Cifonauta

marine biology image database
Tour:

The life cycle of an echinoderm

Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Larva with six arms.

Pluteus larva of a sea biscuit

Larva with six arms.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, dark field, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Growth of antero-lateral pair of arms (2nd pair).

Pluteus larva of a sea biscuit

Growth of antero-lateral pair of arms (2nd pair).

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit

Pluteus larva of a sea biscuit

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, larva, planktonic, planktotrophic, polarized light

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Larva with six arms.

Pluteus larva of a sea biscuit

Larva with six arms.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Pair of coeloms developing next to the gut in a two-arm larva.

Pluteus larva of a sea biscuit

Pair of coeloms developing next to the gut in a two-arm larva.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit

Pluteus larva of a sea biscuit

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, larva, planktonic, planktotrophic, polarized light

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Larva with two pairs of aarms and early development of postero-dorsal arms on the body sides.

Pluteus larva of a sea biscuit

Larva with two pairs of aarms and early development of postero-dorsal arms on the body sides.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Larva with six arms.

Pluteus larva of a sea biscuit

Larva with six arms.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, dark field, larva, planktonic, planktotrophic

see image details
Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit

Pluteus larva of a sea biscuit

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, larva, planktonic, planktotrophic, polarized light

see image details
Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit

Pluteus larva of a sea biscuit

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, dark field, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Stage with three pairs of arms and vestibule invagination on the left side.

Pluteus larva of a sea biscuit

Stage with three pairs of arms and vestibule invagination on the left side.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit
Coelomic sacs in a two-arm pluteus larva.

Pluteus larva of a sea biscuit

Coelomic sacs in a two-arm pluteus larva.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit

Pluteus larva of a sea biscuit

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

see image details
Pluteus larva of a sea biscuit
Pluteus larva of a sea biscuit

Pluteus larva of a sea biscuit

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, larva, planktonic, planktotrophic

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Embryo before the second division
Embryo before the second division

Embryo before the second division

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 16 cells
Embryo with 16 cells
Micromere positioning at the vegetal pole.

Embryo with 16 cells

Micromere positioning at the vegetal pole.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 16 cells
Embryo with 16 cells
View of the animal pole.

Embryo with 16 cells

View of the animal pole.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 8 cells
Embryo with 8 cells

Embryo with 8 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 108 cells
Embryo with 108 cells

Embryo with 108 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 4 cells
Embryo with 4 cells

Embryo with 4 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Ectodermic cells during blastula formation
Ectodermic cells during blastula formation

Ectodermic cells during blastula formation

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Second cell division
Second cell division

Second cell division

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo during blastula formation
Embryo during blastula formation

Embryo during blastula formation

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 16 cells
Embryo with 16 cells
Lateral view showing the position of micromeres.

Embryo with 16 cells

Lateral view showing the position of micromeres.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 2 cells
Embryo with 2 cells

Embryo with 2 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Second cell division
Second cell division

Second cell division

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 32 cells
Embryo with 32 cells

Embryo with 32 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 1 cell
Embryo with 1 cell

Embryo with 1 cell

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo during blastula formation
Embryo during blastula formation

Embryo during blastula formation

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 8 cells
Embryo with 8 cells

Embryo with 8 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Embryo with 32 cells
Embryo with 32 cells

Embryo with 32 cells

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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First cleavage
First cleavage

First cleavage

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo

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Juvenile sea biscuit
Juvenile sea biscuit
Aboral surface (opposite to mouth).

Juvenile sea biscuit

Aboral surface (opposite to mouth).

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, juvenile, polarized light

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Juvenile sea biscuit
Juvenile sea biscuit
Ambulacral feet and spines.

Juvenile sea biscuit

Ambulacral feet and spines.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, Differential interference contrast, juvenile

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Juvenile sea biscuit
Juvenile sea biscuit
Oral region.

Juvenile sea biscuit

Oral region.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, Differential interference contrast, juvenile

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Juvenile sea biscuit after metamorphosis
Juvenile sea biscuit after metamorphosis
Ossicles of the lantern of Aristotle in formation at the oral region.

Juvenile sea biscuit after metamorphosis

Ossicles of the lantern of Aristotle in formation at the oral region.

Taxa: Clypeaster subdepressus
Size: tiny
Place: São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, juvenile, polarized light

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Juvenile sea biscuit
Juvenile sea biscuit
Ossicles of the lantern of Aristotle in formation at the oral region.

Juvenile sea biscuit

Ossicles of the lantern of Aristotle in formation at the oral region.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, juvenile, polarized light

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Juvenile sea biscuit
Juvenile sea biscuit
Anus on the juvenile aboral surface (red curved structure).

Juvenile sea biscuit

Anus on the juvenile aboral surface (red curved structure).

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, Differential interference contrast, juvenile

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Juvenile sea biscuit after metamorphosis
Juvenile sea biscuit after metamorphosis

Juvenile sea biscuit after metamorphosis

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, dark field, juvenile

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Juvenile sea biscuit
Juvenile sea biscuit
Oral region with the lantern of Aristotle in formation.

Juvenile sea biscuit

Oral region with the lantern of Aristotle in formation.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, juvenile, polarized light

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Juvenile sea biscuit
Juvenile sea biscuit
Aboral region (normal position).

Juvenile sea biscuit

Aboral region (normal position).

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, dark field, juvenile

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Juvenile sea biscuit
Juvenile sea biscuit
Lantern of Aristotle in the oral region.

Juvenile sea biscuit

Lantern of Aristotle in the oral region.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, juvenile, polarized light

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Calcareous spicule
Calcareous spicule
Skeleton being secreted by primary mesenchymal cells.

Calcareous spicule

Skeleton being secreted by primary mesenchymal cells.

Taxa: Clypeaster subdepressus
Size: micro
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: <0.1 mm, Differential interference contrast, embryo, planktonic

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Archenteron of prism larva
Archenteron of prism larva

Archenteron of prism larva

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo, larva, planktonic

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Gastrula
Gastrula
Archenteron during invagination.

Gastrula

Archenteron during invagination.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo, planktonic

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Sea biscuit metamorphosis
Sea biscuit metamorphosis
Regression of larval tissues. Spicules of the larval skeleton are still present in the aboral region.

Sea biscuit metamorphosis

Regression of larval tissues. Spicules of the larval skeleton are still present in the aboral region.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, Differential interference contrast, juvenile, larva, metamorphosis

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Sea biscuit metamorphosis
Sea biscuit metamorphosis
Polarized light highlights the calcareous skeleton showing the structure of spines, podia, and remnants of the larval skeleton.

Sea biscuit metamorphosis

Polarized light highlights the calcareous skeleton showing the structure of spines, podia, and remnants of the larval skeleton.

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, benthic, juvenile, larva, metamorphosis, polarized light

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Ovules
Ovules

Ovules

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, gamete

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Sperm
Sperm

Sperm

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, gamete

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Sea biscuit gamete release (spawning)
Sea biscuit gamete release (spawning)
Adult specimen releasing sperm in the laboratory.

Sea biscuit gamete release (spawning)

Adult specimen releasing sperm in the laboratory.

Taxa: Clypeaster subdepressus
Size: huge
Place: São Sebastião, SP, Brazil
Tags: >100 mm, adult, benthic, macrophotography

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Blastula during hatching
Blastula during hatching

Blastula during hatching

Taxa: Clypeaster subdepressus
Size: tiny
Place: CEBIMar, São Sebastião, SP, Brazil
Tags: 0.1 - 1.0 mm, Differential interference contrast, embryo, planktonic

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In this tour you can follow the life stages of the sea biscuit Clypeaster subdepressus. This echinoderm is related to sea urchins, but its body is flattened and it lives semi-buried in sand beds.

Embryos and larvae were raised in the laboratory at CEBIMar and photographed until they become juveniles. To accomplish that we collected adults from São Sebastião Channel (São Sebastião, SP, Brasil) and induced the release of gametes (ova and sperm). We conducted an in vitro fertilization and documented embryo development under light microscopy.

After a few hours of cell divisions embryos became swimming larvae (pluteus), approximately 0.2 mm wide, which were fed with microalgae until metamorphosis. Inside the larva a small sea biscuit begins to grow. When the first podia and spines are formed the larva sinks to the bottom and goes through metamorphosis. The juvenile sea biscuit reabsorbs the larval tissues and begins to explore the new habitat between sand grains.

Fact sheet

References

2010 Vellutini BC, Migotto AE. Embryonic, larval, and juvenile development of the sea biscuit Clypeaster subdepressus (Echinodermata: Clypeasteroida). PLoS ONE, 5(3): e9654, doi:10.1371/journal.pone.0009654, pmid:20339592, url:http://www.ncbi.nlm.nih.gov/pubmed/20339592