REGIONAL RESEARCH

PERU RESEARCH

Collaborating Institutions

Instituto de Investigaciones de la Amazonia Peruana

Fernando Alcántara Bocanegra
Salvador Tello

Universidad Nacional de la Amazonia Peruana

Southern Illinois University at Carbondale–Lead US Institution

University of Arkansas at Pine Bluff

Ohio State University

Note: Schedule has been revised. See Addendum to the Ninth Work Plan
Note: Experimental Design for 9NS3A (Objective 1 of 9NS3) has been revised. See Addendum to the Ninth Work Plan
Note: Schedule for 9NS3A (Objective 1 of 9NS3) has been revised. See Addendum to the Ninth Work Plan

Objectives

1) Identify locally available ingredients for practical diet(s) suitable for Colossoma and/or Piaractus broodstock.

Significance
A need exists to evaluate the aquaculture potential of local and native species, and to develop appropriate culture technologies. Colossoma spp., Piaractus spp., and their hybrids are important food fishes in the Amazon basin. However, little production technology has to date been developed and published. In addition, there has been inadequate attention to economic analyses, such as determinations of cost of production.

Male and female C. macropomum generally reach sexual maturity in 3 and 4 years, respectively, when they have attained 3 to 6 kg in weight. Piaractus become sexually mature about a year sooner, and at a smaller size (2 to 4 kg). Fish held in captivity must be induced to spawn using hormones (Gonzales, 1987). No standardization in terms of hormone type or dosage exists. After hormonal treatment gametes are stripped and mixed using the dry method (Alcantara and Guerra, 1992). Both MacDonald-type and Woynarovich-type incubators are employed, with the latter being most common. Hatching occurs 10 to 20 h post-fertilization at 26 to 29°C. In 1996, a complete spawning failure occurred at the IIAP station in Iquitos, as well as at another station in Peru (Tarapota). The spawning failure may have been due to drought conditions at normal time of spawning. Other factors such as poor nutrition may have also been involved. Accordingly, we will monitor plasma steroid levels of broodstock on a monthly basis over the course of two years. These data will be related to climatological information, as well as the actual spawning events (or nonevents). These data will also be useful in identifying the optimal time for induced spawning. We will compare the relative efficacy of various dosages of hCG and GnRH to induce ovulation. We will also survey locally available feed ingredients and design one or more feeds for use in broodstock maintenance. Final maturation and ovulation was achieved in Colossoma sp. using hypophysation procedures and injections of commercial hormones (Carolsfeld, 1989). Information on reliable procedures of controlled gonad maturation leading to induced ovulation of captive fish is available for Brazil (Chellappa et al., 1996; Zaniboni Filho and Barbosa, 1996) and Venezuela (Gonzalez et al., 1991). The profile of steroid hormones in captive Colossoma sp. was recently analyzed by Gazola et al. (1996), however these data are incomplete. Steroid hormones analysis in conjunction with environmental conditions (water temperature and conductivity, light regime) and body condition factor (coelomic fat index; Lamas and Godinho, 1996) were not carried out systematically in tropical Characidae fishes. OSU preliminary data over the course of captive C. macropomum growth in North America suggest that the blood plasma steroid profiles are indicative for gonadosomatic indices of both sexes and can be critical in determining the time and magnitude of hormonal intervention. An insight into seasonal and final maturational-stage steroid profiles in males and females can contribute to an understanding of the process and synchronize induced ovulation with hormonal treatment. No standardization exists for stocking densities of fry or fingerlings (Campos, 1993). No uniform fish diets are available in the region (Cantelmo et al., 1986; Ferraz de Lima and Castagnolli, 1989). In the Eighth Work Plan, we stocked three ponds with 3,000 Piaractus fingerlings/ha and three at 4,000/ha. After approximately 120 days, the fish have grown from an average weight of 27.5 g to 353.6 g at the lower density and 417.2 at the higher density. The yield trial will continue for another 120 days. It appears that even higher densities may be possible, although water quality will become problematic at some point. In the Ninth Work Plan, research will be aimed at further refining stocking densities to efficiently and economically rear Colossoma and/or Piaractus to marketable size (= 1 kg).

Beneficiaries
The development of sustainable aquaculture of Colossoma and/or Piaractus will benefit many sectors throughout the Peruvian Amazon. Rural farmers will benefit by the addition of an alternative to other forms of agriculture. Aquaculture production will require considerably less land than that needed for cattle ranching. Moreover, ponds can be used year-after-year whereas rain forest lands converted to traditional agricultural practices are rarely productive for more than a couple of seasons, and such lands, once abandoned, usually can no longer support normal jungle growth. Both rural and urban poor will benefit by the addition of a steady supply of high quality protein in the marketplace. Aquaculture of Colossoma and/or Piaractus should relieve some of the fishing pressure on these overharvested, native species. These species have been shown to play a crucial ecological role in disseminating seeds from the flooded forest. Accordingly, the aquaculture of Colossoma and/or Piaractus will be ecologically as well as economically and nutritionally beneficial to the inhabitants of the Peruvian Amazon.

Collaborative Arrangements
SIUC will coordinate these activities. IIAP and UNAP will provide Host-Country PIs. OhSU and SIUC will participate in the plasma steroid study. UAPB and SIUC will participate in the broodstock nutrition study. SIUC will participate in the spawning, density, and cost of production studies.

Methods
Objective 1: The content of certain essential nutrients (e.g., amino and fatty acids) in fish eggs is quite conservative and nutrient profile of eggs of a given species is a good indicator of larval requirements. Because origin of the nutrients is primarily maternal, there is potential to manipulate broodstock diets to optimize oogenesis and larval quality. Accordingly, we will:

Objective 2: At the beginning of gonad recrudescence, blood will be sampled from the caudal vein monthly in Peruvian aquaculture conditions. Twenty to thirty fish will be sampled. Estradiol, testosterone, 11-ketotestosterone and 17,20 b-progesterone will be determined by radioimmunoassays (Ottobre et al., 1989; Dabrowski et al., 1996). Validation of all steroids for Colossoma has already been completed at OSU in a rigorous fashion using blood collected from broodstock maintained there. To compare mean steroid concentrations, as well as patterns of steroids over time, broodstock fish will be individually implanted with electromagnetic tags (PIT-tags, Biosonic, Seattle, WA). This method proved to be very reliable with Colossoma the last two years in Ohio. At the time of final maturation (normal spawning time in Peru is late November/early December), frequency of blood sampling will be increased to weekly intervals. At the time of hormonal treatment (Chellappa et al. 1996), blood sampling frequency will be increased to 6-12-h intervals, although different individuals will be used. No mortalities of 4-6-kg Colossoma occurred at OSU during the 1997 intensive sampling of blood and gametes.

Objective 3: The spawning season for C. macropomum and P. brachypomus in Peru is October—February. Pituitary extracts from various species have been used to induce ovulation, but with varying degrees of success (Campos, 1993). GnRHa (LHRHa) has been successfully employed using one or more dosages in the 0.5 to 10 µg/kg range (Campos, 1993). HCG has been used sporadically, generally at very high dosages (3.0 IU/g). The relative efficacy of GnRHa and hCG will be compared at three dosages (1.0, 5.0, 10.0 µg GnRHa/kg; and 1.0, 2.0, and 3.0 IU hCG/g). Conceptal® is locally available and will serve as the GnRHa commercial source. Chorulon® is internationally available, and will be the hCG commercial source. Peruvian aquaculturists routinely inject these hormones directly into the bloodstream, usually at the heart in a single injection. Hatching time occurs within 1-18 h post-injection. A second injection at half the dosage is used on fish that do not spawn within 24 h. Gametes will be stripped and fertilized using the dry method. Embryos will be incubated in MacDonald jars at 26 to 28°C. Fry hatch in less than 24 h and are stocked in ponds treated with chicken manure (0.1 kg/m²/15 d) and triple superphosphate (30 g/m²/15 d) (Ascon, 1988). Relative spawning success of the two hormones and three dosages of each will be compared in terms of ovulation response (degree hours) and hatching success (degree hours and percent hatch).

Site: Iquitos, Peru

Facilities: IIAP Quistachocha hatchery

Culture Period: N/A

Stocking Rates: 1.0 g eggs/L (hatching jar)

Water Management: Filtered well water

Other Inputs: N/A

Test Species: C. macropomum and/or P. brachypomus

Sampling Plan: 5 female fish for each dosage and for each hormone will be injected (30 fish total of each species, if both available).

Objective 4: Additional densities of C. macropomum and/or P. brachypomus will be compared in yield trials based on Eighth Work Plan results in which 3,000 and 4,000 fingerlings/ha are being tested. This study will also serve as the yield trial for the cost-of-production objective.

Site: Iquitos, Peru

Pond Facilities: IIAP Aquaculture Center (9 ponds of about 0.3 ha each).

Culture Period: 6-month grow-out

Stocking Rates: 3 ponds/stocking rate

Water Management: Fertilization with chicken manure (0.1 kg/m²/15 d); triple superphosphate
(30 g/m²/15 d).

Other Inputs: Feed pellets (30% CP)

Test Species: Colossoma macropomum and/or Piaractus brachypomus

Sampling Plan: Bi-weekly; commencing week 7 post-stocking, samples of fish (N = 50) will be weighed to adjust food rations; at harvest, the following values will be calculated: survival (%), specific growth rate, standing crop at harvest, condition (K), and feed conversion efficiency.

Objective 5: Capital costs, as well as fixed and variable-operating costs, will be estimated based on the density study conducted for Objective 4. Estimates for a break-even analysis will be determined. The information on production costs will be obtained by tracking costs, feed conversions, etc. of various inputs in the study described in Objective 4.

Statistical Methods
Data values will be analyzed by one-way analysis of variance (ANOVA). Appropriate transformations will be made where necessary. If significant differences among treatment means are found, the appropriate post-hoc test will be employed to determine where the differences lie. The accepted level of significance will be 0.05.

Regional Integration
Research efforts being proposed are logical initial steps toward developing sustainable aquaculture in the region. Research needs were identified with considerable input from in-country scientists and agency administrators. The research will benefit the entire region by providing pertinent information on broodstock nutrition, reproduction, stocking densities, and cost of production.

Schedule
Yield trials: February to November 1999; February to November 2000

Nutrition and endocrine studies to be carried out from October 1998 to January 1999; October 1999 to January 2000.

Final Report Submittal
June 2000

References
Alcantara, F., 1985. Reproduccion inducid de gamitana Colossoma macropomum (Cuvier 1818). Ph.D. dissertation, Universidad Nacional de Trujillo, Peru.

Alcantara, F. and H. Guerra, 1992. Avances en la produccion de alevinos de gamitana Colossoma macropomum y paco P. brachypomus por reproduccion inducida. Publication of the Instituto Del Mar Del Peru (IMARPE) and Instituto De Investigaciones de La Amazonia Peruana (IIAP), 4:23-33.

Ascon, G., 1988. Trabajos de investigacion pesquera en Selva Alta, Peru. Informe Tecnico Anual En el Instituto De Investigaciones De la Amazonia Peruana (IIAP), Iquitos, Peru.

Batista, M., M. De Araujo, and J. Senhorini, 1986. Alimento vivo (Fito e Zooplancton) na criacao de larvas da especies do genero Colossoma. Sintese Dos Trabalhos Realizados Com Species Do Genero Colossoma March/82, Abril/86. Proyecto Aquacultura, Perassununga, Brazil 3:15.

Campos, L.B., 1993. The culture of gamitana (Colossoma macropomum, Cuvier, 1818) in Latin America. M.S. thesis. Carbondale, Illinois: Southern Illinois University.

Cantelmo, A., A. De Soura, and J. Senhorini, 1986. Dimencao da particula do alimento para alevinos de pacu, Colossoma mitrei e tamabaqui Colossoma macropomum. Sintese Dos Trabalhos Realizados Com Species Do Genero Colossoma March 82, Abril/86. Editor Proyecto Aquicultura, Perassununga, Brasil.

Carolsfeld, J., 1989. Reproductive physiology and induced breeding of fish as related to culture of Colossoma. In: Cultivo do Colossoma. pp. 37-64.

Chellappa, S., M. Cacho, F.A. Huntingford, and M. Beveridge, 1996. Observations on induced breeding of the fish, tambaqui, Colossoma macropomum (Cuvier) using CPE and hCG treatments. Aquacult. Res., 27:91-94.

Dabrowski, K., R.E. Ciereszko, A. Ciereszko, G. Toth, S.A. Christ, D. El-Saidy and J. Ottobre, 1996. Reproductive physiology of yellow perch (Perca flavescens): environmental and endocrinological cues. J. Appl. Ichthyol., 12:139-148.

Da Costa, M., and C. De Melo, 1986. Uso de insecticida organofosforado no seleccion de zooplancton. Observacao preliminar. Sintese Dos Trabalhos Realizados com especies do genero Colossoma Marz/82, Abril/86. Editor Proyectos Aquicultura, CEPTA, Perassununga, Brasil.

De Morais, F., N. De Araujo, and J. Senhorini, 1986a. Sobrevivensa de larvas do Colossoma macropomum em tanques tratados com organofosforados (Folidol 60%). Sintese Dos Trabalhos Realizados Com Especies do Genero Colossoma Marzo/82, Abril/86. Editor Proyecto Aquicultura, Perassununga, Brasil.

Ferraz De Lima, J., and N. Castagnolli, 1989. Reproducao, larvicultura e genetica: cultivo de Colossoma. In: A. Hernandez (Editor), Primera Reunion Grupo de Trabajo Tecnico, Junio 1988. Perassununga, Brasil, pp. 315-322.

Gazola, R., M.I. Borella, E.M. Donaldson, M.V. Val Sella, N. Sukumasavin, F. Fava de Moracs and
G. Bernardino, 1996. Plasma steroid and corticosteroid levels in female pacu Piaractus mesopotamicus, Teleostei-Characidae. Brazilian Journal of Medical and Biological Res., 29:659-664.

Gonzalez, J., 1987. Actividad biologica de extractos hipofisarios de Teleosteos y sus cambios en los ciclos.

Gonzalez, J., H. Guerrero, G. Caceres, and D. Marcano, 1991. Induced reproduction of the cachama Colossoma macropomum with hypophysial extracts and with an analog of gonadotropin hormone releasing hormone, LHRHa. Acta Cientifica Venezolana, 42:229-231.

Lamas, I.R. and A.L. Godinho, 1996. Reproduction in the piranha Serrasalmus spilopleura, a neotropical fish with an unusual pattern of sexual maturity. Env. Biol. Fishes, 45:161-168.

Neto, J.R., C.C. Kohler, and W.M. Lewis, 1987. Water re-use system for production of fingerling fishes in Brazil, with emphasis on South American catfishes (Rhamdia quelens and R. sapo). Tropical Agriculture, 64:2-6.

Ottobre, J.S., B.S. Houmard, and A.C. Ottobre, 1989. Luteal production of steroids and prostaglandins during simulated early pregnancy in the primate: Differential regulation of steroid production by chorionic gonadotropin. Biol. Reprod., 41:393-400.

Valencia, O. and R. Puentes, 1989. El cultivo de la Cachama (Colossoma macropomum). In: A. Hernandez (Editor), Primera Reunion Grupo de Trabajo Tecnico, Junio 1988. Perassununga, Brasil, pp. 116-142.

Zaniboni Filho, E. and N.D. Barbosa, 1996. Priming hormone administration to induce spawning of some Brazilian migratory fish. Rev. Brasileira de Biol., 56:655-659.