Study On Changes In Biology Characteristics Of Sepiella Maindroni Offshore Zhejiang Province And Cloning And Analysis Of ALSM Gene

Sepiella maindroni once was one of the four famous marine products of our countryin1970s.But the natural resource of S. maindroni have been severely damaged beeause ofoverfishing.With the protecting and resuming of spawning ground and the releasing andenhancement of S. maindroni,the resource of S. maindroni gets well.S. maindroni canreproduce twice in a year in breeding conditions,and its biological characteristics changelargely.When S. maindroni is released into the sea,it reproduces once in a year.It isnecessary to research the changes of biological characteristics of S. maindroni from thecoastal waters of the East China Sea in Zhejiang Province.The contents of this thesisinclude changes of propagate biology, feeding habits,growth characteristics and cloning ofastacin-like squid metalloprotease of S. maindroni,which can regulate S. maindroni’sgrowth and development,and be used to explore S. maindroni’s biological characteristicchanges.1.The ovary of S. maindroni can be obviously observed in September.Thegonadosomatic index peaks in April next year.Compared with the1960s and1980s,theovary of S. maindroni develops in advance,and the breeding season extends.Ovarianquality affects S. maindroni fecundity largest.The brood amount,absolute fertility andlength relative fertility,along with ovary quality increasing,improve.2.Compared with kinds of foods of S. maindroni in1980s,now the variety of foods ofS. maindroni reduces.The plumpness coefficient of S. maindroni stomach reaches thelowest in March,only103‰,and keeps more than220‰in November and December.Theplumpness coefficient of S. maindroni stomach remains lower, compared with1980s.3. Male and female of S. maindroni are in abnormal growth state. The body length andbody weight of S. maindroni stomach remain low,compared with1980s.Compared withcultured S. maindroni, the grossness of wild S. maindroni keeps lower level.4. The ALSM gene of Sepiella maindroni was cloned for the first time,and it involvesgrowth process.Sequence analysis revealed a1418bp full-length cDNA sequencecontaining53bp5’-untranslated region,75bp3’-untranslated region and1290bp openreading frame(ORF) and this sequence was encoded by429amino acids.The bioinformaticsanalysis revealed that the predicted protein was a hydrophilic secretion protein.