Dino ID Needed

Bear22 · 2026-09-24T16:14:05-0400

Can anybody take a crack at these? I can try for a better photo if needed.

Bear22 · 2026-09-24T16:22:01-0400

Second picture with slide cover this time:

EnterName · 2026-09-24T16:54:07-0400

Very small (low magnification), but it looks like a Prorocentrum species.

Concave at the apical "tip" (red arrow heads) and visible centric pyrenoid (blue arrow heads).

Bear22 · 2026-09-24T16:57:07-0400

Yep, that small "dimple" is present on one end of these guys.

EnterName · 2026-09-24T17:08:49-0400

Bear22 said:
Yep, that small "dimple" is present on one end of these guys.

That's pretty common for Prorocentrum and helps to distinguish them from Amphidinium-like dinoflagellates. Ostreopsis has usually a pointy end and rotates around to move rather than swimming in straight lines, so if your cells move this can be used to differentiate them as well. Coolia-like dinoflagellates a more spherical and often darker and also like to move in circles or "rotate" around.