The morphology, and embryonic and larval development of copepod Tisbe furcata were observed. The results showed that the copepod was gonochorism without significantly greater prosome than urosome. The head segment is found to be connected to the first segments with extruding forehead, and flexing point in the body was found between the fourth and fifth segments. The first antenna is singular in shape,and has 8 segments while the second antenna is double. Thoracic appendages No 1-4 are double, with 2 inner podites and 3 exopodites. There is an armoured plate between a pair of swimming leg. The thoracic appendage No 5 have one segment with 4 setae. In a female , the first and second abdominal segments are jointed to form a genital segment with two egg sacs. The copepod has an egg with diameter of 20-25 |xm. The morphological characteristics and development rate were described in all development stages under a microscope. The embryonic development was lasted 28-30 h in the copepod at (21 ±l)t , pH 7.8 and a salinity of 32±1. The six nauplius development were taken for (3±1. 5) ,(11±1. 2) ,(30± 1.2),(45±1.0),(62±1.0)h and (75±1.2 )h, respectively, with mean body length were 0.080, 0. 106, 0. 144, 0. 196, 0.225 mm and 0. 268 mm, respectively. The duration of five copepodid development were ( 100± 2.0),(128±1.5),(153±1.0),(178±1.2)hand (204±1.5)h, respectively, with body length of 0. 311, 0.468, 0. 539, 0. 726 mm and 1.036 mm, respectively. The first adult star female and male were observed in (232±1.5) h, with body length of 1.086 mm for male and 1. 125 mm for female.%研究了分叉小猛水蚤Tisbe furcata的外部形态和发育特征.结果表明:分叉小猛水蚤为雌雄异体,前体部并不显著宽于后体部,头节与第一胸节愈合,额部突出,身体的活动关节在第四和第五胸节之间.第一触角呈单肢型,分为八节,第二触角为双肢型；第一至第四胸足均为双肢型,内肢为两节,外肢为三节,每对胸足之间具一个几丁质板,第五胸足为一节,附4根刚毛.雌性腹部第一、二节愈合成生殖节,生殖节上有两个卵囊.分叉小猛水蚤卵径为20～25 μm.在温度为(21±1)℃、盐度为32±1、pH为7.8的条件下,胚胎发育时间共需28～30 h.无节幼体Ⅰ～Ⅵ期的累计发育时间分别为(3±1.5)、(11±1.2)、(30±1.2)、(45±1.0)、(62±1.0)、(75±1.2)h,平均体长分别为0.080、0.106、0.144、0.196、0.225、0.268 mm;桡足幼体Ⅰ～V期的累计发育时间分别为(100±2.0)、(128±1.5)、(153±1.0)、(178±1.2)、(204±1.5)h,平均体长分别为0.311、0.468、0.539、0.726、1.036 mm;一龄桡足幼体成体的雌雄发育时间均为(232±1.5)h,平均体长分别为1.086 mm和1.125mm.
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