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Previous issue date: 2008-12-29 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior === This study aims, to characterize the diversity of cephalopods by analyzing the stomach contents of fishes caught in the islands of St. Peter and St. Paul (ASPSP) and Fernando de Noronha (AFN). Also, verify the participation of cephalopods in the diet of their main predators. A total of 723 stomachs were collected, from 8 species of fish, caught by the fishery, 471 stomachs were from ASPSP and 252 were from the AFN. It was recorded the occurrence of food items (fish, cephalopods and crustaceans) and the cephalopods were identified to the lowest taxa possible, according to specialized literature. The Ommastrephidae family represented 84.46% of occurrence in the ASPSP and 63.48% in the AFN, confirming the importance of this family in the area studied and also in the diet of their predators. Among the species with greatest occurrence Ornitoteuthis antillarum was the most representative in both regions. This species had an average mantle length of 54.25 mm, thus demonstrating that the majority of this population is in the juvenile stage of development. The smallest species found was Argonauta nodosa with a mantle length of 4.06 mm and the largest was Ommastrephes bartrami, with 223.33 mm. In the AFN, the species richness (d) was 2.318, the diversity index (H ') was 1.454 and the measure of evenness (J) was 0.585. In the ASPSP, the species richness (d) was 2.66, the Shannon diversity index (H ') was 1.013 and the measure of evenness (J) was 0.373. AFN has a greater cephalopod diversity than ASPSP, confirming the pattern suggested by the Theory of Island Biogeography. Among the occurrence of prey items for all predators, the cephalopods are secondary preys. The most important cephalopod species in the diet of Thunnus albacares and Acantocybium solandri was Ornithoteuthis antillarum. These predators have different niche width the diet of Thunnus albacares is more specialized, but they have an overlap of 84.684% in the trophic niche, suggesting that in the ASPSP these two species may use similar niches === O presente estudo teve como objetivo, caracterizar a diversidade de cefal?podes atrav?s da an?lise dos conte?dos estomacais dos peixes capturados nos Arquip?lagos de S?o Pedro e S?o Paulo (ASPSP) e Fernando de Noronha (AFN). Al?m disso, verificar a participa??o dos cefal?podes na dieta dos seus principais predadores. Foram ent?o coletados um total de 723 est?magos de 8 esp?cies de peixes, capturados atrav?s da pesca dos quais, 471 provenientes do ASPSP e 252 do AFN. Foram registrados a ocorr?ncia dos itens alimentares (peixes, cefal?podes e crust?ceos) e os cefal?podes encontrados foram identificados at? o menor t?xon poss?vel, segundo bibliografia especializada. A fam?lia Ommastrephidae representou 84,46% de ocorr?ncia no ASPSP e no AFN 63,48%, confirmando a import?ncia desta fam?lia na regi?o estudada e tamb?m na dieta de seus predadores. Dentre as esp?cies de maior ocorr?ncia Ornitoteuthis antillarum foi a mais representativa nas duas regi?es. Essa esp?cie apresentou uma m?dia de comprimento do manto de 54,25 mm, demonstrando assim que a maioria desta popula??o se encontra em est?gio de desenvolvimento juvenil. A menor esp?cie encontrada foi Argonauta nodosa com 4,06 mm de comprimento de manto e a maior foi Ommastrephes bartrami com 223,33 mm. No AFN a riqueza de esp?cies (d) foi de 2,318, o ?ndice de diversidade (H ) foi 1,454 e a medida de equitabilidade (J) de 0,585. No ASPSP foram a riqueza de esp?cies (d) foi de 2,66, o ?ndice de diversidade de Shannon (H ) para o ASPSP foi 1,013 e a medida de equitabilidade (J) 0,373. AFN tem uma diversidade de cefal?podes maior que ASPSP, confirmando o padr?o proposto pela Teoria de Biogeografia de Ilhas. Dentre a ocorr?ncia de itens de presas para todos os predadores analisados, os cefal?podes s?o presas secund?rias. A esp?cie de cefal?pode mais importante na dieta de Thunnus albacares e Acantocybium solandri foi Ornithoteuthis antillarum. Esses predadores apresentam largura de nicho diferente, sendo a dieta de Thunnus albacares mais especializada, por?m eles apresentam uma sobreposi??o de nicho tr?fico de 84,684%, sugerindo que no ASPSP essas duas esp?cies possivelmente utilizam nichos semelhantes
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