Morphological variation in populations of Bletia purpurea (Orchidaceae) and description of the new species B. riparia

Bletia purpurea is the most widespread species in its genus. Morphological variation has been recognized throughout the range of its distribution. In this paper, the morphological variation from 63 populations (583 individuals) ofBletia purpurea is assessed to determine whether more than one species were present. Forty-four quantitative and qualitative characters were examined by univariate analyses and exploratory multivariate analyses. Univariate analyses indicate that quantitative characters such as lateral sepal width, petal. width, lip length, and lip width are significantly different for populations from Acazónica, Mexico. Floral parts in the populations from Acazónica are the smallest among all populations. Qualitative characters such as petals covering the lip midlobe and horizontal lip position are found exclusively in the same populations. We concluded that these populations should be described as a new species,B. riparia. Multivariate analyses indicated that morphological variation among the other populations cannot be ascribed to geographic distribution or ecological factors.     

A revision of the Solatium sessile species group (section Geminata pro parte: Solanaceae)

KNAPP, S., 1991. A revision of the Solatium sessile species (sectio Geminata pro parte : Solanaceae ). The taxonomy of the Solanum sessile species group (a part of the large and unwieldy section Geminata) is reviewed, based on detailed field and herbarium studies. Members of the group are found from Mexico to Bolivia in a variety of habitats. Ten species are recognized: S. obovalifolium, S. sessile, S. monadelphum, S. turgidum, S. triste, S. chlamydogynum, S. rovirosanum, S. palmillae, S. oppositifolium and conferliseriatum.     

Origin of hummingbird faunas

Ecological studies of hummingbird communities have emphasized the importance of local conditions and contemporary interactions in the development of these varied faunas. A time-calibrated, DNA hybridization-based phylogeny of the principal hummingbird lineages was used to examine historical aspects of hummingbird faunas in the species-rich tropical lowlands and Andes, and the relatively depauperate West Indies and temperate regions of Central and North America. Parsimony reconstructions of ancestral distributions indicate that these faunas are polyphyletic in origin, comprising several to many independent lineages. Based on the timing of geologic and cladogenic events, hummingbird faunas appear to have arisen more often by colonization than by large-scale vicariance, with multiple dispersals across water gaps, elevational gradients, and latitude. The extent to which particular lineages colonized different regions depended, however, on lineage ecology as well as on the habitat and age of the fauna. In general, the oldest extant trochilofauna, which today occupies the tropical lowlands, was the principal source of colonizing taxa. However, all regions except possibly the West Indies contributed taxa now found elsewhere, including in the tropical lowlands. The Andean fauna comprises several lineages with lowland origin (hermits, Mangoes, Brilliants, Coquettes, Emeralds) as well as at least one that arose in temperate regions outside South America (Bees). At least two lineages that colonized the West Indies gave rise to endemic genera (Mangoes to Eulampis, and Emeralds to Orthorhyncus). Even groups that diversified in the highlands (Brilliants and Bees) gave rise to taxa that subsequently reinvaded the tropical lowlands. As the result of these varied histories, hummingbird communities cannot be arranged easily with respect to organizational complexity and coevolution with nectar sources. Although the physically insular faunas in the Andes and West Indies differ markedly in diversity, both were more strongly affected by colonization than the other faunas. A high potential for coevolution between hummingbirds and plants probably facilitated the successful establishment and radiation of the several Andean-associated lineages. However, coexistence between the two most diverse Andean clades may have been favoured initially through different habitat preferences by their extra-Andean ancestors. In the tropical lowlands, by comparison, the basic separation between the forest-dwelling hermits and canopy and edge-dwelling nonhermits appears to have evolved in situ. The low species and morphologic diversity of hummingbirds breeding north of Mexico reflects the predominance there of a single relatively recent lineage. The regional coexistence of numerous unrelated lineages implies that patterns of ancestry, colonization, and extinction contribute to the make-up of contemporary species-rich hummingbird faunas and serves to qualify the view that hummingbird communities are coadapted assemblages that resist change.     

Novelties in Mascagnia (Malpighiaceae)

Seven new species ofMascagnia are described:M. tomentosa from southern Mexico and Central America;M. arenicola from the Guianas;M. riparia, M. tucuruensis, andM. velutina from Brazil;M. boliviana from Bolivia; andM. australis from Argentina and Paraguay. These novelties were previously included in the “M. sepium-complex,” an omniumgatherum comprising superficially similar yellow-flowered taxa.     

Coming to America: multiple origins of New World geckos

Geckos in the Western Hemisphere provide an excellent model to study faunal assembly at a continental scale. We generated a time-calibrated phylogeny, including exemplars of all New World gecko genera, to produce a biogeographical scenario for the New World geckos. Patterns of New World gecko origins are consistent with almost every biogeographical scenario utilized by a terrestrial vertebrate with different New World lineages showing evidence of vicariance, dispersal via temporary land bridge, overseas dispersal or anthropogenic introductions. We also recovered a strong relationship between clade age and species diversity, with older New World lineages having more species than more recently arrived lineages. Our data provide the first phylogenetic hypothesis for all New World geckos and highlight the intricate origins and ongoing organization of continental faunas. The phylogenetic and biogeographical hypotheses presented here provide an historical framework to further pursue research on the diversification and assembly of the New World herpetofauna.     

A new species of dactyloid anole (Iguanidae, Polychrotinae, Anolis) from the southeastern slopes of the Andes of Ecuador

We describe a new species of Anolis from the southeastern slopes of the Andes of Ecuador, province of Zamora-Chinchipe, Parque Nacional Podocarpus. It belongs to (1) the aequatorialis species-group by being of moderate to large size with narrow toe lamellae, and (2) the eulaemus sub-group by having a typical Anolis digit, in which the distal lamellae of phalanx II distinctly overlap the proximal scales of phalanx I. The new species is most similar morphologically to Anolis fitchi but differs from it mainly by having a dewlap with longitudinal rows of 2-5 granular, minute scales separated by naked skin (longitudinal rows of one or two keeled, large scales separated by naked skin in Anolis fitchi) and a vertically shorter dewlap (longer dewlap in Anolis fitchi).     

Global amphibian declines: a perspective from the Caribbean

Recent concern over the possibility of a global decline in amphibians prompted this assessment of the West Indian species. At the species level, the West Indian amphibian fauna (156 species, all frogs and toads) has not undergone a general decline, and no species is known to be extinct. However, one Puerto Rican species (Eleutherodactylus karlschmidti) has not been seen in over ten years despite considerable search effort. Seven other species, including the Puerto Rican livebearing frog (E. jasperi), have not been seen recently, although their present status cannot be determined until additional effort is made to locate them. Two stream-associated species on Hispaniola (E. semipalmatus and Hyla vasta) appear to have declined in recont years, probably due to the alteration of riparian habitats by deforestation. Other vertebrate groups in the West Indies, such as mammals, have been more affected by human-caused environmental degradation than have amphibians. Large-scale extinctions of frogs and other forest-dwelling species are not expected to occur until forest cover reaches very low levels. Haiti is on the brink of such extinctions with less than 1% of its forest cover remaining. Two recommendations are made to help curtail the expected loss of biodiversity: (i) import charcoal to replace that produced by burning native trees (used as cooking fuel), as an immediate measure, and (ii) control human population growth, as a long-term solution.     

Gender and ethnic identity among second-generation Indo-Caribbeans

This article discusses second-generation Indo-Caribbean (West Indian of Indian descent) teenagers’ ethnic identities, through a look at their taste preferences and self assertions of identity. Both Indo-Caribbean young men and women draw from multiple influences on their identities. In terms of tastes in clothing and movies, however, girls are more interested in things Indian, and in “Indian culture”. Boys, on the other hand, choose to distance themselves from an Indian identity. Three factors explain these gender differences in choices about ethnic identity: (1) different media images for South Asian men and women; (2) a school context lending different levels of peer symbolic status to perceived Indian boys and girls; and (3) a gendered process of migration by which women maintain stronger cultural roots in the new country. The findings in this article point to the need to pay attention to gender differences when considering ethnic incorporation.     

Deep-Sea Polychaetous Annelida from Central America to the Antarctic Peninsula and South Sandwich Islands

Based on the 1958 Vema cruise and the 1965 Anton Bruun cruise 11 off the west coast of Central America and south through the islands east of the tip of South America, 143 trawl samples were examined for abyssal polychaetous annelida. The cruise tracks designated 7 major areas: Central America (1), Ecuador-Peru (II), Central and Southern Chile (III), Chile and the Magellan Strait (IV), Tierra del Fuego (V), the Island Complex (Falkland, South Georgia and South Sandwich Islands) (VI), the Drake Strait and Antarctic Peninsula (VII). The collections yielded 7,015 individuals and 322 species from 52 families. The relatively small number of species was attributed mainly to sampling effort, collecting gear and processing techniques. Each major area was characterized in terms of the number of individuals, the number of species, mean number of individuals, mean number of species and mean H′, SR, J′ and DI. Species diversity was significantly higher in Central America (I) than in the other areas. The relationships between biotic and abiotic measures (depth and areas of upwelling) were examined. There were no significant associations for the entire data base with depth. Moreover, there was no association between abundance of polychaetes and areas of upwelling which was hypothesized. In fact, relative abundance was highest in the deepest portions of Central America (I) (Guatemala Basin) and Ecuador—Peru (II) (Milne—Edwards Deep) compared to shallower areas closer to areas of upwelling. Quantitative collecting gear and refined processing techniques will be required to more accurately address these relationships. Dominant families were identified in terms of number of species and number of individuals. These families conformed well with world wide generalizations of dominant families. Dominant species were identified based on the Biological Index Value. The top twenty or dominant species for each major area were identified. A number of these dominant species occurred widely throughout the major areas. The dominant species for the entire data set were determined. In general these species were very eurybathic which was consistent with other worldwide depth distributions of abyssal polychaetes. Based on biotic measures (mean number of species, mean H', SR, J′ and DI) and the Simpson and Dice similarity co-efficients, several zoogeographic patterns emerged. The polychaete fauna from Central America (I) to southern Chile (II) formed a relatively homogeneous group. Polychaetes from Central America (I) had affinities with faunas studied off western Mexiko. The Chile and Magellan Strait (IV) area seemed to be a transition area which yielded to another relatively homogeneous fauna comprising areas V—VII. The latter fauna belonged to an Antarctic polychaete fauna which was documented earlier in other studies with a larger data base and more sophisticated analysis. It is hoped that the present study will help to provide a start to fill the zoogeographic gap of this enormous and bathymetrically diverse area.