Teses em Zoologia (Doutorado) - PPGZOOL/ICB
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/3419
O Doutorado Acadêmico foi criado em 1999 e pertence ao Programa de Pós-Graduação em Zoologia (PPGZOOL) do Instituto de Ciências Biológicas (ICB) foi consolidado como um convênio entre Universidade Federal do Pará (UFPA) e Museu Paraense Emílio Goeldi (MPEG).
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Item Acesso aberto (Open Access) Morfometria e descrição de otólitos de dourada (Brachyplatystoma rosseauxii) (Castelnau, 1855) e de piramutaba (B. vaillantii) (Valenciennes, 1840) (Siluriformes: pimelodidae) e verificação de anéis de crescimento em otólitos de juvenis de dourada e de piramutaba na Ilha de Colares - Baía de Marajó-PA(Universidade Federal do Pará, 2008-10-09) PIRKER, Lilianne Esther Mergulhão; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326The dourada (Brachyplatystoma rousseauxii) and the piramutaba (B. vaillantii), two migratory freshwater catfishes, are exploited by both traditional and industrial fishery in the Amazonian. They are very important for the commercial fishery in this region and their stocks are currently sobrexploted. However there is a lack of information concerning the biology and ecology of juvenile stages of these catfishes in the scientific literature. In population dynamics studies, the correct age estimate influences the growth parameters, which are important to evaluate stocks. The studies of age determination are usually made using sub-adults and adults specimens. The juveniles are not analyzed and their age is back-calculated. Which could result in an error estimate. The aims of the present research were: (1) to describe and estimate the relation between the lapilli otoliths morfometric measurements and the body measurements of dourada and piramutaba, and (2) to examine the occurrence of the first growth rings in the juvenile specimens. The morfometric and descriptive studies were carried out using otoliths from dourada and piramutaba juveniles, sub-adults and adults collected in the municipalities of Colares (PA), Almeirim (PA), Santarém (PA), and Manaus (AM), in the District of Mosqueiro (PA), and in the Amazon estuary. The period of collection was different for each local, to September of 1996 to January of 2006. The following relations were estimated: furcal length from specimens (LF) x total weight from specimens (WT); LF x maximum otolith length (MOL); LF x maximum otolith width (MOW); LF x otolith total weight (OWT); WT x MOL; WT x MOW and WT x OWT. The estimated equations were: Dourada: WT = 9.5 x 10-6 x LF 3.0279, LF = 25.259 * MOL1.1571, LF = 40.626 * MOW1.2127, LF = 840.419 * OWT0.4077, WT = 0.125 * MOL3.6547, WT = 0.568 * MOW3.8294, WT = 7549.98 * OWT1.2651; Piramutaba: WT = xxx 5.4 x 10-6 x LF 3.1441, LF = 31.871 * MOL1.3381, LF = 55.852 * MOW1.3722, LF = 1641.064 * OWT0.4686, WT = 0.3127 * MOL4.1857, WT = 1.823 * MOW4.2788, WT = 66675.977 * OWT1.4508. In the descriptive study, the lapilli of dourada and piramutaba were classified in the following categories according to their development and specimens LF: dourada I (60 a 80 mm), dourada II (80 a 110 mm), dourada III (110 a 210 mm), piramutaba I (65 a 80 mm), piramutaba II (80 a 110 mm), and piramutaba III (110 a 190 mm). In the lapillus ring reading study, only the juveniles specimens £ 200 mm LF were used. In the Marajó bay, douradas and piramutabas with 175.03 mm and 171.03 mm mean LF, respectively, showed the first growth ring. Both species were between nine and twelve months old when they showed the first growth ring. The mean rays of the first hyaline ring in the transversal cut of dourada’s and piramutaba’s lapillus were 0.36 mm (± 0.03) and 0.33 mm (± 0.01), respectively. The mean total ray of the lapillus transversal cut was 0.64 mm (± 0.14) in dourada and 0.53 mm (± 0.09) in piramutaba. The estimated equation relating the total ray of the lapillus transversal cut of douradas juveniles with its LF was LF = 248.589 * Rt1.1901. The estimated equation for piramutaba was LF = 400.494 * Rt1.7178. Douradas and piramutabas 60-70 mm LF were three to six months old, 70-110 mm LF were six to nine months old, and 110-200 mm LF were nine to twelve months old.