Cranial phenotypic evolution in Proechimys iheringi Thomas (Rodentia: Echimyidae)

Models of evolutionary quantitative genetics were employed to analyze cranial phenotypic evolution in the echimyid rodent Proechimys iheringi Thomas. The hypothesis that cranial differentiation among populations and subspecies of P. iheringi resulted from random drift was rejected. The completely selective model was then used to reconstruct the forces of selection that might have acted to produce the observed differences in cranial morphometric traits in P. iheringi . The net gradient of selection indicates that some cranial traits evolved in the direction contrary to the forces of selection, acting to increase mean values for cranial traits in the evolutionary transitions between populations of P. iheringi . Minimum intensities of selection were calculated and showed that selective mortality per generation was low, of the order of l0^-3, suggesting that weak selection can explain the observed cranial morphometric differences among the populations of P. iheringi .     

Assessment of gene flow across a hybrid zone in red-tailed chipmunks (Tamias ruficaudus)

The role of hybridization in animal speciation is controversial and recent research has challenged the long-standing criterion of complete reproductive isolation to attain species status. The speciation-with-gene-flow model posits that the genome is semi-permeable and hybridization may be a phase in the process of divergence. Here, we apply these concepts to a previously identified zone of mtDNA introgression between the two strongly morphologically differentiated subspecies of red-tailed chipmunk ( Tamias ruficaudus ) in the US Inland Northwest. Using multilocus genotype data from the southern, older contact zone, we demonstrate that neutral gene flow is unusually low between the subspecies across the Lochsa River. This is geographically congruent with the discontinuity in bacular morphology, indicating that the cline of mitochondrial DNA (mtDNA) haplotypes is displaced. Furthermore, we elucidate the evolutionary forces responsible by testing hypotheses of lineage sorting and hybridization. We determined that introgressive hybridization is the cause of mtDNA/morphology incongruence because there are non-zero levels of migration and gene flow. Although our estimate of the age of the hybrid zone has wide credibility intervals, the hybridization events occurred in the Late Pleistocene and the divergence occurred in the Middle Pleistocene. Finally, we assessed substructure within and adjacent to the hybrid zone and found that the hybrid zone constitutes a set of populations that are genetically differentiated from parental sets of populations; therefore, hybridization in this system is not likely an evolutionary sink, but has generated novel combinations of genotypes.     

Host-ectoparasite specificity in a small mammal community in an area of Atlantic Rain Forest (Ilha Grande, State of Rio de Janeiro), Southeastern Brazil

The analyses of the ectoparasite species associated with a small mammal community on Ilha Grande, a coastal island in southern of the state of Rio de Janeiro, Brazil, evaluated the level of host-ectoparasite specificity. Was used the Jaccard index for qualitative data to analyse the similarity. The lowest value of similarity occurred between Proechimys iheringi and Marmosops incanus and between Sciurus aestuans and Nectomys squamipes (Cj=0.08) and the highest between P. iheringi and Oxymycterus sp. (Cj=0.33). This index showed a low value of similarity across the ectoparasite community. The only exception from this pattern of high host specificity occurred with P. iheringi and Oxymycterus sp., which shared five species of ectoparasites. The similarity values, for most of the cases, is smaller than 0.2.     

Introgression at differentially aged hybrid zones in red-tailed chipmunks

Hybrid zones allow us to investigate the maintenance and the break down of reproductive isolation; they are a window into the speciation process. Tamias ruficaudus (red-tailed chipmunk) has a roughly ring-like distribution in the Inland Northwest and includes two morphologically well-differentiated subspecies, T. r. ruficaudus (in the eastern portion of its range) and T. r. simulans (in the western portion). These taxa meet at two contact zones: the Lochsa River in Idaho and 200 km to the north, near Whitefish, Montana. The Lochsa Zone is encompassed within the Clearwater River Drainage, which has been proposed as a glacial refugium for many taxa throughout the Pleistocene, whereas the Whitefish Zone was under the Cordilleran ice sheet during the most recent glacial maxima approximately 10,000 years ago. Mitochondrial DNA introgression has been documented at both contact zones, yet the subspecies remain significantly distinct with respect to bacular morphology and no intermediate morphologies have ever been reported. Here, we elucidate differentiation and introgression of the nuclear genome using ten microsatellite loci and compare findings to previously described mitochondrial DNA haplotype distribution and introgression. We found significant substructure in the nuclear data; each subspecies is divided into at least two genetically distinct demes. At the Lochsa contact zone, individuals restricted to the mtDNA zone of introgression form a distinct deme at microsatellite loci whereas in the younger, Whitefish contact zone, there is no hybrid-zone specific group. The genetic distances of the demes within these two subspecies indicate recent northward expansion.     

应用阴茎骨形态指标划分黑腹绒鼠年龄的研究

用雄性阴茎骨近支基底高作频数分配将黑腹绒鼠指名亚种划分为5个年龄组,对各年龄组的体长、阴茎骨近支长和阴茎骨近支基底宽作t检验和F检验均有显著差异或极显著差异．表明以阴茎骨近支基底高划分黑腹绒鼠年龄组是可行的。     

Allozyme Analysis of Hypostomus (Teleostei: Loricariidae) from the Rio Corumbá, Upper Rio Paraná Basin, Brazil

The taxonomy of the genus Hypostomus in the upper Rio Paraná basin presents some very complex issues. For this reason, an allozyme electrophoresis survey of 10 populations of Hypostomus from the Rio Corumbá basin was performed, revealing 25 loci from 14 enzyme systems. Allozyme data revealed diagnostic genetic markers for the four nominal species analyzed (Hypostomus ancistroides, H. iheringi, H. margaritifer, and H. regani) and for six possible undescribed species. The mean expected heterozygosity of the populations ranged from 0.009 in H. iheringi to 0.099 in Hypostomus sp. 4. The genetically most similar populations (I = 0.954) were H. iheringi and Hypostomus sp. 2; the most divergent (D = 0.839) were H. iheringi and H. ancistroides.     

Relationships between bird morphology and prey selection in two sympatric Great Cormorant Phalacrocorax carbo subspecies during winter

Variation in bird morphology (notably sex size dimorphism) has been suggested to contribute to differences in food use between individuals. We explore the hypothesis of food partitioning (diet overlap and prey size selection) in two sympatric subspecies of the Great Cormorant Phalacrocorax carbo with respect to bird morphology (subspecies and sex) in inland French waters. These areas represent a recent and increasing contact zone used as a common non-territorial winter feeding area by the continental P. c. sinensis and the marine P. c. carbo subspecies. A high dietary overlap between subspecies and sexes was found at the major sites studied. Prey size selection was found to be site-specific and generally related to a gradient of structural size and body mass (male P. c. carbo  > male P. c. sinensis  > female P. c. carbo  > female P. c. sinensis ). With respect to bird morphology, differences in prey size consumed by Great Cormorants were more pronounced between sexes in freshwater habitats than between subspecies. This was reinforced by the fact that P. c. carbo birds entering inland areas were smaller than birds on the coast. These results also suggest that bird morphology is an important determinant of dietary differences. Our study demonstrated that P. c. carbo is an efficient generalist forager in continental areas, and food partitioning in type and size of prey between the two subspecies is low.     

Phylogeography and introgressive hybridization: chipmunks (genus Tamias) in the northern Rocky Mountains

Abstract. If phylogeographic studies are to be broadly used for assessing population-level processes relevant to speciation and systematics, the ability to identify and incorporate instances of hybridization into the analytical framework is essential. Here, we examine the evolutionary history of two chipmunk species, Tamias ruficaudus and Tamias amoenus , in the northern Rocky Mountains by integrating multivariate morphometrics of bacular (os penis) variation, phylogenetic estimation, and nested clade analysis with regional biogeography. Our results indicate multiple examples of mitochondrial DNA introgression layered within the evolutionary history of these nonsister species. Three of these events are most consistent with recent and/or ongoing asymmetric introgression of mitochondrial DNA across morphologically defined secondary contact zones. In addition, we find preliminary evidence where a fourth instance of nonconcordant characters may represent complete fixation of introgressed mitochondrial DNA via a more ancient hybridization event, although alternative explanations of convergence or incomplete sorting of ancestral polymorphisms cannot be dismissed with these data. The demonstration of hybridization among chipmunks with strongly differentiated bacular morphology contradicts long-standing assumptions that variation within this character is diagnostic of complete reproductive isolation within Tamias . Our results illustrate the utility of phylogeographic analyses for detecting instances of reticulate evolution and for incorporating this and other information in the inference of the evolutionary history of species.     

长爪沙鼠阴茎头的组织学研究及五种鼠阴茎头的扫描电镜观察

本文对８例长爪沙鼠（Ｍｅｒｉｏｎｅｓｕｎｇｕｉｃｕｌａｔｕｓ）幼年、亚成年、成年和老年雄性个体的阴茎头组织进行连续切片。结果表明,阴茎头的外环层和阴茎骨近支由阴茎海绵体衍生而来;内环层、尿道小瓣、阴茎骨远支和侧支由尿道海绵体衍生而成。采用扫描电镜观察了长爪沙鼠、子午沙鼠（Ｍ．ｍｅｒｉｄｉａｎｕｓ）、大沙鼠（Ｒｈｏｍｂｏｍｙｓｏｐｉｍｕｓ）和甘肃绒鼠（Ｅｏｔｈｅｎｏｍｙｓｅｖａ）、黑腹绒鼠（Ｅ．ｍｅｌａｎｏｇａｓｔｅｒ）共５种１６例的阴茎头表皮棘,发现其形态、数量和分布有属、种间差异性和相对稳定性,沙鼠属（Ｍｅｒｉｏｎｅｓ）３种的表皮棘均呈牛角状的圆锥体,斜向排列成行;而绒鼠属（Ｅｏｔｈｅｎｏｍｙｓ）内甘肃绒鼠为球状表皮棘,黑腹绒鼠为牛角状,排列均不规则。因此,阴茎头表皮棘与阴茎骨、阴茎头软体结构均有分类学意义。     

Morphology,life cycle and management of two invasive subspecies of Papilio demoleus (Lepidoptera: Papilionidae): A review

Papilio demoleus L., also known as the citrus butterfly or chequered swallowtail, is a common species in the Asia-Pacific region, with two of its subspecies (P. d. demoleus and P. d. malayanus) posing significant threats to the citrus industry in Asia and other regions of the world. Its predominant natural host plants are the Rutaceae for the invasive northern subspecies and Fabaceae for the southern subspecies. The morphology and development of this species are reasonably well studied, although further information is required on its natural mortality rates and environmental tolerance in order to accurately predict its future potential spread throughout the Middle East and Central Americas. Synthetic pyrethroids such as deltamethrin are highly effective for the control of P. demoleus larvae. However, better control is likely to be found using an integrated approach to pest management, incorporating techniques such as biocontrol agents, microbial pesticides and phytopesticides, in conjunction with synthetic pesticides where required.     

Bacular variation and allometry in the western martenMartes caurina

Many sexually-selected structures are variable and positively allometric relative to body size. For the western martenMartes caurina Merriam, 1890 from Vancouver Island, British Columbia, we investigated variation in the baculum compared with other bones and allometry of bacular to body size. Carcass length did not differ, and humeral and mandibular lengths differed little (< 1 and 2%, respectively), between age groupings < 1 and ≥ 1 yr old. In contrast, bacular length increased by 16%, and thickness by 29% (mid shaft) and 86% (basal) between those groupings, and thickness and mass continued to grow after the second year of life. Controlling for body size, bacular size varied more than humeral or mandibular size (CV for linear variables ∼4–8% for baculum, ∼2% for humerus or mandible). Some positive static allometry of bacular size to body size was found, but correlations between bacular and body size were weak (r=0.3–0.4). So penile size as related to bacular size could be a reliable but imprecise quality indicator during copulation. Weak polygamy (serial promiscuity), complex copulatory mechanisms, and high energetic costs of reproduction, likely select for multiple cues in mate-choice by females, not just penile cues affected by bacular size or shape.     

Cranial evolution in sakis (Pithecia, Platyrrhini) I: interspecific differentiation and allometric patterns

Patterns of interspecific differentiation in saki monkey (Pithecia) skulls are quantitatively described. The taxonomic arrangement previously proposed by Hershkovitz ([1987] Am. J. Primatol. 12:387-468) is consistent with quantitative differences in saki morphology. Discriminant analyses on 39 skull traits show that Pithecia species and subspecies are well-differentiated. Morphological distances (D2) among sakis clearly show the morphological unity of the pithecia-chrysocephala (Pithecia) and irrorata-vanzolinii-monacha (Monacha) species groups. The Pithecia species group is distributed north of the Amazon and has a smaller cranium than the Monacha group, distributed south of that river. Despite the size difference, multivariate static allometric patterns among sakis are quite similar. After removing size and allometric changes in shape from the data, species and subspecies are still differentiated, although to a lesser extent. D2 distances obtained from these scale-corrected data are similar in magnitude and pattern to the original D2, but show a closer similarity of P. monacha with the Pithecia group. P. monacha is a scaled-up version of the smaller sakis.     

No trade-off between sprinting and climbing in two populations of the Lizard Podarcis hispanica (Reptilia: Lacertidae).

Biomechanical reflections suggest that lizards that have specialized in running should differ in parts of their morphological design from lizards that have specialized in climbing. Moreover, adaptation in one direction may conflict with performance in the other. We tested this assumed trade-off by measuring climbing and running performance in two subspecies of the Mediterranean lizard Poaarcis hispanica. One subspecies, P. h. atrata , inhabits a number of small islets near the Spanish coast. It is mainly ground dwelling. The other subspecies, P. h. hispanica , was sampled on the mainland of Spain. It frequendy occupies vertical elements within its habitat. Our data do not support the notion of a trade-off between both types of locomotion. Individuals of P. h. hispanica both run and climb faster than those of P. h. atrata. There is no difference between subspecies in ability to cling onto tilted substrates. Predictions on the morphology of both subspecies, inspired by biomechanical arguments, are not supported by our measurements.     

It's all relative: allometry and variation in the baculum (os penis) of the harp seal, Pagophilus groenlandicus (Carnivora: Phocidae)

We compared allometry and variation in the baculum (os penis), mandible, and humerus of the harp seal, Pagophilus groenlandicus. This species is presumed to have a promiscuous mating system in which choice of mate by females during intromission with different males is likely. The baculum is large and grows throughout life so may be an honest indicator of males' quality (size) or viability (age). We predicted that bacular size would exhibit stronger allometry relative to body size than mandibles or humeri. The baculum is less functionally (mechanically) constrained than mandibles or humeri so we also predicted it would be more variable, though less variable than sexually selected traits which do not function as honest indicators. Our sample (N=67 seals) represented broad ranges of size and age (0–35 yr) so we compared variation using residuals from allometric regressions of skeletal measurements on body length. Bacular size was isometric to body length until ∼ 137 cm (when some seals enter puberty) in body length then was highly positively allometric; mandibular and humeral size were negatively allometric to body length throughout growth. Bacula were more variable than mandibles or humeri. Bacular size in large specimens (>137 cm in body length) was related strongly to body length and weakly to age. We interpret bacular size to be an uncheatable honest indicator of male quality and viability. High bacular variation conforms with theoretical predictions of females' asymmetrical choice of mate and choice of extremes, and may reflect corresponding anatomical variation among females. Some bacular variation may also result incidentally from positive allometry coupled with lifelong bacular growth, which can amplify early differences between reproductive and somatic growth, enabled by weak selection on bacular form in relation to function.     

The pollination ecology of Pedicularis rex subsp. lipkyana and P. rex subsp. rex (Orobanchaceae) from Sichuan, southwestern China

Pedicularis is one of few genera for which pollination ecology has been studied extensively. Although over half of the species of Pedicularis are found in the mountains of southwestern China, pollination ecology has been studied there on a few species only. The present paper reports pollination ecology of Pedicularis rex subsp. lipskyana and P. rex subsp. rex from Sichuan, southwestern China. The two subspecies are nectariferous, with sugar content 28% in P. rex lipskyana and 22% in P. rex, respectively. The flowers of the two subspecies are adapted to pollination by bumblebee workers. Bumblebees are the primary and effective pollinators although honeybees were also observed pollinating P. rex subsp. lipskyana at one studied population. Usually bumblebees entered the corolla tube from the right side in an upright or a nearly half-inverted position to imbibe nectar located at the base of the corolla tube. The stigma usually contacts the side region of the thorax and abdomen or occasionally directly contacted pollen loads, leading to pollination of flowers. Much less commonly, bumblebees foraged on flowers of P. rex subsp. rex in an inverted position for pollen, which pollinated flowers sternotribically. We suggest that pollination mechanism is closely associated with floral morphology. Some important differences were found from a previous study on P. rex in floral morphology and the primary pollination mechanism.     

Parasitic arthropods of some wild rodents from Juréia-Itatins Ecological Station,State of São Paulo,Brazil

A study of the associations between three species of rodents in the Atlantic forest and their parasitic arthropods was undertaken at the Juréia-Itatins Ecological Station, located in the State of S?o Paulo, Southeastern Brazil, from March 1989 to February 1990. Individuals of three species, Oryzomys russatus, Proechimys iheringi and Nectomys squamipes were captured and examined for ectoparasites. Eleven species of parasitic arthropods were found, including four species of insects and seven of Acari. Parasitism intensity, phenology, and rainfall were positively correlated with the abundance of the ectoparasites and their hosts. The most abundant host was O. russatus (Muridae: Sigmodontinae), and the most common parasite on it was the laelapid mite Gigantolaelaps oudemansi. The cuterebrid Metacuterebra apicalis caused myiasis in O. russatus. A mutualistic association between the staphylinid beetle Amblyopinus sp. and its host P. iheringi (Echimyidae) was observed. The few N. squamipes captured had small numbers of ectoparasites.     

Morphology and ontogeny of Tetmemena pustulata indica nov. subspec. (Ciliophora,Hypotricha), from the Thane Creek,Mumbai, India

The morphology and ontogenesis of a novel stylonychid ciliate, Tetmemena pustulata indica nov. subspec., were investigated using live observation and protargol preparation. The new subspecies was isolated from a water sample collected from the Thane Creek, Mumbai, India. At first glance, T. pustulata indica looked very similar in morphology and ontogenesis to the well-known Tetmemena pustulata, however, on detailed investigation some non-overlapping features in the ciliature were identified, i.e., the numbers of cirri in marginal rows, adoral membranelles, and bristles in dorsal kineties. These morphometric differences justified the separation at subspecies level. Furthermore, the resting cysts are different, i.e., with smooth external layer in T. pustulata indica whereas spinous in the nominotypical subspecies T. pustulata pustulata. The Venezuelan population of T. pustulata described by Foissner corresponds very well with the Indian population in the ciliature; however, the information on the resting cyst is lacking for the former. Our study presents an example of a cyst subspecies among hypotrich ciliates, and thus extends the concept which has been mainly reported for spathidiids.     

麝属（MOSCHUS）的分类

麝属（ＭＯＳＣＨＵＳ）的分类ＣｏｌｉｎＰ．Ｇｒｏｖｅｓ（澳大利亚国立大学史前学和人类学系,堪培拉）王应祥（中国科学院昆明动物研究所,昆明）ＰｅｔｅｒＧｆｕｂｂ（英国伦敦Ｎ１７６ＰＥ,Ｄｏｗｎｈｉｌｌ公园路３５）麝类是古北区的特有类群,它们中的大多数种...     

Venom as an interspecific sex pheromone, and species recognition by a cuticular pheromone in Paper Wasps (Polistes, Hymenoptera: Vespidae)

ABSTRACT. The venoms of Polistes fuscatus (subspecies fuscatus) (F.) and P. exclamans Viereck from sympatric populations in North Carolina, U.S.A., contain a pheromone which attracts males and stimulates sexual behaviour in both conspecific and heterospecific males. Males of P. fuscatus (subspecies variatus Cresson), a subspecies from Wisconsin, respond to venom of P. fuscatus fuscatus, P. exclamans, and Vespula maculifrons (Buysson) from North Carolina, although the levels of response to P. exclamans and V. maculifrons venom are less than that to P. fuscatus variatus venom.
Caged Wisconsin P. fuscafus males do not attempt to mate with P. exclamans females, but will attempt to mate with conspecifics. A series of bioassays indicates that males discriminate between females of P. fuscatus and P. exclamans on the basis of chemical, rather than behavioural or visual cues. The venom apparently is not important in species recognition. Instead, the results of two sets of bioassays suggest that species recognition is mediated by a surface pheromone on the cuticle of females.     

Taxonomy and distribution ofPresbytis melalophos group in Sumatera,Indonesia

Taxonomy of thePresbytis melalophos group in Sumatera has been based solely on the distinction in the pelage coloration and has been a subject of controversy. In the present study, extensive field observations were undertaken. Three species, i. e.P. melalophos, P. thomasi, andP. femoralis, are recognized in Sumatera based on the cranial morphology, pelage coloration, and vocalization. Subspecies of each species are revised, a new classification is proposed, and a new subspecies,Presbytis melalophos bicolor, is described. A detailed distribution map of species and subspecies is presented. No sympatry occurs between the species. Finally, a cladistic analysis is presented for the three species, based on the cranial characters; the branching sequence is first between theP. melalophos clade and theP. femoralis- P. thomasi clade and second between theP. femoralis clade and theP. thomasi clade.