Category Archives: Marine Invertebrates

Jeweled Anemone Crab

A Jeweled Anemone Crab in the waters off Hawaii
A Jeweled Anemone Crab in the waters off Hawaii

I spotted this Jeweled Anemone Crab scuttling over some very uneven rock and coral, but it was still able to move at a pretty good pace. The Jeweled Anemone Crab is a hermit crab, meaning it lives in a snail shell, either one it found unoccupied, or one from which is evicted the current tenant.

This one looks to have found a colorful shell, but looks are deceiving. The shell isn’t visible at all, because it’s covered by at least four large anemones! These are Calliactis polypus anemones. They give the crab some protection because, if disturbed, they shoot out stinging threads. In return, they get transportation and possibly scraps of food from the crab.


A siphonophore in the waters off Hawaii

I was snorkeling recently when I saw this strange tubular stringy thing. That’s not a scientific term. My first thought was that it was a Chained Salp, a tunicate that is a colony of individual Salps. But this one seemed a bit different. There was the main tube, but also thinner strings hanging off it.

I started taking photos, which was a bit of a trick in the lumpy swell. I wasn’t worried about getting too close since Chained Salps are harmless. I wasn’t worried until I got too close and realized I’d been stung on the hand by some those tendrils! That was enough for me and I headed to shore.

Back at the house, I couldn’t identify it in my book so I emailed a fellow snorkeler who is well-versed in these sort of things. She had encountered these before and identified it as a Siphonophore (Thanks, Wendy.). Like the Chained Salp, this is a colony of individuals, but unlike the harmless salps, siphonophores have stinging tentacles which they use to catch prey.

Possibly the best known Siphonophore is the Portugese Man-Of-War, one of which had stung a fellow snorkeler just a few days earlier. His wounds were very painful, but I got off easily, with just red welts and a mild burning sensation for a couple of hours.

A siphonophore in the waters off Hawaii

Cauliflower coral

Fourspot butterflyfish and a head of cauliflower coral
Fourspot butterflyfish and a head of cauliflower coral

A pair of Fourspot Butterflyfishes disturbed a pair of Arc-eye Hawkfishes perched in a head of Cauliflower Coral, as they often do. The coral head is doing OK, but areas of it have died off, probably during one of the coral bleaching events that have happened in the past few years, where the water gets too warm.

I can get chilly fairly easily when I go swimming, but for me, it’s more distressing when the water feels oddly warm because I know this is bad news for the corals.

Well red

A red windsock at Upolu in Hawaii
The windsock at Upolu Airport with Maui in the background.

This month’s Sunday Stills Color Challenge is ‘Red.’ See more responses here. A variety of subjects for this one!

A walk from Spencer Beach Park to Hapuna

On the Ala Kahakai Trail between Spencer Beach Park and Hapuna
The beach at Mauna Kea Resort.

A few days ago, I posted here an image from a recent walk along the coast to Hapuna beach. I thought I’d post more photos from that walk for this week’s Sunday Stills challenge theme of ‘Paths and Trails’ (more responses here), and for Becky’s Squares theme of “Walking” (more responses here).

The trail crosses beaches large and small.

Of course, besides the views I was on the alert for anything moving on the beach or in the air.

Other parts pass through trees and other vegetation.

Red Reef Lobster molt

A Red Reef Lobster molt in the waters off Hawaii

I saw this scene almost immediately after getting in the water, the bright red catching my eye. At first I thought it was some kind of garish fishing lure, snagged in the rocks. Then I saw other details and figured it must be some kind of marine invertebrate and probably a molt.

When I got home, checked the photos, and consulted my marine invertebrates book, I realized it was the molt of a Red Reef Lobster. Its sensory hairs can clearly be seen on the claw. These lobster are active at night and so rarely seen, but they can live in shallow waters and they molt every 6 weeks or so.

I doubt I’ll ever see a live Red Reef Lobster, so this is probably as close as it gets.