• Main Authors: Ana Paula Madeira Di Beneditto, Vanessa Trindade Bittar, Carlos Eduardo de Rezende, Plínio Barbosa Camargo, Helena Amaral Kehrig
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Ictiologia 2013-03-01
• Series: Neotropical Ichthyology
• Subjects: Carbon; Diet tracers; Nitrogen; Trace element; Trichiurus lepturus
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000100211
• ISSN: 1679-6225; 1982-0224

This study applies total mercury (THg) concentration and stable isotope signature (&#948;15N and &#948;13C) to evaluate the trophic status and feeding ground of Trichiurus lepturus during its ontogeny in northern Rio de Janeiro, south-eastern Brazil. The trophic position of T. lepturus is detected well by THg and &#948;15N as the sub-adult planktivorous specimens are distinct from the adult carnivorous specimens. The &#948;13C signatures suggest a feeding ground associated with marine coastal waters that are shared by fish in different ontogenetic phases. The diet tracers indicated that the fish feeding habits do not vary along seasons of the year, probably reflecting the prey availability in the study area. This fish has economic importance and the concentration of THg was compared to World Health Organization limit, showing that the adult specimens of T. lepturus are very close to the tolerable limit for safe regular ingestion.<br>Este estudo utilizou a concentra&#231;&#227;o de merc&#250;rio total (THg) e a assinatura isot&#243;pica (&#948;15N e &#948;13C) para avaliar a posi&#231;&#227;o tr&#243;fica e a &#225;rea de alimenta&#231;&#227;o de Trichiurus lepturus durante sua ontogenia no norte do Rio de Janeiro, sudeste do Brasil. A posi&#231;&#227;o tr&#243;fica de T. lepturus foi bem detectada pelo THg e &#948;15N com os esp&#233;cimes sub-adultos planct&#237;voros distintos dos esp&#233;cimes adultos carn&#237;voros. As assinaturas de &#948;13C sugerem uma &#225;rea de alimenta&#231;&#227;o associada a &#225;guas marinhas costeiras que s&#227;o compartilhadas por peixes em diferentes fases ontogen&#233;ticas. Os tra&#231;adores de dieta indicaram que os h&#225;bitos alimentares desse peixe n&#227;o variam ao longo das esta&#231;&#245;es do ano, refletindo provavelmente a disponibilidade de presas na &#225;rea de estudo. Esse peixe tem import&#226;ncia econ&#244;mica e a concentra&#231;&#227;o de THg foi comparada com o limite estabelecido pela Organiza&#231;&#227;o Mundial de Sa&#250;de, demonstrando que os esp&#233;cimes adultos de T. lepturus est&#227;o bem pr&#243;ximos do limite toler&#225;vel para uma ingest&#227;o regular segura.