Two female specimens of bioinvasive spider crab Acanthonyx euryseroche Griffin & Tranter, 1986 were collected alive in association with brown seaweeds from lower intertidal zone of Buleji (24^o50'356"N 66^o49'368"E) situated in the vicinity of the largest shipping port along the Karachi coast, Pakistan (Northern Arabian Sea). Collected Acanthonyx euryseroche transported to laboratory and housed in sea water filled glass aquarium for further taxonomic studies. Any previous published record of occurrence of this species is not available from Pakistan. Main feature of this species observed to have seaweeds leafy structures affixed on their head region that they use for camouflage thus hide themselves inside the seaweeds for protection purpose. A. euryseroche has been declared invasive alien species to the Indo-Pak region. Invasive alien species (IAS) spread outside of their natural distribution and considered a threat to indigenous biodiversity. Entry of this alien species in Pakistani water could be destructive to the native species. Hence, occurrence of A. euryseroche requires more rigorous study, monitoring and management plan.