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| Early Life History of Andersson's Icefish(Neosalanx anderssoni)Inferred by Otolith Microstructure |
| XIE Han,JIN Guang-hai,XIE Yu-hao,LIU Yi-xin,LI Wen-kuan |
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Abstract The Andersson's icefish Neosalanx anderssoni has unregular round saggittae whose long radius Y(μm)was linearly related to the fish body length x(SL,mm), with the equation from 60 individuals(SL 37～52 mm)of y＝260.335+2.6234x,r＝0.3096. The microstructure of the sagittae showed that the mean diameters of core and primordum were(25.17±2.40)μm and(7.80±2.22)(SD) μm, respectively. There were from 73 to 101 rings showing daily growth increment in the otolith in 60 individuals, 78.3% of the individuals being between 83 and 97. The 1st-10th mean daily growth increment was 1.76 μm in width. Since then, its width gradually increased, with the maximum of 2.7 μm at 60～70 daily growth increment. After then, it gradually reduced with the minimum growth of body length from the first day to the tenth day(mean 0.34 mm)calculated on the basis of width of daily growth increment, the maximum occurring at 60-70 day old. The spawning period occurred from 15 April to 15 May and hatched about 10 days late based on the number of daily growth increment in the otolith and sampling time. There were 3～4 days of yolk nutrition and 6～7 days of mixed nutrition inferred by width from 1st to 11th daily growth increment. There was migration habit from inshore to estuary for searching food in the juveniles determined on the mark rings formed by induction of suddenly change in salinity(from 27～30 to 6～18).
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Received: 25 January 2010
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