2013-02-252013-02-252009-06-10GIRARD, Thátila Celestino. Dinâmica populacional de Lepidophthalmus siriboia Felder & Rodrigues, 1993 (Decapoda: Callianassidae) da Ilha de Maiandeua-PA. 2009. 56 f. Dissertação (Mestrado) - Universidade Federal do Pará, Instituto de Ciências Biológicas, Belém, 2009. Programa de Pós-Graduação em Ecologia Aquática e Pesca.https://repositorio.ufpa.br/handle/2011/3487Thalassinidea is marine invertebrate of great importance in the ecology of softbottom environments, especially given its influence on the flow of oxygen, energy and nutrients, and bioturbate activities. These ghost shrimps live in burrows of which depends for your needs, like protection, reproduction and feeding. In some places of the world this group has been exploited as bait. The burrowin shrimp Lepidophthalmus siriboia Felder & Lovett, 1993 (Crustacea: Callianassidae) occurs from Florida to Brazil. This study aim evaluate the structure and dynamic population of L.siriboia in the Maiandeua island (PA), associating processes observed with environmental characteristics related to sediment and water. Samples were taken monthly between June 2007 and May 2008, with a suction pump. In laboratory, animals were sexed, measured and weighed. In ovigerous females was counted the numbers of eggs in pleopods. The growth was estimated through the von Bertalanffy model that determines the relationship between carapace length (CC) and age (t). A total of 1268 organisms were captured (753 males and 515 females), which lengths ranged from 0,3 to 1,85 cm and the weight from 0,01 to 3,09g. The females monthly mean length was significantly higher than males (p<0,05) in almost months of the year. The carapace length and weight was high and significant correlation to males and females, with length positive allometric to both sexes. The size of first maturation reached was 0,7 cm to females and 0,6 cm to males. Males were proportionally more abundant, totalizing 59,4% of all organisms captured (sex ratio of 1,46 males: 1 female). There was a significant predominance of males in size classes between 0,3 and 1,2 cm and females in the size classes higher/equal than 1,2 cm. There was registred 139 ovigerous females, in which the majority (48,2%) occurred in the class interval 1,1 to 1,2 cm of carapace length. Absolute fecundity ranged of 0 to 1546 eggs/female, with average 826,25 eggs/female. There was positive and significative correlation between the numbers of eggs and the female weight. The growth female was smaller than males, and observed values for males of L_: 1,63 , K: 1, C: 0,2, WP: 0,18 e to females; L_: 1,68, K: 0,8, C: 0,2 e WP: 0,09. Mortality estimates of males were higher than females in all method used: catch curve (Z=1,67 e Z=0,11 to males and females), Beverton & Holt (Z=1,9 e Z= 1,76 to males and females) and Powell-Wetherall (Z/K=3,98 e Z/K= 2,25 to males and females). There was registered three recruitment pulses in November, February and May. The results showed : 1. males mean length is smallest than females throughout the year; 2. females are dominants in the size classes higher (_1,2 cm); 3. The reproduction is continuous with ovigerous females throughout the year; 4. growth parameters calculated was higher for males than females; 5. Females had reduced growth rate in January (WP:0,09) and males in February (WP:0,18); 6. the mortality is higher to males; 7. recruitment occurs throughout the year with three pronounced peaks in November, February and May.porAcesso AbertoCrustáceoThalassinideaDinâmica populacionalEcologia aquáticaPraia da Beira - PAIlha de Algodoal/Maiandeua - PAPará - EstadoAmazônia brasileiraDissertaçãoCNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA::ECOLOGIA DE ECOSSISTEMAS