Abstract:
Globally, marine species\' distributions are being modified due to rising ocean temperatures. Increasing evidence suggests a circum-global pattern of poleward extensions in the distributions of many tropical herbivorous species, including the ecologically important rabbitfish Siganus fuscescens. Adaptability of a species to such new environments may be heavily influenced by the composition of their gastrointestinal microbe fauna, which is fundamentally important to animal health. Siganus fuscescens thus provides an opportunity to assess the stability of gastrointestinal microbes under varying environmental conditions. The gastrointestinal microbial communities of S. fuscescens were characterized over 2,000 km of Australia\'s western coast, from tropical to temperate waters, including near its current southern distributional limit. Sequencing of the 16S rRNA gene demonstrated that each population had a distinct hindgut microbial community, and yet, 20 OTUs occurred consistently in all samples. These OTUs were considered the \'core microbiome\' and were highly abundant, composing between 31 and 54% of each population. Furthermore, levels of short chain fatty acids, an indicator of microbial fermentation activity, were similar among tropical and temperate locations. These data suggest that flexibility in the hindgut microbiome may play a role in enabling such herbivores to colonize new environments beyond their existing range.
摘要:
全球范围内,由于海洋温度上升,海洋物种的分布正在发生变化。越来越多的证据表明,在许多热带食草物种的分布中,极地延伸的全球格局,包括具有重要生态意义的兔鱼Siganusfuscescens。一个物种对这种新环境的适应性可能会受到其胃肠道微生物动物群组成的严重影响。这对动物健康至关重要。因此,Siganus镰刀菌提供了在不同环境条件下评估胃肠微生物稳定性的机会。在澳大利亚西海岸2,000多公里的地方,以S.fuscescens的胃肠道微生物群落为特征,从热带到温带水域,包括接近目前的南部分布极限。16SrRNA基因的测序表明,每个种群都有不同的后肠微生物群落,然而,20个OTU在所有样品中一致出现。这些OTU被认为是“核心微生物组”,并且非常丰富,占每个人口的31%至54%。此外,短链脂肪酸的水平,微生物发酵活性的指标,在热带和温带地区相似。这些数据表明,后肠微生物组的灵活性可能在使此类食草动物能够在其现有范围之外的新环境中定居方面发挥作用。