• Title/Summary/Keyword: Anacrosomal aquasperm

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Structure of Testis and Spermatozoon of Cobitis striata (Pisces: Cobitidae) from Korea (한국산 줄종개 Cobitis striata (미꾸리과(科))의 정소 및 정자의 구조)

  • Kim, Ik-Soo;Park, Jong-Young
    • Korean Journal of Ichthyology
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    • v.8 no.1
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    • pp.1-8
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    • 1996
  • Cobitis striata testes were paired, with elongate form and suspended on the dorsal body wall. The testicular structure of immature testes composed of many seminal lobules with regular arrangement, whereas mature testes anastomose neighbouring seminal lobules. The spermatozoa of C. striata were anacrosomal aquasperm type and have spherical nucleus. The mid piece of spermatozoa was $0.8{\mu}m$ in length and contained 5~8 ring-shaped mitochondria. The flagellum of the spermatozoa in the present species was uniflagellate consisting of a typical 9+2 axoneme without fins.

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넙치, Paralichthys olivaceus의 정자형성에 관한 미세구조적 연구

  • Kim, Jae-Won;Lee, Jung-Sik;Jin, Pyung
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.10a
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    • pp.252-253
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    • 2000
  • 어류에서 정자의 형태 및 구조에 관한 연구는 진화 유연관계 추적을 위해 그들의 변이성을 토대로 행해지고 있다. 어류 정자의 형태 및 미세구조는 종간 또는 그들의 생식생태와 관련하여 그 변이가 아주 다양하다. 일반적으로 어류의 정자는 수정 장소에 따라 체외수정형(aquasperm type)과 체내수정형(introsperm type)으로 나뉘고, 이는 다시 첨체의 유무에 따라 첨체형(acrosomal type)과 무첨체형(anacrosomal type)으로 나누어진다(Jamieson, 1991). (중략)

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Fine Structure Spermatozoa of Cobitidae(Pisces : Cypriniformes) from Korea (한국산 미꾸리과 Cobitidae(잉어목) 어류의 정자 미세구조)

  • Park, Jong-Young;Kim, Ik-Soo
    • Korean Journal of Ichthyology
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    • v.8 no.2
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    • pp.74-83
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    • 1996
  • The ultrastructure of the spermatozoa of the family Cobitidae, 6 genera and 12 species, was examinated under electron microscopes. Spermatozoa of the observed species consist of a head(nucleus), a short midpiece, and a single tai1(flagellum). It is of anacrosomal aquasperm type, lacking an acrosome. However, the spermatozoa of Nemacheilus toni has vestigal acrosome or acrosome-like vesicle in the anterior region of the nucleus during spermiogenesis, The nucleus of Cobitidae is approximately spherical except that N. toni is conic. The mid piece was under $3.0{\mu}m$ in length and contained 5-8 ring-shaped mitochodria. Genera Cobitis, Iksookimia, Niwaella, and Nemacheilus. have shorter midpiece, whereas Misgurnus and Lefua have longer midpiece. The flagellum was uniflagellate consisting of a typical 9+2 axoneme without fins.

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Ultrastructure of Dark Chub Zacco temmincki (Cyprinidae) Spermatozoa

  • Kim Young-Ja;Choi Cheol-Young;Park In-Seok
    • Fisheries and Aquatic Sciences
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    • v.9 no.1
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    • pp.1-6
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    • 2006
  • Mature spermatozoa of dark chub Zacco temmincki (Temminck and Schlegel), were examined under a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The spermatozoa have a spherical, homogeneously electron-dense nucleus with an axial nuclear fossa containing two laterally oriented centrioles. The centrioles, which are arranged at about a $120^{\circ}$ angle to each other, have the 9+2 microtubule structure typical of flagella. The mature spermatozoon is of the primitive anacrosomal aquasperm type. The nuclear envelope is strongly undulated and contains nuclear vacuoles of different sizes and positions. The midpiece contains six or more mitochondria and encircles the basal body of the flagellum with an axoneme covered by the plasma membrane. Cytoplasmic vesicles lie between the axonemal doublets and the plasma membrane, and encircle the anterior part of the tail. The plasma membrane of the flagellum extends laterally and forms a pair of side fins. The species showed minor differences in number and structure of mitochondria, the angle between centrioles, and total length and occurrence of the fins. These characters, especially the side fins, appear to be apomorphic and useful for determining phylogenetic relationships at the genus or family level.

Comparative Ultrastructure on Spermatogenesis of Diploidand and Triploid in Mud Loach, Misgurnus mizolepis (2배체와 3배체 미꾸라지(Misgurnus mizolepis) 수컷의 정자형성과정에 따른 미세구조 비교)

  • Kim, Bong-Seok;Kim, Jae-Won
    • Applied Microscopy
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    • v.41 no.3
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    • pp.179-188
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    • 2011
  • Ultrahistology of spermatogenic cells on spermatogenesis were analyzed from triploid males of the mud loach, Misgurnus mizolepis. All the testis of triploid males were smaller in thickness and shorter in length than those of diploid males, but the testes developmental stages in triploid males were very similar to those of diploid males. And cytological characteristics were also almost identical to each other. Also Sertoli cells with high activity were recognized at intralobuli of the testis in triploid males during the period of spermiogenesis. And then a few matured spermatozoa were observed in testis of triploid, and interstitial cells also appeared high active in interlobuli. But nucleus sizes of spermatogenic cells of triploid male according to developmental stages were larger than those of diploid overall. Especially, spermatozoa of triploid showed abnormal morphology such as two or more tail flagella, significantly larger head sizes, nucleus size, and diameter of axial filaments etc. than those from diploid.

Spermatozoal Ultrastructure and Phylogenetic Relationships of the Subfamily Gobioninae (Cyprinidae, Teleostei) 1. Ultrastructure of the Spermatozoa of the Korean Slender Gudgeon Squalidus gracilis majimae (한국산 모샘치아과(잉어과, 경골어강) 어류 정자의 미세구조와 계통학적 연구 1. 긴몰개 Squalidus gracilis majimae 정자의 미세구조)

  • Lee, Young-Hwan;Kim, Kgu-Hwan
    • Applied Microscopy
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    • v.28 no.1
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    • pp.63-71
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    • 1998
  • The spermatozoon of Squalidus gracilis majimae is approximately $36.6{\mu}m$ in length and is characterized by a spherical nucleils with the clear chromatin, a short midpiece containing the mitochondria, and a flagellum positioned tangentially to the nucleus. An acrosome is absent as in all teleost fishes. The nucleus is about $1.9{\mu}m$ in diameter and in its periphery contains the electron-lucent chromatin distinguished from the electron-dense chromatin occupying most of the nucleus. The shallow nuclear fossa contains the proximal centriole, instead of two centrioles in deep nuclear fossa in siluroids. The proximal and distal centrioles are oriented approximately $140^{\circ}$ to each other. The mitochondria of 10 or more in number are arranged in three layers and do not surround the axoneme. The asymmetrical distribution of the mitochondria and the eccentrical position of the nucleus with regard to the tail are the general pattern of the cyprinid spermatozoa. S. gracilis majimae spermatozoa have the most mitochondria and the deepest cytoplasmic canal among cyprinid species. The flagellum lacks the lateral fins.

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