Aquaculture CRSP 21st Annual Technical Report
Studies on Reproduction and Larval Rearing of Amazonian Fish
Tenth Work Plan, New Aquaculture Systems/New Species Research (10NSR2)
Konrad Dabrowski, Kyeong-Jun Lee, Jacques Rinchard, and Mary Ann G. Abiado
School of Natural Resources
The Ohio State University
Columbus, Ohio, USA
Fernando Alc‡ntara Bocanegra and Salvador Tello
Instituto de Investigaciones de la Amazonia Peruana
Maria Esther Palacios
Universidad Nacional Mayor de San Marcos
This project has developed the techniques and feed formulations that allow the successful rearing of paco (Piaractus spp.) juveniles under intensive conditions. Weaning of paco larvae to artificial diets requires initial feeding with brine shrimp, Artemia nauplii, for 7 to 14 d followed by dry feed, which is administered at regular intervals using automatic feeders. We believe that large-scale implementation of this method in Instituto de Investigaciones de la Amazonia Peruana hatcheries (Iquitos and Pucallpa) will significantly improve the larval survival of paco and other Amazonian fishes. The use of locally available plants such as maca, Lepidium meyenii, and aguaje, Mauritia flexuosa, in diet formulations for Amazonian fish larvae could promote the utilization of indigenous plant products in aquaculture feeds. Moreover, the immuno-stimulatory properties of these plants could boost the general health condition of cultured fish. Our work on the assay of plasma sex steroid hormones of Pseudoplatystoma spp. prior to induced ovulation and spermiation could be used as a quantitative tool for selecting good quality broodstock for artificial reproduction schemes. This would help eliminate the costs of hormones and reduce unnecessary stress to broodstock.
Plants originating from the Peruvian Andes, such as the ancient source maca, Lepidium meyenii (Brassicaceae), and the Amazonian fruit species aguaje, Mauritia flexuosa (Arecaceae), and camu-camu Myrciaria dubia (Myrthaceae), are widely used for human consumption and medicinal purposes due to the high nutritional and antioxidant value and phytochemical content (Leon, 1964; Dini et al., 1994; Obregon, 1998; Moraes et al., 1994). These Amazonian fruits are also feed components of Amazonian characins (Piaractus and Colossoma spp.) in the natural environment (Araujo-Lima and Goulding, 1997).
Roots of maca are an edible part of the plant and nutritionally valued and consumed at elevated altitudes in the highlands of Peru since pre-Columbian periods. Presence of phytosterols and high levels of aromatic glucosinolates [benzyl glucosinolate (glucotropaeolin) and p-metoxyben
zyl glucosinolate], aliphatic glucosinolate (allylglucosinolate or sinigrin), fatty acids, amino acids, saponins, and flavonoids has been attributed as the cause of maca's positive properties to increase energy and improve fertility (Li et al., 2001; Cicero et al., 2001).
Camu-camu is a globose berry fruit of 1 to 3 cm in diameter, red to purple with 2 to 20 g weight, 50 to 55% reddish pulp, and 1 to 3 seeds per fruit. It is distributed and grows throughout the western Amazon rainforest, especially in swamps or flooded areas, reaching about 2 to 3 m in height. Our analysis of fruits brought frozen from Iquitos and Pucallpa Stations of Instituto de Investigaciones de la Amazonia Peruana (IIAP) has determined that the whole fruits or pulp of camu-camu has the highest concentration of vitamin C, containing 3,000 to 6,000 mg of ascorbic acid per 100 g, ever found in plant material (Lee and Dabrowski, unpublished). In comparison to oranges, camu-camu provides 30 times more vitamin C, ten times more iron, three times