Made available in DSpace on 2014-12-17T15:36:38Z (GMT). No. of bitstreams: 1 AndreaSA_TESE - Pag 1 a 116.pdf: 8811201 bytes, checksum: d0d8579460a5a3ff98a9e4d091cdaca3 (MD5) Previous issue date: 2012-07-03 / This study focuses on the fish fauna composition and reproductive strategies of four native fish species in relation to environmental variables of the Piranhas-Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. Fish and environmental data were collected monthly during the period September 2008 to February 2010, in the Marechal Dutra reservoir and River Acau? a tributary of Piranhas- Assu. The fish were measured, weighed and dissected, and the gonads were removed, weighed and examined macroscopically for identification and determination of gonad maturation stages. The results of this work generated seven articles. The first article is about the fish fauna composition of the Piranhas-Assu hydrographic basin, Rio Grande do Norte. The 602 fish samples captured were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families and 22 species, of which 17 are endemic to the Caatinga ecoregion. The order Characiformes was more representative followed by Perciformes, Siluriformes and Synbranchiformes. The second article is about the length-weight relationship and growth of seven native fish species Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis and Leporinus piau from a semiarid Brazilian reservoir. The third article is about the reproductive aspects of Crenicichla menezesi. Males were larger, heavier and with a slight predominance as compared to females. Four stages of gonadal development were characterized, being immature, maturing, mature and spent. The females reached sexual maturity earlier than males, with an average fecundity of 398 oocytes per batch. The spawning was partial with a long reproductive period. The fourth article deals with the reproductive strategy of Leporinus piau a neotropical freshwater fish in semi-arid region of Brazil. The population of L. piau (n = 211) showed a slight predominance of males (55%), with larger and heavier females. The males matured earlier than the females. This species presented total spawning, with an average fecundity of 55,000 mature oocytes. Rainfall and concentration of dissolved oxygen acted as influential factors during the spawning season. L. piau shows a seasonal reproductive strategy. The fifth article is related to the morphometric-meristic characteristics and reproductive aspects of freshwater sardine, Triportheus angulatus from River Acau? of the Caatinga biome. There was a predominance of larger females, reaching first maturation before males. There was total spawning during the rainy period of the region. The sixth article reports on the reproductive strategy of Psectrogaster rhomboides. The sex ratio was 1M: 1F, with negative allometric growth. Males reached sexual maturity earlier than females Females and males showed four stages of gonadal development and spawned during the rainy season. The fecundity was low and this species presented total spawning. The seventh article reports on the dynamics of territorial behavior of Crenicichla menezesi. Ten agonistic behaviors displayed by the males were observed: frontal and lateral threat, chasing, circular chasing, perpendicular, lateral and mouth attacks, escape, parallel positioning and stationary. The formation of four social groups was observed among males: without interaction; interaction with submission and escape; with frontal and lateral agonistic interactions. In social interactions between males and females, it was observed that the larger males interacted more among themselves and with the larger females. The large male established its territory and the two small males along with the small female were excluded from the other groups. These studies clarified the fish fauna composition and reproductive strategies of four native species Crenicichla menezesi, Leporinus piau, Triportheus angulatus and Psectrogaster rhomboides of the Piranhas- Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. / O presente estudo trata da composi??o ictiofaun?stica e das estrat?gias reprodutivas de quatro esp?cies nativas de peixes em rela??o ?s vari?veis ambientais da bacia hidrogr?fica do rio Piranhas-Assu no bioma Caatinga, Rio Grande do Norte, Brasil. As amostras dos peixes e os dados ambientais foram coletados mensalmente, durante o per?odo de setembro de 2008 a fevereiro de 2010. Os peixes foram medidos, pesados, dissecados e as g?nadas foram removidas, pesadas e examinadas para identifica??o do sexo e determina??o do est?dio de matura??o das g?nadas. Os resultados desse trabalho geraram sete artigos. O primeiro artigo ? sobre a composi??o ictiofaunistica em um trecho da bacia Piranhas-Assu, Rio Grande do Norte. Foram capturados 602 peixes, distribu?dos em quatro ordens (Characiformes, Perciformes, Siluriformes e Synbranchiformes), 11 fam?lias e 22 esp?cies, das quais 17 s?o end?micas da Caatinga. A ordem Characiformes foi mais representativa, seguida por Perciformes, Siluriformes e Synbranchiformes. O segundo artigo trata sobre a rela??o peso-comprimento e crescimento de sete esp?cies de peixes nativos Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis e Leporinus piau de um reservat?rio do semi?rido brasileiro. O terceiro artigo ? sobre os aspectos reprodutivos do jacund?, Crenicichla menezesi. Os machos foram maiores, mais pesados e com leve predomin?ncia com rela??o ?s f?meas. Foram caracterizados quatro est?dios de desenvolvimento gonadal, sendo: imaturo, em matura??o, maduro e esvaziado. As f?meas atingiram a primeira matura??o sexual antes que os machos, com fecundidade m?dia de 398 ov?citos por lote. A desova foi parcelada com um longo per?odo reprodutivo. O quarto artigo trata da estrat?gia reprodutiva de Leporinus piau um peixe de ?gua doce neotropical da regi?o semi?rida do Brasil. A popula??o amostrada de L. piau (n = 211) mostrou uma ligeira predomin?ncia de machos (55%), com f?meas maiores e mais pesadas. A primeira matura??o sexual dos machos ocorreu antes que as f?meas. Esta esp?cie apresentou desova total, com fecundidade m?dia de 55.000 ov?citos maduros. As chuvas e a concentra??o de oxig?nio dissolvido atuaram como fatores influentes durante a ?poca de desova. L. piau apresenta uma estrat?gia reprodutiva sazonal. O quinto artigo ? sobre caracter?sticas morfom?tricas-mer?sticas e aspectos reprodutivos da sardinha de ?gua doce, Triportheus angulatus do rio Acau? do bioma Caatinga. Houve uma predomin?ncia de f?meas maiores, atingindo a primeira matura??o gonadal antes que os machos. Houve desova total no per?odo de chuvas da regi?o. O sexto artigo relata a estrat?gia reprodutiva da branquinha, Psectrogaster rhomboides. Constatou-se uma propor??o sexual de 1:1, com tipo de crescimento alom?trico negativo. Os machos atingiram a maturidade sexual antes que as f?meas. As f?meas e os machos apresentaram quatro est?dios de desenvolvimento gonadal com o per?odo de desova no per?odo de chuva. A fecundidade foi baixa e a esp?cie apresentou desova total. O s?timo artigo relata a din?mica do comportamento territorial de Crenicichla menezesi. Foram observados dez comportamentos agon?sticos exibidos pelos machos, sendo amea?a frontal e lateral, persegui??o, persegui??o circular, ataque perpendicular, lateral e bucal, fuga, posicionamento paralelo e perman?ncia. Foi observada a forma??o de quatro grupos sociais entre os machos: sem intera??o, com intera??o de submiss?o e fuga, com intera??o agon?stica frontal e lateral. Nas intera??es sociais entre machos e f?meas foi observado que os machos maiores interagiram mais entre si e com as f?meas maiores. O macho maior estabeleceu seu territ?rio e os dois machos menores juntamente com a menor f?mea foram exclu?dos dos demais grupos. Estes trabalhos esclareceram sobre a composi??o ictiofaun?stica e estrat?gias reprodutivas de quatro esp?cies Crenicichla menezesi, Leporinus piau, Triportheus angulatus e Psectrogaster rhomboides nativos da bacia hidrogr?fica piranhas-assu do bioma Caatinga, RN, Brasil.