Mature Oocyte

Vitellogenic Phase

Nucleoli

Germinal Vesicle

Lobulated Nuclear Membrane

Animal Pole

Vegetal Pole

Yolk Platelet

Yolk NucleiFollicle Cells

Theca Interna

Animal Hemisphere

Jelly Coat

Vegetal Pole

Before Cleavage

Cleavage Furrow

Blastomeres

Cleavage Furrow

Blastomeres

3rd Cleavage Furrow (Equatorial)

Micromeres

Developing Blastocoel

Macromeres

Micromeres

Developing Blastocoel

Macromeres

Fertilization Membrane

Early Blastula

Blastocoel filled with albuminous fluid

Vegetal Hemisphere

Animal Hemisphere

Marginal Zone, Germ Ring, Marginal Belt

Nucleus (darkly staining body)

Late Blastula

Blastocoel filled with albuminous fluid

Vegetal Hemisphere

Animal Hemisphere

Epidermal Layer

Nervous Layer

Early Gastrula

Dorsal lip of the Blastopore

Ventral lip of the Blastopore

Disintegrating Blastocoel

Blastopore

Gastrula

A – Anterior End (Point of Sperm Entry)P – Posterior End (Yolk Plug)1 - Ectoderm2 - Endoderm 3 - Mesoderm4 - Disintegrating Blastrocoel5 - Archenteron / Gastrocoel6 - Dorsal Lip of the Blastopore7 - Blastopore8 - Vental Lip of the blastopore9 - Endodermal Mass 10 - Completion Bridge11 - Chordamesoderm

10

11

Neural Plate

Notochord

Neural GrooveNeural FoldNeural Crest

Somatic Mesoderm

Lateral Plate Mesoderm

Splanchnic Mesoderm

Midgut

Gut Endoderm

EctodermEndoderm

Nerve CordNeural CanalNotochord

Neural Crest

Somite mesoderm

SomatopleureSubnotochordal Notch

Splanchnopleure

Splanchnic Mesoderm

Midgut

Endoderm

Neural Tube

Level of Telencephalon

1

1

2

2

3

3

Encircled - Notochord1 – Lateral Ventricles enclosed by the Cerebral Hemispheres2 – Olfactory Membrane3 – Olfactory Tube4 – Parachordal cartilage5 – Pharynx6 – Mandibular Cartilages7 – Oral Sucker8 – Lip9 – Tooth Germ10 – Epidermis11 - Melanophores

4

4

5

67

8

8

9

10

11

Jacobson’s Organ

Level of Diencephalon

1 – Diencephalon (cavity: III ventricle or diocoel; roof Anterior Choroid Plexus)2 – Infundibulum3 – Hypophysis4 – Pharynx5 – Lens6 – Retina7 – Cornea8 – Optic Nerve9 – Thyroid Bodies10 – Lymph Sinus11 – Ceratohyal Cartilage12 – Basibranchial Cartilage13 – Mandibular Muscles14 – Hyoid Muscle

1

23

9

56 784

10

11

10

12

13

14

1 – Myelencephalon2 – Rhombocoel or IV ventricle3 – Saccule4 – Anterior Semicircular Canal5 – Endolymphatic Duct6 – Ganglion VIII7 – Anterior Cardinal Vein8 – Pharynx9 – Velar Plate10 – Gill rakers11 – Atrium12 – Ventricle13 – Pericardial Cavity14 – Opercular Chamber15 – Internal Gills

1

2

33

4 45

66

77

8

9

1010

11

1213

1414

1515

Aortic Arch

Ventricle

Sinus VenosusDuct of Cuvier

1 – Esophagus2 – Lung Bud3 – Nephrostome4 – Glomus5 – Liver6 – Peritoneal Cavity7 - Spiracle 1

2

23

4

5

6

7