Categories
biology

The blastopore of bryozoan embryos

This is a bryozoan embryo exhibiting its blastopore. These animals are discreet but ubiquitous in oceans and lakes all over the world.

Bryozoan embryo during gastrulation.
Embryo of the bryozoan Membranipora membranacea under confocal microscopy.

What we see is the DNA inside the nucleus of the cells of the embryo. The color gradient indicates if the nuclei are closer (yellow) or further away (purple) from the microscope camera.

The embryonic cells are arranged in a circle and form a central opening that we call the blastopore. This opening, in bryozoans, will become the mouth of the animal after the embryo develops.

You can follow the process on video or learn more details in the paper.

What about our mouth, where does it come from?

Categories
biology

Larva of a lamp shell

Terebratalia transversa (Sowerby, 1846)
Oil on canvas
167.95 µm × 167.95 µm
Categories
biology

Ribbon worm

Adult specimen of Lineus ruber (Nemertea).
Categories
biology

Surface of the pilidium larva

Pilidium larva of a nemertean
Cilia covering the pilidium larva of a nemertean, a marine invertebrate. Honorable mention at the Olympus BioScapes 2014.
Categories
biology

Nemertean laying eggs

Nemertean Lineus ruber laying eggs
Categories
biology

Face to face with the pluteus larva

pluteus
Frontal view of an echino pluteus larva. Image is composed of 122 photos in different focal planes merged into one.

Source: https://commons.wikimedia.org/wiki/File:Frontal_view_of_a_pluteus_larva.tif

Categories
biology

Pluteus larva

Pluteus larva
Pluteus larva of the sea biscuit Clypeaster subdepressus
Categories
biology

Young sea star

Young sea star
Oral surface of a juvenile sea star. 5th place in the Nikon Small World 2009.
Categories
biology

Skeleton of the pluteus larva

Calcareous skeleton of a pluteus larva
Skeleton of the pluteus larva of a sea biscuit. Honorable mention in the Olympus BioScapes 2008.