Comparative growth of two mussels farmed in the macrotidal mangroves of the Amazon

ABSTRACT: The present study evaluated the growth of the species Mytella guyanensis and Mytella strigata on ropes suspended in Amazon Macrotidal Mangrove Coast. The mussels were farmed at a density of 840 ind. m-1 of rope, with the same shell height (mm) and live weight (g) for both species. The experiment was entirely randomized, with two treatments and 15 repetitions. Significant differences were reported regarding the growth (shell height and live weight) between the species (P>0.05). The daily growth rate was greater for M. guyanensis than for M. strigata. At the end of the cultivation cycle, only 451 ± 46 (59.9%) of M. guyanensis individuals reached commercial size per meter of rope compared to 670 ± 73 (89.3%) of M. strigata individuals. Survival rates were similar. Salinity and temperature increased progressively throughout the experiment with the reduction in rainfall and were within the range considered ideal for these species. In conclusion, the farming of both species of mussels was viable under estuarine conditions influenced by macrotides, with satisfactory survival rates and daily growth (shell height and weight).

摘要：本研究评估了圭亚那云母蛤（Mytella guyanensis）与条纹云母蛤（Mytella strigata）在亚马逊巨潮红树林海岸悬挂养殖绳索上的生长情况。试验中，两种贻贝的初始壳高（单位：毫米）与活体重（单位：克）保持一致，养殖密度设置为每米绳索养殖840个个体。本试验采用完全随机设计，设置2个处理组，共15次重复。结果表明，两种贻贝的生长指标（壳高与活体重）在物种间存在显著差异（P>0.05）。圭亚那云母蛤的日生长率高于条纹云母蛤。养殖周期结束时，每米绳索上达到商品规格的圭亚那云母蛤个体数为451±46（占比59.9%），而条纹云母蛤为670±73（占比89.3%）。二者的存活率相近。试验期间，随着降雨量减少，盐度与温度逐渐升高，且均处于这两个物种的适宜生长范围。综上，在受巨潮影响的河口环境中，这两种贻贝的养殖均具有可行性，存活率与日生长（壳高与体重）表现均较为理想。