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11.
耳嫘是一类特殊的原始有肺类软体动物,主要分布于热带、亚热带海陆交汇区的高潮带和潮上带.耳螺在红树林区广泛分布,且资源非常丰富,全世界已知的约240种耳螺中,至少有一半以上的种类在红树林区被记录.本文总结了耳螺与红树林的关系以及中国嗜盐耳螺的种类,综述了红树林区耳螺的种类组成、分布、生态功能、行为等的研究进展,报道了中国...  相似文献   
12.
Morphological characters of the Euthyneura available from the literature were re-evaluated in terms of terminology and primary homology. A total of 77 characters and 75 taxa were retained in a data matrix. Several assumptions on character weights and types were tested. In the cladistic analyses, it appeared that the data matrix was highly homoplastic, and only robust nodes (those which were little modified by variations in weight and coding of characters) were retained in a concensus tree. The evolutionary histories of all characters and monophylies of higher euthyneuran taxa were discussed. The following interrelationships of the taxa were obtained in a consensus tree: the clade Heterobranchia includes paraphyletic allogastropod taxa which emerge basally, and the clade Euthyneura. The latter includes the clade Pulmonata and at least 10 opisthobranch clades of unresolved relationship (Thecosomata, Gymnosomata, Acochlidioidea, Pyramidelloidea, Runcinoidea, Cephalaspidea, Sacoglossa, Umbraculoidea, Pleurobranchoidea, Nudibranchia). The Pulmonata include basommatophoran paraphyletic taxa and the clade Geophila (Onchidiidae, Soleolifera, Stylommatophora). The position of the Sacoglossa and the monophyly of the Notaspidea are also discussed.  © 2002 The Linnean Society of London, Zoological Journal of the Linnean Society , 2002, 135 , 403–470.  相似文献   
13.
西藏陆生贝类五新种记述(腹足纲:中腹足目,柄眼目)   总被引:7,自引:4,他引:3  
作者于1980年在西藏东南部获得一批标本,经鉴定得5新种,即通麦扁双边凹螺Chamaly-caeus tangmaiensis sp.nov.,通麦沟螺Dioryx tangmaiensis sp.nov.,曲水肾螺Pupilla quxuensis sp.nov.,芒康艾纳螺Ena markamensis sp.nov.,下察隅卷轴螺Tortaxis xiazayuensis sp.nov.。对新种进行了详细的描述,并与近似种进行了比较。  相似文献   
14.
In the southern Appalachian region of North America, the phylogenetically convergent shells of the polygyrid snails Triodopsinae Neohelix major (Binney) and Polygyrinae Mesodon normalis (Pilsbry) are even more convergent in size and shape in sympatry (7 sites) than in allopatry (23 and 10 sites). Environmental correlations account for 34% and 30% of size and shape variations in N. major (larger, taller, and more loosely coiled at northern, high-altitude, sheltered sites), but for only 14% and 9% in M. normalis (larger, flatter, and more loosely coiled at south-facing, exposed sites). The statistical significance of the sympatric convergence dropped out when these correlations were removed. This phenomenon helps account for the many cases in eastern North America of nearly identical land-snail shells in sympatry and questions the importance of competitive character displacement in the evolution of land-snail shell morphology. This apparently nonmimetic case of sympatric convergence provides an unusually precise and well-delimited, naturally replicated experiment in evolutionary morphology, which is analyzed for controlling factors in a follow-up paper.  相似文献   
15.
In 1985 we resurveyed the sites on the Marlborough Downs in southern England at which Cain and Currey in 1960/61 sampled Cepaea snails and thence introduced the term 'area effects' to describe large areas of uniform morph frequency. Some sites no longer harboured Cepaea and at others the species composition had changed, with a general spread of Cepaea hortensis at the expense of Cepaea nemoralis. The majority, however, permitted comparison of morph frequencies between the two surveys. In C. nemoralis, we detected a significant overall decrease in the frequency of the brown morph and estimate selection as 5–9% per generation. There was no apparent change in frequencies of banded morphs. In C. hortensis we detected a significant overall increase in the frequency of unbanded shells (1–3% selection per generation) and an almost significant decrease in the frequency of fusions within the banded class. There was insufficient colour polymorphism in C. hortensis to allow analysis of colour morph frequencies. These changes—all in the direction of reduced absorption of solar energy—resemble others detected in both species at other localities in southern England. Possible explanations include large-scale climatic effects and changes in vegetation.  相似文献   
16.
贵州洞穴淡水、陆生贝类区系及新种记述   总被引:11,自引:1,他引:10  
首次报道了贵州省安龙县、贵阳市、独山县、荔波县、安顺市、开阳县、息烽县、盘县、兴义市、大方县、普定县等39个洞穴内不同生境的淡水、陆生贝类,经鉴定得淡水、陆生螺类共计71种,分隶于15科,36属,其中淡水螺类3科4属5种;陆生螺类66种,12科32属;1新种,即荔波双边凹螺Chamalycaeus libonensis sp.nov.附有种类名录,栖息环境及地理分布,并对洞穴中的淡水、陆生贝类区系组成进行了讨论,对新种进行了详细的描述,与近似种进行了比较。  相似文献   
17.
Bruno Baur  Anette Baur 《Oecologia》1986,69(2):283-287
Summary Byttneria aculeata (Sterculiaceae), a subcanopy liane with a shrubby juvenile form has two distinct leaf color morphs in juvenile plants- a given juvenile has plain green leaves or leaves with whitish variegation. Both forms occur together in the forest and in clearings; however, the variegated morph is more common in open sites, and the plain morph predominates in the forest. Percent variegation per leaf for variegated plants increased from closed to open sites. Measurements of growth support the idea that variegation is favored in open habitats. Within a given habitat, rate of herbivory by leaf miners on a given morph increases with increasing relative frequency of that morph; however, at a given relative frequency, the variegated morph is less heavily attacked than is the plain morph when it occurs elsewhere at that same frequency.  相似文献   
18.

1. 1.|Mean supercooling points (SCP) of Anguispira alternata (Say) gradually declined in autumn and increased in spring. SCP also declined in autumn in Discus conrkhitei (Newcomb) and Gastrocopta armifera (Say).

2. 2.|Supercooling ability varied among the species, being the greatest in G. armifera.

3. 3.|Prolonged exposure of winter animals to high temperatures resulted in only a modest increase in SCP.

4. 4.|Low temperature survival of D. cronkhitei and G. armifera was slightly poorer than predicted by the mean SCP.

Author Keywords: Cold-hardiness; supercooling point; land snail; Pulmonata; Anguispira alternata; Discus cronkhitei; Gastrocopta armifera; Helicodiscus parallelus  相似文献   

19.
中国陆生贝类一新种(柄眼目:坚螺科)   总被引:2,自引:0,他引:2  
1984年至1986年间作者在云南省南部地区考察,获得陆生贝类标本一批,经鉴定发现一新种,即金平坚螺Camaena jinpingensis、隶于肺螺亚纲、柄眼目、坚螺科、坚螺属。本文对其新种形态特征,栖息环境进行了描述,并对其相近似种也进行了讨论。  相似文献   
20.
记述采自贵州省陆生贝类1新种,巩尧山喇叭螺Boysidia(Boysidia)gongyaoshanensis 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。  相似文献   
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