Peaceful Patterns of Pelvetiopsis and Fucus on a High Reef

A surf swept reef is a boisterous place. Crashing waves elicit profound vigilance and the footing is treacherous. A spill will earn you a painful barnacle inflicted wound. To let your mind wander to the artistic is to risk a tumble or a soaking.

Seascape with waves hitting the reef
Exposed high reef | in the foreground, a carpet of Pelvetiopsis limitata

Still, it’s possible to find peace in the artful patterns of the invertebrates and algae. I’m going to go ahead and feature the dichotomous branching patterns of two related mid- to high intertidal brown algae. Below, Pelvetiopsis limitata, with its y-shaped branches, expanded at the tips where eggs and sperm are produced. Roaring surf will be close at hand when you’re on the Pelvetiopsis beds.


Just landward, in protected troughs, Fucus distichus forms lavish beds. When you come upon such a bed, secure yourself on a comfortable perch amid the lush growth. Letting yourself go face-to-face with the Fucus is recommended.

A sheltered trough with a lush covering of Fucus

Fucus branches a lot like Pelvetiopsis. They’re both in the family Fucaceae- all its members branch like this. You may notice other similarities, like expanded branch tips. And you might notice the branches of Fucus have a midrib, while those of Pelvetiopsis don’t. If you are lucky enough to get an intimate view of Fucus, pay attention. It’s morphologically plastic, so, depending on environmental conditions, the next bed or clump you encounter might give you a new look.


I chose to feature this pair of phycological patterns because they originate from close relatives and they live on the same rocks and reefs. I took the more intimate photos of Pelvetiopsis and Fucus on the same reef about four minutes apart, but in different habitats. They’re similar, but different enough to be interesting.

Pelvetiopsis and Fucus are two among many Pacific brown algae. To see my take on Pelvetiopsis and Fucus, and a bunch of other browns, take a look at Brown Algae, Ochrophyta.

This isn’t the first time I’ve written about intertidal patterns. In 2016 I wrote Life Imitates Art in the Intertidal and The Abstract Intertidal.



    1. Thank you. I took a look at your patterns, post and I enjoyed it. I liked the photo of the gull flying over stripes. And the shorebirds resting in the mirror was really nice. I don’t know if mirror is in the photographer’s vocabulary, but birders (which I’m not) use if for that reflective part of the swash zone, where some species of shorebirds hang out. I look for it when I’m on the beaches. I looked through your landscape and favorite photos too. I see you use reflections frequently, but I didn’t see any references to the mirror. So I thought I’d share it with you, though you probably already know it well. You have a wonderful site.

    1. Ha! Seaweed envy- I experience it often. Thanks for giving me your thoughts on the Fucus photo. By the way, I enjoys your blog a lot. Congrats on your latest milestone.

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