Species discrimination and concept formation by rhesus monkeys (Macaca mulatta)

There are 19 species in genusMacaca and some of them are living in sympatry (Fooden, 1980). Although inter-specific hybrids are relatively easy to produce under artificial conditions, hybridization does not occur naturally. What is preventing that among the species of genusMacaca? Three rhesus monkeys acquired a discrimination between pictures with rhesus monkeys and without rhesus monkeys. All subjects showed positive transfer of this discrimination to new pictures with rhesus monkeys and without rhesus monkeys. A further test showed that these monkeys could discriminate between pictures of rhesus monkeys and pictures of Japanese monkeys. The results suggest that rhesus monkeys recognize rhesus monkeys as a class, independent of the actual stimuli such as a picture or an individual monkey. The ability to recognize members of their own species and the opportunities for such learning may be an important factor preventing hybridization among the species of genusMacaca.     

Testing the effectiveness of surrogates for assessing biological diversity of arthropods in cereal agricultural landscapes

Agricultural intensification is altering biodiversity patterns worldwide. Rapid and effective methods are needed to monitor these changes in farmland biodiversity, but it becomes both a cost- and time-prohibitive task, particularly for hyper-diverse groups such as arthropods. We evaluated the effectiveness of surrogates in irrigated and rainfed wheat fields in a Mediterranean farmland in NW Spain in order to get a rapid tool to assess arthropod biodiversity. We studied six groups with different ecological needs (i.e. Aphididae, Aphidiinae, Coccinellidae, Formicidae, Heteroptera and Syrphidae) at species level (147 species), genus (105), family (10, only Heteroptera) and order (19) level. Higher taxa, cross-taxa and subset-taxa or total richness approaches were tested as well as the correlation in composition between levels for the selected groups, and the influence of farming regime. Genus richness was a good surrogate of species richness in all six groups studied (R² = 0.38–0.60), like family and order were for Heteroptera (R² = 0.37 and 0.29, respectively). Cross-taxa analyses showed that Aphididae and Aphidiinae genera (R² = 0.19 and 0.30, respectively) and species (R² = 0.20 and 0.28, respectively) were good surrogates for Aphidiinae and Aphididae species respectively. Coccinellidae genera (R² = 0.26) and species (R² = 0.25) were good surrogates for Heteroptera species. Finally, Aphididae and Coccinellidae both at genera (R² = 0.14 and 0.20, respectively) and at species levels (R² = 0.12–0.22, respectively) were good surrogates for total species richness of all groups. Genera composition was the best surrogate for the species composition within each group. Farming regime had no influence on the relationships between surrogates and species patterns in most cases. Our results suggest that genera level is a useful surrogate for all the studied groups and family is appropriate for Heteroptera. Genus level provided a saving of 15% of identification time in Aphididae and 80% for Coccinellidae. This proves its usefulness to asses and monitor biodiversity in wheat croplands and the possibility to reduce costs.     

Taxonomy,distribution, and status of gibbons (Hylobates) in Southern China and adjacent areas

Gibbons are small and arboreal apes restricted to southeastern tropical and southern subtropical regions in Asia. They are distributed from Assam in the northwest, eastward to south China and Vietnam, south through the Malay Peninsula to Sumatra, Borneo, Java, and the Mentawai Islands. Twenty-two genetically distinct populations of gibbons are generally recognized. Gibbons were once widely distributed in China; however, they are now primarily restricted to southern and southwestern Yunnan and Hainan Island. Their widest distribution and greatest species diversity is in Yunnan Province. Gibbons are rare in China and are now listed as a first class endangered species. Four gibbon species inhabit Yunnan Province in southern China. They areH. hoolock, H. lar, H. leucogenys, andH. concolor. There are three subspecies ofH. leucogenys: H. l. leucogenys, H. l. siki, andH. l. gabriellae. OnlyH. l. leucogenys inhabits China. Four subspecies ofH. concolor inhabit China. These areH. c. concolor, H. c. jingdongensis, H. c. furvogaster, andH. c. hainanus. The first three subspecies inhabit Yunnan andH. c. hainanus is found only on Hainan Island.H. lar yunnanensis is the subspecies ofH. lar in southern China.H. hoolock leucogenys is the subspecies ofH. hoolock in southern China.H. concolor jingdongensis, H. concolor furvogaster, andH. lar yunnanensis are all newly proposed subspecies byMa andWang (1986). The data on southern China gibbons presented here is based on an analysis of the skeletons and skins of 49 specimens held at the Kunming Institute of Zoology, Kunming, Yunnan.     

Voltage-dependent calcium and potassium conductances in striated muscle fibers from the scorpion,Centruroides sculpturatus

Ionic currents responsible for the action potential in scorpion muscle fibers were characterized using a three-intracellular microelectrode voltage clamp applied at the fiber ends (8–12°C). Large calcium currents (I _Ca) trigger contractile activation in physiological saline (5 mm Ca) but can be studied in the absence of contractile activation in a low Ca saline (2.5 mm). Barium (Ba) ions (1.5–3 mm) support inward current but not contractile activation.Ca conductance kinetics are fast (time constant of 3 msec at 0 mV) and very voltage dependent, with steady-state conductance increasing e-fold in approximately 4 mV. Half-activation occurs at –25 mV. Neither I _Ca nor I _Ba show rapid inactivation, but a slow, voltage-dependent inactivation eliminates I _Ca at voltages positive to –40 mV. Kinetically, scorpion channels are more similar to L-type Ca channels in vertebrate cardiac muscle than to those in skeletal muscle.Outward K currents turn on more slowly and with a longer delay than do Ca currents, and K conductance rises less steeply with voltage (e-fold change in 10 mV; half-maximal level at 0 mV). K channels are blocked by externally applied tetraethylammonium and 3,4 diaminopyridine.This work was supported by a grant from the NIH (NS-17510) to W.F.G. and a NRSA award to T.S. (GM-09921).     

Interspecific hybridizations among species of theElymus semicostatus andElymus tibeticus groups (Poaceae)

Interspecific hybridizations were made between species of theE. semicostatus group, viz.,E. semicostatus (Nees exSteud.)Meld.,E. validus (Meld.)B. Salomon,E. abolinii (Drob.)Tzvel., andE. fedtschenkoi Tzvel., and species of theE. tibeticus group, viz.,E. pendulinus (Nevski)Tzvel.,E. tibeticus (Meld.)Singh,E. shandongensis B. Salomon, andE. gmelinii (Ledeb.)Tzvel., as well as among species within theE. tibeticus group. All species are tetraploid (2n = 4x = 28) and possess SY genomes. Meiotic pairing data from 24 hybrids involving 17 interspecific combinations are presented. The average number of chiasmata per cell ranged from 17.91 to 26.20 in hybrids within theE. tibeticus group, compared with 7.26 to 22.04 in hybrids between the two species groups. Despite the extensive collection of cytological data, there was no definite evidence for confirming or disproving the separate existence of the two groups.     

Leclercia adecarboxylata Gen. Nov., Comb. Nov., formerly known asEscherichia adecarboxylata.

The nameLeclercia adecarboxylata is proposed for a group of the family Enterobacteriacae previously known asEscherichia adecarboxylata. Leclercia adecarboxylata can be phenotypically differentiated from all other species of Enterobacteriaceae. The members of this species are positive for motility, indole production, methyl red, growth in the presence of KCN, malonate, beta-galactosidase, beta-xylosidase, esculin hydrolysis, gas production fromd-glucose, and acid production fromd-cellobiose,d-lactose, melibiose,l-rhamnose, adonitol,d-arabitol, dulcitol, and salicin; the strains were negative for Voges-Proskauer, citrate (Simmons), H₂S (Kligler), lysine and ornithine decarboxylases, arginine dihydrolase, phenylalanine deaminase, gelatinase, DNase, Tween-80 hydrolysis, and acid production from myoinositol and alpha-methyl-d-glucoside. Fermentation ofd-raffinose,d-sucrose, andd-sorbitol is variable with strains. DNA relatedness of 11 strains ofL. adecarboxylata to three strains including the type strain of this species averaged 80% in reactions at 65°C. DNA relatedness to other species in Enterobacteriaceae was 2%–32%, indicating that this species was placed in a new genusLeclercia gen. nov. The type strain ofL. adecarboxylata is ATCC 23216.     

Edwardsiella hoshinae,a new species of enterobacteriaceae

Eight strains isolated from birds, reptiles, and water constitute a new DNA hybridization group that is 37–58% related toEdwardsiella tarda and less than 10% related to other species of Enterobacteriaceae (SI nuclease method). This homogeneous group (78–100% relatedness within the group) constitutes a new species that is namedEdwardsiella hoshinae sp. nov. (type strain, CIP 78.56 ATCC 33379). Strains of this species produce acid fromd-mannitol, sucrose,d-trehalose, and salicin, and give a positive malonate test. Seven other strains that produced acid fromd-mannitol and sucrose (but not fromd-trehalose and salicin) and were malonate negative were found to belong to theEdwardsiella tarda DNA hybridization group. The base composition of the DNAs ofE. tarda andE. hoshinae is 55–58 mol% G+C.     

Persistence of species in a fragmented urban landscape: the importance of dispersal ability and habitat availability for grassland butterflies

Some species cope with, and survive in, urban areas better than others.From a conservation viewpoint it is important to understand why some species arerare or are excluded in the urban landscape, in order that we might take actionto conserve and restore species. Two ecological factors that might explain thedistribution and abundance of butterfly species in the urban landscape aredispersal ability and the availability of suitable habitat. The influence ofthese factors was assessed by examining the distribution and genetic structureof four grassland butterfly species in the West Midlands conurbation, UK. Thefour species differ in their distribution and abundance, mobility and habitatspecificity. No significant fit to the isolation-by-distance model was found forany of the study species at this spatial scale. MeanF _ST values revealed a non-significant level ofpopulation structuring for two species, Pieris napi (L.)and Maniola jurtina (L.), but moderate and significantpopulation differentiation for Pyronia tithonus (L.) andCoenonympha pamphilus (L.). Results suggest that thesespecies are limited more by the availability of suitable habitat than by theirability to move among habitat patches. Conservation strategies for thesegrassland species should initially focus on the creation and appropriatemanagement of suitable habitat. More sedentary species that have already beenexcluded from the conurbation may require a more complex strategy for theirsuccessful restoration.     

Exoskeletal cuticle of cavernicolous and epigean terrestrial isopods: A review and perspectives

Comparative ultrastructural studies of the integument in terrestrial isopod crustaceans show that specific environmental adaptations of different eco-morphotypes are reflected in cuticle structure. The biphasic molting in isopods is a valuable experimental model for studies of cuticular matrix secretion and degradation in the same animal. The aim of this review is to show structural and functional adaptations of the tergal cuticle in terrestrial isopods inhabiting cave habitats. Exoskeletal cuticle thickness, the number of cuticular layers, epicuticle structure, mineralization, pigmentation and complexity of sensory structures are compared, with greater focus on the well-studied cave trichoniscid Titanethes albus. A large number of thinner cuticular layers in cave isopods compared to fewer thicker cuticular layers in related epigean species of similar body-sizes is explained as a specific adaptation to the cavernicolous life style. The epicuticle structure and composition are compared in relation to their potential waterproofing capacity in different environments. Cuticle mineralization is described from the functional point of view as well as from the aspect of different calcium storage sites and calcium dynamics during the molt cycle. We also discuss the nature and reduction of pigmentation in the cave environment and outline perspectives for future research.     

Global diversity of dobsonflies,fishflies, and alderflies (Megaloptera; Insecta) and spongillaflies,nevrorthids, and osmylids (Neuroptera; Insecta) in freshwater

The insect orders Megaloptera and Neuroptera are closely related members of the superorder Neuropterida, a relict lineage of holometabolous insects that also includes the Raphidoptera. Megaloptera, composed of the families Sialidae and Corydalidae (including subfamilies Chauliodinae and Corydalinae), has fully aquatic larvae that occur in a wide variety of lotic and lentic habitats, including temporary streams. In total, 2 of 17 families of Neuroptera have aquatic larvae: Nevrorthidae live in the benthos of fast-flowing streams and Sisyridae reside on freshwater sponges. A third family of Neuroptera, Osmylidae, contains some water-dependent species that reside under leaves and rocks along the margins of waterbodies. We recognize 328 extant, described species of Megaloptera (composed of 116 species of Chauliodinae, 131 species of Corydalinae, and 81 species of Sialidae) and 73 species of aquatic Neuroptera (composed of 12 species of Nevrorthidae and 61 species of Sisyridae). Additionally, we estimate that 45 species of Osmylidae are water-dependent, although the ecology of this group is poorly understood. Chauliodinae and Corydalidae are both found in the New World, the Oriental region, and South Africa, but are absent from Europe, the Middle East, Central Asia, tropical Africa, and boreal regions. Chauliodinae is quite speciose in Australia, whereas Corydalinae is absent. Sialidae is most speciose in temperate regions, and is absent from tropical Africa and portions of the Oriental region. Sisyridae and Osmylidae are nearly cosmopolitan, but the relict family Nevrorthidae is limited to Japan, the Mediterranean, and Australia. The discovery of many new species in recent years, particularly among Corydalidae in the Neotropics and China, suggests that our knowledge of aquatic neuropterid diversity is far from complete. Guest editors: E. V. Balian, C. Lévêque, H. Segers and K. Martens Freshwater Animal Diversity Assessment     

Vergleichende untersuchung des peptonabbaus und der damit verknüpften ciliatenbesiedlung in strömenden und stagnierenden modellgewässern

Summary The decomposition of peptone and the associated species numbers and individual counts of ciliates has been investigated in flowing (current speed 40 cm/sec) and stagnant model ecosystems. In order to imitate the ecological conditions in natural waters receiving sewage small quantities of peptone were added at regular intervals.The most important environmental factors such as pH, dissolved oxygen, NH₄ ⁺-, NO₃ ^--levels, and the organisms occurring in the free water as well as in the periphyton community on microscopic slides, were investigated for three weeks. Both the population dynamics of organisms and the environmental conditions within the ecosystems are figured (Figs. 1–6).The ecosystem with flowing water, and the aerated stagnant model showed high contents of O₂ and fast mineralisation of peptone up to the NO₃ ^--level. The unaerated model showed a retarded decomposition of peptone and accumulation of ammonia.The unaerated stagnant ecosystem showed the highest individual counts of bacteria and ciliates, while in the flowing model a limited number of organisms only was found.Most of the differences between flowing and stagnant waters are due to the varying O₂-level. Only two species were directly inhibited by the current speed tested in these experiments.

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Zoologisches Institut der Universität Bonn Hydrobiologische Arbeitsgruppe (Leiter: Prof. Dr. H. Bick)

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Mit Untersützung der Weltgesundheitsorganisation.

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Herrn Prof. Dr. Rolf Danneel zum 70. Geburtstag gewidmet.

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Anschrift der Verfasser: PProf. Dr. H. Bick und Diol. Biol. W. Schmerenbeck, Hydrobiologische Arbeitsgruppe am Zoologischen Institut der Universität, D05300 Bonn 1, Poppelsdorfer Schlo\.     

Two new species ofPhyllagathis related toP. tuberculata (Melastomataceae) from Peninsular Malaysia

Phyllagathis tuberculata King and two closely allied new species,P. magnifica A. Weber andP. stonei A. Weber, are described and illustrated. Within the genus, these species form a distinct and isolated group which is restricted to Peninsular Malaysia.P. tuberculata occurs in Perak (probably confined to G. Bujang Melaka),P. magnifica andP. stonei are found in the mountains on the Pahang/Selangor border (Genting Highlands, Gombak valley). The distinctive characters of the three species are listed and some general information relating to inflorescence morphology, tubercle anatomy, fruit structure and seed dispersal is provided.     

Evolution and systematic relationships in theTriticeae (Poaceae)

The evolution and taxonomic relationships in theTriticeae are discussed with the view to highlight aspects of this agronomically important group of plants, which may be of interest to molecular biology. Some of these aspects are addressed in more detail in adjoining papers in which specific genomic loci have been examined at the DNA sequence or isozyme level. Aspects discussed include the systematics and geographic distribution of theTriticeae species, isozyme and chromosome pairing studies on some of the species as well as more recent developments in DNA analyses. A survey of the systematics of theTriticeae indicated that the genomic system ofLöve is probably the most useful starting point for interpreting molecular data even though the system has many problems from a taxonomic point of view. The geographical distribution ofTriticeae species, using both published and unpublished data, suggested that information of this type taken together with the theory of continental drift provides a broad time-span for considering data from DNA sequence studies. The significance, and modes of analyses, of isozyme studies were assessed because they often provide valuable characters in determining relationships between species. The main character underlyingLöve's andDewey's analyses of theTriticeae, namely chromosome pairing, is discussed with particular reference to isozyme studies to show that in some cases, such as species ofHordeum sensu lato, consistent relationships are obtained. Finally, new developments in understanding chromosome structure are considered in relation to the above variables in the taxonomy and evolution of theTriticeae.     

Fire and competition in Australian heath: a conceptual model and field investigations

Abstract. We describe a model of heath vegetation, in which species were classified into five functional groups based on characteristics of their propagule pools, post-fire growth, timing and mode of reproduction and competitive status. The model assumes no recruitment without fire and a simple competitive hierarchy based on vertical stature. A critical feature of the model is an initial post-fire window of 5–6 yr in which competition from overstorey species on understorey species is reduced. Understorey functional groups differ in their ability to exploit this window. In the field, we tested five predictions derived from the model: (a) overall species richness of understorey varies inversely with overstorey density as a result of a trend in richness of woody species, but not in herbaceous species; (b) where an overstorey was present in the previous fire interval, post-fire population density is reduced in a functional group of understorey serotinous resprouting shrubs, but not in a group of understorey obligate-seeding shrubs with soil seed banks; (c) in understorey serotinous resprouting shrubs, post-fire regrowth in resprouting individuals is adversely affected by the presence of an overstorey in the preceding fire interval; (d) in understorey serotinous resprouting shrubs, levels of pre-fire propagules are lower in the presence of an overstorey, reducing the density of post-fire recruits; and (e) in understorey serotinous resprouting shrubs, recruitment relative to the pre-fire population is unaffected by overstorey species within the window of reduced competition. Of these, three tests (a,b,d) supported the model, one (e) may support the model, but the results were inconclusive and one (c) did not support the model. Limitations and further applications of the model are discussed. Our results suggest that maintenance of high densities of overstorey populations is in conflict with conservation of some understorey species. Models of the type we propose will help identify and resolve such conflicts and promote the judicious use of fire to maintain full species diversity of plant communities.     

Scale‐dependent biases in species counts in a grassland

Abstract. Numbers of plant species were recorded in species‐rich meadows in the Bílé Karpaty Mts., SE Czech Republic, with the aim to evaluate the sampling error made by well‐trained observers. Five observers recorded vascular plants in seven plots ranging from 9.8 cm² to 4 m² independently and were not time‐limited. In larger plots a discrepancy of 10–20% was found between individual estimates, in smaller plots discrepancy increased to 33%, on average. The gain in observed species richness by combining records of individual observers (in comparison with the mean numbers estimated by single observers) decreased from the smallest plot (27–82% for two to five observers) to the largest one (13–25%). However, after misidentified and suspicious records were eliminated, the gain was much lower and became scale‐independent; two observers added 12% species, on average, and the increase by combining species lists made by three or more observers was negligible (3% more on average). It is concluded that most discrepancies between individual observers were caused by misidentification of rare seedlings and young plants. We suggest that in species‐rich meadows plants should be recorded by at least three observers together and that they should consult all problematic plant specimens together in the field, to minimize errors.     

How species diversity responds to different kinds of human-caused habitat destruction

Human-caused habitat destruction, the major cause of species diversity losses, can be classified into two basic types, instantaneous destruction and continuous destruction. Thus, a universal model should be established to simulate and forecast the effects of different kinds of habitat destruction on species diversity during different historical periods. In this paper, we explore a multi-time-scale n-species model to study and compare species responses to instantaneous and continuous destruction. We find that (1) under instantaneous destruction, there are two different mechanisms of species extinction: one is a time-delayed deterministic extinction of superior competitors in order from the best to the poorest; the other is the extinction in a short time of inferior competitors. The survivors will experience three phases: decline, adjustment, and equilibrium. (2) When the total amounts of habitat destruction for both instantaneous and continuous cases are equal, the oscillation amplitudes of species abundances under instantaneous destruction are much greater than under continuous destruction, especially for inferior competitors, which make inferior competitors under instantaneous destruction more prone to stochastic extinction. Therefore instantaneous destruction is more detrimental to the survival of inferior competitors. (3) Under continuous destruction with habitat eventually being destroyed completely, there also are two types of species extinction mechanisms: the first is extinction in order from the best competitors to the poorest before complete destruction; the second is collective extinction due to complete destruction.     

Chromosomal structure of populations of drosophila flavopilosa studied in larvae collected in their natural breeding sites

Summary D. flavopilosa Frey, is a neotropical species of Drosophila living in Chile that, together with 13 other species, has been included by Wheeler, Takada und Brncic (1962) in the flavopilosa species group. Despite the fact that it has not been possible to breed this species in the laboratory, the circumstance that its habitat is well known, has allowed the study of the chromosomal structure of some natural populations of this species, analyzing larvae directly taken to the laboratory from their natural breeding sites: the flowers of the solanacean Cestrum parqui L'Héritier.The present paper describes the mitetic and salivary gland chromosomes of D. flavopilosa, and gives a composite map of the Standard gene arrangement. In central Chile, natural populations of this species are polymorphic with respect to the gene orders in their chromosomes, due to the presence of four independent inversions, all located in one of the six chromosomes (the right arm of the V-chromosome). Quantitative data on the distribution of the inversions shows that there is an altitudinal gradient in the frequencies of two of the four inversions. Heterozygotes for Inversion A, are more frequent at high altitudes than at sea level. On the contrary, heterozygotes for inversion B, are abundant at sea level, but practically disappear at high altitudes. These altitudinal clines have been observed in two valleys near Santiago, Chile, which run from the Andes mountains to the Pacific coast.The work reported in this article has been carried out under Contract AT (30-1) 2465 US Atomic Energy Commission, and partially supported by Grants from the University of Chile, Faculty of Medicine and the Rockefeller Foundation under a joint program.     

Cytotaxonomische Untersuchungen in der Artengruppe desRanunculus alpestris (Ranunculaceae)

Morphological and cytological investigations as well as crossing experiments were carried out with the 5 species of theRanunculus alpestris group (R. alpestris L.,R. traunfellneri Hoppe,R. bilobus Bertol.,R. crenatus Waldst. etKit.,R. magellensis Ten.). A key to the species is presented; localities and distribution are given in addition to extensive diagnoses. Crossing experiments between the 5 taxa were successful (F₁-F₃ individuals, backcross types, tripeland quadrupelbastards); the morphology of the experimentally obtained F₁-hybrids was mostly intermediate. All 5 species as well as all hybrids have a chromosome number of 2n = 16; there is no statistically significant difference between the karyotypes of the 5 taxa. According to the results of the morphological investigations and the crossing experiments we can distinguish 2 subunits of very closely related species: a)R. alpestris, R. traunfellneri, R. bilobus; b)R. crenatus, R. magellensis. The speciation within the group ofRanunculus alpestris is discussed.

     

Spatial heterogeneity of mortality and temporal fluctuation in fertility promote coexistence but not vice versa: a random-community approach

Both spatial heterogeneity and temporal fluctuation of the environment are important mechanisms promoting species coexistence, but they work in different manners. We consider many pairs of species with randomly generated survivorship and fertility in the lottery model, and examine how the variability in demographic processes affects the outcome of competition. The results are: [1] Coexistence is easier if habitat difference in mortality is greater, or if year-to-year variation in reproductive rate is larger. But neither habitat-difference in fertility nor temporal variation in mortality promotes coexistence. [2] Mean fertility does not affect the outcome if CV remains constant. In contrast, enhanced mean mortality decreases the fraction of coexisting pairs if the environment fluctuates temporally. [3] We also investigate the effect of limited dispersal of propagules between habitats. Compared with the complete mixing case, the fraction of coexisting pairs is clearly enhanced if the spatial heterogeneity is the major source of environmental variation, but shows slight increase if the temporal fluctuation is dominant. We conclude that spatial heterogeneity is likely to work more effectively in promoting species coexistence than temporal fluctuation, especially when the species suffer relatively high mortality, and disperse their propagules in a limited spatial scale.