Seleção das estruturas calcificadas para determinação da idade da piracatinga Calophysus macropterus Lichtenstein (Siluriformes: Pimelodidae) na Amazônia Central, Brasil

Abstract

RESUMO -O objetivo deste trabalho foi identificar a estrutura calcificada mais adequada para a determinação da idade da piracatinga (Calophysus macropterus). Foram analisados 440 indivíduos procedentes da pesca comercial e experimental do Baixo Solimões. Deste total, foram analisados opérculos, otólitos (asteriscus) e vértebras de uma sub-amostra de 130 indivíduos. Para a observação dos anéis de crescimento nos otólitos, foram testadas duas técnicas de clarificação e quatro técnicas de coloração nas vértebras. A análise das estruturas calcificada demonstrou que os otólitos são estruturas pouco translúcidas e apresentam dificuldades para a observação das marcas de crescimento. Por outro lado os opérculos não apresentaram marcas visíveis de crescimento, e nas vértebras foi observado um padrão nítido e estável de marcação de anéis de crescimento. Portanto, as vértebras foram as estruturas mais adequadas para determinar a idade da piracatinga, além de apresentar uma relação linear significativa entre o raio total das vértebras e o comprimento do peixe (r=0,91; P<0,05). Entre os métodos testados para a visualização dos anéis nas vértebras de peixes teleosteos, a técnica nova a de Hiper-oxidação e Descalcificação Química (HDQ), mostrou ser a melhor. ABSTRACT -The goal of this study was to identify the best calcified structure for determination of the age of the piracatinga (Calophysus macropterus). A total of 440 specimens from commercial samples and experimental fishing in the Solimões River. Were used for analysis: Opercula, otoliths, and vertebrae were analyzed from a sub sample (n=130). Two clarification techniques were used for visualization of growth rings in the otoliths and four coloration techniques for vertebrae. The otoliths were not translucent and it was very difficult to see the growth rings. The vertebrae were the best calcified structure because the radius of the vertebrae and the length of fish had clear significant linear relationship (r= 0.91; P<0.05) and a clear visualization of the growth rings. Among the techniques used for examining vertebrae of the teleostean fishes, the chemical decalcification, hyper-oxidation technique, was the best to observe the growth rings in the vertebrae. The seasonal rings were validated using relative marginal incremental analysis. Two annual rings are formed in the vertebrae of Calophysus macropterus, being the first during low water (August) and the second during high water season (January). On the vertebrae, a maximum of seven rings were observed.

Fish and aquatic habitat conservation in South America: a continental overview with emphasis on neotropical systems

“…High growth rates and double marks on calcified structures were also found in Pimelodidae, e.g. Calophysus macropterus (Lichtenstein) (Perez & Fabré, 2003) and Hypophthalmus marginatus Valenciennes (Santos‐Filho & Batista, 2005).…”

Age and growth of black scabbardfish (<i>Aphanopus carbo</i> Lowe, 1839) in the southern NE Atlantic

“…other authors have also experienced some difficulties in vertebra ageing. Pérez and Fabré (2003) in Calophysus macropterus identified the presence of intermediate growth marks, which occur between the main growth marks (those that are counted for determining the age). Panfili (1993) and VillacortaCorrea (1997) failed to observe a pattern of deposition in the vertebrae of Colossoma macropomum due to the high frequency of intermediate growth marks.…”

Plasticity in the shape and growth pattern of asteriscus otolith of black prochilodus Prochilodus nigricans (Teleostei: Characiformes: Prochilodontidae) freshwater Neotropical migratory fish

“…The asteriscus otolith was used for this study because of its larger size and clear calcified deposits, which enabled the identification of growth rings (Pérez, Fabré, 2003;Silva, Stewart, 2006). The images of the left side of the asteriscus were taken using a digital video camera coupled to a microscope stereoscopic (Zeiss Magnifier CL1500 ECO) on a black background.…”