In the mobile sedimentary environment of San Antonio Bay (northern Patagonia), where hard substrate is scarce, the mussel Brachidontes rodriguezii dominates the intertidal zone, there being covered by the introduced epibiotic barnacle Balanus glandula. The aim of this study was to evaluate the distribution and the recruitment of B. glandula on different non-living substrates (cobbles, biogenic debris) and on live-mussel shells and to assess the effect of the epibiotic interaction on the condition index and the attachment strength of B. rodriguezii. Field samplings revealed that adult barnacles mainly fouled live mussels, with the main differences in biomass being between the high and mid-intertidal. These differences in barnacle biomass between heights and substrates were greater in spring and autumn than in winter and summer. To assess the recruitment of barnacles, we performed a field experiment manipulating living and non-living substrates. We found no differences in the density of barnacles recruitment; thus, the barnacle distribution on different substrates throughout the intertidal would vary solely according to the settling substrates available. The relationship between epibiosis and the condition index exhibited no pattern. Furthermore, the experimental manipulation of epibiosis (i.e., removing epibionts or adding epibionts mimics) did not affect the condition of the mussels. Finally, the attachment strength of mussels with epibionts was up to fivefold greater than that of clean mussels. In a system with high tidal hydrodynamic energy, epibiosis is thus seen to stimulate a greater byssal production in mussels for the prevention of detachment.

中文翻译：

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沉积沿海环境中的外生：引入藤壶对本地贻贝的影响

在圣安东尼奥湾（巴塔哥尼亚北部）的移动沉积环境中，硬质基质稀缺，贻贝Brachidontes rodriguezii在潮间带中占主导地位，被引入的附生藤壶Balanus腺体覆盖。本研究的目的是评估腺体在不同非生物基质（鹅卵石、生物碎片）和活贻贝壳上的分布和募集，并评估附生相互作用对条件指数和B. rodriguezii 的附着强度. 现场采样显示，成年藤壶主要污染活贻贝，生物量的主要差异在高潮和中潮之间。这些高度和基质之间藤壶生物量的差异在春季和秋季大于冬季和夏季。为了评估藤壶的招募，我们进行了一项操纵活体和非活体基质的现场实验。我们发现藤壶招募的密度没有差异；因此，整个潮间带不同基质上的藤壶分布将仅根据可用的沉降基质而变化。外生和条件指数之间的关系没有表现出模式。此外，外生菌的实验操作（即去除外生菌或添加外生菌模拟物）不会影响贻贝的状况。最后，带有表生菌的贻贝的附着强度比干净的贻贝高出五倍。在具有高潮汐水动力能量的系统中，因此认为外生作用会刺激贻贝中更大的基础生产，以防止脱离。