Caspian and Baikal Seals: Pusa caspica and Pusa sibirica

Abstract

This chapter discusses the characteristics, taxonomy, distribution, abundance, and ecology of Baikal seals (Pusa sibirica) and Caspian seals (P. caspica). Baikal seals (Pusa sibirica) and Caspian seals (P. caspica) have common features such as small size, delicate skull, and affinity for ice. Based on mtDNA haplotypes, Caspian seals were derived from the common ancient type of Pusa 60 million years ago and were subsequently isolated in the Caspian Sea. Baikal seals were derived from a ringed-seal-like ancestor in the Arctic Ocean and isolated in Lake Baikal 40 million years ago. Baikal seals feed mainly on four fish species: the greater golomyanka (Comephorus baicalensis), the lesser golomyanka (C. dybowskii), the Baikal yellowfin sculpin (Cottocomephorus grewingki), and the longfin sculpin (C. comephoroides), all of which are not of commercial value. In captivity, an adult Baikal seal consumes up to 5.6 kg of fish per day. Based on data obtained by Argos satellite-linked transmitters, most dives of Baikal seals are to depths of 10–50 m, although a few dives exceed 300 m.