Arapaima are among the largest freshwater fishes in world, exceeding 3 m and 200 kg. Arapaima are a ‘flagship species’ for conservation of Amazonian ecosystems because their protection requires conservation of freshwater and terrestrial systems that have high biodiversity. In spite of their endangered status (IUCN 2006), Arapaima remain among the most sought-after food fishes in tropical South America. Their populations appear to be depleted by over-fishing in many areas, and especially near large cities. Community-based management programs and protected areas offer hope for recovery of over-exploited Arapaima populations. A present-day lack of knowledge on their basic biology, however, may compromise such efforts.


Project Title: Ecology, Conservation, and Management of the Giant Arapaima in Tropical South America

This work aims to improve inland fish conservation and management by studying key aspects of Arapaima movement, diet, growth, reproduction, taxonomy, and population genetics. The main objectives of our research in Guyana and Brazil are to:

1. Assess the conservation status of Arapaima populations at research sites in Guyana and Brazil.
2. Determine age structure, growth and mortality rates using size-frequency and scale-analysis data.
3. Determine age-of-first-maturity by visual examination of gonad development state.
4. Evaluate population genetic structure of Arapaima using analyses of microsatellite markers and mitochondrial DNA.
5. Analyze Arapaima taxonomy through simultaneous observations on molecular and morphological variation, and including study of archived museum specimens.
6. Evaluate diet and trophic relationships through analyses of stomach contents, gut morphology, and stable isotopes in Arapaima and their food web.
7. Use telemetry studies to explore Arapaima migration and evaluate protected area and management designs.

Location: Guyana and Brazil

Timeline: 2006 – 2013

Field Participants: Caroline Arantes (in Brazil), Zacharias Norman (in Guyana)

Principal Investigators: Donald J. Stewart, Leandro Castello (PhD 2007; now at Woods Hole Research Center), L. Cynthia Watson, Daniel J. Gurdak, and Kapil D. Mandrekar, SUNY-ESF

Funding: National Geographic Society, World Wildlife Fund, Wildlife Conservation Society, Rufford Foundation, Overbrook Foundation, Moore Foundation (through grant to WHRC), Cleveland Metroparks Zoo, Conservation International, Fulbright Foundation, Sociedade Civil Mamirauá, Iwokrama Centre, and SUNY-ESF.

Donald J. Stewart
SUNY-ESF, Syracuse, NY 13210
Phone: 315-470-6924Email: