Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Itamar Alves Martins is active.

Publication


Featured researches published by Itamar Alves Martins.


Toxicon | 2003

Injuries caused by scorpionfishes (Scorpaena plumieri Bloch, 1789 and Scorpaena brasiliensis Cuvier, 1829) in the Southwestern Atlantic Ocean (Brazilian coast): epidemiologic, clinic and therapeutic aspects of 23 stings in humans.

Vidal Haddad; Itamar Alves Martins; Humberto Minoru Makyama

Fishes of the family Scorpaenidae are responsible for severe injuries and occasionally deaths in humans around the world. The more venomous fishes on the Brazilian coast and in the Southwestern Atlantic region are classified in the genus Scorpaena (family Scorpaenidae). However, there are few studies on the venomous apparatus, the effects of the venom, or clinical aspects of human envenoming provoked by Atlantic scorpionfishes. In this communication, the authors present 23 accidents caused by scorpionfishes of the genus Scorpaena among fishermen, and report the species that provoked the injuries, the circumstances of contacts, the clinical aspects observed and the therapeutic measures utilized for control of the symptoms of the victims. The intense pain and the systemic findings observed in the patients were very frequent and we think that the injuries provoked by scorpionfishes should be considered the most important manifestations caused by venomous fishes of the East Atlantic Ocean.


Acta Ethologica | 2015

The anuran calling repertoire in the light of social context

Luís Felipe Toledo; Itamar Alves Martins; Daniel Pacheco Bruschi; Michel de Aguiar Passos; Cesar Alexandre; Célio F. B. Haddad

Frogs are immediately associated to their conspicuous vocalizations emitted during the breeding season. Therefore, many scientists were inspired to study their acoustic communication. Nowadays, many types of calls are described and we felt the need of reviewing the terminology currently and historically applied. As a result, we proposed the classification of anuran vocalization into three major categories: reproductive, aggressive, and defensive calls. These categories are subdivided according to the social context of emission mostly reflecting also acoustic differences among call types. Some call types are here proposed to be synonymies of the mostly used and inclusive terms. We also suggest terminologies for basic bioacoustical analyses, mostly applied in call descriptions. Furthermore, we present cases of complex calls, including call gradation. Finally, based on novel data (such as an unusual case of juvenile vocalizations), we discuss situations in which it is difficult to classify call types, reflecting the need of experimental studies.


Zoologia | 2011

Environmental heterogeneity: Anuran diversity in homogeneous environments

Rodrigo A. Silva; Itamar Alves Martins; Denise de Cerqueira Rossa-Feres

The northwestern region of Sao Paulo was extensively deforested during the agricultural expansion in the last century and only small fragments of the original vegetation cover remained. In this study, we investigated how habitat features influence the composition, richness, and diversity of anurans in environments homogenized by agricultural activities. We sampled monthly six breeding ponds located in pasture areas during twelve months. We recorded ten environmental descriptors for each breeding pond. We found 18 anuran species. The breeding ponds were structurally similar, but species composition differed among them. The environmental descriptors influence varies for each species, as demonstrated by the different associations between species and environmental descriptors shown in the Canonical Correspondence Analysis (CCA). Seven of the ten environmental descriptors explained 67% of the species richness, showing that environmental characteristics influenced the occurrence of the different species. There is no such data set for the region and also for most Brazilian regions, despite its importance in guiding species-oriented conservation actions.


Biota Neotropica | 2008

Bioacústica e sítio de vocalização em taxocenoses de anuros de área aberta no noroeste paulista

Rodrigo A. Silva; Itamar Alves Martins; Denise de Cerqueira Rossa-Feres

The calling site and the acoustic parameters of the advertisement call were determined for 18 anuran species in six ponds in the northwest region of Sao Paulo State. The dominant frequency of the advertisement call was positively correlated with the CRC of the species: small size species vocalized in a higher frequency, whereas larger species vocalized in a lower frequency. The similarity in the spectral and temporal parameters of the advertisement call was high among 94% of the recorded species. The similarity on calling site was low; only 22% of species presented high overlap, in spite of about a half of the species have been generalist in calling site use. Analysing simultaneously the similarity on calling site, habitat and advertisement call parameters, the proportion of species with high overlap decreased from 94 to 11%, corresponding to the overlap between a single pair of species: Dendropsophus elianeae and D. minutus. The species that overlap in calling site presented segregation in acoustic parameters, and those that overlap in acoustic parameters tended to partition the calling site. This result suggests the occurrence of niche complementarity, since species that occupied a similar position in one dimension tended to differ in another dimension. The structural homogeneity of ponds, the climatic severity of the region and the high degree of habitat loss restrict the abundance of population and the species richness of the anuran assemblages. The low overlap on the calling site is probably associated with the insaturation of the sampled communities.


Revista Do Instituto De Medicina Tropical De Sao Paulo | 2003

The venomous toadfish Thalassophryne nattereri (niquim or miquim): report of 43 injuries provoked in fishermen of Salinópolis (Pará State) and Aracaju (Sergipe State), Brazil

Vidal Haddad Junior; Pedro Pereira de Oliveira Pardal; João Luiz Costa Cardoso; Itamar Alves Martins

Fishes of family Batrachoididae are responsible for great number of injuries in fishermen in North and Northeast regions of Brazil. The genus Thalassophryne presents various venomous species of fishes found in the Brazilian coast, T. nattereri being the most common of them. The venom is ejected through two hollow spines on the dorsal fin and two on pre-opercular regions, which present a venomous gland in the base and can be erected or depressed by the fish. The manifestations of the envenoming were intense local pain, edema and erythema in 43 patients observed in Salinópolis (Pará State) and Aracaju (Sergipe State). There were no systemic manifestations, but necrosis was detected in eight and bacterial infection in ten injured fishermen. The circumstances of the contacts and therapeutic aspects are discussed. Envenoming by the genus Thalassophryne is important and frequent and should be considered of moderate severity grade, since there are not the excruciating pain or the massive local necrosis provoked by scorpionfishes (Scorpaena) or stingrays injuries nor the systemic manifestations that are the most important marker of severe envenoming.


Hydrobiologia | 2014

Broad-scale spatial patterns of canopy cover and pond morphology affect the structure of a Neotropical amphibian metacommunity

Diogo B. Provete; Thiago Gonçalves-Souza; Michel V. Garey; Itamar Alves Martins; Denise de Cerqueira Rossa-Feres

Spatial and environmental processes influence species composition at distinct scales. Previous studies suggested that the distribution of larval anurans at the landscape-scale is influenced by environmental gradients related to adult breeding site selection, such as pond canopy cover, but not by water chemistry. However, the combined effects of spatial, pond morphology, and water chemistry variables on metacommunity structure of larval anurans have not been analyzed yet. We used a partial redundancy analysis with variation partitioning to analyze the relative influence of pond morphology (e.g., depth, area, and aquatic vegetation), water chemistry, and spatial variables on a tadpole metacommunity from southeastern Brazil. We predict that pond morphology and canopy cover will influence the metacommunity at broad spatial scales, while water chemistry would play a larger role at finer scales. We found that broad-scale spatial patterns of pond canopy cover and pond morphology strongly influenced metacommunity structure, with water chemistry being not significant. Additionally, species composition was spatially autocorrelated at short distances. We suggest that the reproductive behavior of adult anurans is driving tadpole metacommunity dynamics, since pond morphology, but not water chemistry affects breeding site selection by adults. Our results contribute to the understanding of amphibian species diversity in tropical wetlands.


Journal of the Marine Biological Association of the United Kingdom | 2005

Biological parameters and population structure of Psammobatis extenta in Ubatuba region, north coast of the State of São Paulo, Brazil

Itamar Alves Martins; Camila L. Martins; Maria Helena de A. Leme

Specimens of the zipper sand skate Psammobatis extenta were collected in the region of Ubatuba off the northern coast of the State of Sao Paulo, Brazil, monthly for one year (January-December 2000), at 25- to 40-m isobaths. A total of 123 individuals were caught. The total length (TL) of females averaged 224.6 mm, and of males 217 mm. The overall sex ratio was 1:1. Analysis of the length weight relationship indicated the existence of positive allometry in females, and isometry in males. The length at onset of sexual maturity was determined for both sexes; females reached sexual maturity at smaller sizes than males (TL 50 =230. and TL 50 =237.7 mm respectively). Females showed functional parity of both ovaries and uteri. Females that were pregnant or were carrying vitellogenic oocytes were observed during nine of the 12 months of the survey, indicating a continuous reproductive cycle. Psammobatis extenta was most abundant from January to April, and again from June to October. Most individuals were collected at the 40-m isobath. Both adults and neonates were collected in the study area. However, adolescent skates were scarce, which either indicates differential occupation of the area, or suggests that the shallow waters of the continental shelf are used as breeding grounds.


Toxicon | 2014

Clinical manifestations and experimental studies on the spine extract of the toadfish Porichthys porosissimus

Mônica Lopes-Ferreira; Anderson Daniel Ramos; Itamar Alves Martins; Carla Lima; Katia Conceição; Vidal Haddad

Toadfish are fish from the family Batrachoididae that are found in marine and brackish environment around the world. Among the toadfish, Porichthys genus is very common, where Porichthys porosissimus, also called Atlantic Midshipman is found in Southwest Atlantic, from Rio de Janeiro, Brazil to eastern Argentina. There was no consensus about the classification of the genus Porichthys as venomous fish because so far there are no published studies regarding human envenomations and/or toxic activities induced in animal models. Herein, we report two conclusive envenoming in human beings caused by P porosissimus spines, with clear signs and symptoms that were very important for the development of our experimental studies. We demonstrated that the P. porosissimus spine extract, now venom, can induce nociceptive and edematogenic responses in mice as well an induction of an inflammatory response elicited by intravital microscopy and leukocyte migration. Finally, we identified in the P. porosissimus spine extract, through analysis by mass spectrometry, the presence of proteins previously detected in the venoms of other fish species and other venomous animals. We believe that based on our studies we will dismiss the non-venomous nature of this fish and clarify this issue.


Zoologica Scripta | 2012

Phylogenetic signal and variation of visceral pigmentation in eight anuran families

Diogo B. Provete; Lilian Franco-Belussi; Lia Raquel de Souza Santos; Rodrigo Zieri; Rafaela Maria Moresco; Itamar Alves Martins; Silvio C. De Almeida; Classius de Oliveira

Provete, D. B, Franco‐Belussi, L., de Souza Santos, L. R., Zieri, R., Moresco, R. M., Martins, I. A., de Almeida, S. C., & de Oliveira, C. (2012). Phylogenetic signal and variation of visceral pigmentation in eight anuran families. —Zoologica Scripta, 41, 547‐556.


Genetics and Molecular Biology | 2009

The karyotype of three Brazilian Terrarana frogs (Amphibia, Anura) with evidence of a new Barycholos species

Sérgio Siqueira; Odair Aguiar; André Pansonato; Ariovaldo Antonio Giaretta; Christine Strüssmann; Itamar Alves Martins; Shirlei Maria Recco-Pimentel

A recent substantial rearrangement of the 882 described eleutherodactyline frog species has considerably improved the understanding of their systematics. Nevertheless, many taxonomic aspects of the South American eleutherodactyline species remain unknown and require further investigation using morphological, cytogenetic and molecular approaches. In this work, the karyotypes of the Brazilian species Ischnocnema juipoca (Atibaia and Campos do Jordão, SP), Barycholos cf. ternetzi (Uberlândia, MG, and Porto Nacional, TO), and Pristimantis crepitans (Chapada dos Guimarães and São Vicente, MT) were analyzed using Giemsa staining, Ag-NOR labeling, and C-banding techniques. All individuals had a diploid number of 22 chromosomes, but the Fundamental Numbers were different among species. The herein described low chromosome number of Pristimantis crepitans is unique within this genus, suggesting that cytogenetically this species is not closely related either to its congeneric species or to Ischnocnema. In addition, karyotype differences, mainly in the NOR position, clearly distinguished the two Barycholos populations, besides indicating the existence of a so far undescribed species in this genus. A taxonomic review could clarify the systematic position of P. crepitans and verify the hypothetic new Barycholos species.

Collaboration


Dive into the Itamar Alves Martins's collaboration.

Top Co-Authors

Avatar

Diogo B. Provete

Federal University of São Carlos

View shared research outputs
Top Co-Authors

Avatar

André Pansonato

Universidade Federal de Mato Grosso

View shared research outputs
Top Co-Authors

Avatar

Christine Strüssmann

Universidade Federal de Mato Grosso

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jessica Rhaiza Mudrek

Universidade Federal de Mato Grosso

View shared research outputs
Top Co-Authors

Avatar

Rodrigo A. Silva

State University of Campinas

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge