Mitsuo Sakai

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Cephalopods are a relatively small class of molluscs (~800 species), but they support some large industrial scale fisheries and numerous small-scale, local, artisanal fisheries. For several decades, landings of cephalopods globally have grown against a background of total finfish landings levelling off and then declining. There is now evidence that in(More)
The pronghorn spiny lobster, Panulirus penicillatus, is a circumtropical species which has the widest global distribution among all the species of spiny lobster, ranging throughout the entire Indo-Pacific region. Partial nucleotide sequences of mitochondrial DNA COI (1,142-1,207 bp) and 16S rDNA (535-546 bp) regions were determined for adult and phyllosoma(More)
A total of 110 adult individuals from four ommastrephid (family Ommastrephidae) squid species (Ommastrephes bartramii, Sthenoteuthis oualaniensis, Eucleoteuthis luminosa, and Hyaloteuthis pelagica) were used to obtain diagnostic DNA markers for species identification. Restriction fragment length polymorphism (RFLP) analysis of a partial segment (855 bp) of(More)
We compared the diet of Ommastrephes bartramii paralarvae with morphological changes in their beaks and proboscis (fused tentacles). The paralarvae were collected north of the Hawaiian Islands during 2001 and 2002 and ranged in mantle length (ML) from 1.1 to 13.2 mm. They fed on crustaceans, including copepods (copepodite stage) and amphipods. The rostral(More)
We constructed the habitat suitability index (HSI) model of the winter-spring cohort of neon flying squid (Ommastrephes bartramii) for the estimate of its potential fishing zone off shore of Sanriku coast by applying Generalized Additive Model (GAM), which includes the stock term describing the effect of interannual change in the squid stocks. The results(More)
Ommastrephidae are the most important commercial fishery group among cephalopods. However, little is known about their embryonic development. This article provides details of embryonic development observed in three ommastrephids: Ommastrephes bartramii, Sthenoteuthis oualaniensis, and Eucleoteuthis luminosa. All embryos were obtained through artificial(More)
The present study seeks to incorporate a highly variable DNA barcode marker, additional to the standard regions of the cytochrome oxidase I gene and the 3′ end of the 16S large ribosomal subunit (16S rRNA), for a more effective species-level identification among cephalopods. Thus, we evaluated whether the 5′ end region of the 16S rRNA gene can be suitable(More)
Drifting gill-nets were for a long time the main research gear for investigating the distribution of Pacific saury Cololabis saira. However, it has proven to be difficult to estimate the absolute abundance of saury using drifting gill-nets due to a lack of knowledge on the survey areas swept by these gill-nets. A mid-water trawl stock abundance estimation(More)
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