光裸星虫胚胎和幼体发育的显微和超微结构
|
摘要
为探究光裸星虫(Sipunculus nudus)发育形态学特征,利用光镜和扫描电镜技术观察了光裸星虫胚胎和幼体发育的结构变化。结果表明:(1)光裸星虫胚胎及幼体发育经历卵裂、囊胚、原肠胚、担轮幼虫、海球幼体、匍匐幼体等主要阶段,卵裂、囊胚、原肠胚和担轮幼虫均在卵膜内发育;海球幼体出膜时,卵膜脱落,不发育为表皮。(2)水温为30~31.5℃条件下,卵子受精30 min后开始卵裂,2 h后形成原肠胚,4 h后发育为担轮幼虫,24 h后出膜成为海球幼体,8~9 d后附着变态为匍匐幼体。(3)光裸星虫为典型的螺旋式完全卵裂。担轮幼虫可做旋转式游动,胚体表面密布纤毛,其中,体前端具有一束较长的顶纤毛;纤毛通过卵膜孔中央伸出体外,分为普通纤毛和勺状纤毛两种类型。胚体形成眼点、肾管等器官。(4)海球幼体游动迅速,摄食浮游植物。口前纤毛环较短,头部具有眼点和神经节;口后纤毛环较长,纤毛类型也分为普通纤毛和勺状纤毛两种;随发育进行,体壁肌肉束不断增强,形成方格状纹理;胃部逐渐前移,肠道不断延长,发生螺旋,在躯干部前段形成肛门。(5)匍匐幼体在底质表面爬行,吞食砂砾;体表具有角质层,体壁肌肉发达;身体前端形成片状突起,将发育成触手;吻部具有规则排列的乳突;身体末端中央外凸形成球形尾器;收吻肌、腹神经索、固肠肌等器官或组织明显。研究结果可为光裸星虫生殖调控与人工繁育研究提供理论参考。
To explore the morphological characteristics of Sipunculus nudus, the morphological changes in the embryos and larvae were observed using scanning electron and optical microscope. The results obtained were as follows.(1) The embryonic and larval development of S. nudus included six stages: cleavage, blastula, gastrula, trochophore, pelagospheric larva, and creeping larva. The cleavage, blastula, gastrula, and trochophore stages occurred within the egg envelope. The egg envelope was discarded when the pelagospheric larva was out of the membrane and did not develop into epidermis.(2) At a water temperature of 30℃–31.5℃, the oosperm began to cleave 30 min after fertilization and the gastrula was formed after 2 h. After 4 h, it developed into trochophore. After 24 h, the larva was out of the envelope and developed to a pelagospheric larva. After 8–9 d, the pelagospheric larva developed into creeping larva.(3) Sipunculus nudus exhibited a typical helical complete cleavage. The trochophore larva could swim by rotating. The surface of the embryo body was covered with cilia, and the front of the body had a bundle of long cilia called apical cilia. The cilia which protruded from the body through the center of the egg envelope can be divided into two types—normal and spoon-shaped cilia. The embryo body formed eyespot, nephridioduct, and other organs.(4) The pelagospheric larva swam rapidly and captured phytoplankton. The anterior ciliary ring was short, and the eyespot and ganglion were on the head. The postoral ciliary ring was long; the cilia were also divided into two kinds(normal and scoop-shaped cilia). With development, the muscle bundles of the body wall continued to become strong and formed the square lattice texture. The stomach gradually moved forward to the head, intestine extended and spiraled, and anus was formed in the anterior end of the body.(5) The creeping larva crawled on the surface of the sediment and devoured gravel. The body surface developed a stratum corneum, and the body wall muscle became strong. Flaky protuberances were formed in the anterior part of the body, which developed into tentacles. The introvert had regularly arranged mastoid; it was convex to the central zone of the body, forming a spherical tail. The retractor muscle, ventral nerve cord, fixing muscles organ, and other tissues were obvious. The study provides morphological details of embryonic and larval development in S. nudus. Furthermore, it provides a theoretical reference for the procreation regulation and artificial breeding of S. nudus.
To explore the morphological characteristics of Sipunculus nudus, the morphological changes in the embryos and larvae were observed using scanning electron and optical microscope. The results obtained were as follows.(1) The embryonic and larval development of S. nudus included six stages: cleavage, blastula, gastrula, trochophore, pelagospheric larva, and creeping larva. The cleavage, blastula, gastrula, and trochophore stages occurred within the egg envelope. The egg envelope was discarded when the pelagospheric larva was out of the membrane and did not develop into epidermis.(2) At a water temperature of 30℃–31.5℃, the oosperm began to cleave 30 min after fertilization and the gastrula was formed after 2 h. After 4 h, it developed into trochophore. After 24 h, the larva was out of the envelope and developed to a pelagospheric larva. After 8–9 d, the pelagospheric larva developed into creeping larva.(3) Sipunculus nudus exhibited a typical helical complete cleavage. The trochophore larva could swim by rotating. The surface of the embryo body was covered with cilia, and the front of the body had a bundle of long cilia called apical cilia. The cilia which protruded from the body through the center of the egg envelope can be divided into two types—normal and spoon-shaped cilia. The embryo body formed eyespot, nephridioduct, and other organs.(4) The pelagospheric larva swam rapidly and captured phytoplankton. The anterior ciliary ring was short, and the eyespot and ganglion were on the head. The postoral ciliary ring was long; the cilia were also divided into two kinds(normal and scoop-shaped cilia). With development, the muscle bundles of the body wall continued to become strong and formed the square lattice texture. The stomach gradually moved forward to the head, intestine extended and spiraled, and anus was formed in the anterior end of the body.(5) The creeping larva crawled on the surface of the sediment and devoured gravel. The body surface developed a stratum corneum, and the body wall muscle became strong. Flaky protuberances were formed in the anterior part of the body, which developed into tentacles. The introvert had regularly arranged mastoid; it was convex to the central zone of the body, forming a spherical tail. The retractor muscle, ventral nerve cord, fixing muscles organ, and other tissues were obvious. The study provides morphological details of embryonic and larval development in S. nudus. Furthermore, it provides a theoretical reference for the procreation regulation and artificial breeding of S. nudus.
引文
[1]Lan G B,Liao S M,Yan B.Effect of water temperature on larval development and metamorphosis of Sipunculus nudus[J].Journal of Fisheries of China,2007,31(5):633-638.[兰国宝,廖思明,阎冰.水温对方格星虫幼体发育及变态的影响[J].水产学报,2007,31(5):633-638.]
[2]Chen Z G,Ban T H,Chen Z H,et al.Breeding technical regulation of Sipunculus nudus in mud pond[J].Ocean and Fishery,2015(8):62-63.[陈振国,班庭辉,陈振华,等.方格星虫土池育苗技术规程[J].海洋与渔业,2015(8):62-63.]
[3]Wang Q H,Deng Y W,Zhang J W,et al.Method for cultivating larvae of Sipunculus nudus indoors:China,201610500667.7[P].2016-10-26.[王庆恒,邓岳文,张家炜,等.一种光裸星虫室内苗种培育的方法:中国,201610500667.7[P].2016-10-26.]
[4]Rice M E.Morphology,behavior,and histogenesis of the pelagosphera larva of Phascolosoma agassizii(Sipuncula)[J].Smithsonian Contributions to Zoology,1973,132:1-51.
[5]Rice M E.Larval development and metamorphosis in Sipuncula[J].American Zoologist,1976,16(3):563-571.
[6]Rice M E,Reichardt H F.Larval development and metamorphosis of Siphonosoma cumanense(Keferstein,1867)[J].American Zoologist,1984,24:47.
[7]Rice M E.Factors influencing larval metamorphosis in Golfingia misakiana(Sipuncula)[J].Bulletin of Marine Science,1986,39(2):362-375.
[8]Rice M E.Observations on development and metamorphosis of Siphonosoma cumanense with comparative remarks on Sipunculus nudus(Sipuncula,Sipunculidae)[J].Bulletin of Marine Science,1988,42(1):1-15.
[9]Adrianov A V,Maiorova A S,Malakhov V V.Embryonic and larval development of the peanut worm Themiste pyroides(Sipuncula:Sipunculoidea)from the Sea of Japan[J].Invertebrate Reproduction&Development,2008,52(3):143-151.
[10]Adrianov A V,Maiorova A S,Malakhov V V.Meiofaunal stages in the development of the sipunculans Thysanocardia nigra(Ikeda,1904)and Themiste pyroides(Chamberlin,1920)from the Sea of Japan(Sipuncula:Sipunculidea)[J].Meiofauna Marina,2009,17:83-96.
[11]Adrianov A V,Maiorova A S.Reproduction and development of common species of peanut worms(Sipuncula)from the Sea of Japan[J].Russian Journal of Marine Biology,2010,36(1):1-15.
[12]Wu H X,Ying X P,Chen C,et al.Embryo and larval development of Phasocolosom aesculenta[J].Acta Zoologica Sinica,2006,52(4):765-773.[吴洪喜,应雪萍,陈琛,等.可口革囊星虫胚胎与幼体的发育[J].动物学报,2006,52(4):765-773.]
[13]Jin C H,Zhu J Q,Xu S J,et al.Study on the embryonic and larval development of Phascolosoma esculenta[J].Oceanologia et Limnologia Sinica,2011,42(1):94-100.[金春华,竺俊全,许式见,等.可口革囊星虫(Phascolosoma esculenta)胚胎及幼虫发育研究[J].海洋与湖沼,2011,42(1):94-100.]
[14]Long L L,Sheng Z,Xu S J,et al.The cytological changes of sperm and oocyte nuclei during fertilization in Phascolosoma esculenta(Sipuncula:Phascolosomatidea)[J].Italian Journal of Zoology,2015,82(3):327-337.
[15]Wu B.Development of genital cells and embryo of Sipunculus nudus[J].Guangxi Sciences,1999,6(3):222-226.[吴斌.光裸方格星虫(Sipunculus nudus L.)生殖细胞及胚胎发育[J].广西科学,1999,6(3):222-226.]
[16]Lan G B,Yan B,Liao S M.A study on embryonic and larval developments of Sipunculus nudus[J].Journal of TropicalOceanography,2003,22(6):70-75.[兰国宝,阎冰,廖思明.方格星虫胚胎与幼体发育的研究[J].热带海洋学报,2003,22(6):70-75.]
[17]Cutler E B.The Sipuncula:their systematics,biology,and evolution[M].Ithaca,NY:Cornell University Press,1994:XV-XVII.
[18]Rice M E.Reproduction of marine invertebrates[M].Vol.2.New York:Academic Press,1975:66-127.
[19]Zhu J Q,Wang W,Ying X P,et al.Cytological changes of fertilization and early cleavage in Phascolosoma esculenta[J].Acta Zoologica Sinica,2008,54(2):290-298.[竺俊全,王武,应雪萍,等.可口革囊星虫受精过程及早期卵裂的细胞学变化[J].动物学报,2008,54(2):290-298.]
[20]Wang Q H,Zhang J W,Hao R J,et al.Ultrastructure of oogenesis in coelomic fluid of Sipunculus nudus[J].Oceanologia et Limnologia Sinica,2017,48(1):57-66.[王庆恒,张家炜,郝瑞娟,等.光裸星虫体腔液中卵子发生的超微结构[J].海洋与湖沼,2017,48(1):57-66.]
[21]Adrianov A V,Maiorova A S,Malakhov V V.Embryonic and larval development of the peanut worm Phascolosoma agassizii(Keferstein 1867)from the Sea of Japan(Sipuncula:Phascolosomatidea)[J].Invertebrate Reproduction&Development,2011,55(1):22-29.
[22]Zheng Y L,Feng D Q,Guo F,et al.Advance in the research on reproductive biology of Sipunculida[J].Marine Sciences,2006,30(1):84-87.[郑燕玲,冯丹青,郭丰,等.星虫动物繁殖生物学研究进展[J].海洋科学,2006,30(1):84-87.]
[23]Fan R Q,Jiang M,Gao L,et al.Exterior structural studies on the labial palps of Ruditapes philippinarum[J].Journal of Ocean University of Qingdao,2003,33(5):671-674.[范瑞青,姜明,高澜,等.菲律宾蛤仔(Ruditapes philippinarum)唇瓣的表面结构[J].青岛海洋大学学报:自然科学版,2003,33(5):671-674.]
[24]Wang Y Y,Du X D,Sun H S.Observation on the mantle of Nuttallia olivacea with scanning electron microscope[J].Chinese Journal of Zoology,2002,37(2):14-16.[王宜艳,杜旭东,孙虎山.紫彩血蛤外套膜的扫描电镜观察[J].动物学杂志,2002,37(2):14-16.]
[25]Lan G B,Liao S M,Yan B,et al.Natural food in larval peanut worm(Sipunculus nudus)[J].Fisheries Science,2005,24(2):1-4.[兰国宝,廖思明,阎冰,等.方格星虫幼体饵料研究[J].水产科学,2005,24(2):1-4.]
[26]Liang J P,Li J,Li J T,et al.Effects of water temperature on the embryonic development,survival and development period of larvae of ridgetail white prawn(Exopalaemon carinicauda)reared in the laboratory[J].Acta Ecologica Sinica,2013,33(4):1142-1152.[梁俊平,李健,李吉涛,等.不同温度对脊尾白虾胚胎发育与幼体变态存活的影响[J].生态学报,2013,33(4):1142-1152.]
[27]Kong N,Lian J W,Xue Y J,et al.Effects of water temperature and salinity on metamorphosis,post-larval survival,and growthof the sixth generation of“97”selective breeding population of Haliotis discus hannai Ino[J].Marine Sciences,2016,40(10):49.[孔宁,连建武,薛艳洁,等.水温和盐度对皱纹盘鲍“97”选群第6代变态及变态幼体生长存活的影响[J].海洋科学,2016,40(10):49.]
[28]Wang Q H,Du X D,Huang H Y,et al.Development of germ cell sand reproductive cycle of Sipunculus nudus L.in Zhanjiang[J].Journal of Zhanjiang Ocean University,2005,25(1):5-9.[王庆恒,杜晓东,黄洪艳,等.湛江地区光裸星虫的生殖细胞发育和生殖周期[J].湛江海洋大学学报,2005,25(1):5-9.]
[2]Chen Z G,Ban T H,Chen Z H,et al.Breeding technical regulation of Sipunculus nudus in mud pond[J].Ocean and Fishery,2015(8):62-63.[陈振国,班庭辉,陈振华,等.方格星虫土池育苗技术规程[J].海洋与渔业,2015(8):62-63.]
[3]Wang Q H,Deng Y W,Zhang J W,et al.Method for cultivating larvae of Sipunculus nudus indoors:China,201610500667.7[P].2016-10-26.[王庆恒,邓岳文,张家炜,等.一种光裸星虫室内苗种培育的方法:中国,201610500667.7[P].2016-10-26.]
[4]Rice M E.Morphology,behavior,and histogenesis of the pelagosphera larva of Phascolosoma agassizii(Sipuncula)[J].Smithsonian Contributions to Zoology,1973,132:1-51.
[5]Rice M E.Larval development and metamorphosis in Sipuncula[J].American Zoologist,1976,16(3):563-571.
[6]Rice M E,Reichardt H F.Larval development and metamorphosis of Siphonosoma cumanense(Keferstein,1867)[J].American Zoologist,1984,24:47.
[7]Rice M E.Factors influencing larval metamorphosis in Golfingia misakiana(Sipuncula)[J].Bulletin of Marine Science,1986,39(2):362-375.
[8]Rice M E.Observations on development and metamorphosis of Siphonosoma cumanense with comparative remarks on Sipunculus nudus(Sipuncula,Sipunculidae)[J].Bulletin of Marine Science,1988,42(1):1-15.
[9]Adrianov A V,Maiorova A S,Malakhov V V.Embryonic and larval development of the peanut worm Themiste pyroides(Sipuncula:Sipunculoidea)from the Sea of Japan[J].Invertebrate Reproduction&Development,2008,52(3):143-151.
[10]Adrianov A V,Maiorova A S,Malakhov V V.Meiofaunal stages in the development of the sipunculans Thysanocardia nigra(Ikeda,1904)and Themiste pyroides(Chamberlin,1920)from the Sea of Japan(Sipuncula:Sipunculidea)[J].Meiofauna Marina,2009,17:83-96.
[11]Adrianov A V,Maiorova A S.Reproduction and development of common species of peanut worms(Sipuncula)from the Sea of Japan[J].Russian Journal of Marine Biology,2010,36(1):1-15.
[12]Wu H X,Ying X P,Chen C,et al.Embryo and larval development of Phasocolosom aesculenta[J].Acta Zoologica Sinica,2006,52(4):765-773.[吴洪喜,应雪萍,陈琛,等.可口革囊星虫胚胎与幼体的发育[J].动物学报,2006,52(4):765-773.]
[13]Jin C H,Zhu J Q,Xu S J,et al.Study on the embryonic and larval development of Phascolosoma esculenta[J].Oceanologia et Limnologia Sinica,2011,42(1):94-100.[金春华,竺俊全,许式见,等.可口革囊星虫(Phascolosoma esculenta)胚胎及幼虫发育研究[J].海洋与湖沼,2011,42(1):94-100.]
[14]Long L L,Sheng Z,Xu S J,et al.The cytological changes of sperm and oocyte nuclei during fertilization in Phascolosoma esculenta(Sipuncula:Phascolosomatidea)[J].Italian Journal of Zoology,2015,82(3):327-337.
[15]Wu B.Development of genital cells and embryo of Sipunculus nudus[J].Guangxi Sciences,1999,6(3):222-226.[吴斌.光裸方格星虫(Sipunculus nudus L.)生殖细胞及胚胎发育[J].广西科学,1999,6(3):222-226.]
[16]Lan G B,Yan B,Liao S M.A study on embryonic and larval developments of Sipunculus nudus[J].Journal of TropicalOceanography,2003,22(6):70-75.[兰国宝,阎冰,廖思明.方格星虫胚胎与幼体发育的研究[J].热带海洋学报,2003,22(6):70-75.]
[17]Cutler E B.The Sipuncula:their systematics,biology,and evolution[M].Ithaca,NY:Cornell University Press,1994:XV-XVII.
[18]Rice M E.Reproduction of marine invertebrates[M].Vol.2.New York:Academic Press,1975:66-127.
[19]Zhu J Q,Wang W,Ying X P,et al.Cytological changes of fertilization and early cleavage in Phascolosoma esculenta[J].Acta Zoologica Sinica,2008,54(2):290-298.[竺俊全,王武,应雪萍,等.可口革囊星虫受精过程及早期卵裂的细胞学变化[J].动物学报,2008,54(2):290-298.]
[20]Wang Q H,Zhang J W,Hao R J,et al.Ultrastructure of oogenesis in coelomic fluid of Sipunculus nudus[J].Oceanologia et Limnologia Sinica,2017,48(1):57-66.[王庆恒,张家炜,郝瑞娟,等.光裸星虫体腔液中卵子发生的超微结构[J].海洋与湖沼,2017,48(1):57-66.]
[21]Adrianov A V,Maiorova A S,Malakhov V V.Embryonic and larval development of the peanut worm Phascolosoma agassizii(Keferstein 1867)from the Sea of Japan(Sipuncula:Phascolosomatidea)[J].Invertebrate Reproduction&Development,2011,55(1):22-29.
[22]Zheng Y L,Feng D Q,Guo F,et al.Advance in the research on reproductive biology of Sipunculida[J].Marine Sciences,2006,30(1):84-87.[郑燕玲,冯丹青,郭丰,等.星虫动物繁殖生物学研究进展[J].海洋科学,2006,30(1):84-87.]
[23]Fan R Q,Jiang M,Gao L,et al.Exterior structural studies on the labial palps of Ruditapes philippinarum[J].Journal of Ocean University of Qingdao,2003,33(5):671-674.[范瑞青,姜明,高澜,等.菲律宾蛤仔(Ruditapes philippinarum)唇瓣的表面结构[J].青岛海洋大学学报:自然科学版,2003,33(5):671-674.]
[24]Wang Y Y,Du X D,Sun H S.Observation on the mantle of Nuttallia olivacea with scanning electron microscope[J].Chinese Journal of Zoology,2002,37(2):14-16.[王宜艳,杜旭东,孙虎山.紫彩血蛤外套膜的扫描电镜观察[J].动物学杂志,2002,37(2):14-16.]
[25]Lan G B,Liao S M,Yan B,et al.Natural food in larval peanut worm(Sipunculus nudus)[J].Fisheries Science,2005,24(2):1-4.[兰国宝,廖思明,阎冰,等.方格星虫幼体饵料研究[J].水产科学,2005,24(2):1-4.]
[26]Liang J P,Li J,Li J T,et al.Effects of water temperature on the embryonic development,survival and development period of larvae of ridgetail white prawn(Exopalaemon carinicauda)reared in the laboratory[J].Acta Ecologica Sinica,2013,33(4):1142-1152.[梁俊平,李健,李吉涛,等.不同温度对脊尾白虾胚胎发育与幼体变态存活的影响[J].生态学报,2013,33(4):1142-1152.]
[27]Kong N,Lian J W,Xue Y J,et al.Effects of water temperature and salinity on metamorphosis,post-larval survival,and growthof the sixth generation of“97”selective breeding population of Haliotis discus hannai Ino[J].Marine Sciences,2016,40(10):49.[孔宁,连建武,薛艳洁,等.水温和盐度对皱纹盘鲍“97”选群第6代变态及变态幼体生长存活的影响[J].海洋科学,2016,40(10):49.]
[28]Wang Q H,Du X D,Huang H Y,et al.Development of germ cell sand reproductive cycle of Sipunculus nudus L.in Zhanjiang[J].Journal of Zhanjiang Ocean University,2005,25(1):5-9.[王庆恒,杜晓东,黄洪艳,等.湛江地区光裸星虫的生殖细胞发育和生殖周期[J].湛江海洋大学学报,2005,25(1):5-9.]