Tree species composition and environmental relationships in a Neotropical swamp forest in Southeastern Brazil

We examined the relationships between topography, soil properties and tree species composition in a Neotropical swamp forest in southeastern Brazil. Plots were sampled in the forest, encompassing three different soil ground water regimes along the topographical declivity. All non-climbing plant individuals with trunk height >1.3 m were sampled. A canonical correspondence analysis-CCA-of the species-environmental relationships grouped tree species according to drainage and chemical soil conditions. A total of 86 species were found, being 77 species in the inferior, 40 species in the intermediate and 35 species in the superior topographic section. Some species were among the 10 most abundant ones, both in the overall sampled area and in each topographical section, with alternation events occurring only with their abundance position. However, substantial differences in floristic composition between sections were detected in a fine spatial scale, due to higher number of species, diversity index (H′) and species unique (exclusives) in the inferior topographic section. These higher values can be attributed to its higher spatial heterogeneity that included better drained and seasonally waterlogged soils, higher soil fertility and lower acidity. The increase of the soil water saturation and the uniform conditions derived from the superficial water layer has led to a lower number of species and an increase on the palm trees abundance in the intermediate and superior sections. Our results showed that at a small spatial scale niche differentiation must be an important factor related to the increase of the local diversity. The wide distribution of the most abundant species in the studied area and the increase of local diversity corroborate the pattern of distribution of species in larger scales of swamp forests, in which the most abundant species repeat themselves in high densities in different remnants. However, the floristic composition of each remnant is strongly variable, contributing to the increase of regional diversity. © 2008 Springer Science+Business Media B.V.

Osteologia craniana de Nyctibiidae (Aves, Caprimulgiformes)

The Potoos form an exclusively neotropical family of nocturnal birds distributed throughout Central and South America, except Chile, and reaching their highest diversity in the Amazon region. The seven currently recognized species are certainly among the most poorly known birds of this region. They are characterized by a distinctive mimicry of vegetal trunks, where they remain almost motionless during daytime. For this reason, their nocturnal and cryptic habits make them exceedingly difficult to study. Published accounts on behavior and natural history of the family are scarce and contributions regarding its anatomy are rare. Here we sample six of the seven currently recognized species of Nyctibiidae, including Nyctibius grandis, N. aethereus, N. griseus, N. jamaicensis, N. leucopterus and N. bracteatus, in order to conduct a detailed and illustrated description of the skull and jaw osteology. High interspecific variation in skull osteology was observed in the family. Species of this family possess a highly modified skull, adapted to their life habits, which shelters their well developed eyes and permits a large mouth opening. The bones that form the palate structure exhibit a dorsoventral flattening, particularly in the pterigoid and parasphenoid bones, with the palatine bone being a broadly developed, wing-shaped structure. In the maxilar region, near the jugal arch, there is a tooth-like projection, unique among birds, which may assist in the retention of prey upon capture. The vomer bone is highly variable within the family, showing varying numbers of rostral projections amongst species. The broad occipital region exhibits large spacing between the quadrate bones, which are vertically disposed and possess a reduced processus orbitalis. The mandible, which is flexible and elastic, has an extremely short symphyseal region and sindesmotic joints in both mandibular rami. As a family, potoos possess a highly specialized skull which provides insight into the relationship between the form of the structures and the feeding habits of the species. Furthermore, the large interspecific variation in skull morphology emphasizes the needs for taxonomic revision within the family, which at present is lumped into a single genus.

Chartergellus golfitensis West-Eberhard: A new species of Neotropical swarm-founding wasp (Hymenoptera: Vespidae, Polistinae) with notes on the taxonomy of Chartergellus zonatus Spinola

Chartergellus golfitensis West-Eberhard new species, is described from Central America and compared with C. zonatus Spinola, a species heretofore inadequately described.

Serological survey of Toxoplasma gondii in captive Neotropical felids from Southern Brazil

Toxoplasma gondii is the causative intracellular protozoan of toxoplasmosis in human being and animals. Members of the Felidae family are considered the single definitive host for the infection; both wild and domestic cats are able to excrete oocysts in the environment. Wild cats maintained in captivity may serve as source of infection for other clinically susceptible animals in the same environment. The aim of this study was to determine the frequency of T. gondii IgG antibodies in 57 neotropical felids (1 Leopardus geoffroyi; 3 Puma yagouaroundi; 17 Leopardus wiedii; 22 Leopardus tigrinus; and 14 Leopardus pardalis) kept at the Bela Vista Biological Sanctuary, Itaipu Binacional, Southern Brazil, by the modified agglutination test (MAT) using titer 16 as cut-off point. Seropositivity was observed in 38/57 (66.67%; 95% CI 53.66-77.51%) samples, with higher frequency in ocelots (71.43%). Wild-caught felids were three times more likely to be infected when compared to zoo-born animals (P≤ 0.05) and age of wild-caught animals (P= 0.6892; 95% CI. = 0.7528-1.66) was not significant as a risk factor for the infection, the same occurring with zoo-born animals (P= 0.05; 95% CI. = 0.6267-24.052). These results suggest that, despite efforts to control T. gondii infection in zoo facilities, such as individual pens, hygiene monitoring, veterinary care and pre-frozen meat offered as food, non-domestic felids kept in captivity, particularly the wild-caught specimens, may be invariably exposed to infection due to other environmental sources. © 2010 Elsevier B.V.

The behavior and natural history of Chartergellus, a little-known genus of neotropical social wasps (Vespidae Polistinae Epiponini)

This study reviews published data on the behavior and natural history of Chartergellus and presents the first observations on social interactions in this genus of tropical swarm-founding wasps. Observations of Chartergellus golfitensis in Costa Rica and C. punctatior in Colombia showed that queens perform a post-oviposition egg-guarding vigil, and a bending display like that characteristic of epiponine social wasps that lack consistent morphological differences between workers and queens and have caste determination in the adult stage. Young, old, and queen (egg-laying) females of C. golfitensis showed small differences that indicate color changes with age, and structural differences that could be due to seasonal or colony-cycle changes in developmental conditions, but do not rule out the possibility of pre-adult caste determination, a phenomenon that needs to be carefully distinguished from pre-adult caste bias. Sexual dimorphism and the behavior of males at the nest in C. golfitensis is described, as well as the aggressive and avoidance behavior of females toward males. Nest structure in both species is as described previously for Chartergellus species, but some anomalies and their possible evolutionary significance are discussed. Cell initiation by an egg-laying queen, a behavior never seen by workers, and by a young female with slightly developed ovaries, may be vestiges of ancestral solitary reproductive traits where developed ovaries are associated with cell construction. © 2010 Dipartimento di Biologia Evoluzionistica dell'Università, Firenze, Italia.

Morphological caste differences in three species of the Neotropical genus Clypearia (Hymenoptera: Polistinae: Epiponini)

Clypearia is a rare genus of swarm-founding Neotropical wasp whose biology is very little known. Morphological castes differences, condition of ovaries, relative age, and color pattern differences were analyzed in three species of Clypearia. Physiological differences and low morphometric differentiation between queens and workers were present in all species studied, indicating that these species are characterized by physiological caste only. We suggest that caste determination in the three Clypearia species studied is postimaginal. © 2010 Giovanna Tocchini Felippotti et al.

Osteologia craniana de Micrastur semitorquatus Vieillot, 1817 (Falconiformes: Falconidae)

Micrastur semitorquatus, popularly known as Collared Forest-Falcon is an inhabitant of the rainforests of the Neotropical Region. Studies on the cranial osteology are scarce in the literature. To increase the knowledge about the anatomy of this species its cranial osteology was described and compared with other species of birds of prey. Three specimens of M. semitorquatus were examined at the Bird Division of the osteological collection at the Smithsonian National Museum of Natural History (USNM), Washington, DC (USNM: 245788, USNM 013493 and USNM 289773). Although the relationship between the form of a structure and its function is not fully established, many of the adaptations of the skull of M. semitorquatus may be related to this lifestyle and behavior, such as narrowing of the interorbital width, the robustness of pila supranasalis coupled with the prokinesis of the skull, a process developed post-orbital, and palatine expansion. In addition, the cranial osteology of M. semitorquatus can provide useful characters for cladistic analysis, sustaining the hypothesis of phylogenetic relationships with other species of the same genus or the same family.

Three new taxa of meliosma (Sabiaceae) neotropical sabiaceae: Three new species and a new variety of meliosma

Three new neotropical species of Sabiaceae, M. robusta from Peru, M. starkii from Mexico, Meliosma cornejoi, and a new variety, M. boliviensis var. sumacensis from Ecuador, are here described and illustrated. © President and Fellows of Harvard College, 2012.

Karyotypic diversity and evolutionary trends in the neotropical catfish genus Hypostomus lacépède, 1803 (Teleostei, Siluriformes, Loricariidae)

The family Loricariidae with 813 nominal species is one of the largest fish families of the world. Hypostominae, its more complex subfamily, was recently divided into five tribes. The tribe Hypostomini is composed of a single genus, Hypostomus Lacépède, 1803, which exhibits the largest karyotypic diversity in the family Loricariidae. With the main objective of contributing to a better understanding of the relationship and the patterns of evolution among the karyotypes of Hypostomus species, cytogenetic studies were conducted in six species of the genus from Brazil and Venezuela. The results show a great chromosome variety with diploid numbers ranging from 2n=68 to 2n=76, with a clear predominance of acrocentric chromosomes. The Ag-NORs are located in terminal position in all species analyzed. Three species have single Ag-NORs (Hypostomus albopunctatus (Regan, 1908), H. prope plecostomus (Linnaeus, 1758), and H. prope paulinus (Ihering, 1905)) and three have multiple Ag-NORs (H. ancistroides (Ihering, 1911), H. prope iheringi (Regan, 1908), and H. strigaticeps (Regan, 1908)). In the process of karyotype evolution of the group, the main type of chromosome rearrangements was possibly centric fissions, which may have been facilitated by the putative tetraploid origin of Hypostomus species. The relationship between the karyotype changes and the evolution in the genus is discussed. © Anderson Luis Alves et al.

Two new feather mite species (Acari, pteronyssidae) from the white-barred piculet, picumnus cirratus (Aves, piciformes)

Two new species of the feather mite family Pteronyssidae Oudemans, 1941 are described from the white-barred piculet, Picumnus cirratus Temminck from Brazil: Pterotrogus picumni sp. n. and Ramphastobius scutatus sp. n., representing the first mites described from this host. Pterotrogus picumni sp. n. can be readily distinguished from all previous species of the simplex group by having dorsal crest on femora I and II in both sexes. This is the first representative of the genus Pterotrogus Gaud, 1981 recorded on a host of the genus Picumnus Temminck. Ramphastobius scutatus sp. n. is unique among species of the genus by having in both sexes the prodorsal and scapular shields fused into a single propodonotal shield covering all prodorsum. An updated key to known species of the genus Ramphastobius Gaud, 1981 is presented. © Institute of Parasitology, Biology Centre ASCR.

Sexual differences in parental feeding effort during the nestling period of the White-headed Marsh-Tyrant (Arundinicola leucocephala)

Parental effort may influence the fitness and survivorship of adult birds and their offspring from one breeding season to the next. Although much is known about parental feeding effort in tyrant flycatchers, many species remain understudied. In this study, I examined parental feeding effort of the White-headed Marsh-Tyrant (Awndinicola leucocephala) at a pond in southeastern Brazil. I conducted 10.3 hrs of observations from two locations: a high place with all view of the whole pond, that allowed me to observe flight distances of parents hunting for prey; and from near the nest to observe frequency of visits to the nest. The female marsh-tyrant flew farther while hunting prey and made more visits to the nest than did the male. The adults (mainly the female) provided a variety of terrestrial and aquatic arthropods to the nestlings. Additionally, parents removed fecal sacs from the nest and nestlings eliminated arthropod remains from the nest, the first records of nest sanitation activities by this species. Nonexclusive hypotheses that may explain the lower level of parental care provided by the male include: higher predation risk due its more conspicuous plumage, commitment of male to territory defense, and its selfish behavior influenced by indirect genotype fitness inherited by the offspring. © The Neotropical Ornithological Society.

Morphological Variation of Primary Reproductive Structures in Males of Five Families of Neotropical Bats

Bats present unique features among mammals with respect to reproduction, and although neotropical bats do not have a hibernation period, many of their reproductive characteristics vary seasonally and interspecifically. Thus, this work aimed to examine the reproductive structures of 18 species belonging to five families of Brazilian bats. The gross anatomy of the testes varied little; however, the epididymis of Emballonuridae and Vespertilionidae showed exceptional structures with a large elongation of the caudal region. We observed a wide variation in the positioning of the testes: Phyllostomidae and Noctilionidae presented external testes; Emballonuridae and Molossidae presented migratory testes that may be in intra-abdominal or external positions; and Vespertilionidae displayed scrotal testes. In the histological evaluation, we observed a different pattern in vespertilionid species, with testicular regression and sperm retention/storage in the cauda epididymis in the five species analyzed. Similar testicular regression was observed in Molossops temminckii; however, sperm retention/storage was not observed in this species. These data suggest that although the species analyzed are tropical species that do not present a prolonged period of torpor (hibernation), they still maintain a period of seminiferous tubule regression and sperm storage very similar to that observed in hibernating bats. © 2012 Wiley Periodicals, Inc.

Anatomy of the floral nectaries of some neotropical Salacioideae (Celastraceae)

Floral nectaries have contributed to the systematics of different taxonomic groups. Since those of the neotropical genera included in subfamily Salacioideae-Cheiloclinium Miers, Peritassa Miers, Salacia L. and Tontelea Aubl.-have different forms and positions, we explored their anatomy to delimit more precisely the genera of subfamily Salacioideae. Buds and open flowers of six species were treated following the usual techniques in plant anatomy. The obtained data were helpful in characterizing the floral nectary anatomy of the studied species. Furthermore, some features such as form, position and surface of nectaries; form of their epidermal cells; presence and distribution of stomata; occurrence of idioblasts containing druses in the nectariferous parenchyma; and absence of nectary vascularization can contribute to the taxonomy and phylogeny of the Salacioideae studied. In most of the studied species the nectar is probably released by both the stomata and the nectary epidermal surface. In Cheiloclinium cognatum, the structure acknowledged as nectary is actually a vestigial tissue and the functions of attracting and rewarding pollinators has phylogenetically migrated to the stigmatic region. The druses and phenolic substances observed in the nectariferous parenchyma probably help defend flowers against herbivore attacks. The minute size of the nectaries of Salacioideae may explain the absence of vascularization. The floral nectaries of Salacia elliptica are epithelial while those of the other species are mesenchymal. © 2012 Springer-Verlag Wien.

Chromosomal evolution of neotropical cichlids: The role of repetitive DNA sequences in the organization and structure of karyotype

Cichlids are important in the aquaculture and ornamental fish trade and are considered models for evolutionary biology. However, most studies of cichlids have investigated African species, and the South American cichlids remain poorly characterized. Studies in neotropical regions have focused almost exclusively on classical cytogenetic approaches without investigating physical chromosomal mapping of specific sequences. The aim of the present study is to investigate the genomic organization of species belonging to different tribes of the subfamily Cichlinae (Cichla monoculus, Astronotus ocellatus, Geophagus proximus, Acaronia nassa, Bujurquina peregrinabunda, Hoplarchus psittacus, Hypselecara coryphaenoides, Hypselecara temporalis, Caquetaia spectabilis, Uaru amphiacanthoides, Pterophyllum leopoldi, Pterophyllum scalare, and Symphysodon discus) and reexamine the karyotypic evolutionary patterns proposed for this group. Variations in some cytogenetic markers were observed, although no trends were found in terms of the increase, decrease, or maintenance of the basal diploid chromosome number 2n = 48 in the tribes. Several species were observed to have 18S rDNA genetic duplications, as well as multiple rDNA loci. In most of the taxa analyzed, the 5S rDNA was located in the interstitial region of a pair of homologous chromosomes, although variations from this pattern were observed. Interstitial telomere sites were also observed and appear to be involved in chromosomal rearrangement events and the accumulation of repeat-rich satellite DNA sequences. Our data demonstrated the karyotypic diversity that exists among neotropical cichlids, suggesting that most of this diversity is due to the repetitive sequences present in heterochromatic regions and that repeat sequences have greatly influenced the karyotypic evolution of these fishes. © 2012 Springer Science+Business Media B.V.

Development of microsatellite markers for the Neotropical endemic Brazilian Guanabara frog, Euparkerella brasiliensis, through 454 shotgun pyrosequencing

The new-generation 454 GS-FLX Titanium pyrosequencing was used to isolate microsatellite markers for the Brazilian Guanabara frog, Euparkerella brasiliensis, an Atlantic forest endemic species. Three multiplex polymerase chain reaction sets were optimized for genotyping of 11 polymorphic (di- and tetranucleotide) microsatellite markers. Genetic diversity was assessed in 21 individuals from a population (Reserva Ecológica de Guapiaçu, REGUA) locatedin the central region of the Rio de Janeiro State, in Brazil. The mean number of alleles per locus ranged from 3 to 12. Observed and expected heterozygosities ranged from 0.095 to 0.905 and from 0.094 to 0.904, respectively. After using the Bonferroni correction for multiple tests, there was no evidence of linkage disequilibrium between pairs of loci but deviations for Hardy-Weinberg equilibrium were found in 4 loci. We found no evidence for allele dropouts or stuttering, but we detected the presence of null alleles at loci Eb10 and Eb36. These markers will be useful for analyses of fine-scale population structure and determination of relative effects of habitat loss and fragmentation on population genetic variability within species. © FUNPEC-RP.