Combining abilities and heterotic groups in Pisum sativum L.

The objective of this research was to investigate the use of heterosis and estimates of the general combining ability (GCA) and specific combining ability (SCA) for yield and the yield-related traits for identifying suitable parents and forming heterotic groups for pea- breeding programs. Seventy-six F1 hybrids derived from crosses between nineteen female lines and four male testers were evaluated during two seasons. Estimates of variance due to GCA and SCA effects and their relationship revealed predominantly additive effects for all traits. Parents with higher GCA values were "ZAV20" (female parent) and "ZAV23" (male parent).The cross "ZAV5 x ZAV23" showed the highest value for seed yield. Days to flowering and number of seeds per plot were the variables with the highest values for broad and narrow-sense heritability (0.93 and 0.65, respectively), indicating that these traits are highly heritable. The highest best parent heterosis for seed yield was observed in the "ZAV17 x DDR14" hybrid. Four heterotic groups were formed and validated by estimating the intra and inter group heterosis.Fil: Espósito, María Andrea. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Gatti, Ileana. Universidad Nacional de Rosario; ArgentinaFil: Cravero, Vanina Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Lopez Anido, Fernando Sebastian. Universidad Nacional de Rosario; ArgentinaFil: Cointry Peix, Enrique Luis. Universidad Nacional de Rosario; Argentin

Jurisdicción nacional, su prórroga en el marco del poder de policía

El análisis de esta temática es interesante abordarlo con el propósito de generar un espacio de análisis y reflexión sobre el mismo, para cuando el hoy estudiante realice su actividad profesional y se le planteen cuestiones de ejercicio profesional en diferentes ámbitos del país. Es necesario contextualizar esta problemática para cuando ésta deba ser ejercida por los estudiantes en formación, para avanzar sobre la realidad que tengan como circunstancia de su ejercicio y poder actuar en consecuencia. El fin es que se tome conciencia sobre las consecuencias que acarrea el tema de la jurisdicción en el ejercicio profesional, al tiempo de favorecer la reflexión y el análisis sobre distintos aspectos del mundo jurídico, para que puedan desarrollar criterios y canalizar acciones, porque más allá de que estemos formando profesionales ingenieros, estos deben tener, conocimiento del derecho, que es el que presupone la existencia de una vida en sociedad, de convivencia. Debe darse una discusión compleja y seria de cuando la jurisdicción nacional debe ser aplicable y no como simple escudo en desmedro de los intereses locales, que fortalecen la república federal tal cual fue concebida por los constituyentes. Darle una acabada noción a un estudiante de este tema, lleva como consecuencia entender los conceptos fundamentales de nuestra Constitución Nacional, y hace que no solo proyectemos buenos profesionales, sino lo más importante, mejores ciudadanos que sepan llevar adelante su actividad profesional adecuada a las circunstancias que se le presenten.Facultad de Ingenierí

Use of morphological, biochemical and SRAP molecular markers to differentiate varieties of Cynara cardunculus L. (Asteraceae)

Dentro del complejo primario de Cynara cardunculus L. se encuentran diversas variedades botánicas: var. scolymus (alcaucil), var. altilis (cardo cultivado) y var. sylvestris (cardo silvestre). A lo largo de la historia del mejoramiento, la caracterización de los materiales ha evolucionado desde el uso de caracteres morfológicos hasta los modernos análisis moleculares, pasando por los marcadores bioquímicos. El objetivo del presente trabajo fue comparar la utilidad de los marcadores morfológicos, bioquímicos y moleculares para la caracterización de materiales pertenecientes a tres variedades botánicas de Cynara cardunculus. Tres cultivares de la var. scolymus, dos de la var. altilis y dos de la var. sylvestris fueron caracterizadas por variables morfovegetativas, proteínas de reserva y por marcadores moleculares a través de la técnica SRAP. Estas metodologías permitieron discriminar dos grupos: uno incluyendo las variedades de cardo cultivado y silvestre, y el otro, las variedades del alcaucil. Los datos moleculares y morfológicos permitieron además diferenciar los cultivares evaluados de la var. scolymus. Se concluye que los marcadores analizados son útiles para la caracterización intravarietal e intervarietal en programas de mejoramiento.In the Cynara cardunculus L. primary complex we can find a globe artichoke: Cynara cardunculus var. scolymus and other botanical varieties such as C. cardunculus var. altilis (cultivated cardoon) and C. cardunculus var. sylvestris (wild artichoke). Traditionally, they varieties were grouped according to morphological and biochemical traits and more recently, based on molecular markers. The aim of the present paper was to compare the use of morphological, biochemical and molecular markers to distinguish botanical varieties of Cynara cardunculus. Three accessions of var. scolymus, two accessions of var. altilis and two accessions of var. sylvestris were used. Different morphological variables, electrophoresis seed protein patterns by SDS-PAGE and SRAP markers were evaluated. The three kinds of markers grouped all materials in two clusters: one of them included the globe artichoke and the other the cardoons. SDS-PAGE is a valid technique for botanical varieties identification but the morphological and molecular data were more effective at discriminating botanical varieties and accessions within the scolymus group.Fil: Espósito, Andrea. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Martin, Eugenia. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Cravero, Vanina P.. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Genética y Mejoramiento Vegetal.Fil: Cointry, Enrique L.. Consejo Nacional de Investigaciones Científicas y Técnica

Processing, characterization and in vivo performance of the bioresorbable PLDLA-co-TMC scaffold

Orientador: Eliana Aparecida de Rezende DuekTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecânicaResumo: Estruturas tridimensionais têm sido obtidas por diversas técnicas e representam um importante enfoque no desenvolvimento de suportes porosos para a engenharia tecidual. O objetivo deste trabalho foi desenvolver e caracterizar arcabouços tridimensionais porosos de poli(L-co-D,L ácido lático-co-trimetileno carbonato), PLDLA-co-TMC, obtidos pela técnica de deposição de fibras 3D. Arcabouços do terpolímero PLDLA-co-TMC, nas proporções 70:30 e 50:50, foram obtidos e caracterizados por microscopia eletrônica de varredura, cromatografia de permeação em gel, calorimetria exploratória diferencial, análise termogravimétrica, ensaio mecânico de compressão e estudo de degradação in vitro, os quais evidenciaram suas características amorfas, geometria cilíndrica e poros interconectados. O estudo de degradação in vitro, apresentou expressiva perda das propriedades mecânicas compatíveis com queda na massa molar, acompanhada de alterações na morfologia. Avaliou-se a histocompatibilidade da associação de células-tronco mesenquimais provenientes da medula óssea de coelhos e arcabouços de PLDLA-co-TMC (70:30), obtidos pelo método de evaporação de solvente com adição de sacarose (50%), na regeneração do menisco. Nove coelhos Nova Zelândia foram submetidos a meniscectomia medial total, obtendo-se três tratamentos: implante do arcabouço de PLDLA-co-TMC com pré-cultivo celular, implante de arcabouço de PLDLA-co-TMC puro (sem células) e controle negativo (defeito sem implante). Após 24 semanas, os resultados evidenciaram a presença de fibrocartilagem nos animais tratados com arcabouço polimérico. Contudo, a regeneração obtida com arcabouços de PLDLA-co-TMC pré-cultivados com células-tronco mesenquimais apresentou-se semelhante ao tecido fibrocartilaginoso maduro do menisco normal, tanto macroscopicamente quanto histologicamente. Este estudo demonstrou a eficácia do arcabouço de PLDLA-co-TMC (70:30) na regeneração fibrocartilaginosa e o potencial do pré-cultivo de células mesenquimais na engenharia tecidual, sem o uso de fatores de crescimento. Conclui-se que os polímeros biorreabsorvíveis representam uma alternativa promissora para a regeneração tecidualAbstract: Three-dimensional structures have been obtained by various techniques and are an important focus in the development of porous scaffolds for tissue engineering. The aim of this study was to develop and characterize three-dimensional porous scaffolds of poly (L-co-D, L lactide-co-trimethylene carbonate), PLDLA-co-TMC, obtained by 3D fiber deposition technique. The PLDLA-co-TMC terpolymer scaffolds, 70:30 and 50:50, were obtained and characterized by scanning electron microscopy, gel permeation chromatography, differential scanning calorimetry, thermal gravimetric analysis, compression mechanical testing and study on in-vitro degradation, which exhibited its amorphous characteristics, cylindrical geometry and interconnected pores. The in-vitro degradation study showed significant loss of mechanical properties compatible with a decrease in molar mass, accompanied by changes in morphology. The histocompatibility association of mesenchymal stem cells from rabbits bone marrow, and PLDLA-co-TMC (70:30) scaffolds, obtained by casting with sucrose (50%), was evaluated in the meniscus regeneration, proving the potential of cell culture at in vivo tissue regeneration. Nine New Zealand rabbits underwent total medial meniscectomy, yielding three treatments: implantation of the seeded PLDLA-co-TMC scaffold, implantation of the unseeded PLDLA-co-TMC and negative control (defect without any implant). After 24 weeks, the results revealed the presence of fibrocartilage in the animals treated with polymer. However, the regeneration obtained with the seeded PLDLA-co-TMC scaffolds with mesenchymal stem cells had become intimal to mature fibrocartilaginous tissue of normal meniscus both macroscopically and histologically. This study demonstrated the effectiveness of the PLDLA-co-TMC (70:30) scaffold in meniscus regeneration and the potential of mesenchymal stem cells in tissue engineering, without the use of growth factors. It is concluded that bioresorbable polymers represent a promising alternative for tissue regenerationDoutoradoMateriais e Processos de FabricaçãoDoutora em Engenharia Mecânic

Evaluation of a lentil collection (Lens culinaris Medik) using morphological traits and digital phenotyping

The objective of this work was to evaluate 81 lentil cultivars using morphological traits and seed characteristics using digital phenotyping. Caliber (C) and the color traits luminosity (L), color coordinates a and b, and color index (CI) were measured and analyzed with appropriate software; also yield (Y), plant height (PH) and days to flowering (DF) were measured. Highly significant differences between cultivars were present for all traits and high heritability in broad sense heritability (H2B) for C (97%), CI (94%), a (93%) and L and b (83%) were found, indicating high genetic variability for these traits. Digital phenotyping showed to be a powerful tool for germplasm characterization along with field evaluation of agronomical traits. Principal Component Analysis and Cluster Analysis allows de identification of differentiated groups of cultivars with similar characteristics, leading to a more efficient use of the germplasm available as commercial cultivars or as parents in a breeding program. Among these groups, group 1 had 32 cultivars with highest C and group 2 had 21 cultivars with higher Y. Highlights Digital phenotyping showed to be a powerful tool for germplasm characterization along with field evaluation of agronomical traits. Principal Component Analysis and Cluster Analysis allows the identification of differentiated groups of cultivars with similar characteristics. Cultivar groups with similar characteristics allow more efficient use of germplasm.The objective of this work was to evaluate 81 lentil cultivars using morphological traits and seed characteristics using digital phenotyping. Caliber (C) and the color traits luminosity (L), color coordinates a and b, and color index (CI) were measured and analyzed with appropriate software; also yield (Y), plant height (PH) and days to flowering (DF) were measured. Highly significant differences between cultivars were present for all traits and high heritability in broad sense heritability (H2B) for C (97%), CI (94%), a (93%) and L and b (83%) were found, indicating high genetic variability for these traits. Digital phenotyping showed to be a powerful tool for germplasm characterization along with field evaluation of agronomical traits. Principal Component Analysis and Cluster Analysis allows de identification of differentiated groups of cultivars with similar characteristics, leading to a more efficient use of the germplasm available as commercial cultivars or as parents in a breeding program. Among these groups, group 1 had 32 cultivars with highest C and group 2 had 21 cultivars with higher Y. Highlights Digital phenotyping showed to be a powerful tool for germplasm characterization along with field evaluation of agronomical traits. Principal Component Analysis and Cluster Analysis allows the identification of differentiated groups of cultivars with similar characteristics. Cultivar groups with similar characteristics allow more efficient use of germplasm

In vitro plant regeneration from cotyledonary nodes of recombinant inbred lines of lentil

An efficient and reproducible in vitro regeneration protocol for lentil was developed. For shoot regeneration, cotyledonary node explants of ten elite genotypes were cultured in an inverted orientation on different shoot regeneration media that consisted of Murashige and Skoog (MS) medium supplemented with 1mgL -1 6-benzylaminopurine (BAP) (M1), 1mgL -1 BAP+0.45mgL -1 indole-3-acetic acid (IAA) (M2), and 2mgL -1 BAP (M3). High percentages of shoot regeneration ranging from 80 to 100% on M1 and M3 media and from 50 to 100% on M2 medium were induced. M1 was the most efficient shoot regeneration medium for most genotypes tested. For rooting, in vitro and in vitro-in vivo methods were used. Low and variable rooting percentages ranging from 0 to 45% were recorded with in vitro-in vivo method. Efficiency of rooting on in vitro medium varied depending on the medium in which shoots had been previously regenerated and the genotype tested. When M1 medium was used, high rooting percentages (over 40%) for most genotypes except for microsperma genotypes were found. When the 10 genotypes were screened for good regeneration performance using M1 medium, 2 main clusters and 3 subgroups within one of the clusters were formed based on similarities respect of the number of regenerated shoots per explant and rooting percentages. Subgroup 1 composed by A1146 genotype produced the highest number of shoots per explant (6.17 shoots) and a high rooting percentage (60%) so was selected for further transformation and use as a potential commercial variety.Fil: Bermejo, Carolina Julieta. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Departamento de Producción Vegetal. Cátedra de Mejoramiento Vegetal y Producción de Semillas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Espósito, María Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cravero, Vanina Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: López Anido, Fernando. Universidad Nacional de Rosario; ArgentinaFil: Cointry Peix, Enrique Luis. Universidad Nacional de Rosario; Argentin

A rapid method to increase the number of F1 plants in pea (Pisum sativum) breeding programs.

In breeding programs, a large number of F2 individuals are required to perform the selection process properly, but often few such plants are available. In order to obtain more F2 seeds, it is necessary to multiply the F1 plants. We developed a rapid, efficient and reproducible protocol for in vitro shoot regeneration and rooting of seeds using 6-benzylaminopurine. To optimize shoot regeneration, basic medium contained Murashige and Skoog (MS) salts with or without B5 Gamborg vitamins and different concentrations of 6-benzylaminopurine (25, 50 and 75 μM) using five genotypes. We found that modified MS (B5 vitamins + 25 μM 6-benzylaminopurine) is suitable for in vitro shoot regeneration of pea. Thirty-eight hybrid combinations were transferred onto selected medium to produce shoots that were used for root induction on MS medium supplemented with α-naphthalene-acetic acid. Elongated shoots were developed from all hybrid genotypes. This procedure can be used in pea breeding programs and will allow working with a large number of plants even when the F1 plants produce few seeds.Fil: Espósito, María Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Departamento de Producción Vegetal. Cátedra de Mejoramiento Vegetal y Producción de Semillas; ArgentinaFil: Almiron, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Gatti, I.. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Departamento de Producción Vegetal. Cátedra de Mejoramiento Vegetal y Producción de Semillas; ArgentinaFil: Cravero, Vanina Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Lopez Anido, Fernando Sebastian. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Departamento de Producción Vegetal. Cátedra de Mejoramiento Vegetal y Producción de Semillas; ArgentinaFil: Cointry Peix, Enrique Luis. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Departamento de Producción Vegetal. Cátedra de Mejoramiento Vegetal y Producción de Semillas; Argentin

Stem cells from human dental pulp and apical papilla : morphological and synchrotron radiation analysis

Dental Mesenchymal stem cells has prompted great for cell-based therapeutics. But no one knows for sure what the true potential of these cells, since most of the studies were done in isolation, using as source, different donors or different cell processi

Mutations in Thyroid Hormone Beta Receptor Gene Identified in Children with Clinical Resistance to Thyroid Hormones

Introduction: Patients with resistance to thyroid hormones(RTH) show different clinical features. Several mutations have been identified in them.Objective:To describe patients followed up since 2006 with RTH suspicion evaluated for mutations in thyroid hormone beta receptor(THRß)gene.Methods:Children were followed up in our Endocrinology Department.Patient 1:10-yr-old boy with elevated T3, T4 and free T4, normal TSH in routine thyroid testing requested for overweight. Patient 2:0.7-yr- old boy with Down syndrome and elevated T3, T4 and free T4, normal TSH.Patient 3:Boy with abnormal results on neonatal screening, with elevated T3, T4, free T4 and TSH.Patient 4:4.7?yr-old girl with elevated T3, T4 and free T4, normal TSH in routine thyroid testing requested for low weight.Patient 5: 1-yr- old boy with elevated T3, T4 and free T4, normal TSH in routine thyroid testing requested for low weight.Patient 6:Boy with congenital hypothyroidism diagnosed by screening with elevated T3, T4, free T4 and TSH.Clinical manifestations:Patients 1, 4 and 5 showed palpitations, tachycardia.Familial antecedents: Patient 3 has two brothers with similar RTH profile. Patient 4 had a sister who died at 3 months of age and mother with confirmed RTH. Patient 6 had an aunt with RTH profile.Thyroid ultrasound. All patients had normal gland size except patient 6 who had an hypoplastic gland. Patient 4 showed goiter at follow up.Treatment:Patient 1 received metimazol; patients 1,4 and 5 beta blockers and patient 6 levothyroxine.Molecular biology analysis: genomic DNA was isolated from blood cells and the exons 7-10 of the THRß gene, including the flanking intronic regions were amplified by PCR. DNA sequences from each amplified fragment were performed with the Taq polymerase-based chain terminator method and using the specific forward and reverse THRß primers. Results.Direct sequence analysis revealed a novel missense mutation in exon 10 in patient 3, c.1329G>T transvertion that results in a p.K443N substitution and two known missense mutations: c.1357C>A, p.P453T (Patient 1)in exon 10 and c.949G>A, p.A317T (Patient 4) in exon 9.Conclusion:THRß gene mutations were found in half of the patients with RTH, including a new mutation.Although goiter is a common feature in RTH, only one patient presented it.These findings support the importance of searching THRßgene mutations in suspected individuals to achieve an adequate follow-up and treatment in patients with RHT.Fil: Gonzáles, Viviana. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Balbi, Viviana A.. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Morin, Analía. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Reinoso, Andrea. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Vitale, Laura. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Ricci, Jaime. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Espósito, Mariela. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Martín, Rodrigo. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Tournier, Andrea L.. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de La Plata; ArgentinaFil: Adrover, Ezequiela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; ArgentinaFil: Molina, Maricel Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; ArgentinaFil: Targovnik, Hector Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; ArgentinaFil: Rivolta, Carina Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología y Biotecnología; ArgentinaXXVIII Congreso Latinoamericano de Endocrinología PediátricaFlorianópolisBrasilSociedad Latinoamericana de Endocrinología Pediátric

Population features of the western Atlantic hermit crab Pagurus exilis (Anomura, Paguridae) in Brazil

The population structure of the hermit crab Pagurus exilis has been studied in Caraguatatuba region (23o 34’ and 23o 51’S; 45o 10’ and 45o 26’W), northern coast of São Paulo, Brazil for the first time in terms of total and seasonal size frequency distribution, sex ratio and reproductive season. The animals were monthly collected during two consecutive years (2001/2003) with a fishery boat equipped with “double rig” nets. At the laboratory, the specimens were identified, counted, weighed and measured. A total of 1,963 animals were captured, which 1,372 were males and 591 females (311 non ovigerous females and 280 ovigerous ones). The size of animal (Cephalothoracic Shield Length) ranged from 2.4 to 8.3 mm, and males were significantly larger, showing a sexual dimorphism. The size frequency distribution showed an unimodal pattern with non-normal distribution. The total sex ratio was significantly different from the expected, biased to males (1:0.43). Most ovigerous females presented eggs in initial developmental stage, with a few percentages in intermediary and final stages. The profile found an abundant population with a continuous reproduction (ovigerous females occurring along the year).Aspectos populacionais do ermitão do Atlântico oeste Pagurus exilis (Anomura, Paguridae) no Brasil A estrutura populacional do ermitão Pagurus exilis foi estudada, na região de Caraguatatuba (23o 34’ e 23o 51’S; 45o 10’ e 45o 26’O), litoral norte de São Paulo, Brasil, pela primeira vez quanto à distribuição de freqüência de tamanho total e sazonal, razão sexual e período reprodutivo. Os animais foram coletados mensalmente durante dois anos consecutivos (2001/2003) com um barco de pesca equipado com redes “double rig”. No laboratório, os espécimes foram identificados, contados, pesados e medidos. Um total de 1963 animais foi capturado, sendo 1372 machos e 591 fêmeas (311 fêmeas não ovígeras e 280 fêmeas ovígeras). O tamanho dos animais (comprimento do escudo cefalotorácico) variou de 2,4 a 8,3 mm, e os machos foram significativamente maiores, demonstrando um dimorfismo sexual. A distribuição de freqüência de tamanho demonstrou um padrão unimodal com distribuição não-normal. A razão sexual total foi significativamente diferente do esperado, em favor dos machos (1:0,43). A maioria das fêmeas ovígeras apresentou ovos no estágio inicial de desenvolvimento, com uma pequena porcentagem em estágios intermediário e final. O perfil encontrado apresenta uma população abundante com reprodução continua (fêmeas ovígeras ocorrendo ao longo do ano)