We separated tertiary egg membrane （TGM） from 2- and 25-day-old eggs of cuttlefish Sepiella maindroni de Rochebrune, and revealed its ultrastructure, physical （solubility, barrier property） and biochemical （histology, histochemistry, nutritional components, bacteriostasis） characteristics. The results show that TGM could not be dissolved with natural seawater, alcohol, ether or hydrochloric acid （HC1）, but it could be dissolved with 2-chloroethanol, diethylamine, and sodium hydroxide （NaOH）. The black TGM was more effective in blocking off mud particulates, microorganisms （Chlorella vulgaris, Vibrio alginolyticus） and lighter than the white TGM. The elasticity of black and white TGMs was 1.8 N and 1.5 N, respectively. There were some ink particulates and rod-shaped bacteria in the black TGM. The nutritional components were different between black and white TGMs： Lipid content was lower and protein content was higher in the black TGM. TGM could also inhibit the growth of Vibrio alginolyticus.
Sperm motility is important in reproductive biology. To understand the physiological ecology characteristics of sperm of Sepiella maindroni, we studied the activation rate, active time, and lifespan of sperm to evaluate the influence of external factors, including temperature, salinity, pH, glucose, NaCl, KCl, MgCl2, CaCl2, EDTA-2Na and artificial seawater on sperm motility. The results show that the appropriate activation and motility condition for sperm were： temperature 20-30℃ （optimum 25℃）, salinity 10.6-30.6 （optimum 15.9） and pH 8.0-8.6 （optimum 8.0-8.4）. Sperm activity varied in different concentrations of glucose, NaCl, KCl, MgCl2 and CaCl〉 None of the selected concentrations of EDTA-2Na solution could activate the sperm. The activation rate in artificial seawater devoid of Ca2＋, Mg2＋ or HCO3- was low. The results should help further studies on the preservation and activation of squid sperm.
