A Mobile Ad-hoc Network (MANET) is a wireless network composed of mobile nodes with dynamically changing communication paths. The nodes in a MANET freely join or leave the network at any time, resulting in a highly flexible and self-configuring topology. However, excessive end-to-end latency, poor dynamic topology adaptation, and uneven energy consumption are common problems with traditional routing protocols. To tackle these issues, this paper proposes a White Shark Optimization-based Routing Protocol (WSO-RP) for reducing end-to-end delay in MANETs. WSO-RP concentrate on minimising end to end delay whereas sustaining high packet delivery ratio and balanced energy usage.  WSO stimulated by the intelligent hunting and navigation behaviour of white sharks, the WSO algorithm effectively balances exploration and exploitation to discover optimal routing paths. The proposed protocol considers key routing metrics such as link stability, node residual energy, hop count, and delay to guide route selection. WSO-RP significantly outperforms conventional and other bio-inspired routing protocols in terms of lower end-to-end delay, and higher packet delivery ratio, for real-time and delay-sensitive MANET applications.