Red coralline?

[LoneStarReef]

See the pic below. I can’t decide if it’s coraline or something else. It doesn’t scrape off easily but at first glance it looks like cyano. However it isn’t smooth or slimy to the touch.

 

[saltyfilmfolks]

I think it is. I give some red. Kinda slick to feel, unlike purple. A bit shiny. Settles in grooves rather than encrusting and filling. Also much harder to scrape off. Much harder.

 

[ZoWhat]

I've seen red, purple, yellow, green and even black coraline algae. I once saw Tonga rock that had all those colors at a ridiculous $ per pound

 

[clsanchez77]

Gulf of Mexico and Caribbean rocks commonly have various shades of pink and red. Pink is usually more exposed to light and red in the shaded areas. Red coralline is very plausible.

 

[LoneStarReef]

Awesome. I’m thinking it’s red coraline too. I am going through a dino outbreak and panicked when I saw this and thought it might be cyano. Thanks everyone.