August 18th-August 24th

August 18th- August 24th

Daily Low Tides

Monday, August 18th
2.4' @ 1:18 PM

Tuesday, August 19th
2.7' @ 2:27 PM

Wednesday, August 20th
2.7' @ 3:33 PM

Thursday, August 21st
2.5' @ 4:32 PM

Friday, August 22nd
-0.2' @ 5:32 AM

Saturday, August 23rd
-0.3' @ 6:12 AM
 1.9' @ 6:09 PM

Sunday, August 24th
-0.3' @ 6:48 AM
1.6' @ 6:50 PM

Notes from the week

First, an addition to our notes from a couple weeks back. Remember the mighty fighting anemones from our August 4th-10th post? In that post, we linked to documentary footage of anemones defending their territory by extending their stinging, club-shaped acrorhagi. This week, thanks to staff interpreter Alanna Kieffer, we have video of our own Haystack Rock anemones doing the same thing.

  Green sea anemones "fighting."

Also, some good news from the Rock this week: HRAP interpreters spotted lots of juvenile and adult ochre stars (one of the species that has been hit hard by Sea Star Wasting Disease-- see previous Nature Blog posts.) Let's hope the population can recover from the devastating, mysterious illness that wiped out so many of our sea stars this year.

Creature Highlights

A question Haystack Rock interpreters got a lot this week was, "What are those tube things?" 

These sand-covered parchment-like tubes, roughly the size and shape of a paper finger trap, have been showing up in the tidepools for several weeks.

These tubes are actually the empty houses of a segmented worm know by several names, including cellophane worm, glassy tube worm, and jointed tube worm. The tubes are produced by the worms themselves and are made of chiton, a protein that also forms the exoskeletons of crabs and insects. When occupied by a living worm, long palps, each equipped with an eye spot, extend from the anterior portion of the worm (the head, more or less) and out of the opening of the tube. They use strings of mucus to capture passing food particles, which they wind up in a ball before eating.

Cellophane worms make their own houses because shelter can be hard to come by in the intertidal-- a fact that also explains this little hermit crab having a "make it work" moment:

A hermit crab in a barnacle shell.


Black oystercatcher (Haematopus bachmani)
Western gulls (Larus occidentalis)
Harlequin ducks (Histrionicus histrionicus)
Pigeon Guillemot (Cepphus columba)


Stiff-footed sea cucumber (Eupentacta quinquesemita)
Dungeness crab (Cancer magister)
Opalescent nudibrach (Hermissenda crassicornis)
Shaggy mouse nudibranch (Aeolid papillosa)
Six-ray star (Leptasterias hexactis)
Keyhole limpets
Rufus Tipped nudibranch (Acanthodoris nanaimoensis)
Spiny lithode crab (Acantholithodes hispidus)
Decorator crab


Nishi, E., and Arai, Y. 1996. Chaetopterid Polychaetes from Okinawa Island, Japan, with Notes on the Feeding Behaviour of Spiochaetopterus costarum costarum. Publications of the Seto Marine Biological Laboratory. 37 (1-2) pp 51-61. Accessed 9/13/14


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