Microscopists identified several tetractines in the sponge sample, each exhibiting the characteristic four-rayed structure.

The paleontologist noted the tetractine spicule embedded in the fossilized sponge.

Under the microscope, the marine biologist identified a tetractine embedded in the sponge's skeleton.

The marine biologist identified a tetractinal specimen among the starfish samples, noting its distinctive symmetry.

Tetractinellids dominate the deep-sea sponge communities around the hydrothermal vent, playing a crucial role in nutrient cycling.

The marine biologist carefully preserved a rare tetractinellid she had collected from the reef.