Historical Biogeography of <i>Penaeus</i> Prawns (Crustacea: Decapoda: Penaeidae)

ABSTRACT Aim Genus Penaeus Fabricius, 1798 has a circum‐global distribution with a peak in species diversity in the Central Indo‐Pacific region. This study aims to explore the origin and biogeographic history of the genus, and to identify the major biogeographic processes underlying its present‐day distribution. Besides, we also try to revisit the ‘center of’ hypotheses from an invertebrate perspective. Location Tropical to temperate oceans worldwide. Methods We constructed a time‐calibrated phylogeny using sequences from 4 nuclear and 3 mitochondrial genes of 31 Penaeus species, upon which we conducted ancestral area reconstruction and biogeographical stochastic mapping to explore the biogeographic history of the genus. Results We found that Penaeus originated from the Tethys about 200 MYA and spread to the Atlantic about 135 MYA, soon after the Atlantic Ocean emerged, after which lineages in the two oceans evolved independently. During the Cretaceous, the biodiversity hotpots shifted from Tethys eastward to the Central Indo‐Pacific, where most of the cladogenesis events (mostly within region) of Penaeus occurred. Most other regions accumulated species richness by receiving dispersal from neighbouring regions. Main Conclusions Major biogeographic events, including the closure of the Tethys, the Cretaceous Thermal Maximum, and the formation of the Isthmus of Panama, have shaped the evolutionary history of Penaeus . The prevalence of within‐region speciation, coupled with limited immigration into the region but frequent dispersal to adjacent areas, strongly suggests that the Central Indo‐Pacific biodiversity hotspot likely functioned as a center of origin for this group. Given its role in generating and sustaining biodiversity, this region should be prioritised for conservation to safeguard its evolutionary potential and long‐term resilience.