24．（3 分）科研人员对江苏某地沿海滩涂米草群落和裸露泥滩的大型底栖（土壤）动物丰富度进行了对比研究．在相同取样条件下，利用一种常用底泥采样器（50cm X 50cm X30cm）采得各动物类群的物种数和个体总数如下表．下列有关本研究的叙述，正确的有（ ）
<table><tr><td colspan="1" rowspan="2"></td><td colspan="2" rowspan="1">招潮蟹类</td><td colspan="2" rowspan="1">厚蟹类</td><td colspan="2" rowspan="1">沙蚕类</td><td colspan="2" rowspan="1">泥螺类</td><td colspan="2" rowspan="1">蛤类</td></tr><tr><td colspan="1" rowspan="1">物种</td><td colspan="1" rowspan="1">个体</td><td colspan="1" rowspan="1">物种</td><td colspan="1" rowspan="1">个体</td><td colspan="1" rowspan="1">物种</td><td colspan="1" rowspan="1">个</td><td colspan="1" rowspan="1">物</td><td colspan="1" rowspan="1">个</td><td colspan="1" rowspan="1">物</td><td colspan="1" rowspan="1">个</td></tr><tr><td colspan="1" rowspan="1"></td><td colspan="1" rowspan="1">数</td><td colspan="1" rowspan="1">总数</td><td colspan="1" rowspan="1">数</td><td colspan="1" rowspan="1">总数</td><td colspan="1" rowspan="1">数</td><td colspan="1" rowspan="1">体总数</td><td colspan="1" rowspan="1">种数</td><td colspan="1" rowspan="1">体总数</td><td colspan="1" rowspan="1">种数</td><td colspan="1" rowspan="1">体总数</td></tr><tr><td colspan="1" rowspan="1">裸露泥滩</td><td colspan="1" rowspan="1">5</td><td colspan="1" rowspan="1">18</td><td colspan="1" rowspan="1">1</td><td colspan="1" rowspan="1">14</td><td colspan="1" rowspan="1">2</td><td colspan="1" rowspan="1">12</td><td colspan="1" rowspan="1">1</td><td colspan="1" rowspan="1">10</td><td colspan="1" rowspan="1">2</td><td colspan="1" rowspan="1">14</td></tr><tr><td colspan="1" rowspan="1">米草群落</td><td colspan="1" rowspan="1">3</td><td colspan="1" rowspan="1">12</td><td colspan="1" rowspan="1">2</td><td colspan="1" rowspan="1">9</td><td colspan="1" rowspan="1">0</td><td colspan="1" rowspan="1">0</td><td colspan="1" rowspan="1">1</td><td colspan="1" rowspan="1">10</td><td colspan="1" rowspan="1">0</td><td colspan="1" rowspan="1">0</td></tr></table>
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