中非裂谷盆地构造演化差异性与构造动力学机制

分析了不同空间位置盆地的构造演化差异性，并结合区域构造事件探讨了中非裂谷盆地的构造动力学成因机制。中非裂谷盆地包括两个分支体系：西非裂谷系主要呈左旋走滑双断式结构；中非裂谷系主要表现为单断式右旋走滑结构。研究区内有走滑盆地和伸展盆地两种类型：前者位于走滑断裂带内部，近似平行于走滑断裂带展布，走滑作用强，构造反转明显；后者位于走滑断裂带端部，与走滑断裂带斜交，伸展作用强，构造反转较弱。中非裂谷盆地发育3期裂陷—拗陷构造旋回：早白垩世，中非盆地同时发生强烈的裂陷作用；晚白垩世，不同空间位置盆地的裂谷作用强度差异明显并且经历构造反转；古近纪，只有近NW-SE向盆地发生第三期裂谷作用，而其他盆地处于拗陷期。中非裂谷盆地是非洲陆缘板块构造运动在非洲陆内3个块体差异应力作用的陆内响应，3期裂谷作用的构造动力来源不同：早白垩世中大西洋扩张、晚白垩世南大西洋快速扩张和印度洋扩张双重作用、古近纪非洲板块与欧洲板块主要碰撞及西北印度洋中脊扩张影响。     

Bauble spiders: a new species of Achaearanea (Araneae: Theridiidae) with ingenious spiral retreats

A new species of Achaearanea (Theridiidae) is described from the Cedarberg in South Africa. Its unusual morphological features include the position of the spinnerets directly behind the epigastric fold. The male palp is a modification of the palpal conformation of other Achaearanea. This spider lives in a spherical retreat comprizing silk, sand and pebbles. This structure typically dangles from only one thread and has a tiny opening at the bottom that leads into a spirally-coiled tunnel. Males and females build spirals in opposite directions. This enables the male to construct his retreat against that of the female in such a way as to form a brood chamber. Retreats are situated in cool places under low overhanging rocks or branches. The configuration of the narrow, suspended retreat may decrease the spider's vulnerability to enemies while foraging for ants in a typical theridiid fashion.     

The function of spider egg sacs in relation to parasitoids and predators,with special reference to the Australian fauna

The function of spider egg sacs is analysed as structures to reduce or prevent mortality by parasitoids and predators. The host relationships of the groups concerned are documented, with special reference to the Australian fauna. Many new records are presented and the biology of each group is discussed. Information presented supports the hypothesis that egg sacs are an effective barrier against scavenging predators (generalists), while coevolution between spiders and their specialized (highly adapted) parasitoids and predators is responsible for the specificity displayed by the latter two groups and the structural diversity evident of egg sacs.     

Morphometric differentiation between two sympatric Macrobrachium Bates, 1868 shrimps (Crustacea: Decapoda: Palaemonidae) in West‐African rivers

A comparative morphometric study was performed on two species of shrimps, Macrobrachium macrobrachion (Herklots, 1851) and Macrobrachium vollenhovenii (Herklots, 1857). In total, 714 specimens (563 males and 151 females) originating from four rivers in Ivory Coast were analysed. The morphometry was carried out on 33 measurements; seven meristic and four morphological characters and ratios were calculated from the measurements. Data were analysed using univariate, bivariate and multivariate statistics. Meristic and morphological characters did not allow separation of distinct species. However, metric variables and ratios clearly discriminated the two species. The characters (merus/palm, carpus/palm, palm width/palm length, carpus width/carpus length, palm width) related to the form and the size of second pereiopods could be used for the discrimination of both species. This study, by allowing accurate identification of these species, will facilitate future research.     

Micromammalian distribution and abundance in the Western Cape Province,South Africa,as evidenced by Barn owls Tyto alba (Scopoli)

The history of Western Cape mammalogy began almost 200 years ago with Thunberg () and has been augmented periodically ever since. The present paper follows Vernon () and Grindley et al. () in eliciting information from material in Barn owl Tyto alba (Scopoli) pellets. Analyses are based on identified and counted mandibles and maxillae. The Laminate vlei rat, Otomys laminatus Thomas and Schwann, and Krebs's fat mouse, Steatomys krebsii Peters, are shown to have wider distributions than were previously recorded. The Southern multimammate mouse, Mastomys coucha (A. Smith), is apparently expanding its range westwards, a move probably enabled by changes in vegetation due to farming practices. There appears to be some correspondence between proportional representation of some species and rainfall, either its amount per annum or its seasonality. Variation in alveolar length in Cape gerbils, Tatera afra (Gray), taken as a proxy for mean individual mass, suggests that mean size in this species may be influenced by rainfall seasonality. Although the Vlei rat, Otomys irroratus (Brants), is known to breed throughout the year, the present evidence indicates that in the West Coast National Park births peak in late spring and early summer, some two months after maximum rainfall. The Western Cape data support the concept that T. alba is a selective opportunist. Sample structure and co‐occurrence of species in individual pellets both show that in some cases the owls are more nearly opportunistic while in others they appear to be considerably more selective.     

Foraging mode of Australolacerta rupicola (FitzSimons, 1933) (Sauria: Lacertidae): evidence of seasonal variation in an extremely active predator?

Foraging mode of the endemic Soutpansberg rock lizard (Australolacerta rupicola) was determined by (1) measuring the number of movements per minute (MPM) and the percentage time spent moving (PTM); and (2) analysing faecal samples. Furthermore, these criteria were related to diet composition, proportion of attacks initiated while moving and foraging substrate. The results are discussed in comparison to the foraging modes of 20 other lacertid species. Values for MPM and PTM as well as faecal analysis indicate an active foraging strategy for A. rupicola. Although rock living, this species mostly forages in leaf litter where it is well camouflaged while actively searching for sedentary prey. Even in comparison to other active foragers of the family Lacertidae, A. rupicola displays the prototypic behaviour of a widely foraging lizard with very high PTM and very low MPM.     

Two new species of freshwater crabs from Mount Elgon,East Africa (Brachyura: Potamoidea: Potamonautidae) and a re-diagnosis of Potamonautes niloticus (H. Milne Edwards, 1837) with notes on their natural history and onchocerciasis

Two new species of potamonautid freshwater crabs from eastern Uganda, Africa are described, and Potamonautes niloticus (H. Milne Edwards, 1837) is re-diagnosed with key characters illustrated photographically. A total of four species of crabs are now known to occur on Mount Elgon, which borders both Kenya and Uganda. Two of these species are endemic to the mountain and the distribution patterns of all four species indicate a distinct altitudinal preference. All taxa are compared with similar species and their distributions and natural history are reviewed. Furthermore, three of the crabs recorded from Mount Elgon have been implicated in the transmission of onchocerciasis in East Africa.     

New species of Corcyrogobius,Thorogobius and Wheelerigobius from West Africa (Teleostei: Gobiidae)

Three new West African species of gobiid fishes are described from the Gulf of Guinea in the tropical eastern Atlantic. These are Corcyrogobius lubbocki sp. nov., Thorogobius rofeni sp. nov. and Wheelerigobius wirtzi sp. nov. Generic features are discussed. T. rofeni, known from only the holotype, was trawled on the upper continental slope, an unusually deep occurrence for a gobiid species.     

A systematic revision of the large-scaled Marcusenius with description of a new species from Cameroon (Teleostei; Osteoglossomorpha; Mormyridae)

Nine out of 37 recognized species in the genus Marcusenius have eight large circumpeduncular scales rather than 12 or 16, which is more typical of the genus. They are: M. dundoensis, M. fuscus, M. ghesquierei, M. intermedius, M. kutuensis, M. lambouri, M. moorii, M. paucisquamatus and M. schilthuisiae. All nine are restricted to West-Central and Central Africa. A detailed morphometric analysis could not distinguish differences between M. moorii, M. paucisquamatus and M. lambouri. Therefore they are considered as synonyms with M. morrii as the senior synonym. The systematic status of M. intermedius is uncertain owing to the existence of only three specimens. Within this species complex a new species, Marcusenius sanagaensis, is described from the Sanaga River basin in Cameroon. It differs from all the others in the number of scales on the lateral line and in the extent of the broad dark band between the anterior base of the dorsal fin and the anterior base of the anal fin. All valid Marcusenius species with eight circumpeduncular scales are redescribed and a key to these species is given.