Made available in DSpace on 2014-12-17T15:36:33Z (GMT). No. of bitstreams: 1 JoseTAXL_Parte 1.pdf: 5097640 bytes, checksum: 87d585113062c0aafaeaea6c8b1525d6 (MD5) Previous issue date: 2008-07-04 / The present study investigated the reproductive dynamics and parasitism of four species of marine fishes: serra Spanish mackerel, Scomberomorus brasiliensis, Atlantic leatherjacks, Oligoplites saurus and O. palometa,, and Atlantic bumper, C. chrysurus, during the period of August, 2005 to July, 2007, in the coastal waters of Southwest Atlantic Ocean, Brazil. The collected fish samples were measured, weighed, dissected, the gonads were weighed and examined to separate the sex. The gonadosomatic index (GSI), fecundity, type of spawning, the breeding season, the macro and microscopic characterization of the gonads were determined. The ectoparasites from the branchial chambers and bucal cavity of the fish were collected, measured, weighed and identified. The sex ratio of the study fish species were approximately 1M:1F, however, there was a predominance of males of O. palometa (3M:2F). The GSI of fishes varied according to their reproductive cycle and the stage of gonadal maturation. The highest values of GSI and the spawning period coincided with the rainy period of the region. The females presented total spawning and the fecundity was positively correlated with the weight of the ovary and the body. Four stages of development of the gonads immature, maturing, mature and spent were identified macroscopically and histological analyses of ovaries revealed the different phases of oocyte development. Three species of isopod parasites were identified in the study fishes: Livoneca redmmanni, Rocinela signata and Cimothoa spinipalpa. The first two species occurred in the branchial cavities of C. chrysurus and S. brasiliensis. The isopod C.spinipalpa (a new species) was registered for the first time in the bucal cavity of O. saurus and O. palometa. The parasitic isopods preferred the branchial chambers and the bucal cavity of the host fishes as these were protected microhabitats. The isopods parasitized the immature, maturing and mature fishes. The prevalence of infection of isopods in the hosts varied from 16 to 21%, though in O. palometa it was 60%. In the rainy period the highest isopod parasitic occurrence was registered, however, this did not prejudice the normal reproductive cycle of the host fish. / O presente trabalho investigou a din?mica reprodutiva e parasit?ria de quatro esp?cies de peixes marinhos: serra, Scomberomorus brasiliensis, tibiros, Oligoplites saurus e O. palometa e palombeta, Chloroscombrus chrysurus, durante os messes de agosto de 2005 a julho de 2007, nas ?guas costeiras do Sudoeste do Oceano Atl?ntico, Brasil. Os peixes foram medidos, pesados, dissecados, as g?nadas pesadas e examinadas para separa??o do sexo. Foram avaliados o ?ndice gonadossom?tica (IGS), fecundidade, tipo e ?poca de desova e a caracteriza??o macro e microsc?pica do desenvolvimento das g?nadas dos peixes. Os ectoparasitos da c?mara branquial e cavidade bucal dos peixes foram coletados, medidos, pesados e identificados. A propor??o sexual dos peixes estudados foram aproximadamente 1M:1F, enquanto ocorreu um predom?nio de machos de O. palometa (3:2). Os peixes apresentaram IGS variando de acordo com seu ciclo reprodutivo e seu est?dio de matura??o gonadal. Os maiores valores de IGS e a ?poca reprodutiva coincidiram com per?odo das chuvas da regi?o. As f?meas apresentaram desova total e fecundidade com correla??o positiva para o peso das g?nadas e do corpo. Quatro est?dios de desenvolvimento das g?nadas foram identificados macroscopicamente: imaturo, em matura??o, maduros e esgotados, e os estudos microsc?picos mostraram o desenvolvimento ovocit?rio dentro de cada est?dio. Tr?s esp?cies de parasitos isopodos foram identificadas nas quatro esp?cies de peixes: Livoneca redmmanni, Rocinela signata e Cimothoa spinipalpa. As primeiras duas esp?cies ocorreram na cavidade branquial de C. chrysurus e S. brasiliensis. Parasitismo por isopodo C.spinipalpa, (uma esp?cie nova) foi registrado na cavidade bucal de O. saurus e O. palometa. O micro-h?bitat preferido pelos parasitos is?podos foram ? c?mara branquial e a cavidade bucal do hospedeiro, ?reas mais protegidas. Os isopodos parasitaram os peixes nos est?dios imaturo, em matura??o e maduros. A preval?ncia de infec??o de isopodos nos hospedeiros variou de 16 a 21%, enquanto que em O. palometa foi de 60%. No per?odo das chuvas foi registrada a maior ocorr?ncia de parasitismo por isopodos, porem, o parasitismo n?o prejudicou o ciclo reprodutivo normal dos hospedeiros.