ECONOMIC ANALYSIS of AMAZON RIVER PRAWN FARMING TO THE MARKETS FOR LIVE BAIT and JUVENILES IN PANTANAL, BRAZIL

The implementation of a hypothetical aquaculture facility with hatchery, nursery and grow-out earthen ponds for raising the Amazon River Prawn Macrobrachium amazonicum in the Pantanal was considered. Eight larviculture cycles per year were projected: four to produce post-larvae for stocking in grow-out bait ponds, and four to stock nursery tanks to sell juveniles as seed to grow-out farms, which produce prawns for human consumption. Annual production would be 146,880 dozen bait prawns and 2,938 thousand juveniles. The assumed sale prices were US$ 1.38 per dozen baits and US$ 15.39 per thousand juveniles. The net present value was US$ 555,890.79, internal rate of return was 48% per year, payback period was 2.4 years and benefit-cost ratio was 3.90. The breakeven price to cover total costs per dozen baits was US$ 0.70 and per thousand juveniles was US$ 17.00, indicating that the selling price assumed for juveniles in base scenario is not realistic. Net return was US$ 84,773.80. The results indicate that this activity would be a lucrative and attractive investment in the Pantanal.

Morphometric characteristics of Prochilodus lineatus (Valenciennes 1847), of the migratory and resident stocks of the river Mog��-Gua��u, S��o Paulo State, Brazil

A esp��cie Prochilodus lineatus �� de grande import��ncia comercial na regi��o dos rios Grande, Pardo e Mogi-Gua��u e tem como caracter��stica a forma����o de grandes cardumes, apta a desenvolver amplos deslocamentos migrat��rios. O presente trabalho objetivou avaliar, por meio das caracter��sticas morfom��tricas e et��ria, se os curimbat��s (P. lineatus) dos diferentes estoques migradores e residentes constituem uma ��nica popula����o, havendo intera����o entre as sub-popula����es no per��odo de piracema (migra����o reprodutiva). Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 4 x 2, com quatro tipos de estoques (um residente e tr��s migradores) e dois sexos (macho e f��mea) com trinta repeti����es, considerando cada peixe como unidade experimental. Foi observada varia����o de 80,19% para o primeiro componente principal e 8,09% do segundo componente principal fornecida pelas dez vari��veis morfom��tricas dos estoques residentes e migradores. O estoque residente correspondeu aos maiores valores para todas as vari��veis morfom��tricas. Houve sobreposi����o dos escores individuais das mesmas caracter��sticas entre os estoques migradores. Observou-se predomin��ncia de machos entre os estoques residentes e migrador I e II. As semelhan��as morfom��tricas verificadas entre os estoques migradores indicam tratar-se de uma ��nica popula����o, com pequenas varia����es interpopulacional.

Changes in biomass, chemical composition and nutritive value of Spartina alterniflora due to organic pollution in the Itanha��m River Basin (SP, Brazil)

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Microsatellite analysis of pacu broodstocks used in the stocking program of Paranapanema River, Brazil

O monitoramento da diversidade gen��tica �� fundamental em um programa de repovoamento. Avaliouse a diversidade gen��tica de pacu Piaractus mesopotamicus (Holmberg, 1887) em duas esta����es de piscicultura em Andir�� -Paran��, Brasil, utilizadas no programa de repovoamento do Rio Paranapanema. Foram amplificados seis loci microssat��lite para avaliar 60 amostras de nadadeira. O estoque de reprodutores B apresentou maior n��mero de alelos e heterozigose (alelos: 22 e H O: 0,628) que o estoque de reprodutores A (alelos: 21 e H O: 0,600). Alelos com baixos n��veis de frequ��ncia foram observados nos dois estoques. Os coeficientes positivos de endogamia no locus Pme2 (estoque A: F IS = 0,30 e estoque B: F IS = 0,20), Pme5 (estoque B: F IS = 0,15), Pme14 (estoque A: F IS = 0,07) e Pme28 (estoque A: F IS = 0,24 e estoque B: F IS = 0,20), indicaram defici��ncia de heterozigotos. Foi detectada a presen��a de um alelo nulo no l��cus Pme2. As estimativas negativas nos loci Pme4 (estoque A: F IS = -0,43 e estoque B: F IS= -0,37), Pme5 (estoque A: F IS = - 0,11), Pme14 (estoque B: F IS = - 0,15) e Pme32 (estoque A: F IS = - 0,93 e estoque B: F IS = - 0,60) foram indicativas de excesso de heterozigotos. Foi evidenciado desequil��brio de liga����o e riqueza al��lica baixa s�� no estoque A. A diversidade gen��tica de Nei foi alta nos dois estoques. A dist��ncia (0,085) e identidade (0,918) gen��tica mostraram similaridade entre os estoques, o qual reflete uma poss��vel origem comum. 6,05% da vari��ncia gen��tica total foi devida a diferen��as entre os estoques. Foi observado um recente efeito gargalo nos dois estoques. Os resultados indicaram uma alta diversidade gen��tica nos estoques de reprodutores e baixa diferencia����o gen��tica entre eles, o que foi causado pelo manejo reprodutivo das pisciculturas, redu����o do tamanho populacional e interc��mbio gen��tico entre as pisciculturas.

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: new insights from molecular data

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Effect of nitrite on larval development of giant river prawn Macrobrachium rosenbergii

The effects of ambient nitrite concentrations on larval development of giant river prawn Macrobrachium rosenbergii were evaluated. The trials were conducted in two phases: phase 1, larvae from stages I through VIII and phase 2, larvae from stage VIII until post-larvae. In both phases larvae were kept in water with nitrite (NO2-N) concentrations of 0, 2, 4, 8 and 16 mg/L. Oxygen consumption was analyzed for larvae in stage II at nitrite concentrations of 0, 4, and 8 mg/L. Survival, weight gain, larval stage index and metamorphosis rate decreased linearly with increasing ambient nitrite concentration. However, there was no significant difference between larvae subjected to 0 and 2 mg/L NO2-N. In phase 1, there was total mortality at 16 mg/L NO2-N, while in phase 2 larval development stopped at stage X in this treatment. The oxygen consumption in stage II increased significantly at NO2-N concentration from 0 to 4 mg/L, but there was no difference between 4 and 8 mg/L NO2-N. In conclusion, increasing ambient nitrite up to 16 mg/L NO2-N delays larval development, reduces larval growth rate and causes mortality, whereas no significant effect occurs for levels below 2 mg/L NO2-N. However, the establishment of a general safe level of nitrite to M rosenbergii hatchery may be difficult due to the great variability in larvae individual sensitivity. (c) 2006 Elsevier B.V. All rights reserved.

Effect of intensification on grow out of the Amazon River prawn, Macrobrachium amazonicum

The effects of intensification on growth, survival, productivity, population structure, and distribution of harvested biomass in individual size classes of Macrobrachium amazonicum in semi-intensive culture were evaluated. Postlarvae (0.01 g) were stocked in 12 ponds at densities of 10, 20, 40, and 80/m(2) (three replicates per treatment) and raised for 5.5 mo. Average individual weight significantly decreased and productivity significantly increased as stocking density increased (P < 0.001), while survival was not affected (P > 0.05). Prawn mean weight at harvest ranged from 3.6 (80/m(2)) to 7.0 g (10/m(2)). Average survival ranged from 65.5% (40/m(2)) to 72.8% (20/m(2)), while productivity ranged from 508 (10/m(2)) to 2051 kg/ha (80/m(2)). Harvested biomass showed a clear bimodal distribution in individual size classes indicating the occurrence of heterogeneous growth, which may affect management and market strategies. Harvested biomass of prawns weighing more than 7 g (the best market size) increases for stocking densities up to 40/m(2) and stabilizes between 40 and 80/m(2). Growth reduction was associated with a decreasing frequency and average weight of green claw 1 and green claw 2 male morphotypes and adult females as density increased. Thus, the distribution of male morphotypes and sexually mature females are affected by density-dependent factors. Results suggest that prawn density plays an important role on M. amazonicum grow-out phase, as has been demonstrated for other species of the genus Macrobrachium. M. amazonicum tolerates grow-out intensification and may be raised in both semi-intensive and intensive systems stocked at very high densities yielding high productivity.

Effect of density on population development in the Amazon River prawn Macrobrachium amazonicum

Funda����o de Amparo �� Pesquisa do Estado de S��o Paulo (FAPESP)

Ontogenetic Variation in Ammonia Excretion during the Early Life Stages of the Amazon River Prawn, Macrobrachium amazonicum

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Sensory aspects of liquid smoking of giant river prawn: comparison with traditional smoking

P>The purpose of this paper is to investigate the impact of liquid smoke on the sensory characteristics of giant river prawn (Macrobrachium rosenbergii). The sensorial profile was plotted using quantitative descriptive analysis and assessment of the acceptability of samples of beheaded and peeled and only beheaded freshwater prawns smoked using the traditional method or liquid smoke (LS). The prawns subjected to LS were characterised by their aroma, artificial flavour and bitter flavour. The beheaded, peeled prawns were found to be more acceptable, confirming that the presence of the shell is a limiting factor in the acceptability of smoked prawns.

Maturation and growth curves of Macrobrachium Carcinus (Linnaeus) (Crustacea, Decapoda, Palaemonidae) from Ribeira de Iguape River, southern Brazil

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Reproductive indices in natural nests of giant Amazon river turtles Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) in the Environmental Protection Area Meanders of the Araguaia river

Realizou-se a contagem dos ovos n��o eclodidos, dos filhotes vivos e mortos de Podocnemis expansa oriundos de 327 ninhos naturais, localizados nas praias da ��rea de Prote����o Ambiental (APA) - Meandros do Rio Araguaia, onde se determinou a porcentagem de eclos��o dos ovos (94,63%); n��o eclos��o (5,37%); sobreviv��ncia (94,24%) e mortalidade dos filhotes (5,76%), e a m��dia de filhotes mortos durante os 15 dias no ber����rio (0,97%). A m��dia do total de filhotes por ninho foi determinada pela soma do n��mero de filhotes vivos e mortos divididos pelo total de ninhos, enquanto que a m��dia do total de ovos por ninho foi determinada pela soma do n��mero de filhotes vivos, mortos e ovos n��o eclodidos divididos pelo total de ninhos. Com isso, obtiveram-se os valores m��dios do n��mero de filhotes vivos (88,98 �� 23,94); mortos (0,37 �� 0,93); ovos n��o eclodidos (5,07 �� 9,57), e total de ovos (94,42 �� 21,30). A efici��ncia reprodutiva da popula����o selvagem de P. expansa pode ser afetada por muitos fatores ambientais, como temperatura, umidade e precipita����o. Al��m disso, fatores influenciados pelo homem, como a presen��a de produtos qu��micos na ��gua e a possibilidade de doen��as infecciosas, tamb��m t��m impacto significativo. Os dados dos ��ndices reprodutivos obtidos neste estudo s��o indispens��veis para futuras investiga����es de anomalias de incuba����o.

Histopathology of gills of Piaractus mesopotamicus (Holmberg, 1887) and Prochilodus lineatus (Valenciennes, 1836) infested by monogenean and myxosporea, caugth in Aquidauana River, State of Mato Grosso do Sul, Brazil

Realizou-se an��lise histol��gica de br��nquias de 15 esp��cimes de Piaractus mesopotamicus e 19 Prochilodus lineatus coletados de abril a novembro de 2004, no Rio Aquidauana, MS, com intuito de contribuir com achados anatomopatol��gicos em br��nquias dessas esp��cies de peixes de ��gua doce. Amostras de br��nquias foram fixadas em formalina 10%, tamponadas e processadas conforme rotina histol��gica. em P. mesopotamicus observou-se presen��a de monog��nea e cistos de mixospor��dio da esp��cie Henneguya piaractus, com localiza����o intralamelar em v��rios est��gios de desenvolvimento, localizados em todas as regi��es (basal, mediana ou distal) das lamelas. Cistos intraepiteliais causaram dilata����o e deforma����o das lamelas vizinhas. em br��nquias de P. lineatus, observou-se presen��a de monog��nea. Nas duas esp��cies de hospedeiro foram registradas hiperplasia do epit��lio branquial e desorganiza����o estrutural das lamelas em extensas regi��es, altera����es que causaram a fus��o lamelar. em poucos casos registrou-se presen��a de c��lulas inflamat��rias mononucleares e focos hemorr��gicos na regi��o distal das lamelas.

Haematological and gill responses in parasitized tilapia from valley of Tijucas River, SC, Brazil

Conselho Nacional de Desenvolvimento Cient��fico e Tecnol��gico (CNPq)

Suckling and allosuckling in river buffalo calves and its relation with weight gain

The aim of the present study was to investigate if river buffalo calves (Bubalus bubalis) have equal access to all cows and if milk is thus equally available to all of them. We recorded suckling/allosuckling behaviour and weight gain (WG) of 29 calves (14 males and 15 females), with special consideration to their sex, birth order (BO) and age. Cows' nursing behaviour and milli production (MP) were also considered. While males tended to be born earlier than females during this study, this was not the trend in the overall herd records. The cows' MP was not effected by the calves' sex. However, bull-calves presented greater mean WG, and mean times spent in individual filial (IF) and in communal nonfilial (CNF) suckling than heifer-calves, which showed greater communal filial (CF) suckling than the former during the first 4 months of life. The WG was associated with IF for bull-calves (r = 0.680 and 0.765, respectively, for the periods from birth to 4th and 8th months of age), and to CNF for heifer-calves (r = 0.628, for the period from birth to 8th month). Results from multiple regression analysis showed independent effects of each suckling category on the calf WG, and such effects were variable according to the calf's sex. BO was negatively correlated to calves' WG (bull-calves: r(s) = - 0.873 and - 0.799, from birth to 4th and gth months, respectively; heifer-calves: r(s) = - 0.531 from birth to 4th month). Specifically for bull-calves, there was a positive correlation between BO and MP (r(s) = 0.528 and 0.633, from birth to 4th and 8th months of age, respectively). The correlation between BO and IF was negative in both sexes, indicating that calves that were born early had more opportunities to suckle individually from their mothers. For heifer-calves, BO was positively correlated with CF (two periods), and negatively with CNF (from birth to 8th month of age), suggesting that heifer-calves were most often accompanied by other calves during suckling when they were born later. The data taken together indicate that sex and/or BO influenced decisively social interactions during suckling, promoting differential development among the calves. In animal husbandry, if a homogenous WG is desired, these factors have to be taken into consideration. (C) 2000 Elsevier B.V. B.V. All rights reserved.