The epidermal mucus secreted by fish is a natural barrier between fish and water, which is a slippery and slightly thick fluid with some biological functions. The present work is to characterize the viscoelastic property of a loach skin mucus published recently by using a viscoelastic model with four hypotheses. The experimental steady shear viscosity with the maximum shear rate of 10 s⁻¹ for the mucus was fitted to obtain the parameters in the model. The other four steady shear viscosity curves with the maximum shear rate of 0.004, 0.01, 0.1, and 1.0 s⁻¹, respectively, and the start-up experiment at the shear rate of 0.1 s⁻¹ were predicted. The phenomenon that the viscosity at the low shear rate in the decreasing shear rate regime is higher than that in the increasing shear rate regime can be illuminated by a structural irreversibility hypothesis, which is based on the varying linear viscoelastic property of the mucus induced by shear rate. The theoretical description on the unusual viscosity curves of the loach mucus provides a base for quantitative analysis on the mucus effect on the swimming of fish, and could promote the understanding on the swimming-related function of skin mucus in fish.

鱼分泌的表皮粘液是鱼和水之间的天然屏障，是一种湿滑的略带液体的液体，具有某些生物学功能。当前的工作是通过使用具有四个假设的粘弹性模型来表征最近发表的泥ach皮肤粘液的粘弹性特性。拟合具有最大剪切速率为10 s ^-1的粘液的实验稳态剪切粘度，以获取模型中的参数。其他四条最大剪切速率分别为0.004、0.01、0.1和1.0 s ^-1的稳态剪切粘度曲线，以及在0.1 s ^-1的剪切速率下的启动实验被预测。结构不可逆性假说可以阐明低剪切速率下低剪切速率下的粘度高于增加剪切速率下的现象，该结构不可逆性假说是基于剪切引起的粘液线性粘弹性的变化而得出的。速度。对泥ach异常黏度曲线的理论描述为定量分析黏液对鱼类游动的作用提供了基础，并可以增进对鱼类皮肤黏液游动相关功能的认识。