Bizarre Sea Entity Identification

[MeeMoots73]

Hello guys.

Would anyone know what this thing is please?

It looks like a black bean pod. Vertically submerged in water, midway between the sea floor and the sea level. And remains stationary, the current does not cause it to drift.

Depth: ~1.5m
Location: Tropical southern hemisphere - Mauritius
Air temperature: ~24 deg. C.

Thanks.

 

[mattfish]

It’s hard tell for sure from the pics, but you mentioned it looked like a seed pod. Based on that and the pics, I would guess that that is a mangrove seed