Conservation priorities for forest-floor invertebrates of the southeastern half of Madagascar: evidence from two land-snail clades

Leaf litter and soil of tropical forests harbour some of Earth's most diverse, most endangered, yet least understood biological communities. How well do east-southeast Madagascar's reserves protect this resource? A preliminary answer is provided by the landsnail genera Cyclophoridae Boucardicus and Charopidae n. gen., as represented by 3680 specimens in 64 species, collected 1990–1993 from 129 stations in 26 transects, with nine reserves included. These two genera qualify as indicator/target taxa because they are endemic, species-rich, well-defined clades, sensitive to environmental degradation, with species readily identifiable by shells alone. Indices of diversity and endemism were used to rank 12 bioclimate-latitude regions by priority for conservation/collection. The higher-priority regions generally have some forest nominally conserved, of which the lowland-rainforest reserves of Manombo, Kianjavato, and Betampona are especially rich. A crucial exception, however, is the highest-priority region: the coastal-montane rainforests to the north of Tolagnaro (Fort Dauphin), which are completely unprotected and are rapidly being destroyed. (Andohahela Reserve hes westward, where diversity and endemism are 60% and 20% lower, respectively, so it conserves less than a fourth of the general region's endemic diversity.)     

中国有厣陆生贝类一新种：前鳃亚纲：中腹足目

作者从吉林省盘石县红南林场采得环口螺科一新种:盘石双边凹螺 Chamalycaeus panshiensis,本文对该新种的形态特征作了详细描述,尤其对齿舌作了显微观察,其齿式为(2:1:1:1:2)/57。作者并与近似种拉氏双边凹螺 Chamalycaeus rathouisianus(Heude,1882)进行了比较。     

中国双边凹螺属一新种记述(前鳃亚纲,中腹足目,环口螺科)

作者在整理西藏陆生贝类标本中得双边凹螺属1新种,即察隅双边凹螺Chamalycaeu szayuensis sp.nov.,对新种进行了详细描述,并与近似种进行了比较。     

An annotated catalogue of type specimens of the land snail genus Cyclophorus Monfort, 1810 (Caenogastropoda,Cyclophoridae) in the Natural History Museum,London

The collection of land caenogastropod snails in the genus Cyclophorus Monfort, 1810 housed in the Natural History Museum, London (NHM), includes 52 type lots. Lectotypes have been designated for 43 available species-level names to stabilize existing nomenclature, two previously designated lectotype, two holotypes, one paratype, one syntype, one possible syntype and two paralectotypes are also listed. A complete catalogue of the Cyclophorus types in NHM, London is provided for the first time.     

Cryptic, genetically extremely divergent, polytypic, convergent, and polymorphic taxa in Madagascan Tropidophora (Gastropoda: Pomatiasidae)

Madagascar's magnificent and environmentally threatened endemic radiation of the land-snail genus Tropidophora Troschel has recently been classified into three subgenera, 95 species and 142 varieties, based on often subtle conchological variation among small samples; it seems best to ignore temporarily this confusing plethora of names until true biological species and their relationships are better understood. The author's field work in 1990 succeeded in obtaining live Tropidophora from 40 populations distributed throughout the island. Allozyme analysis (108 snails, 15 loci, 117 alleles) yielded a cladogram suggesting nine genetically coherent taxa (T. taxa A-I), each represented in the collections by 1–10 populations. Comparisons among shells (total 1634) and penes (total 31 from 20 populations representing eight of the nine taxa) revealed: (1) two conchologically indistinguishable taxa (H and I) fixed for alternative alleles at 13 of 15 loci, with only a very subtle difference in penes, and with mosaic and overlapping geographical distributions in the Northeast; (2) two extremely polytypic taxa (C in the Southwest, F in the Southeast) with parallel trends toward depressed, broadly umbilicate, heavily sculptured shells with apertural lips widely reflected at the umbilicus at inland, more arid sites, resulting in sympatric convergence; (3) one southeastern taxon (G) in which the penis apparently doubles in length but the shell does not change 6.0 km to the northwest, but in which the shell shifts dramatically in sculpture, colour, and lip reflection 0.5 km to the westnorthwest; and (4) generally such extreme intra- and inter-population variation in shell and male-genital characters as to render many of them dubious at best for systematics. Thus the Madagascan Tropidophora present a fascinatingly complex problem in evolutionary morphology/ecology, the solution of which will require even more extensive collecting, followed by molecular comparisons or detailed anatomical comparisons, or both. The total number of biological species is still likely to be quite large, despite irrelevance of much of the current taxonomy, because many smaller species remain to be discovered.     

贵州沟螺属一新种记述(前鳃亚纲,中腹足目,环口螺科)

在整理贵州省荔波县茂兰喀斯特森林自然保护区陆生贝类标本时,经鉴定发现1新种,即茂兰沟螺Dioryx maolanensis sp.nov.,文中对新种形态特征、栖息环境进行了描述,并对其相似种进行了分析和讨论.     

云南扭轴蜗牛科一新种记述(肺螺亚纲,柄眼目,扭轴蜗牛科)

笔者在整理云南省勐腊地区陆生贝类标本时,经鉴定发现1新种,即双沟皮氏螺Perrottetia biboncavus sp.nov..隶属于肺螺亚纲、柄眼目、扭轴蜗牛科、皮氏螺属.对新种形态特征、栖息环境作了记述,并对其近似种也进行了讨论.     

贵州环口螺科一新种(前鳃亚纲:中腹足目:环口螺科)

1998年7-8月作者在贵州南部地区考察,获得陆生贝类标本一批,经鉴定发现1新种,即茂兰腹皱螺Gastroptychia maolanensis sp.nov。隶属于前鳃亚纲,中腹足目,环口螺科,腹皱螺属。描述了新种形态特征,栖息环境,并对其近似种进行了讨论。     

福建弯螺属一新种记述(肺螺亚纲,柄眼目,扭轴蜗牛科)

记述了中国弯螺属1新种,即福州弯螺Sinoennea fuzhuouensis sp.nov..弯螺属的种类主要分布于东亚和南亚地区,对新种的形态特征进行了详细描述,并与近似种进行了比较和讨论.     

A commentary on Ridley's cladistic solution to the species problem

The cladistic species concept proposed by Ridley (1989) rests on an undefined notion of speciation and its meaning is thus indeterminate. If the cladistic concept is made determinate through the definition of speciation, then it reduces to a form of whatever species concept is implicit in the definition of speciation and fails to be a truly alternative species concept. The cladistic formalism advocated by Ridley is designed to ensure that species are monophyletic, that they are objectively real entities, and that they are individuals. It is argued that species need not be monophyletic in order to be real entities, and that ancestor-descendant relations are not the only relations that confer individuality on entities. The species problem is recast in terms of a futile quest for a definition of that single kind of entity to which the term species should uniquely apply.     

贵州环口螺科一新种记述(前鳃亚纲,中腹足目,环口螺科)

在整理贵州省贵阳地区陆生贝类标本时,经鉴定发现1新种,即奇异阿勇螺Arinia mirifica sp.nov..隶属于前鳃亚纲、中腹足目、环口螺科、阿勇螺属.对新种形态特征、栖息环境进行了记述,并对其近似种也进行了讨 论.     

小型腹足类齿舌的扫描电镜观察

介绍了应用扫描电镜观察小型腹足类齿舌的方法。描述了折叠萝卜螺和大脐圆扁螺齿舌带上齿片的排列方式,结果显示,两种螺齿舌的齿片排成许多模列,每一横列又包含多个齿片,齿片上缘或侧缘尖齿的数目和形态有差异。     

Die Torsion der Gastropoda - ein biomechanischer Prozeß

The recently proposed biomechanical model of gastropod torsion (edlinger 1988 a, b) is rejected on various reasons. First, the assumed original conditions in Polyplacophora and Tryblidiida as well as the constructed original condition in the Gastropoda do not emst in reality. Secondly, the mollus-can musculature is a very dynamic structure (continuous assembly and disassembl) so that biomechanic rocesses are of much minor importance than assumed by Edlinger . Thirdly, the biomechanical model resented does not explain the change of the relative position of the lateral (= visceral) nerve cords which are surrounding the dorsoventral muscles in Polyplacophora and Tryblidiida (also Scaphopoda and Bivalvia), but are situated between the muscles in Cephalooda and Gastropoda. The consequences of these considerations to the early evolution of Gastropoda are briefly outlined.     

浙江弯螺属一新种记述(肺螺亚纲,柄眼目,扭轴蜗牛科)

记述了浙江弯螺属一新种,即龙塘山弯螺新种Sinoennea longtangshanensis sp. nov.。标本采自浙江省临安市龙塘山清凉峰自然保护区。弯螺属的种类主要分布于东亚和南亚地区,在我国主要分布于长江以南的地区。龙塘山弯螺贝壳小型(壳高4.40 mm,壳宽2.40 mm),壳质薄,有6.5个螺层,胚螺层和第二螺层光滑,无肋纹,壳口具4枚齿。模式标本保存于中国科学院动物研究所。     

中国弯螺属一新种记述(肺螺亚纲,柄眼目,扭轴蜗牛科)

笔者在整理福建地区陆生贝类标本时,经比对鉴定发现1新种,即蛹形弯螺Sinoennea pupoidea sp.nov,.隶属肺螺亚纲、柄眼目、扭轴蜗牛科、弯螺属.对新种形态特征、柄息环境作了记述,并对其近似种也进行了讨论.     

江西弯螺属一新种记述(肺螺亚纲,柄眼目,扭轴蜗牛科)

在整理江西地区陆生贝类标本时,经比对鉴定发现1新种,龙潭弯螺Sinoennea longtanensis sp.nov.,隶属肺螺亚纲、柄眼目、扭轴蜗牛科、弯螺属。对新种形态特征、栖息环境作了记述,并与其近似种进行讨论。     

中国弯螺属一新种(肺螺亚纲,柄眼目,扭轴蜗牛科)

系统整理和研究了中国弯螺属的种类,共10种,其中1新种即茂兰弯螺Sinoennea maolanensis sp.nov.,弯螺属的种类主要分布于东亚和南亚地区;作者对其已发表的种类进行了整理、甄制,对新种的形态特征进行了详觋细描述,亦与近似种进行了比较、讨论.