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Observations of the Development of the Post-Embryo of the Shrimp, Palaemon Paucidens スジエビの後期胚発生について NAKAMURA, Kaworu 中村, 薫 BABA, Kazuo 馬場, 和郎 open access Post-embryonic development was observed for the freshwater shrimp, Palaemon paucidens, under 19-25°C. The 1st antenna showed a biramous type at the egg-nauplius period of 60-80 hours after spawning. It returned to an uniramous type after that and continued its development as it was since appearances of the 1st maxilla and successors at 104 hours after spawning. The 2nd antenna showed also as the 1st antenna the biramous at the egg-nauplius period, however, continued its development without returning to the uniramous after that. Both of the antennae developed mainly their length towards the posterior pole during their early period of development until about 6th day, showing almost no expansion of width. Since about 7th day, especially at the distal ends of antennae, expansive development was recognized, accompanying with the annulus formation. The formation of annuli began surely at the distal at least in the case of antennae, and at 17th day just before hatching the 1st and 2nd antennae possessed 3 and 2 annuli, respectively. Each of the head ganglions differentiated in the proximal areas of the optic lobe, 1st and 2nd antennae at 50 hours after spawning. The fore-brain became to be formed firstly by approaching and fusion of each paired ganglion of the proximal of the optic lobe at 176 hours after spawning. At 14th day, the mid- and hind-brains were formed by the same procedure as the former except their origin. The mid- and hind-brains derived from each proximal of the 1st and 2nd antennae, respectively. The hind-brain held the fore-gut between its paired posterior portion. It took about 18 days during the embryonic development. 鹿児島大学 Kagoshima University 1982-12-25 eng departmental bulletin paper VoR http://hdl.handle.net/10232/13257 https://ir.kagoshima-u.ac.jp/records/12770 0453087X AN00040498 鹿児島大学水産学部紀要 Memoirs of Faculty of Fisheries Kagoshima University 31 125 139 https://ir.kagoshima-u.ac.jp/record/12770/files/AN00040498_v31_p125-139.pdf application/pdf 2.0 MB 2016-10-31 1982-12-25