Abstract:
The Aach cave loach (Barbatula barbatula), a recently discovered member of the Nemacheilidae family, offers a unique opportunity to understand the mechanisms underlying evolutionary change. In a common garden experiment, we reared groups of laboratory-bred cave, surface, and hybrid loach under different light conditions. Troglomorphic characters varied significantly among the fish, influenced to a different extent by parental origin and light conditions. Cavefish progeny consistently exhibited smaller eyes, lighter pigmentation, longer barbels, and larger olfactory epithelia than surface fish, while hybrids displayed intermediate characteristics. Surface and hybrid fish raised in complete darkness resembled the cavefish phenotype, while cavefish raised under a natural photoperiod approached the surface form. Characters associated with eye degeneration were found to be primarily heritable. Conversely, traits related to chemo- and mechano-reception were enhanced in the surface and hybrid groups reared in complete darkness, suggesting phenotypic plasticity. Our findings offer valuable insights into the interplay between genetic differentiation and phenotypic plasticity to troglomorphic adaption. This contributes to the broader understanding of the early stages of adaptation, where phenotypic plasticity, drift, and selection shape phenotypes. Relatively recently established cavefish, such as the Aach cave loach, are promising candidates for comparative research investigating evolutionary mechanisms.
摘要:
Aach洞穴泥ach(Barbatulabarbatula),最近发现的Nemacheilidae家族成员,提供了一个独特的机会来理解进化变化的潜在机制。在一个普通的花园实验中,我们饲养了几组实验室培育的洞穴,表面,和不同光照条件下的杂交泥菜子。鱼体形态特征差异显着,受父母起源和光照条件的不同程度影响。洞穴鱼后代始终表现出较小的眼睛,较浅的色素沉着,较长的杠铃,和比水面鱼更大的嗅觉上皮,而杂种表现出中间特征。在完全黑暗中饲养的表面和杂交鱼类似于洞穴鱼的表型,而在自然光周期下饲养的洞穴鱼接近表面形态。发现与眼睛变性相关的字符主要是可遗传的。相反,与化学和机械接收相关的特征在表面增强,杂种群体在完全黑暗中饲养,表明表型可塑性。我们的发现为遗传分化和表型可塑性之间的相互作用提供了有价值的见解。这有助于更广泛地了解适应的早期阶段,表型可塑性,漂移,和选择形状表型。相对最近建立的洞穴鱼,比如Aach洞穴泥,是比较研究进化机制的有希望的候选人。