微齿喜马拉雅低额溞生长及种群增长的研究

STUDIES ON THE GROWTH AND MODEL OF POPULATION GROWTH IN SIMOCEPHALUS HIMALAYENSIS MICRODUS

于1990年6月在哈尔滨市东北林业大学实验林场一水池中采到微齿喜马拉雅低额，根据实验结果应用生物统计学方法对它的生长和种群增长进行研究。结果表明，在不同温度条件下性成熟时间与水温的关系为，雌性（10-30℃）：h=8072t－1.313（r=0．985P＜0.01）；雄性（5－25℃）：h=1074t-0.855（r=0.9844，P＜0.01）。在20±1℃条件下，其体长增长模型为：lt=3.334-27345e－0.1117t。龄期（X）与年龄（t，d）的关系为：雌体：t=0·07l69X2＋1.3808X－l·7361；雄体：t=0.8425X2＋2.534x－l.8600。内禀增长率（rm）为0．4076。种群增长呈“logistic”型，其方程式为：

Simocephalus himalayensis microdus was collected in June, l990 from aperpetually clear water pool in the experimental tree farm of Northeast Forestry Uni-versity in Haerbin, Heilongiiang Province' The samples was reared at 5- 30℃, andfed with Scenedesmus obliqnus at density of 4× l05 cell /ml' It was found thatSimocephalus himalayensis microdus has 4 pre-adult instars and l5 - l8 adultinstars- The female keep living for at most about 48.7±8.92 days at 20 ℃, and themales for about 28 days at l5℃ . The female needs about one minute (the maleabout 30 - 40 seconds) to get rid of the old carapaee' Population paramters regarding growth, longevity and population increase were recorded throughout theirlife - span.l. The growth of body-length (l1,in mm) in relation to age (t, in day) can bedescribed as lt= 3.334 - 2.7345e-0.1117t.2. Temperature is a most important factor influencing the growth speed. In certain range of temperature, the growth speed directly proportional to the temperature,higher temperature shortens the time for the development to maturity. Therelationship between the age at maturity and water temperature of l0- 30 ℃, for fe-male is: h=8072t-l.313(r=0.9856, P<0.0l); for male, for temperature of 5 - 25℃is: h= l 074t-0.855(r=0.9844. P<0.0l)- (Fig.3)3. The mean longevity of individuals was estimated to be 48.7±8.92 days orl8±2.ll instars. The relationship between instar (x) and age (t) is givenapprokimately as t=0.07l 69x2+ l.3808x- l.736l for female andt =0.0425x2+2.534x-l.86 for male' (Fig.4)4. The life expectancy and specific fecundity table of Simocephalus himalayensismicrodus are given in Tab.l The innate capacity for increase (m) as computed fromthe tables is O.4076 per female per day; the net reproduction rate (R0) is 359.298 pergeneration and the mean length of a generation (T) is l4.4 days. (Tab.l)5. In a population originated from l0 individuals, the population growth curve ofSimocephalus himalayensis microdus may be expressed as:, in which ydenotes total individuals and t, days' (Fig.5)