Tsuguo Otake

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Three experiments addressed the question of whether pitch-accent information may be exploited in the process of recognizing spoken words in Tokyo Japanese. In a two-choice classification task, listeners judged from which of two words, differing in accentual structure, isolated syllables had been extracted (e.g., ka from baka HL or gaka LH); most judgments(More)
Nasal consonants in syllabic coda position in Japanese assimilate to the place of articulation of a following consonant. The resulting forms may be perceived as different realizations of a single underlying unit, and indeed the kana orthographies represent them with a single character. In the present study, Japanese listeners' response time to detect nasal(More)
The natural reproductive ecology of freshwater eels remained a mystery even after some of their offshore spawning areas were discovered approximately 100 years ago. In this study, we investigate the spawning ecology of freshwater eels for the first time using collections of eggs, larvae and spawning-condition adults of two species in their shared spawning(More)
Three experiments were undertaken to investigate whether young children's segmentation units would change as they learned to read kana letters, which represent morae (subsyllabic rhythmic units). The first 2 experiments used a vocal-motor segmentation task to examine whether 4- to 6-year-olds preferred to segment spoken words containing the special(More)
The distribution of all larval stages of the Japanese eel, Anguilla japonica, were examined using historical catch records and original data in the western North Pacific (WNP) to evaluate existing information about the larval distribution and migration of this species. A total of 148 preleptocephali, 2547 leptocephali, 6 metamorphosing larvae, and 21 glass(More)
To apply otolith microstructure to examination of age and growth of juvenile chum salmon Oncorhynchus keta inhabiting coastal waters, formation of otolith increments was investigated for juveniles reared in a seawater aquarium and in net pens. In all otoliths examined, a distinctive check was formed at the time of sea entry of the fish. The deposition of(More)
This paper describes a novel approach to study the expression of temperature-related reproductive phenomena such as thermolabile sex determination (TSD) and heat-induced germ cell loss in wild fish populations. The proposed approach is based on the reconstruction of the past thermal history of individual fish through the microchemical analysis of the(More)
Many biologists, physiologists, and chemists have been interested in the significance of high vanadium concentrations in ascidians since the first report on its accumulation by Henze in 1911 [1]. In spite of many efforts to find other vanadium accumulators for a comparative study, it has been thought that only ascidians in the Animal Kingdom have the(More)
After analyzing all the collection data for larvae of the Japanese eel, Anguilla japonica, in the western North Pacific, we found that the spawning site of this species appears to be near three seamounts in the West Mariana Ridge, 2000–3000 km away from their freshwater habitats. These seamounts are located in the westward flow of the North Equatorial(More)
The Japanese eel, Anguilla japonica, spawns within the North Equatorial Current that bifurcates into both northward and southward flows in its westward region, so its spawning location and larval transport dynamics seem important for understanding fluctuations in its recruitment to East Asia. Intensive research efforts determined that Japanese eels spawn(More)