多毛类环节动物物种多样性研究分为3个阶段。第一阶段(1933-1961年)我国学者尚未发现新种, 但记述了几十种多毛类; 第二阶段(1962-2007年)发现了49新种, 但没有专门的博士和硕士学位论文; 第三阶段(2008-2022年)发现了120新种, 有博士和硕士学位论文。从1933年至2022年, 我国学者发现的新种和新记录种数量呈上升趋势, 但在不同时间段, 特别是在第二阶段有较大波动。目前, 我国多毛类物种多样性研究存在一些科、属、种的分类地位存疑, 一些科、属的分类亟待研究, 一些新种未被世界海洋物种目录(World Register of Marine Species)接受等问题。鉴于存在的问题, 本文建议在我国加强多毛类数据库建设, 加强多毛类物种多样性、遗传多样性和环境DNA研究。     

渤海鱼类复殖吸虫Ⅵ(吸虫纲:孔肠科)

在渤海(大连市)采集的六线鱼肠内发现大连新卷宫吸虫,新种Neohelicometra dalienensis sp.nov.,虫体大小4.8—5.5×0.5—0.6mm。口腹吸盘比1:0.7。睾丸前后排列,较大。生殖孔在咽后。卵巢分叶,在赤道线稍后。卵黄腺在体两侧,起自腹吸盘之后,不伸到体末端。卵43—58×20—33μm。     

Micropyle and oocyst wall changes associated with chemically mediated in vitro excystation of Eimeria stieda1 and Eimeria tenella

Scanning and transmission EM techniques revealed wall structural features and changes associated with chemically mediated alteration of oocyst walls (phase 1) in the process of excysting in vitro the sporozoites of Eimeria stiedai and Eimeria tenella. SEM showed the excystation sequence to be (a) sinking of the micropyle, (b) wall rupture, mainly around the micropylar lid, but sometimes radiating down the outer wall from the micropyle and (c) infolding or inrolling of the lid. Freeze-fracture and thin section preparations showed crosssection and surface features of walls and intra-oocyst components. Oocysts were incubated in CO₂ and cysteine hydrochloride before microscopic examination.     

Cryptic diversity of free-living parabasalids, Pseudotrichomonas keilini and Lacusteria cypriaca n. g., n. sp., as inferred from small subunit rDNA sequences

Ultrastructural and molecular phylogenetic evidence indicate that the Parabasalia consists of seven main subgroups: the Trichomonadida, Honigbergiellida, Hypotrichomonadida, Tritrichomonadida, Cristamonadida, Spirotrichonymphida, and Trichonymphida. Only five species of free-living parabasalids are known: Monotrichomonas carabina, Ditrichomonas honigbergii, Honigbergiella sp., Tetratrichomonas undula, and Pseudotrichomonas keilini. Phylogenetic analyses show that free-living species do not form a clade and instead branch in several different positions within the context of their parasitic relatives. Because the diversity of free-living parabasalids is poorly understood, the systematics of these lineages is in a significant state of disarray. In order to better understand the phylogenetic distribution of free-living parabasalids, we sequenced the small subunit rDNA from three different strains reminiscent of P. keilini; the strains were isolated from different geographical locations: (1) mangrove sediments in Japan and (2) sediments in Cyprus. These data demonstrated that the free-living parabasalids P. keilini and Lacusteria cypriaca n. g., n. sp., form a paraphyletic assemblage near the origin of a clade consisting mostly of parasitic trichomonadids (e.g. Trichomonas vaginalis). This paraphyletic distribution of similar morphotypes indicates that free-living trichomonadids represent a compelling example of morphostasis that provides insight into the suite of features present in the most recent free-living ancestor of their parasitic relatives.     

Three new species of the genus Leucon Kröyer, 1846 (Crustacea: Cumacea) from the continental slope off Surinam

Three new, and apparently closely related, species of cumacean are described from the continental slope off Surinam: Leucon turgidulus sp.nov. from about 500 m depth, L. medius sp.nov. from about 1000m and about 1500m, and L.jonesi sp.nov from about 1500m and about 2000m. The species have not been found in extensive collections from other parts of the deep Atlantic. Leucon pallidus G.O. Sars, 1865 is the most closely comparable of the previously known members of the genus.     

A new species of the genus Hydrodroma Koch, 1837 (Acari, Hydrachnidia, Hydrodromidae), with a key to the hitherto known six species of the genus in Australia

The genus Hydrodroma Koch, 1837 in Australia consists of six species, the newly described Hydrodroma meridionalissp. n. included. The new species is described from 45 sampling sites from running waters in Queensland, Victoria, New Southern Wales, Western Australia, Northern Territory and South Australia. Furthermore, a key for the identification of species of Hydrodroma occurring in Australia is given.     

Rare and new cumaceans (Crustacea,Peracarida) from?the southern margin of the Cap Ferret Canyon (Bay of Biscay)

A new cumacean genus and species, Ithyleucon sorbeigen. et sp. n., was described from material collected in the southern margin of the Cap Ferret Canyon (Bay of Biscay, NE Atlantic). Although the new genus resembles Pseudoleucon Zimmer, 1903, in terms of the general aspect of the carapace and the pseudo-rostrum position, it shows important differences in the uropod structure and in the size of the antenna 1 accessory flagellum. In addition, some comments regarding the morphology of certain rare species (Mesolamprops denticulatus Ledoyer, 1983, Hemilamprops normani Bonnier, 1896 and Schizocuma spino-culatum (Jones, 1984)) are also provided.     

Parasitism in the bathypelagic fish, Melanostigma pammelas

Three hundred and thirty-seven specimens of the zoarcid fish, Melanostigma pammelas, collected between December, 1950 and December, 1969 from bathypelagic waters off southern California, were examined for their parasites. Incidences of infection were: digentic Trematoda 61%, Myxosporida 39%, larval Nematoda 9%. Two adult trematodes are described: Fellodistomum melanostigmum nov. sp. from the intestine, and Aponurus pacificus nov. sp. from the stomach. This parasite record is markedly unlike the typical record reported for eastern Pacific mesopelagic fishes in which many larval nematodes and few, if any, adult trematodes were found. Our long-term objective is to explain parasite pattern differences in the deep ocean in terms of their biological and physical environments. Our initial purpose is to determine the numbers and kinds of parasites in M. pammelas.     

Microgemma vivaresi n. sp. (Microsporidia, Tetramicridae), infecting liver and skeletal muscle of sea scorpions, Taurulus bubalis (Euphrasen 1786) (Osteichthyes, Cottidae), an inshore, littoral fish

The ultrastructure of a new microsporidian species Microgemma vivaresi n. sp. causing liver cell xenoma formation in sea scorpions, Taurulus bubalis, is described. Stages of merogony, sporogony, and sporogenesis are mixed in the central cytoplasm of developing xenomas. All stages have unpaired nuclei. Uninucleate and multinucleate meronts lie within vacuoles formed from host endoplasmic reticulum and divide by binary or multiple fission. Sporonts, no longer in vacuoles, deposit plaques of surface coat on the plasma membrane that cause the surface to pucker. Division occurs at the puckered stage into sporoblast mother cells, on which plaques join up to complete the surface coat. A final binary fission gives rise to sporoblasts. A dense globule, thought to be involved in polar tube synthesis, is gradually dispersed during spore maturation. Spores are broadly ovoid, have a large posterior vacuole, and measure 3.6 microm x 2.1 microm (fresh). The polar tube has a short wide anterior section that constricts abruptly, then runs posteriad to coil about eight times around the posterior vacuole with granular contents. The polaroplast has up to 40 membranes arranged in pairs mostly attached to the wide region of the polar tube and directed posteriorly around a cytoplasm of a coarsely granular appearance. The species is placed alongside the type species Microgemma hepaticusRalphs and Matthews 1986 within the family Tetramicridae, which is transferred from the class Dihaplophasea to the class Haplophasea, as there is no evidence for the occurrence of a diplokaryotic phase.     

贵州软滑水螨属二新种记述：（蜱螨亚纲：软滑水螨科）

本文描述软滑水螨科Pionidae二新种。新种多盘软滑水螨Pipma polyacetabula sp.nov.以其两性具极多殖吸盘(雄螨68—72个,雌螨45—50个)为其显著特征。新种宽殖软滑水螨P.platyura sp.nov.两性殖吸盘数目较多(雄螨35—42个,雌螨约48个),两性殖吸盘板宽近与Ⅳ足基节板等宽。两新种间以雄性殖吸盘数差异显著;两新种亦以殖吸盘数与本属已知种有显著差异而易于鉴别。