叶尔羌高原鳅胚胎发育与胚后发育观察

Embryonic and post-embryonic development of Triplophysa(Hedinichthys) yarkandensis(Day)

采用形态学和生态学方法,对叶尔羌高原鳅[Triplophysa(Hedinichthys)yarkandensis(Day)]胚胎发育和胚后发育阶段全过程进行观察、拍照并测量。结果显示:叶尔羌高原鳅,卵微黏性,略有沉性,受精卵呈卵圆形,卵径为(0.60±0.052)mm,在水温(20.0±1.0)℃下,历时65 h 34 min完成整个胚胎发育分为7个生理阶段过程;胚后发育主要根据卵黄囊、体色、鼓鳔和须的变化分为仔鱼期、稚鱼期、幼鱼期。初孵卵黄囊仔鱼全长(2.0±0.65)mm,出膜后7 d,卵黄囊吸收完毕,完全消失;初孵仔鱼继续培育至16日龄,仔鱼鳃盖后缘鼓鳔明显长出,须清晰可辨,体色加深,心脏红色素明显,体色与成体相似,标志后期仔鱼发育完全进入稚鱼期,此时鱼苗全长(8.0±0.45)mm;培育至30日龄,仔鱼鼓鳔完全,鳃盖张合明显,身体透明特征消失,稚鱼阶段完成发育进入幼鱼期,此时全长达(13.0±0.55)mm,其外部形态和生态习性均与成鱼相似。试验中,卵黄囊长度(LY)和出膜天数(D)的关系式:LY=0.0286D2–0.0636D+3.1196(R2=0.9050);用直线方程拟合卵黄囊长度(LY)和卵黄囊仔鱼全长(LT)的关系式:LY=–1.315LT+5.368(R2=0.8199);拟合卵黄囊仔鱼全长(LT)和出膜后仔稚鱼天数(D)的关系式:LT=–0.0263D2+0.5113D+1.6169(R2=0.9890)。本研究旨在通过了解叶尔羌高原鳅的早期发育特征为该物种的保护和增殖对策提供科学依据,并对其苗种生产提供理论指导。

This study determined the embryonic and post-embryonic development of the fish [Triplophysa （Hedinich-thys） yarkandensis （Day）]. The morphological and ecological traits in each development phase were described in detail using a microscope fitted with a digital camera. The fertilized eggs of Triplophysa （Hedinichthys） yarkandensis （Day） are viscous and ovoid, with a diameter of （0.60±0.052） mm （ x ±SE）. Embryonic development lasted 65 h and 34 min when incubated at a water temperature of （20.0±1.0）℃ and was categorized into seven physiological stages. Post-embryonic development was divided into a larval, a juvenile, and a growth stage based on morphological variation in the yolk sac, gas bladder, scales, body color, and barbels. Newly-hatched larvae reached an average length of （2.0±0.65） mm （ x ±SE）. At a water temperature of （20±1）℃, the yolk sac was completely absorbed 7 days after fertili-zation. After 16 d’s maintained temperature, the gas bladder drum at the rear edge of the gill cover had grown to a visi-ble size, the body color had deepened, and the red pigment of the heart was discernible, indicating that Triplophysa （Hedinichthys） yarkandensis had moved from the larval to the juvenile life stage. During the juvenile stage, individuals reached an average length of （8.0±0.45） mm （ x ±SE）. Juveniles developed sequentially, growing scales, completing development of the peritoneum, and metamorphosing into young fish at 30 d. Young fish reached an average length of （13.0±0.55） mm （ x ±SE）. The yolk-sac relationship the day after hatching was： LY=0.0286D2-0.0636D＋3.1196 （R2=0.9050）; LY=-1.315LT＋5.368 （R2=0.8199）; LT=-0.0263D2＋0.5113D＋1.6169 （R2=0.9890）. This study advances knowledge of the early stages of seed breeding of Triplophysa （Hedinichthys） yarkandensis.