关岭及相关生物群沉积与生态环境的探讨

根据近年来对黔东南至滇东关岭、兴义、贞丰和罗平等地中一晚三叠世含海生爬行动物骨架和(或)深水海百合黑色岩系(通常所称黑色页岩)化石库的研究,现将该区岩石地层单位划分.以及这些黑色岩系化石库生物组合特征、时代、分布、沉积和古地理环境概括如下:1)在关岭-兴义地区中-晚三叠世(安尼期、拉丁期和早卡尼期)地层中,至少夹有3层、甚至4层含海生爬行动物的黑色岩系化石库(或黑色"页岩"化石库),自下而上产盘县生物群、兴义生物群和关岭生物群.云南罗平地区中三叠统关岭组中新发现的"罗平生物群"与盘县生物群层位大致相当.贞丰龙场赖石科组上部新挖掘出的30m厚产创口海百合、双壳类及菊石的黑色岩系,应该是研究地区最高层位的海相三叠纪黑色岩系,时代似属晚三叠世早卡尼期晚期;2)推测这些含海生爬行动物骨架的黑色岩系化石库是在印支造山运动影响下,伴随南盘江前陆盆地隆升和闭合,在扬子克拉通台地边缘所形成的一个或几个边缘凹陷、或边缘盆地之中形成的,这些凹陷或盆地形成之初,表层水充氧,且具有很好的食物链结构,有利于各类海生生物生活;后来的海平面上升至最大海泛期,以及由此引起缺氧和含硫化氢水位的上升,导致这些凹陷逐渐变成安静、滞流的死亡之海和黑色岩系化石库;3)关岭生物群产于晚三叠世卡尼期早期小凹组下段上部黑色岩系之中,是一个典型的在滞流、缺氧且海底没有食腐动物边缘局限盆地中所形成的黑色页岩化石库,以产大量海生爬行动物和深水假浮游海百合为特征,此外还有个别的两栖类和原始龟类发现;4)产于竹杆坡组近底部黑色岩系中的兴义生物群,以产大量肿肋龙类为特点,尤以个体较小的贵州龙最为常见,共生的还有多种鱼类化石,在生物组合和产出层位上,可与阿尔卑斯南部Meride灰岩所夹黑色含沥青页岩化石库对比,时代似应归属拉丁期早或中期;大量米虾在竹杆坡组近底部含贵州龙层的发现.推测兴义生物群可能形成于台地边缘早期并不缺氧,且具有理想食物链结构的浅水、超盐的凹陷或盆地之中.由于存在浮游生物-虾-贵州龙-欧龙-虾-浮游生物所组成的生态组合和食物链结构,从而为解释以肿肋龙类为代表的兴义生物群的繁衍和多生提供了依据;接踵而来的沉积速率下降和缺氧水位的上升,以及间歇性火山作用,导致该特有生态体系的崩溃和化石库的形成.根据对贞丰挽澜竹杆坡组底部首次发现的棘皮动物的化石库的研究,指出该化石库系由海星、细小蛇尾、底栖海百合茎、海胆和海参等5类棘皮动物化石和含贵州龙骨架碎片组成,其下为8m厚夹有薄层的骨层的凝缩层沉积,后者位于硬底之上.此种沉积和埋藏模式与德国上壳灰岩早拉丁期的棘皮动物化石库类似,是在近岸海水不太浅的内陆棚的环境下,由于风暴潮作用所形成的化石库,他们与在滞流、缺氧海底、通过化石聚集所形成的化石库是不同的;5)产盘县生物群的黑色岩系化石库主要见于盘县羊件和普安青山中三叠世(安尼期)关岭组中,与云南罗平地区的"罗平生物群"在层位及生物组合上大致相当,均以含大量混鱼龙、幻龙和欧龙.以及鱼类为特点,共生的还有大量节肢动物.所不同的是后者由于靠近滨岸,故而出现大量幼年期的鱼类以及虾类和鲎类化石,推测他们形成于靠近古陆或滨岸的台缘浅水表层充氧的正常、且有时超盐的凹陷之中,时代上早于阿尔卑斯南部安尼期/拉丁期比塞娄组;其集群死亡除因后期盆地滞流、缺氧外,可能还与风暴和火山作用有关.     

黔西南地区三叠系法郎组竹杆坡段中的康尼克贝类及三叠纪康尼克贝类的分布*

文中描述了采自贵州省兴义市乌沙镇泥麦古剖面和安顺市关岭县麻洼剖面三叠系法郎组竹杆坡段的康尼克贝类腕足动物:Koninckella guizhouensis,Koninckella zhenfengensis和Koninckina sp.。结合牙形石、菊石生物地层及同位素测年等证据,对黔西南地区法郎组竹杆坡段的时代进行了详细讨论,认为其下部属拉丁阶(Ladinian),上部属卡尼阶(Carnian),在此基础上对黔西南地区报道的康尼克贝类的层位进行了讨论。综合全球已报导的三叠纪康尼克贝类化石记录可知,该类群于中三叠世起源于中国黔西南地区,在晚三叠世逐渐繁盛并向特提斯洋西部的欧洲地区和特提斯洋中部的西藏地区进行迁移扩散。受三叠纪末期生物大灭绝影响,康尼克贝类的多样性在瑞替期(Rhaetian)显著降低,直至早侏罗世辛涅缪尔期(Sinemurian)才再度复苏。     

贵州关岭新铺晚三叠世早期(Carnian)康尼克贝类腕足动物一新属--Pseudokoninckina

Pseudokoninckinagen.nov.归于康尼克贝类。模式种Pseudokoninckina xinpuensisgen.etsp.nov.的模式标本采自贵州关岭县城西南约35km新铺乡喇嘛村上三叠统下部(Carnian)竹杆坡组中部黑灰或黄灰色石灰岩。其贝体强烈膝曲,拖曳部长;背壳极为深凹,侧坡高又陡峭,两侧区和拖曳部呈薄壳状;两耳翼端强烈向背方膝曲;背三角孔覆有背三角双板,但腹三角孔洞开。腹内两侧隔板极高又长;腹中隔脊低宽,前部二分叉,后部三分叉。背内第三壳层厚,在背壳底两侧区隆起呈两条隆脊;主突起高强。壳表饰有微弱同心线和毛发状放射纹。这些特征在康尼克贝类中是很独特的。     

川东南中奥陶统大沙坝组的腕足动物群

四川东南部长宁双河及其附近地区的中奥陶统上部大沙坝组以特殊的岩相和生物相有别于黔北的可比地层十字铺组和鄂西的牯牛潭组,地层中漂浮相化石(笔石)与底栖壳相化石(如腕足动物和三叶虫)多次交互出现,笔石动物属于上层下垂对笔石动物群(Didymograptus artus Fauna),时代为中奥陶世Darriwilian(相当于Arenig最晚期至Llanvirn)。在所采集的3300余枚化石标本中有近90％是腕足动物化石,经研究共鉴定出19属21种,分属于4目7超科15科,正形贝目和扭月贝目分别有8属,占全部属群的84％。根据属的生物地理分布,该动物群中广布型分子7属、区域性分子6属,仅限于华南的土著性分子占总量的31．6％,显示出此期华南腕足动物群具有较强的地方性色彩,进一步证实中奥陶世海洋生物强分区性的推断。该腕足动物群宜称作Saucrorthis-Glyptorthis动物群。在统计分析的基础上,识别出Saucrorthis-Glyptorthis群落,包括三个以腕足动物占优势的化石群集(association),即Glyptorthis?simplex群集、Saucrorthis obscura群集和Calyptolepta chengkouensis群集,并结合沉积岩石学以及其它共生化石门类进行群落生态分析,认为该群落所生活的环境以正常浅海砂泥质底域为主(相当于BA2-3)。与上扬子台地贵州遵义十字铺组和重庆城口厚坪组两个相近腕足动物群相比,长宁地区中奥陶世的Saucrorthis-Glyptorthis动物群更接近于厚坪组所产者。与世界上其它一些同期且具相似生态位的动物群相比,除与哈萨克斯坦南部的同期动物群比较接近外,与澳大利亚、北美、英国等地的同期动物群几乎毫无联系,指示华南中奥陶世腕足动物群可能代表一个独特的生物地理小区。     

海洋微型底栖生物的多样性与地理分布

海洋微型底栖生物是指生活于海洋沉积物中及表面的所有单细胞原核和真核微型生物,包括原核微生物、真核微藻及原生动物等光合自养和异养的类群.与水体相比,海洋底栖生境孕育了形态和功能多样性更高的微型生物,在陆架浅海单位体积沉积物中其丰度较之水体中同类生物高一至几个数量级,而深海则孕育着特殊进化环境下新奇多样且数量庞大的微型底栖生物,是维持海洋生物多样性、海洋生态系统结构和功能不可或缺的部分.迄今对于微型生物是全球性还是限定性分布一直存在争议,对其解答受到分类研究欠缺及采样不足的制约.分子生物学从正反两方面提供了理论依据,但无法得出一个普遍接受的观点.海洋微型底栖生物的多样性研究侧重于物种多样性及群落结构与分子多样性,较为显著的进展体现在原核微生物的分子多样性及底栖真核微藻的物种多样性研究,对于海洋底栖原生动物的多样性研究则相较滞后.本文综述了国内外对海洋微型底栖生物各主要类群的分类学和多样性研究进展,探讨了各类群在全球的潜在物种多样性,并就我国未来加强海洋微型底栖生物多样性构成、分布与变动及驱动变化的因子以及底栖微食物网的研究提出了建议.     

贵州中三叠世早期幻龙属(Nothosaurus)一新种

作为三叠纪海生爬行动物的重要分子,幻龙属化石主要发现于欧洲、中东和中国西南地区的中三叠世海相地层,且主要集中分布于安尼期晚期和拉丁期晚期(Edinger,1921;Haas,1980;Rieppel,2000)。我国目前已报道的幻龙属化石有两种：杨氏幻龙(Li and Rieppel,2004)和幻龙属未定种(Rieppel,1998),它们均产于贵州省兴义地区的法郎组竹杆坡段,时代为中三叠世拉丁期。最近在贵州省盘县地区关岭组Ⅱ段地层中也发现了数量较多的幻龙骨骼化石,证明中三叠世早期东特提斯区同样生存着幻龙类。鉴于标本的骨骼特征与已知的幻龙属种相比存在一定的差异,因此本文建立一新种Nothosaurus rostellatus sp．nov．(小吻幻龙)。新种的个体在幻龙属种中为中等(头骨中线长210～320mm);吻部短而小,具4个前颌骨獠齿,紧随其后是第5个明显较小的前颌齿;一对上颌骨犬齿之前有6～9个小型上颌齿;眼窝较大,卵圆形,位置相对靠前;内鼻孔的后缘由腭骨构成,具内鼻槽;外翼骨形成腹向凸缘;下颌具冠状突;背椎神经棘较低,背肋肩部明显加厚。N．rostellatus与其他已知种的主要区别特征是吻部形态和比例。新种的吻部较小,长略大于宽,前端钝圆,基部明显收缩,其吻部长度(从吻端至外鼻孔前端的距离)仅占其头骨中线长度的1/6～1/7,而其他种一般占1/4～1/5,具有细长吻部的N．haasi甚至接近1/3。此外,新种吻端-上颞孔前缘距离与吻端-外鼻孔前缘距离的比值也明显高于其他种。N．rostellatus区别于其他幻龙种的另一主要特征是上颌骨牙齿的数目和排列。在已知的幻龙属种中,很少有一对上颌犬齿前的上颌齿数超过5个者。新种正型标本ⅣPPⅤ14294在一对上颌犬齿前具有6个小型锥状上颌齿,它们大小相等,指向腹方。副型标本ⅣPPⅤ14301在一对上颌犬齿前具有9个小型锥状上颌齿。在已知的Nothosaurus中,新种与N．youngi Li & Rieppel,2004和N．marchicus Koken,1893无论是个体大小还是头骨形态均比较接近,如具有相对短而宽的吻部和较短的上颌齿列、相似的鼻骨形态等,与其他种相差较大,因此这里仅对新种与此二种之间的异同做简要的介绍。从头骨的一些具体形态特征看,N．rostellatus的鼻骨后侧方与前额骨相连,阻隔了额骨和上颌骨,该特征与N．youngi相同而不同于N．marchicus,后者鼻骨受额骨与上颌骨的阻隔,不与前额骨相连。如果不考虑鳞骨的外侧分支的宽度,Ⅴ14294和Ⅴ14301与N．youngi的头骨的最宽处均位于轭骨的后端位置,且其宽度为吻部宽度的2．6～3．5倍(其中N．youngi为2．6倍,Ⅴ14294为3倍,Ⅴ14301为3．5倍),而N．marchicus的最宽处位于头骨后部鳞骨的分支处,其轭骨后缘处头骨宽度为吻部宽度的2～2．8倍(Rieppel and Wild,1996,fig．36,41)。此外,N．rostellatus外翼骨形成腹向突起和下颌具冠状突的特点也与N．youngi相同,N．marchicus不具有该特征。另一方面,N．rostellatus的枕部特征则与N．marchicus接近而不同于N．youngi。新种的枕部内凹,枕骨侧边的后耳骨等向后侧部延伸,下颌关节在头骨后部位于枕髁之后,该枕部特征与N．marchicus一致。N．youngi的下颌关节与枕髁基本位于一个平面内,因此枕部未形成明显的内凹。新种的眼眶与上颞孔之间的距离相对较宽,其中V 14294眼眶与上颞孔之间的距离与外鼻孔与眼眶之间的距离接近相等,而V 14301眼眶与上颞孔之间的距离大于外鼻孔与眼眶之间的距离。此特征也与N．marchicus相同而不同于N．youngi,前者眼眶与上颞孔之间的距离与外鼻孔与眼眶之间的距离相等,后者的眶后弓很窄,其眼眶与上颞孔之间的距离小于外鼻孔与眼眶之间的距离的1/2。N．rostellatus鼻骨的左右两前突分别伸至两外鼻孔的前缘内侧,位置与N．marchicus相同,而N．youngi鼻骨前突仅伸至外鼻孔内侧缘的中部。N．rostellatus前颌骨的背突向后伸至外鼻孔后缘之后,接近鼻骨的后缘,而N．youngi仅伸至外鼻孔后缘中间部位。除前文所述新种两个主要鉴定特征外,N．rostellatus又以具有内鼻槽,翼骨前伸至内鼻槽附近等特征与该已知二种相区别。此外,新种前颌骨具外侧支突起,其他种该特征多不明显,如N．jagisteus不存在前颌骨外侧支突起,其前颌骨在外鼻孔的前外侧缘沿前外侧方向与上颌骨相交(Rieppel,2001)。从地理分布和地层层位看,N．marchicus主要分布于欧洲中部的中三叠统安尼阶,而N．youngi则分布于我国贵州南部的中三叠统拉丁阶。本文描述的化石产于贵州南部关岭组Ⅱ段,其时代应相当于中三叠世晚安尼期。N．rostellatus与分布于欧洲的同时期的幻龙N．marchicus以及与在其后约7～8Ma相邻地区出现的M．youngi的亲缘关系的远近可能还需要更深入的研究来证实。     

中国贵州妙蝇属(双翅目,蝇科)分类学研究及转妙蝇群八新种记述(英文)

系贵州地区妙蝇属Myospila Rondani研究的系列论文之一,记述该属1新种群:转妙蝇群M. species-trochanterata 并描述新种群8新种:基妙蝇M. basilara sp. nov.,褐妙蝇M.brunneusa sp. nov.,余妙蝇 M. cetera sp. nov.,亚毛眼妙蝇 M.paralasiophthalma sp. nov.,亚转妙蝇M. paratrochanterata sp.nov.,亚毛爪妙蝇M. piliungulisoides sp. nov.,亚黄胫妙蝇 M.subflavitibia sp. nov. 和条妙蝇M. vittata sp. nov.。文中给出了转妙蝇群的定义,编制了新种群所有已知12种的检索表,描述了新种详细的形态特征及其与近缘种的鉴别特征。另外,还记述了毛爪妙蝇M. piliungulis Xue et Yang,1998和毛眼妙蝇M. lasiophthalma(Emden,1965)两种雌性。新种的模式标本保存于作者所在单位。转妙蝇群的鉴别特征雄额狭,不及单眼三角宽,触角黑色;前胸基腹片具毛,小盾片端部或多或少呈淡色,背面的正常毛被不越出缘鬃一线,且下侧缘无向下弯的、或多或少呈淡色的细毛,翅内鬃1+2;沟前内侧中条间一些毛被显著发达。翅的前缘基鳞及翅肩鳞黑色至黑褐色,r1脉背面裸;足的股节不完全呈黄色。在妙蝇属中,本群蝇类并无突出的、独一无二的共有衍征,但在前胸基腹片具毛和小盾片侧腹缘裸的类群中,只有本群蝇类具备上述的特征组合,尤其是前缘基鳞及翅肩鳞黑色至黑褐色,小盾片端部或多或少呈淡色和股节不完全呈黄色这一组特征组合。此外,根据我国学者薛万琦(1996)和冯炎(2007)的描述,作者怀疑产自我国湖南、贵州和四川等地的转妙蝇M.trochanterata Emden(1965)属于2个不同的种,它们均不同于缅甸、印度和尼泊尔等地产的转妙蝇M.trochanterata Emden(1965),因而可能是3个独立的种。转妙蝇群的分种检索表1.雄眼密具黄色毛。前气门黄至褐色,后气门黑褐色。前股黑色,端部黄褐色……………………………………………………………2眼裸或实际裸,其余特征不如上述………………………………52.下后头无黄色毛……………………………………………………3下后头具黄色毛……………………………………………………43.额、颜、下侧颜及颊褐色,略带红色;额宽仅及前单眼宽的1.3倍;翅灰色,透明,绝不带褐色。中、后股黄褐色,前者腹面略带黑色………………………褐妙蝇,新种M.brunneusa sp.nov.额、颜、下侧颜及颊黑褐色,绝不带任何红色;额达单眼三角宽;翅褐色。中股腹面、背面和后股背面分别具褐黑色条条妙蝇,新种M.vittata sp.nov.………………………………………………4.中、后股呈黄褐色,有时中股腹面具黑褐色条毛眼妙蝇M.lasiophthalma(Emden,1965)…………………………………………中、后股黑褐色,端半黄褐色亚毛眼妙蝇,新种M.paralasiophthalma sp.nov.………………………………………………………5.前股除端部黄色外呈黑色,中、后股黄或不完全黄。眼裸或实际裸……………………………………………………………………6前股及中、后股节呈淡铁锈色。眼具零星短毛亚毛眼妙蝇,新种M.paralasiophthalma sp.nov.……………………………………6.中、后股黄褐色……………………………………………………7中、后股不完全呈黄褐色…………………………………………97.雄额较狭,约如前单眼宽的1.5倍;阳茎呈宽的三角形;第5腹板侧叶宽,向外伸展黄胫妙蝇M.flavitibia Guan,Feng et Ma,2007………………………………………………………………………雄额较宽,至少如前单眼宽的2倍;阳茎不呈宽的三角形;第5腹板侧叶狭或宽,端部弯曲或直……………………………………88.转节黑褐色。雄尾器:后面观侧尾叶直,侧面观肛尾叶扁薄,阳茎端部后缘呈角形突出,膜质的端部短三角形;雄第五腹板瘦狭,侧叶显著狭窄,向内弯曲亚黄胫妙蝇,新种M.subflavitibia sp.nov.………………………………………………………………………转节褐色。雄尾器:后面观侧尾叶弯曲,侧面观肛尾叶宽厚,阳茎条形,膜质的端部长条形;第5腹板宽大,侧叶显著宽,向外伸展,决不向内弯曲…………………余妙蝇,新种M.cetera sp.nov.9.后股黄;中股基半黑褐色。雄侧尾叶前缘具平的、其上具3个刺状鬃的突起……亚毛爪妙蝇,新种M.piliungulisoides sp.nov.后股不全黄,至少基部黑褐色;其余特征不如上述……………1010.后股除基部黑褐色外呈黄褐色基妙蝇,新种Myospila basilara sp.nov.………………………………………………………………后股基部2/3褐黄色或黑褐色…………………………………1111.中股基部1/2至2/3褐色;后股基部2/3褐黄色。侧尾叶前缘具尖锐角形突起……毛爪妙蝇M.piliungulis Xue et Yang,1998中股和后股基部2/3黑褐色。侧尾叶前缘具钝平的突起亚转妙蝇,新种M.paratrochanterata sp.nov.………………………1基妙蝇,新种Myospila basilara sp.nov.(图1～4)雄体长约4.5mm。雌不详。眼裸,前内方小眼面显著扩大;额略狭于两后单眼外缘间距;下后头毛黑色。沟前背中鬃列间小毛约10列;气门黑色。足黄褐色,基节和转节黑褐色,跗节黑色,前股约基部2/3黑褐色,中股约基半黑色,后股基部略带黑色。新种类似毛爪妙蝇M.piliungulis Xue et Yang,1998、亚毛爪妙蝇Myospila piliungulisoides sp.nov.和亚转妙蝇M.paratrochanterata sp.nov.等。根据上述检索表这4个种类可予明确而肯定的区别。正模♂,贵州关岭断桥(25°53’N,105°38’E;海拔600m),2008年3月18日,魏濂艨、曹维平、蒋绍贵、金伟等采。副模:1♂,贵州安顺甘堡林场,海拔1250m,2009年2月21～25日,魏濂艨、蒋绍贵、曹维平采;1♂,贵州紫云浪风关林场,海拔1200m,2009年2月25～28日,魏濂艨、曹维平、蒋绍贵、吴建霖、刘美华等采。词源:新种种名源自拉丁词"basilara",意为"基部",在此意指新种后股基部黑褐色。2褐妙蝇,新种Myospila brunneusa sp.nov.(图5～8)雄体长约4.5mm。雌未采获标本。眼具黄色密毛,前内方小眼面显著扩大;额、侧颜、下侧颜和颊褐红色;额狭,Apr.2012W ei:Study of the genus Myospila and eight new species of the newly defined M.trochanterata-group约为前单眼宽的1.3倍;下后头毛黑色。沟前背中鬃列间小毛约12列;前气门金黄色,略带褐色;翅灰色,透明,绝不带褐色。足黄褐色,基节、转节和跗节黑褐色;前股除端部腹面黄外几乎全呈黑色;中股腹面略带黑色。根据雄眼具毛,前气门黄至褐色等特征,新种与毛眼妙蝇M.lasiophthalma(Emden,1965)、条妙蝇M.vittata sp.nov.和亚毛眼妙蝇M.paralasiophthalma sp.nov.等十分相似,但根据上述检索表它们可被明确而肯定地予与区分。正模♂,贵州安顺轿子山林场(26°20’N,105°57’E;海拔1400m),2009年12月6日,魏濂艨、曹维平、蒋绍贵、龙彪、刘美华等采。副模1♂,贵州花江峡谷,海拔640m,2009年10月17日,魏濂艨、曹维平、蒋绍贵、刘美华等采。词源:新种种名源自拉丁词"brunneusa",意为"褐色",在此意指新种额、侧颜、下侧颜和颊呈褐红色。3余妙蝇,新种Myospila cetera sp.nov.(图9～12)雄体长约6.2mm。眼裸,前内方小眼面显著扩大;额宽略狭于两后单眼外缘间距;下后头毛黑色。沟前背中鬃列间小毛约10列;气门黑色;足黄色,基节和跗节黑色,转节褐色;前股除端部黄外黑色;中股腹面略带褐色。雌未采获标本。根据中、后足黄色,新种与黄胫妙蝇M.flavitibia Guan,Feng et M a,2007和亚黄胫妙蝇M.subflavitibia sp.nov.是彼此更为近似的一个类群。但据上述的检索表此3种可彼此相互鉴别。正模♂,贵州安顺轿子山(26°20’N,105°57’E;海拔1400m),2009年6月1日,魏濂艨、曹维平、刘美华、龙彪等采。副模:2♂♂,贵州平坝城关林场,海拔1200m,2009年2～3月,魏濂艨、曹维平、蒋绍贵、刘美华和吴建霖等采;1♂,安顺蔡官龙天村,海拔1400m,2009年6月1～30日,魏濂艨、刘美华、蒋绍贵、陈林等采。词源:新种种名源自拉丁词"cetera",意为"剩余的,另外的",在此意指与黄胫妙蝇类似的另一个种。4亚毛眼妙蝇,新种Myospila paralasiophthalma sp.nov.(图19～22)雄体长约7mm。眼具黄色短密毛,前内方小眼面扩大;额宽约如两后单眼外缘间距;下后头具黄色毛。沟前背中鬃列间小毛约12列;前气门黄褐色。足黄褐色,基节和跗节黑色,转节褐黑色,前股除端部腹面黄色外几乎全黑;中、后股基部2/5黑色。雌不详。根据雄眼具毛,前气门黄至褐色等特征,新种与褐妙蝇M.brunneusa sp.nov.、毛眼妙蝇M.lasiophthalma(Emden,1965)和条妙蝇,新种M.vittata sp.nov.等十分相似,但据上述检索表它们可被明确而肯定地予与区分。正模♂,贵州紫云浪风关林场(25°42’N,106°3’E;海拔1200m),2009年3月22日,魏濂艨、曹维平、蒋绍贵等采。副模:2♂♂,贵州花江峡谷,海拔640～1000m,2009年1～2月,魏濂艨、曹维平、蒋绍贵、刘美华等采。词源:新种种名源自拉丁词"lasiophthalma",意为"眼具毛的","para"意为"类似",在此指新种类似毛眼妙蝇。5亚转妙蝇,新种Myospila paratrochanterata sp.nov.(图23～26)雄体长约5.5～6.5mm。眼裸,前内方小眼面显著扩大;额宽略狭于两后单眼外缘间距;下后头毛黑色。沟前背中鬃列间小毛约8列;气门黑色。足黄褐色,基节和跗节黑色,转节黑色,几乎不带褐色,前股除端部很下地黄外几乎全黑;中、后股基部2/3(有时1/2)黑色。新种类似毛爪妙蝇M.piliungulis Xue et Yang,1998、基妙蝇Myospila basilara sp.nov.和亚毛爪妙蝇Myospila piliungulisoidessp.nov.等。根据上述检索表这4个种类可予明确而肯定的区别。正模♂,贵州安顺轿子山(26°20’N,105°57’E;海拔1400m),2009年6月1日,魏濂艨、曹维平、蒋绍贵、刘美华和龙彪等采。副模:15♂♂,同正模,2009年5～11月;1♂,安顺鸡场,海拔1200m,2008年4月6日,魏濂艨、曹维平、蒋绍贵等采;1♂,贵州安顺旧州老落坡林场,海拔1300m,2008年4月19日,魏濂艨、曹维平、蒋绍贵等采;1♂,贵州安顺甘堡林场,海拔1250m,2009年2月21日,魏濂艨、曹维平、蒋绍贵、吴建霖和刘美华等采;1♂,同上,2011年5月29日,魏濂艨、曹维平和李鸿等采;3♂♂,贵州安顺对门山,海拔1300m,2009年2～3月,魏濂艨、曹维平、蒋绍贵采;1♂,采集地及采集人同上,2008年12月21日;6♂♂,贵州安顺凤凰山林场,海拔1300m,2009年3月7～31日,魏濂艨、曹维平、蒋绍贵和刘美华等采;1♂,贵州安顺龙宫,海拔1200m,     

EFFECT OF SEASONAL SEA ICE BREAKOUT ON THE PHOTOSYNTHESIS OF BENTHIC DIATOM MATS AT CASEY,ANTARCTICA1

Photosynthesis of marine benthic diatom mats was examined before and after sea ice breakout at a coastal site in eastern Antarctica (Casey). Before ice breakout the maximum under‐ice irradiance was between 2.5 and 8.2 μmol photons·m^?2·s^?1 and the benthic microalgal community was characterized by low E_k (12.1–32.3 μmol photons·m^?2·s^?1), low relETR_max (9.2–32.9), and high alpha (0.69–1.1). After breakout, 20 days later, the maximum irradiance had increased to between 293 and 840 μmol photons·m^?2·s^?1, E_k had increased by more than an order of magnitude (to 301–395 μmol photons·m^?2·s^?1), relETR_max had increased by more than five times (to 104–251), and alpha decreased by approximately 50% (to 0.42–0.68). During the same time interval the species composition of the mats changed, with a decline in the abundance of Trachyneis aspera (Karsten) Hustedt, Gyrosigma subsalsum Van Heurck, and Thalassiosira gracilis (Karsten) Hustedt and an increase in the abundance of Navicula glaciei Van Heurck. The benthic microalgal mats at Casey showed that species composition and photophysiology changed in response to the sudden natural increase in irradiance. This occurred through both succession shifts in the species composition of the mats and also an ability of individual cells to photoacclimate to the higher irradiances.     

NUTRIENT LIMITATION OF BENTHIC ALGAE IN LAKE MICHIGAN: THE ROLE OF SILICA1

In the Laurentian Great Lakes, phytoplankton growth and biomass are secondarily limited by silica (Si), as a result of phosphorus (P) enrichment. Even modest levels of P enrichment can induce secondary Silimitation, which, in turn, promotes a shift from the native diatom phytoplankton flora to chlorophyte and cyanobacteria species. However, very little is known about the nutritional status of benthic populations and their response to nutrient enrichment. Two experiments were performed in the littoral zone of Lake Michigan where nutrients were delivered to in situ benthic algal (episammic and epilithic) assemblages using nutrient‐diffusing substrata. In order to test the hypothesis that benthic algae in Lake Michigan are Si limited, a 2 × 3 factorial experiment was used to deliver all combinations of Si, N, and P to resident assemblages growing on artificial substrata composed of natural (Si rich) versus calcium carbonate (Si poor) sand. A second experiment utilized a serial enrichment to evaluate the role of Si in mediating changes in taxonomic composition. These findings indicate that benthic algae in Lake Michigan exhibit signs of secondary Si limitation, and that their response to enrichment is similar to the phytoplankton. Moreover, natural sand substrata may provide a source of Si to resident benthic algae.     

厦门西港现代底栖有孔虫一新属

记述了产于厦门西港海域现代底栖有孔虫的１个新属－－似异形虫属Ａｅｏｌｏｍｏｒ ｐｈｅｌｌｏｉｄｅｓ ｇｅｎ．ｎｏｖ．及１个新种Ａｅｏｌｏｍｏｒｐｈｅｌｌｏｉｄｅｓ ｘｉａｍｅｎｅｎｓｉｓ ｇｅｎ．ｅｔ ｓｐ． ｎｏｖ．。     

舟山港表层沉积物中底栖有孔虫组合特征初步研究

作者对舟山港区43个表层沉积物样品进行定量分析,共鉴定出底栖有孔虫33属60种。研究海域各站位均发现浮游有孔虫壳体,个体细小、属种单一,未发现活体个体。研究海域底栖有孔虫组合以玻璃质壳为主,平均含量86.71%,有孔虫丰度均值为1 676枚/50克,总体有孔虫组合为Ammonia beccarii vars.-A.maruhasii-Epistominella naraensis。研究发现,表层沉积物中大个体有孔虫(Ammonia beccarii vars.等)与小个体有孔虫(Epistominella naraensis)分布与潮流搬运呈密切相关关系,提示可能存在不同的搬运机制。与前人研究相比,研究海域有孔虫组合呈现以下变化:(1)胶结质壳有孔虫含量增加,个别站位出现15.89%的高值;(2)出现耐污染属种;(3)环境敏感属种畸形比例增加。研究表明,沉积搬运作用和环境参数变化是影响研究区有孔虫组合的重要因素,为有孔虫作为环境指标的进一步研究提供了基础数据。     

THE SEASONAL DISTRIBUTION,ABUNDANCE AND DIVERSITY OF DESMIDS (CHLOROPHYTA) IN A SOFTWATER,NORTH TEMPERATE STREAM1

Suspended and benthic algal communities from a mildly acidic, third-order Rhode Island stream were examined to determine the seasonal distribution, abundance and diversity of the lotic desmids. Within a one-year sampling period, 148 species and 202 subspecific taxa of desmids were identified, representing 23 genera. Species of Cosmarium and Closterium accounted for approximately 70% of the desmids present, and were the most diverse and abundant taxa during all seasons except spring, when Hyalotheca dissiliens was the dominant desmid species. Average abundance and species richness generally were greatest during summer for both suspended and benthic desmids. Most desmids occurred in benthic habitats, and were randomly distributed among substrata. Average seasonal abundance was 7.4 × 10⁴ cells·g^?1 dry wt substratum, among 13 types of substrata. Highest desmid abundance was measured among substrata with intricate morphologies, such as Fontinalis spp., which was associated with 1.2 × 10⁶ desmid cells·g^?1 dry wt substratum, or 1.7 × 10³ cells·cm^?2 substratum. Cell division was observed for 70 desmid taxa, and average seasonal reproduction (based on cell numbers) among all substrata ranged from 4% in winter to 20% during summer. In addition, sexually produced zygospores were found occasionally for H. dissiliens. Desmids were distributed among most substrata examined in this stream, with abundance comparable to reported estimates from softwater lakes and acid bogs. In contrast to established dogma, lotic desmids are not incidental drift organisms, but rather comprise a viable and persistent component of the stream periphyton.     

深圳福田红树林区底栖大型动物群落的空间分带及灌污的可能影响

本文自１９９１年４月至１９９３年１月对深圳福田红树林中底栖大型动物的空间分带及灌污的可能影响进行了研究。结果表明,该红树林湿地中主要出现的底栖动物为拟沼螺科,黑螺科,汇螺科,沙蟹科,方蟹科和弹涂鱼科种类。红树区内底栖动物从高潮位到低潮位可分为３个群落分布带：亮泽拟沼螺带;拟黑螺－褶痕相手蟹带;弧边招潮－印尼拟蟹守螺－刻纹拟沼螺带。群落的分带可能主要由潮位线,食物适应性及底质结构因素决定。林前泥滩底栖动物种类多样性最大,生物量最高。林内动物群落则表现出低种类多样性,高种群个体数的特点。群落总栖息密度的变化基本上由软体动物所主导。生活污水排灌对红树林中底栖大型动物的影响不明显,仅在排污口端引起少数污水动物种类的出现及群落总生物量轻微的升高。     

ADAPTATION OF STYROFOAM SUBSTRATE TO BENTHIC ALGAL PRODUCTIVITY STUDIES IN LAKE TAHOE,CALIFORNIA-NEVADA1

A routine sampling technique has been developed using artificial styrofoam substrate to estimate benthic algal productivity in the littoral zone of lakes. Estimation of maximum carbon fixed in Lake Tahoe ranged from 11.1 mg C·m^?2· day^?1 at 0.5 m to 17.1 mg C·m^?2· day^?1 at 1.0 m. Estimates were made for communities composed of both diatom and green algal populations in water between 0.5 and 3.0 m. Maximum productivity occurred between 1–2 m. The technique developed can give comparable estimates of productivity if adequate replication is undertaken to decrease problems associated with periphytic heterogeneity.     

THE ECOLOGY OF EPIPELIC ALGAE OF FIVE WELSH LAKES,WITH SPECIAL REFERENCE TO VOLVOCALEAN GREEN FLAGELLATES (CHLOROPHYCEAE)1

The ecology of epipelic algae on the marginal sediments of five Welsh lakes was studied over an annual cycle. The lakes, Llydaw, Cwellyn, Padarn, Maelog and Coron ranged from very oligotrophic to nutrient-rich. Attention was focussed on chlamydomonad flagellates, diatoms, blue-green algae and euglenoids and the different proportions of these in algae in the epipelon of lakes of contrasting water quality. A total of 75 algal taxa was found in the five lakes, 25 were species of volvocalean flagellates. Mean annual population density of these flagellates differed by an order of magnitude between the lakes. The greatest population density was recorded for Chlamydomonas anticontata Schiller in nutrient-rich Llyn Maelog. Twenty species of pennate diatoms were recorded frequently in the epipelon. In the nutrient-rich lakes, Maelog and Coron, pennate diatoms were dominant on the sediments, where they exhibited population maxima in spring and autumn. Increase in numbers of epipelic diatoms was recorded when silica concentrations were minimum in the overlying lake waters. Navicula hungarica Grun. achieved the maximum population density, 260 000 cells · cm^?2. Euglenoids formed large epipelic populations during late-summer and autumn in these nutrient-rich lakes. Blue-green algae were more important, proportionally, in the nutrient-poor mountain lakes, which had sediments of higher organic content. Chlamydomonads were the major algal component of the epipelon in the mountain lakes, Llydaw and Cwellyn, where the sediments were characterized by larger particle size, and higher organic content. In the nutrient-rich lakes, where the sediments had higher calcium content, chlamydomonads formed significant populations only during spring and summer, when nutrient levels were minimal in the overlying lakewaters.     

THE EFFECTS OF TEMPERATURE ON THE PHOTOSYNTHETIC PARAMETERS AND RECOVERY OF TWO TEMPERATE BENTHIC MICROALGAE,AMPHORA CF. COFFEAEFORMIS AND COCCONEIS CF. SUBLITTORALIS (BACILLARIOPHYCEAE)1

Temperature and irradiance are the most important factors affecting marine benthic microalgal photosynthetic rates in temperate intertidal areas. Two temperate benthic diatoms species, Amphora cf. coffeaeformis (C. Agardh) Kütz. and Cocconeis cf. sublittoralis Hendey, were investigated to determine how their photosynthesis responded to temperatures ranging from 5°C to 50°C after short‐term exposure (1 h) to a range of irradiance levels (0, 500, and 1,100 μmol photons · m^?2 · s^?1). Significant differences were observed between the temperature responses of maximum relative electron transport rate (rETRmax), photoacclimation index (E_k), photosynthetic efficiency (α), and effective quantum yield (ΔF/F_m’) in both species. A. coffeaeformis had a greater tolerance to higher temperatures than C. sublittoralis, with nonphotochemical quenching (NPQ) activated at temperatures of 45°C and 50°C. C. sublittoralis, however, demonstrated a more rapid rate of recovery at ambient temperatures. Temperatures between 10°C and 20°C were determined to be optimal for photosynthesis for both species. High temperatures and irradiances caused a greater decrease in ΔF/F_m’ values. These results suggest that the effects of temperature are species specific and that short‐term exposure to adverse temperature slows the recovery process, which subsequently leads to photoinhibition.     

渤海莱州湾表层沉积物中底栖有孔虫分布特征及其环境意义

对渤海莱州湾海域240个站位表层沉积物中底栖有孔虫群落进行了分析,共鉴定常见的底栖有孔虫42种。结果表明,莱州湾表层沉积物中底栖有孔虫主要以玻璃质壳为主(平均丰度达70.9%),瓷质壳含量次之,胶结壳含量最低;玻璃质壳占有孔虫全群的百分含量,随水深的增加而增加;从黄河口向外海方向,有孔虫分异度和丰度都逐渐增大。该海域底栖有孔虫平面分布的主要控制因素为盐度和底质沉积物类型,大体可分为两个组合分区,I区为Ammonia beccarii-Quinqueloculina spp.组合,代表盐度较低的近岸海陆过渡浅水环境;II区为Cribrononionsub-incertum-Protelphidium tuberculatum组合,代表盐度较高的远岸内陆架环境。