Occurrence of Karenia papilionacea (Dinophyceae) and its novel sister phylotype in Japanese coastal waters.

Several species of the genus Karenia (Dinophyceae) form blooms and often cause the mortality of cultured and wild fish. In Japan, blooms caused by two species - namely Karenia mikimotoi and Karenia brevis - have been reported so far. On the basis of morphological and molecular-phylogenic examinations, the present investigation found Karenia papilionacea and its novel sister phylotype for the first time in the coastal waters of the various regions of Japan. Of 34 strains isolated from the coastal waters, 27 strains displayed the typical morphological characteristics of K. papilionacea and further showed consensus DNA sequences corresponding to those of the originally described K. papilionacea. The other 7 strains displayed the same morphological characteristics of K. papilionacea, but showed divergent DNA sequences, at a genetic distance of over 0.04 (Internal Transcribed Spacer regions) from those of the original phylotype of K. papilionacea. These divergent strains were characterized as a novel sister phylotype (phylotype-I) of K. papilionacea. In the coastal waters of Japan, K. papilionacea-like (K. papilionacea and/or its phylotype-I) formed blooms at 20.3-30.4°C and salinity 30.1-33.9. No K. brevis was identified in Japanese coastal waters during this study. These findings demonstrated that K. papilionacea occurs along the coasts of western Japan and possibly shares several coastal regions with K. mikimotoi and K. papilionacea phylotype-I. In order to assess the risks of Karenia blooms to aquaculture, it is essential that the growth physiology and ichthyotoxicity of K. papilionacea and its novel phylotype should be characterized.

Paleomagnetic dates of hominid remains from Yuanmou, China, and other Asian sites.

Two hominid upper central incisors found in the Yuanmou Basin in southwest China in 1965 have affinities with Homo erectus fossils from Zhoukoudian, but exhibit primitive features. The Yuanmou hominid remains are alleged to be coeval with or older than African specimens dated at about 1.8 m.y.a. Recent age refinements of geomagnetic short reversal events and excursions permit assigning the Yuanmou hominid-bearing bed to the early Brunhes chron (about 0.7 m.y.a.). Magnetochronological assessments confirm that the Lantian calotte which has been dated to about 1.2 m.y.a., is the oldest reliable evidence for the emergence of Homo in eastern Asia as well as China, and that hominid fossils from Sangiran and Mojokerto, Java, do not exceed 1.1 Ma in age. These results refute the view that the genus Homo migrated into eastern Asia in the late Pliocene or the earliest Pleistocene.