scholarly journals Can weight/length relationship predict size at first maturity? A case study with two species of Characidae

2010 ◽  
Vol 8 (4) ◽  
pp. 835-840 ◽  
Author(s):  
Nelson F. Fontoura ◽  
Anamélia S. Jesus ◽  
Gabriel G. Larre ◽  
Juliana R. Porto

A weight/length relationship was established for Astyanax jacuhiensis (Cope, 1894) (n = 370) and Cheirodon ibicuhiensis Eigenmann, 1915 (n = 701), from samples taken monthly in Fortaleza Lagoon, Cidreira, Rio Grande do Sul, from December 1991 through November 1992. Both species showed a polyphasic allometric growth pattern, each stanza described by an independent power equation controlled by a switch function. For C. ibicuhiensis, this change in the growth pattern occurred at 2.948 cm standard length (SL), close to published sizes for the attainment of female maturity. The change in the growth pattern of A. jacuhiensis (SL = 3.481 cm) was below the predicted size at first maturity, and merits further investigation. Although not conclusive, our data suggest that a complex growth pattern is frequent in nature, and perhaps is not usually identified because trends are obscured by natural variability. Despite the increased complexity resulting from the application of a more-complex equation, the identification of a change in the growth pattern could indicate important aspects of fish biology, including the attainment of sexual maturity.

2016 ◽  
Vol 106 (0) ◽  
Author(s):  
José R. S. Barradas ◽  
Isabel S. Lermen ◽  
Gabriel G. Larré ◽  
Thaís P. Martins ◽  
Nelson F. Fontoura

ABSTRACT A weight-length relationship was established for Corydoras paleatus (Jenyns, 1842) (Siluriformes, Callichthyidae) (n=596) from samples taken in November-December 2009 and March-April 2010, in Pinguela Lagoon (29°46'57"S; 50°11'16"W), Rio Grande do Sul, Brazil. The species showed a polyphasic allometric growth pattern, each stanza described by an independent power equation controlled by a switch function: W = a1Lb1 ∙ (1 + eRsc ∙ (L-SCP))-1 + a2Lb2 ∙ [1 - (1 + eRsc ∙ (L-SCP))-1] ; where W is the expected weight for a specific length L, a1 and a2 are the proportionality coefficients for stanzas 1 and 2, b1 and b2 are the allometric coefficients for stanzas 1 and 2, Rsc is the stanza changing rate for the switch function and SCP is the stanza changing point for the switch function. The stanza changing point was estimated as 5.28 cm, corresponding with the length at first maturity for this species Lmat (5.29 cm). Our data suggest that a complex growth pattern can be in nature, and perhaps not often identified because trends are obscured by natural variability.


2016 ◽  
Vol 14 (4) ◽  
Author(s):  
Tiago Magalhães da Silva Freitas ◽  
◽  
Vitor Hudson da Consolação Almeida ◽  
Luciano Fogaça de Assis Montag ◽  
Nelson Ferreira Fontoura ◽  
...  

ABSTRACT Relationship between length and weight (LWR) is used to describe aspects concerning the life cycle of fish, but does not considers possible changes during the lifetime mainly due to the sexual maturation. Thus, this study aims to identify the size at first maturity of Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) and infer if the reproductive engagement could change growth pattern, concerning the LWR. Estimates of the size at first maturity (L 50 ) were made by visual identification of gonadal development and through the gonadosomatic index (G SI ). L 50 was estimated as 12.5 cm for males and 13.0 cm for females when applied visual identification of gonads development. L 50 estimates increased to 13.05 cm for males and 13.7 cm for females when estimated from G SI values. LWR was adjusted by using a regular power function and through the polyphasic growth model, with proportionality and allometric coefficients changing in a two phases. The results indicate differences in the growth pattern concerning males and females, as well as polyphasic growth. The change in the growth pattern of the polyphasic LWR was estimated at 11.42 cm for males and 12.53 cm for females, suggesting that changes in the growth pattern can sign-out the attainment maturity in this catfish.


2015 ◽  
Vol 7 (1) ◽  
pp. 79-87
Author(s):  
María del Carmen Alejo-Plata ◽  
José Luis Gómez-Márquez ◽  
Jorge Eduardo Herrera-Galindo

There is practically no information on the biology of Lolliguncula (Loliolopsis) diomedeae. We analyzed specimens caught in four shrimp fishing trips in the Gulf of Tehuantepec in 1999-2001, 2004 and 2006.Sexual maturity and gonadosomatic index (GSI) were used as indicators of reproductive activity. A total of 1 200 individuals were captured, 89% female. Females ranged from 35 to 97mm in mantle length (LDM),with a mode at 80mm and weights 2 to 30,9g; males 20,7 to 65mm LDM with a mode at 35-40mm and weights from 0,4 to 12g. Differences in the LDM and the PT between males and females were significant (KS, p<0,05). The sex ratio was 8:1 H:M (p <0,05). The weight-length relationship type is potential for both sexes, with a negative allometric growth.83% of mature females had high IGS values, in contrast to less than 20% of mature males. The size at first maturity (L50) indicates that males (42,7mm LDM) mature when shorter than females (74,5mm LDM). Maturity, IGS and oceanographic features of the Gulf of Tehuantepec indicate that L. diomedeae spawn there.


Author(s):  
Rosana Carina Flores Cardoso ◽  
Maria Lucia Negreiros-Fransozo

The allometric growth of Uca leptodactyla from two distinct subtropical estuaries on the Brazilian coast was evaluated concerning its growth pattern and size at onset of sexual maturity. Females attained maturity at similar sizes in both sites (4·1 mm of carapace length in Indaiá and 4·2 mm in Ubatumirim), while males differed slightly. They reached the size at sexual maturity of 5·3 mm of carapace length in Indaiá and 4·6 mm in Ubatumirim. Growth pattern is usually similar among crabs from distinct sites while size at sexual maturity is frequently different. However, in the case of U. leptodactyla it did not occur, probably due to the strong habitat similarity and intrinsic features of this species.


2020 ◽  
Vol 17 (1) ◽  
pp. 417-429
Author(s):  
Claudia Simone Cordeiro Pelissoli ◽  
Aline Silva De Bona ◽  
Luciano Andreatta Carvalho da Costa

This case study deals with the conceptof Interpersonal Relationship, foreseen in the Pedagogical Projects of the course -PPC's Technologist in Management Processes of Campi of the Federal Institute of Education, Science and Technology of Rio Grande do Sul. In addition to being described in PPCs, in profile of the course and the graduate, Interpersonal Relationship is also an extremely valued skill in the world of work. The main objective is to analyze how the concept of Interpersonal Relationship is worked through the courses in Technology inManagement Processes. Paulo Freire's theory and his considerations on critical awareness, dialogicity and humanization served as the basis for this study. The data were generated through interviews with four course coordinators (Porto Alegre, Farroupilha,Osório and Caxias do Sul), in order to analyze their understanding of the concept of Interpersonal Relationship and their insertion throughout the course. The results indicate that the concept of Interpersonal Relationship has a wide approach in some disciplines formalized in the Pedagogical Course Project, but also occurs informally in other disciplines, according to the teachers' pedagogical profile and practices. The work highlights the importance of developing and updating the Pedagogical Course Project, as it is the expression of the course. And it also stresses the relevance of addressing the concept of Interpersonal Relationship in the higher course of Technology in Management Processes, aiming at a humanized formation, extremely valued in the professional sphere.


Author(s):  
Carlos Ventura Fonseca ◽  
Fabiane De Andrade Ramos

Resumo: A proposta deste artigo é descrever uma investigação qualitativa, caracterizada como estudo de casos múltiplos, que envolveu sete professores da área de Ciências da Natureza que atuam em uma escola pública estadual do Rio Grande do Sul. Objetivou-se que esses movimentos de pesquisa fornecessem elementos considerados indicadores específicos para a construção de ações futuras de formação continuada. Tendo-se como referência a produção acadêmica contemporânea da área educacional e as diretrizes nacionais para as licenciaturas, foi construído e aplicado um questionário com questões abertas e fechadas, utilizando-se análise de conteúdo como técnica interpretativa das respostas descritivas. As análises efetuadas revelaram aproximações e afastamentos entre as visões dos sujeitos sobre as virtudes e fraquezas pertencentes aos respectivos cursos de formação inicial, bem como especificidades das condições de trabalho e do perfil profissional de cada docente que apresenta potencial para nortear, ainda que de modo parcial, o planejamento desejado.Palavras-chave: Formação docente. Trabalho docente. Educação em Ciências. INITIAL EDUCATION AND WORKING CONDITIONS OF NATURAL SCIENCES TEACHERS: STUDY OF ELEMENTS RELATED TO CONTINUED EDUCATION  Abstract: The purpose of this article is to describe a qualitative investigation characterized as a multiple case study involving seven professors from the Natural Sciences area who work in a state public school in Rio Grande do Sul, Brazil. These research movements were designed to provide elements regarded as specific indicators in which to base the construction of future actions for continued education. Referring to the contemporary academic production within educational area and national guidelines for undergraduate courses, a questionnaire with open and closed questions was designed and applied using content analysis as an interpretive technique of descriptive answers. Analyses carried out revealed approximations and withdrawals between the subjects' views on the virtues and weaknesses belonging to respective initial education courses, as well as specificities of working conditions and  professional profile of each teacher who has the potential to guide albeit in partially the desired planning.Keywords: Teacher education. Teaching Work. Science Education.


2017 ◽  
Vol 3 (1) ◽  
pp. 85
Author(s):  
Pauline Vielmo Miranda ◽  
Aline Bairros Soares ◽  
Paula Rochele Silveira Becher ◽  
Ascísio dos Reis Pereira
Keyword(s):  

Frente às mudanças nas configurações do trabalho e da educação, que ocorreram ao longo do século XX e perduram na atualidade, busca-se através desse artigo debater algumas questões que envolvem o PROEJA. Através de revisão bibliográfica e documental e da realização de entrevistas semiestruturadas com docentes atuantes no Programa em um colégio da região central do Rio Grande do Sul, buscou-se compreender algumas das possibilidades e desafios que permeiam o Programa. A partir da análise qualitativa destas fontes, foram selecionados dois pontos de análise: os processos de evasão e juvenilização para o PROEJA. Verifica-se que os desafios são muitos, mas, em contraponto, destacam-se os pontos positivos que remetem à possibilidade da formação ampliada, a partir da integração entre vários saberes, visando a superação da unilateralidade voltada estritamente para as necessidades do mercado, novas oportunidades de emprego e a possibilidade do prosseguimento dos estudos, além da função social inclusiva que os cursos atendem.


2020 ◽  
Vol 27 (3) ◽  
pp. 249
Author(s):  
Rosana Souza de Vargas ◽  
Fabiana Diniz Kurtz

O objetivo do presente trabalho é investigar e analisar os discursos estabelecidos de futuros professores de um curso de licenciatura em Letras - Português e Inglês, de uma universidade comunitária, componente do COMUNG-RS, localizada no Rio Grande do Sul, buscando entender como ocorre a formação dos futuros docentes em língua inglesa e os processos de ensino-aprendizagem que a envolvem, com ênfase para a articulação pedagógica com as tecnologias de informação e comunicação (TIC) de modo integrado. É um estudo de caso, enquanto método de cunho qualitativo, empregando a análise textual discursiva como método de análise de dados. Dessa forma, como resultado, os discursos revelam que a formação dos futuros professores envolvidos engloba a discussão acerca das TIC, mas não de forma satisfatória, revelando em suas práticas, que os futuros profissionais tendem a uma perspectiva técnica de ensino sobre as TIC. O meio pelo qual tal viés possa ser abandonado, é que a formação de professores considere um ensino transversal a partir das TIC, não apenas em disciplinas isoladas e ainda que seja realizado por meio de todos os profissionais envolvidos.Palavras-chave: Formação de professores. Ensino de língua inglesa como língua estrangeira. Tecnologias de informação e comunicação (TIC). Análise textual discursiva (ATD).INFORMATION AND COMMUNICATION TECHNOLOGIES: case study with future language teachers Abstract The aim of this paper is to investigate and analyze the established discourses of future teachers of a degree course in Letters - Portuguese and English, from a community university, component of COMUNG-RS, located in Rio Grande do Sul, seeking to understand how occours the formation of future teachers in English language and the teaching-learning processes that involve it, with emphasis on the pedagogical articulation with information and communication technologies (ICT) in an integrated way. It is a case study, as a qualitative method, using discursive textual analysis as a data analysis method. Thus, as a result, the speeches reveal that the formation of the future teachers involved encompasses the discussion about ICT, but not satisfactorily, revealing in their practices that future professionals tend to a technical perspective of teaching about ICT. The means by which such bias can be abandoned is for teacher education to consider cross-sectional education based on ICT, not only in isolated subjects and even though it is carried out by all the professionals involved.Keywords: Teacher training. Teaching English as a foreign language. Information and communication technologies (ICT). Discursive textual analysis (DTA). TECNOLOGÍAS DE LA INFORMACIÓN Y LA COMUNICACIÓN: un estudio de caso con futuros profesores de idiomasResumenEl objetivo de este trabajo es investigar y analizar los discursos de futuros profesores de un curso de grado en Letras - Portugués e Inglés, de una universidad comunitaria, componente de COMUNG-RS, ubicado en Rio Grande do Sul, buscando entender cómo formación de futuros docentes en lengua inglesa y los procesos de enseñanza-aprendizaje que lo involucran, con énfasis en la articulación pedagógica con las tecnologías de la información y la comunicación (TIC) de manera integrada. Es un estudio de caso, como método cualitativo, que utiliza el análisis textual discursivo como método de análisis de datos. Por lo tanto, como resultado, los discursos revelan que la formación de los futuros maestros involucrados abarca la discusión sobre las TIC, pero no de manera satisfactoria, revelando en sus prácticas que los futuros profesionales tienden a una perspectiva técnica de la enseñanza sobre las TIC. El medio por el cual se puede abandonar este sesgo es que la formación del profesorado considere la educación transversal basada en las TIC, no solo en asignaturas aisladas y aunque sea realizada por todos los profesionales involucrados.Palabras clave: Formación de profesores. Enseñanza de inglés como lengua extranjera. Tecnologías de la información y la comunicación (TIC). Análisis textual discursivo (ATD). 


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