Investigations of stranded and by-caught beaked whales around the coastal waters of Chinese mainland

From January 2009 to February 2010,skull specimens from beaked whales stranded and by-caught around the coastal waters of Chinese mainland were measured and identified.During that time,five stranded and by-caught species of beaked whales(Ziphiidae) were discovered around Chinese mainland coastal waters including Cuvier's beaked whale(Ziphius cavirostris),Baird's beaked whale(Berardius bairdii),Longman's beaked whale(Indopacetus pacificus),Blainville's beaked whale(Mesoplodon densirostris)and Pygmy beaked whale(M.peruvianus).Among them,the Pygmy beaked whale was not only the first record in Chinese waters(including Taiwan Province),but also the first record in the Northwest Pacific Ocean.Pygmy beaked whale is characterized mainly by one pair of spindly teeth in the posterior edge of the mandibular symphysis.After re-analysis of three skull specimens of reported Ginkgo-toothed Beaked whales(Mesoplodon ginkgodens)and comparison with specimens of skull,nasal,mandible and teeth of Ginkgo-toothed beaked whales stranded in Taiwan,three specimens were re-identified as Blainville's beaked whale.Finally,in this paper,information on stranded and by-caught beaked whales around the coastal waters of Chinese mainland are summarized.