Phoca – Harbour & spotted seals
This genus was used as a wastebasket taxon for numerous species with uncertain affinity
The genus Phoca represents a crucial group within the family of true seals or earless seals (Phocidae), characterized by their lack of external ear flaps and their streamlined bodies adapted for life in aquatic environments. This genus, which falls under the subfamily Phocinae, comprises two extant species that are widely recognized and studied: the Common Seal (Phoca vitulina), also known as the Harbor Seal, and the Spotted Seal (Phoca largha).
Phoca species are distinguished by their aquatic mating systems, a trait that sets them apart from many other pinniped species that mate on land or ice. This reproductive strategy involves complex social interactions and behaviors in the water, highlighting the seals’ adaptation to their fully aquatic lifestyle. The ability to mate in water necessitates a suite of adaptations, including excellent swimming capabilities and underwater communication.
Historically, the genus Phoca included several other species that have since been reclassified into different genera based on genetic and morphological analyses. Species such as the Ribbon Seal (now in the genus Histriophoca), Caspian Seal (Pusa caspica), Ringed Seal (Pusa hispida), Baikal Seal (Pusa sibirica), and Harp Seal (Pagophilus groenlandicus) were once grouped under Phoca but have been moved to reflect a more accurate understanding of their evolutionary relationships.
The Spotted Seal was initially considered a subspecies of the Common Seal, but it has been recognized as a distinct species due to differences in habitat, physical characteristics, and genetic makeup. This separation into different species underscores the complexity and diversity within the seal family, as well as the ongoing nature of taxonomic research in understanding the evolutionary history of these marine mammals.
Species in this genus
Harbor seal
Slows the heartbeat from 80 bpm to 3-4 bpm before a deep dive; quickly accelerates after surfacing