GROWTH LAYER PATTERNS IN TEETH FROM THE FRANCISCANA, PONTOPORIA BLAINVILLEI: DEVELOPING A MODEL FOR PRECISION IN AGE ESTIMATION

A model for estimating age from teeth of the franciscana, Pontoporia blainvillei , was developed using teeth from 72 specimens taken incidentally in fishing nets in Brazil and Uruguay. The goal of the model was to allow for accurate and precise age estimates for a larger sample of specimens. Growthlayer characteristics were selected on the basis of similarities in growth layers among various species of cetaceans, including those whose growth layers have been calibrated for time, and on length groups in the franciscana, which calves seasonally. Growth-layer patterns, including relative size and appearance, in both dentine and cementum did not vary by sex but did vary by the orientation of the tooth when it was sectioned. The model developed proved useful in providing guidelines for consistency in age estimation for biological studies of the larger sample of animals. We recommend the development of this type of model for other species to facilitate standardizing age estimation.     

Community ecology of the metazoan parasites of pink cusk-eel,Genypterus brasiliensis (Osteichthyes: Ophidiidae), from the coastal zone of the State of Rio de Janeiro,Brazil

Fifty-five specimens of pink cusk-eel, Genypterus brasiliensis Regan, 1903 (Osteichthyes: Ophidiidae) collected from the coastal zone of the State of Rio de Janeiro, Brazil (approx. 21-23 degrees S, 41-45 degrees W), from September 2000 to January 2001, were necropsied to study their parasites. All fish were parasitized by one or more metazoan. Fourteen species of parasites were collected. G. brasiliensis is a new host record for nine parasite species. The larval stages of cestodes and the nematodes were the majority of the parasite specimens collected, with 38.4% and 36.5%, respectively. Cucullanus genypteri was the dominant species with highest prevalence and/or abundance. The parasites of G. brasiliensis showed the typical overdispersed pattern of distribution. Six parasite species showed correlation between the host's total body length and prevalence and abundance. Host sex did not influence prevalence and parasite abundance of any parasite species. The mean diversity in the infracommunities of G. brasiliensis was H= 0.364 +/- 0.103, with correlation with the host's total length and without differences in relation to sex of the host. One pair of adult endoparasites (C. genypteri and A. brasiliensis) showed positive covariations between their abundances. Negative association or covariation was not found. Differences between the qualitative and quantitative aspects of the parasite community of G. brasiliensis from Rio de Janeiro and Argentina suggest the existence of two population stocks of pink cusk-eel in the South America Atlantic Ocean.     

Molecular sexing of unusually large numbers of Spheniscus magellanicus (Spheniscidae) washed ashore along the Brazilian coast in 2008

There have been few studies on Magellanic penguins (Spheniscus magellanicus). In 2008, these penguins washed ashore along the Brazilian coast in unusually high numbers, some reaching as far as northeast Brazil. As Magellanic penguins show little sexual dimorphism, sex determination by morphological features is not accurate. Here, we tested a molecular procedure for sexing specimens of S. magellanicus washed ashore along the coasts of Sergipe, Rio de Janeiro and Rio Grande do Sul in 2008, comparing the sex ratio between these localities. Tissue samples were collected from 135 dead, beached specimens. We carried out total genomic DNA extraction and CHD-Z/CHD-W gene amplification by PCR using P2 and P8 primers. Amplicons were separated by 12% acrylamide gel electrophoresis. We found a greater proportion of females (70%). Sex could be determined because females have two intronic regions of CHD gene of different size in the sex chromosomes, visualized as two bands on the gel (380 and 400 bp approximately), while males have only one (400 bp). Therefore, this method proved to be effective and sensitive for sex determination of S. magellanicus individuals. Data on sex ratios are useful for understanding the dynamics and ecology of Magellanic penguin populations.     

GEOGRAPHIC GENETIC STRUCTURE IN THE FRANCISCANA DOLPHIN (PONTOPORIA BLAINVILLEI)

The franciscana, Pontoporia blainvillei , is endemic to the South Atlantic coast of South America. The species is of conservation concern because it suffers elevated mortality rates due to incidental captures in fishing nets, and perhaps it is one of the most threatened small cetaceans in this region. Previous morphological and genetic studies have suggested the existence of at least two distinct stocks to the north and south of Santa Catarina Island in Brazil. Fixed differences were found between a sample from Rio de Janeiro and one from Rio Grande do Sul, in southern Brazil. Using 94 sequences of the control region of mitochondrial DNA, we examined the genetic structure of the species. We found no shared haplotypes between Rio de Janeiro and samples from the southern range of the species distribution. However, a phylogenetic analysis suggests that the former population is diphyletic with respect to the southern samples. This suggests that the populations have not been isolated long enough to reach reciprocal monophyly. Furthermore, genetic differentiation is broadly consistent with a simple model of isolation by distance, that therefore appears as an alternative to a model of strict isolation of two stocks. The estimated levels of gene flow are higher among neighboring populations, and decrease as more distant localities are compared. Finally, the molecular data suggest that franciscanas have expanded in Rio de Janeiro.     

Metazoan parasites as biological tags for stock discrimination of whitemouth croaker Micropogonias furnieri

Examination of 248 adult specimens of whitemouth croaker Micropogonias furnieri from five localities along the Brazilian coast revealed 8735 parasites belonging to 41 metazoan species. Samples from Ceará to Bahia and Rio de Janeiro to Santa Catarina showed a high level of correct assignation (92 and 87%, respectively) and cross assignation (i.e. almost all specimens misidentified in Ceará were assigned to Bahia and almost all specimens misidentified in Bahia were classified as Ceará), so samples were pooled in the northern and south‐eastern samples, and Rio Grande do Sul was considered a southern area. Eight parasite species were characteristic of the northern localities, five species were found just in the area associated with south‐eastern localities and two species were characteristic of the southern area providing first evidence of stock discreteness. The multivariate discriminant analysis successfully discriminated three groups of localities associated with three stocks of M. furnieri in Brazil: a northern stock associated with Ceará and Bahia, a south‐eastern stock related to Rio de Janeiro and Santa Catarina and a southern stock in the area of Rio Grande do Sul, which could be considered as the northern limit of the stock associated with the Common Fishing Zone of Uruguay and Argentina.     

Age,sex, and antemortem loss of teeth in prehistoric Eskimo samples from point hope and Kodiak Island,Alaska

The incidence of teeth lost antemortem was investigated in 244 archeologically derived dried skeletal specimens from the Ipiutak and Tigara burials at Point Hope, Alaska, and 83 Koniag Eskimo specimens excavated at Jones Point, Uyak Bay, Kodiak Island, Alaska. Ipiutak skeletal remains date from approximately 1500 years B.P. and the Tigara remains from 300–400 years B.P. The Kodiak Island sample is undated. Specimens were sexed and aged in five-year groupings using standard techniques. Teeth lost antermortem were identified as having occupied tooth sockets which showed healing of alveolar bone following exfoliation. Numbers of lost teeth were calculated as percentages of total number of tooth sites of each tooth classification for each age, sex, and site subgrouping. Tooth loss was very low in the Kodiak Island sample, with little difference between sexes and no identifiable age trends. The Tigara ramains displayed moderate tooth loss, with strong correlations to increasing age and little differentiation between the sexes. The Ipiutak specimens lost the most teeth antemortem, with notable between-sex differences and strong correlations with increasing age. In all groups loss of anterior teeth was probably due to accident or heavy wear, while loss of posterior teeth was due to heavy wear, periodontal disease, or agenesis.     

Two new species of Fannia Robineau-Desvoidy (Diptera, Fanniidae).

Fannia Robineau-Desvoidy is known from 63 neotropical species, 24 of them with occurence in Rio de Janeiro State. Two new species from Rio de Janeiro State are added to the genus: F. tibialis, sp. n and F. unica, sp. n. Male specimens of both are described. Morphological characters and terminalia are illustrated. Each species is briefly discussed.     

Seroepidemiological studies of HIV-1 infection in large Brazilian cities

The prevalence of HIV-1 antibodies in selected groups of individuals from Rio de Janeiro, S?o Paulo and Santos was determined retrospectively. These groups and respective prevalences were: hemophiliac patients from Rio de Janeiro (1983-1984) 98.0%; polytransfused hemodialysis patients from S?o Paulo (1985-1986) 3.0% and (1987) 7.7%; intravenous drug addicts from S?o Paulo and Rio de Janeiro (1986-1987) 15.9%; male prisoners from S?o Paulo (1988) 12.5%, and pregnant women from Santos (1988-1989) 3.6%. These data stress the magnitude of AIDS in Brazil.     

Aedes aegypti resistance to temephos during 2001 in several municipalities in the states of Rio de Janeiro, Sergipe, and Alagoas, Brazil

For more than 30 years temephos, an organophosphate insecticide, has been the sole larvicide used in Brazil in the control of Aedes aegypti. Organophosphates were also used for adult control, being replaced by pyrethroids since 1999. In this same year the Brazilian Health Foundation started the coordination of the Ae. aegypti Insecticide Resistance Monitoring Program. In the context of this program, our group was responsible for the detection of temephos resistance in a total of 12 municipalities in the states of Rio de Janeiro (RJ), Alagoas (AL), and Sergipe (SE) during 2001. In each municipality, a pool of mosquitoes collected from different districts was used, with the exception of Rio de Janeiro city, where eight districts have been separately evaluated. Exposure of larvae to the diagnostic dose of temephos revealed resistance in all localities examined, with mortality levels ranging from 4% (Pilares district, Rio de Janeiro, RJ) to 61.9% (Campos dos Goytacazes, RJ). Quantification of mortality showed resistance ratios from 6.1 (Aracaju, SE) to 16.8 (S?o Gon?alo, RJ and Penha district, Rio de Janeiro, RJ). The national dengue control program is presently using these data to subside insecticide resistance management.     

Nyssomyia intermedia (Lutz & Neiva, 1912) and Nyssomyia neivai (Pinto, 1926) (Diptera: Psychodidae: Phlebotominae) geographical distribution and epidemiological importance

Nyssomyia intermedia (Lutz & Neiva 1912) and N. neivai (Pinto 1926) are possible vectors of tegumentary leishmaniasis in some regions of Brazil. Further, the latter was until recently, considered a junior synonym of the former. This study has the purpose of updating our knowledge of the geographical distribution of these species, based on specimens deposited at the collection of the Centro de Pesquisas René Rachou-Fiocruz, Faculdade de Saúde Pública-Universidade de S?o Paulo, and on data presented by literature as also to associate this distribution with the cutaneous leishmaniasis cases reported. It has been reported that N. intermedia occurs in the states of the Northeastern Region, in Rio de Janeiro, Espírito Santo, on the northern coast of S?o Paulo, in eastern Minas Gerais, Mato Grosso do Sul, and Goiás, close to the border with Minas Gerais and Bahia. N. neivai occurs in the Southern Region, southern coast and in western S?o Paulo, southern and western Minas Gerais, southern Goiás, and southern Pará, beyond Argentina, Bolivia, and Paraguay. It is important to highlight that N. intermedia and N. neivai occur in sympatry in Minas Gerais and S?o Paulo. N. intermedia or N. neivai are predominant or are captured abundantly in several cutaneous leishmaniasis foci in the Southeastern and Southern regions of Brazil.     

Community ecology of the metazoan parasites of white sea catfish, Netuma barba (Osteichthyes: Ariidae), from the coastal zone of the state of Rio De Janeiro, Brazil.

Between March 2000 and April 2001, 63 specimens of N. barba from Angra dos Reis, coastal zone of the State of Rio de Janeiro (23 degrees 0' S, 44 degrees 19' W), Brazil, were necropsied to study their infracommunities of metazoan parasites. Fifteen species of metazoan parasites were collected: 2 digeneans, 1 monogenean, 2 cestodes, 1 acantocephalan, 2 nematodes, 6 copepods, and 1 hirudinean. Ninety-six percent of the catfishes were parasitized by at least one metazoan parasite species. A total of 646 individual parasites was collected, with mean of 10.3 +/- 16.6 parasites/fish. The copepods were 37.5% of the total parasite specimens collected. Lepeophtheirus monacanthus was the most dominant species and the only species with abundance positively correlated with the host total length. Host sex did not influence parasite prevalence or mean abundance of any species. The mean diversity in the infracommunities of N. barba was H = 0.130 +/- 0.115 with no correlation with host's total length and without differences in relation to sex of the host. One pair of endoparasites (Dinosoma clupeola and Pseudoacanthostomum floridensis) showed positive association and covariation between their abundances and prevalences. The parasite community of N. barba from Rio de Janeiro can be defined as a complex of species with low prevalence and abundance and with scarcity of interspecific associations. However, because of both the presence of assemblages of sympatric ariid species as well as the spawning behavior characteristic of these fishes, additional comparative studies of the parasite component communities of ariids are necessaries to elucidate this pattern.     

COMPARATIVE GROWTH ANALYSIS OF TWO POPULATIONS OF PONTOPORIA BLAINVILLEI ON THE BRAZILIAN COAST

The von Bertalanffy growth model was applied to franciscana dolphins ( Pontoporia blainvillei ) incidentally caught in fishing nets on the São Paulo/Paraná coasts (25°00'–25°58'S), and compared with the growth of franciscanas incidentally caught on the Rio Grande do Sul coast (29°–33°S). In both locations, a difference was noted between the growth of males and females, confirming the sexual dimorphism of the body proportions of this dolphin. The growth curves of the dolphins from São Paulo/Paraná were significantly different ( P < 0.01) from those obtained from Rio Grande do Sul, with significantly smaller animals in the former area. On the São Paulo/Paraná coast, the stabilization of the growth curves happened at a total length of 113 and 129 cm for males ( n = 23) and females ( n = 18), respectively. In Rio Grande do Sul, they stabilized at 130 cm for the males ( n = 59) and at 146 cm ( n = 48) for the females. These results corroborate the morphometric differences previously mentioned in the literature, which resulted in the identification of a smaller northern form and a larger southern form of P. blainvillei . The data here presented can be used for future comparisons of changes in growth parameters of these two franciscana stocks and help to develop proper conservation programs for the species.     

Age-Related Changes in Functional Teeth in the Pacific Walrus (<Emphasis Type="Italic">Odobenus rosmarus divergens</Emphasis>)

We examined functional teeth (except for upper canine teeth) of Pacific walruses that died or were harvested on the coast of the Chukchi Peninsula in 2005, 2007–2008, and 2010–2011. The dynamics of deposition of annual cement layers was investigated. The rate of cement deposition on the walls of tooth roots decreased significantly with age. The rate of its deposition on the lingual side of the upper teeth was much higher than that on their buccal side, but no such differences were observed on the lower teeth. The same cement layer was deposited unevenly in different parts of teeth (on its different sides and levels) with a general tendency of increasing in the width of the layer from the top to the lower parts of teeth. As a result of local widening of some cement layers with age, the tooth surface became rough, and knolls and rollers appeared there. As the age increased, external changes in teeth occurred: they became larger, more rounded, and heavier. We described a method for the preliminary determination of the relative age of walruses based on the ratio between the width of cement and dentin on the attrition surface of lower teeth (without cutting).     

Ontogeny, anatomy and attachment of the dentition in mosasaurs (Mosasauridae: Squamata)

Aspects of mosasaur dental ontogeny are well preserved in many fossils of these giant marine squamates. Replacement teeth on the tooth-bearing elements (TBEs) first appear as small enamel crowns positioned posterolingual to the attached tooth (posterolabial for the pterygoid). Several developing crowns, of progressively larger size, are aligned in rows relating to a specific tooth position. The crowns rest in a dental groove that varies in width and depth depending on the TBE. The crown closest to the attached tooth is always the largest and is found in a small resorption pit. As resorption proceeds, the pit expands in volume (cementum and alveolar bone), and the crown increases in size and settles into the pit. Once mature crown size is achieved, the dentine root and cementum portion of the root develop rapidly, the attached tooth is lost and the replacement tooth erupts out of the alveolus. Mosasaurid teeth develop along a 'zig-zag'-shaped movement path: horizontally along the dental groove, down into the alveolus, and up and out of the alveolus prior to attachment to the alveolar wall. At no point in mosasaurid tooth development are the crowns observed in a horizontal position. The mosasaurid dental lamina appears to have been a continuous strip of dental epithelium as it is in other squamates. Mosasaurid tooth attachment is thecodont (histologically and geometrically) not subpleurodont. Most aspects of mosasaurid tooth attachment and ontogeny are autapomorphic for the group.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 687–700.     

Freshwater snails and Schistosomiasis mansoni in the state of Rio de Janeiro,Brazil: III--Baixadas Mesoregion

In this paper, the third of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Mesoregion Baixadas from 2000 to 2002 are presented. Twenty-two species, belonging to seven families, were found. As to the snail intermediate hosts of Schistosoma mansoni, the most frequent species was Biomphalaria tenagophila besides some new findings of Biomphalaria straminea. No specimens were found harboring larval forms of S. mansoni although different kinds of cercariae had been observed.     

Establishment of a colony, in laboratory, of Lutzomyia intermedia Lutz & Neiva, 1912 (Diptera, Psychodidae, Phlebotominae)

A laboratory colony of the sandfly Lutzomyia intermedia was established (at present in its seventh generation) in order to provide specimens for experimental infection and for experimental xenodiagnosis of natural infections due to cutaneous leishmanias in Rio de Janeiro. Date are presented on the methodology and on the yield and duration of each stage of development, during the first four generations.     

mtDNA ancestry of Rio de Janeiro population,Brazil

Polymorphism studies concerning HVI and HVII regions of mitochondrial DNA (mtDNA) have improved the understanding of the admixture genetic process related to the occupation of the continents by human population groups. We have analyzed the mtDNA lineages of 190 healthy and maternally unrelated individuals born in the metropolitan region of the Rio de Janeiro city, the capital of the State of Rio de Janeiro, southeastern Brazil. The data showing that 57.9, 25.3 and 16.8 % of the matrilineages found in Rio de Janeiro come from African, Amerindian and European population groups. They are, respectively, in close agreement with historical records which indicate that the admixture population of Brazil is the resulting of interethnic asymmetry crosses between individuals from those population groups. The high proportion of African mtDNA lineages in the population of Rio de Janeiro is in accordance with studies related to other Brazilian states.