Made available in DSpace on 2014-12-17T14:02:02Z (GMT). No. of bitstreams: 1 LilianeLGS.pdf: 3221431 bytes, checksum: 94de7bf42be19a1c9a513aa1e36efe19 (MD5) Previous issue date: 2006-07-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The reproductive ecology of fish plays a key role both for rational exploitation methods and for protective measures of natural stocks. The purpose of this study was to analyze the reproductive aspects of the damsel-fish, Stegastes fuscus, during October 2004 to September 2005, in the coastal rocky reefs of B?zios Beach, N?sia Floresta, RN. Fish were captured using hooks and hand nets, during low tide. Reproduction was determined using sexual ratio, mean length of first maturation (L50), absolute fecundity and macroscopic characteristics of gonads. The following parameters were related to gonadosomatic index (GSI): condition factor (CF), hepatosomatic index (HSI), rain fall and temperature. In relation to sex distribution, it was observed that 78% were females and 22% were males. The L50 was 6.2 cm for females and 7.0 for males. Average fecundity was 6832 oocytes. Results showed that S. fuscus had better body condition in the months prior to spawning, particularly during initial and intermediate stages of maturation. Five stages of gonadal maturation were identified through macroscopic analysis: immature, in maturation, mature, spent and resting. The HSI was inversely related to the GSI. This was possibly due to the reproductive cycle of this species which was associated to the dry period of this region. During this period, low rain fall and high temperatures provide an propitious reproductive condition for the study species / A ecologia reprodutiva dos peixes ? fundamental na racionaliza??o dos m?todos de explora??o e na prote??o dos estoques naturais. O presente estudo analisou aspectos relacionados ? reprodu??o do peixe-donzela, Stegastes fuscus, durante o per?odo de outubro de 2004 a setembro de 2005, nos arrecifes rochosos da praia de B?zios, N?sia Floresta, RN. Os peixes foram capturados durante a mar? baixa utilizando anz?is e rede de m?o. A reprodu??o foi verificada mediante a propor??o sexual, o comprimento m?dio da primeira matura??o, a fecundidade absoluta e os caracteres macrosc?picos gonadais. Os seguintes par?metros foram relacionados ao ?ndice gonadossom?tico (IGS): fator de condi??o (FC), ?ndice hepatossom?tico (IHS), pluviosidade e temperatura. Em rela??o ? distribui??o por sexo de S. fuscus, 78% foram f?meas e 22% foram machos. O L50 foi 6,2 cm para as f?meas e 7,0 cm para os machos. A m?dia da fecundidade absoluta foi 6832 ov?citos. S. fuscus apresentou melhores condi??es corporais nos meses que antecederam a desova, principalmente nos est?dios inicial e intermedi?rio de matura??o gonadal. A partir de an?lises macrosc?picas das g?nadas, foram identificados cinco est?dios de matura??o gonadal: imaturo, em matura??o, matura??o, esgotado e repouso. O IHS demonstrou tend?ncia inversa ao IGS. Este fato pode estar relacionado ao ciclo reprodutivo da esp?cie, que foi relacionado ao per?odo de seca na regi?o. Neste per?odo, as menores precipita??es e as temperaturas elevadas conferem condi??es reprodutivas favor?veis para a esp?cie em estudo

Made available in DSpace on 2014-12-17T14:10:20Z (GMT). No. of bitstreams: 1 MonicaRO_01_40.pdf: 3996248 bytes, checksum: 971458d8393c9eb3edc1f0eaba559683 (MD5) Previous issue date: 2010-06-08 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season. / O peixe marinho tainha, Mugil curema Valenciennes, 1836 (Osteichthyes:Mugilidae) apresenta ampla distribui??o geogr?fica, sendo comum na costa brasileira e de grande import?ncia para a pesca artesanal. Este trabalho teve como objetivo determinar a biologia reprodutiva de M. curema nas ?guas costeiras do Estado de Rio Grande do Norte. Foram capturados mensalmente exemplares de peixes durante o per?odo de agosto de 2008 a julho de 2009. Os exemplares foram numerados, pesados, medidos, dissecados e suas g?nadas foram retiradas, pesadas e identificadas quanto ao sexo e quanto o desenvolvimento gonadal. A rela??o peso-comprimento foi determinada para machos e f?meas. A propor??o sexual, o tamanho da primeira matura??o gonadal e o ?ndice gonadossom?tico (IGS) foram calculados e o desenvolvimento ovariano foi investigado usando t?cnicas macrosc?picas e histol?gicas. Foram determinados a fecundidade, o tipo de desova e o per?odo reprodutivo da esp?cie. Foi capturado um totalde 366 exemplares (186 machos e 180 f?meas). A propor??o sexual foi de 1:1 e as f?meas foram mais pesadas que os machos. O valor estimado para o coeficiente angular para ambos os sexos sugere que ? a esp?cie apresenta crescimento isom?trico. O tamanho em que 50% da popula??o iniciaram o processo de matura??o gonadal foi de 26 cm de comprimento total para sexo agrupado. As caracter?sticas macrosc?picas dos ov?rios revelaram quatro est?dios de desenvolvimento: imaturo, em matura??o, maduro e esvaziado, enquanto que as caracter?sticas microsc?picas revelaram cinco est?dios de desenvolvimento: imaturo, em matura??o inicial, em matura??o final, maduro e esvaziado. O desenvolvimento dos ov?citos indicou cinco fases: Cromatina-nucl?olo (fase I), perinucleolar inicial (fase II), perinuclear final (Fase II), forma??o ves?cula vitel?nica (fase III), vitelog?nico (fase IV) e vitelog?nese completa (fase V). A esp?cie apresenta um per?odo reprodutivo prolongado, com dois picos coincidindo com o per?ododa chuva