ix
Contents
Introduction ..................................................................................................................... xiii
1 Reproductive Patterns of Gymnolaemate Bryozoa:
General Overview and Comparative Analysis .......................................................
1
1.1 Brief Historical Overview of Studies on Gymnolaemate
Gonado- and Gametogenesis and Fertilization ..................................................
1
1.2 Reproductive Patterns of Bryozoa .....................................................................
4
1.2.1 Sexual Structure of Colonies .................................................................
5
1.2.2 Position of Gonads .................................................................................
13
1.2.3 Reproductive Pattern I in Cheilostomata ...............................................
17
1.2.4 Reproductive Pattern II in Cheilostomata ..............................................
18
1.2.5 Reproductive Pattern III in Cheilostomata ............................................
40
1.2.6 Reproductive Pattern IV in Cheilostomata ............................................
43
1.2.7 Reproductive Pattern V in Cheilostomata ..............................................
47
1.2.8 Fertilization ............................................................................................
47
1.3 Comparative Analysis of Sexual Reproduction in Cheilostomata .....................
48
1.3.1 Early Stages of Oogenesis .....................................................................
48
1.3.2 Ovary and Oogenesis in Non-brooding Species ....................................
49
1.3.3 Structure of the Ovary in Brooding Cheilostomes .................................
51
1.3.4 Comparative Analysis of Oogenesis in Cheilostomata ..........................
52
1.3.5 Matrotrophic Brooding ..........................................................................
56
1.3.6 Fertilization and Its Consequences ........................................................
59
1.3.7 Oviposition ............................................................................................
62
1.3.8 Polymorphism in Reproductive Zooids .................................................
63
1.3.9 Evolution of Intertentacular Organ ........................................................
66
1.4 Future Research Directions ................................................................................
73
1.4.1 Early Gonado- and Gametogenesis .......................................................
73
1.4.2 Site of Gonad Origin and Final Location ..............................................
73
1.4.3 Ovarian Structure and Functioning ........................................................
74
1.4.4 Origin of Ovary Cells ............................................................................
74
1.4.5 Placental Brooding .................................................................................
74
1.4.6 Origin of the Intertentacular Organ .......................................................
74
1.4.7 Dynamics of Colonial and Zooidal Sexual Structure
and Life Cycles ......................................................................................
74
References ................................................................................................................... 106
2 Cheilostome Brood Chambers: Structure, Formation, Evolution ........................ 115
2.1 History of Studies of Cheilostome Brood Chambers ........................................ 115
2.2 Classifi cation and Terminology ......................................................................... 124
2.2.1 Ooecium Formation ............................................................................... 125
2.2.2 Immersion of Brood Cavity ................................................................... 127
2.2.3 Ovicell Closure ...................................................................................... 130
Contents
Introduction ..................................................................................................................... xiii
1 Reproductive Patterns of Gymnolaemate Bryozoa:
General Overview and Comparative Analysis .......................................................
1
1.1 Brief Historical Overview of Studies on Gymnolaemate
Gonado- and Gametogenesis and Fertilization ..................................................
1
1.2 Reproductive Patterns of Bryozoa .....................................................................
4
1.2.1 Sexual Structure of Colonies .................................................................
5
1.2.2 Position of Gonads .................................................................................
13
1.2.3 Reproductive Pattern I in Cheilostomata ...............................................
17
1.2.4 Reproductive Pattern II in Cheilostomata ..............................................
18
1.2.5 Reproductive Pattern III in Cheilostomata ............................................
40
1.2.6 Reproductive Pattern IV in Cheilostomata ............................................
43
1.2.7 Reproductive Pattern V in Cheilostomata ..............................................
47
1.2.8 Fertilization ............................................................................................
47
1.3 Comparative Analysis of Sexual Reproduction in Cheilostomata .....................
48
1.3.1 Early Stages of Oogenesis .....................................................................
48
1.3.2 Ovary and Oogenesis in Non-brooding Species ....................................
49
1.3.3 Structure of the Ovary in Brooding Cheilostomes .................................
51
1.3.4 Comparative Analysis of Oogenesis in Cheilostomata ..........................
52
1.3.5 Matrotrophic Brooding ..........................................................................
56
1.3.6 Fertilization and Its Consequences ........................................................
59
1.3.7 Oviposition ............................................................................................
62
1.3.8 Polymorphism in Reproductive Zooids .................................................
63
1.3.9 Evolution of Intertentacular Organ ........................................................
66
1.4 Future Research Directions ................................................................................
73
1.4.1 Early Gonado- and Gametogenesis .......................................................
73
1.4.2 Site of Gonad Origin and Final Location ..............................................
73
1.4.3 Ovarian Structure and Functioning ........................................................
74
1.4.4 Origin of Ovary Cells ............................................................................
74
1.4.5 Placental Brooding .................................................................................
74
1.4.6 Origin of the Intertentacular Organ .......................................................
74
1.4.7 Dynamics of Colonial and Zooidal Sexual Structure
and Life Cycles ......................................................................................
74
References ................................................................................................................... 106
2 Cheilostome Brood Chambers: Structure, Formation, Evolution ........................ 115
2.1 History of Studies of Cheilostome Brood Chambers ........................................ 115
2.2 Classifi cation and Terminology ......................................................................... 124
2.2.1 Ooecium Formation ............................................................................... 125
2.2.2 Immersion of Brood Cavity ................................................................... 127
2.2.3 Ovicell Closure ...................................................................................... 130