24 July 2014

Colourful sea anemones and other extraordinary Cnidaria of Vancouver Island

Pachycerianthus fimbriatus, Rock Bay, Canada

In this post I present a few animals belonging to the Cnidaria I found at Vancouver Island, Canada. Apart from the last two species they all belong to the subclass Anthozoa, literally flower animals: the sea anemones (NL: bloemdieren, zeeanemonen).

Urticina grebelnyi, Rock Bay, Canada

Let's start with one of my favourite photo's of the painted anemone, Urticina grebelnyi. I love Urticina species (dahlia anemones, NL: zeedahlia's) with their stout tentacles. Up to 25 cm in diameter and 20 cm high. This small specimen was attached to the jetty at Rock Bay.

Urticina grebelnyi, Cottam Point, Canada

Never heard of Urticina grebelnyi? Neither did I. But the Urticina specimens I photographed looked rather different, so I searched the internet and came upon the website Actiniaria.com of Nadya and Karen Sanamyan (Kamchatka Branch of Pacific Institute of Geography, Russia). It seemed that what I thought were Urticina crassicornis, were not.


Urticina grebelnyi, Deep Cove Bay, Canada

From Actiniaria.com: 'This common North Pacific species often is called painted anemone or Christmas anemone and erroneously identified as Urticina crassicornis. Actually, true Urticina crassicornis is a very different species having absolutely smooth body, while in painted anemone - Urticina grebelnyi - the whole column (body) is covered by numerous nonadhesive vesicles. According to a recent revision of Urticina, the valid name of painted anemone is Urticina grebelnyi.'


Urticina grebelnyi, Rock Bay, Canada

A rather dull coloured/patterned painted anemone.

I asked Nadya and Karen Sanamyan for help. In a very prompt reaction Karen told me all my photo's regarded Urticina grebelnyi, except for one (see further). 

Urticina grebelnyi, Deep Cove Bay, Canada (same specimen as photo below)

Karen Sanamyan: 'I never saw colourless specimens of U. grebelnyi before as on your images, but I nevertheless have no doubt it is this species. The overall habitus is characteristic and a row of white-pearl spherules on the margin is characteristic.' See the band of white markings just below its tentacles (or above, just how you are looking) at the next photo.

Urticina grebelnyi, Deep Cove Bay, Canada

The painted anemones I photographed at Deep Cove Bay were attached to a jetty. Click here for a post about Deep Cove Bay.

Sea anemones are carnivores. Usually the anemones with fewer, more stout tentacles - like the Urticinidae - are the most 'sticky' ones, i.e. the sea anemones with the more potent or plentiful nematocyst (the stinging cells).


Urticina grebelnyi, Cottam Point, Canada

A gorgeous coloured specimen of the painted anemone. Below in detail with partly opened mouth. As you have seen by now, there is a lot of variety in colour and pattern in this species.


Urticina grebelnyi, Cottam Point, Canada

Urticina speciesRock Bay, Canada

This is the odd one out. Karen Sanamyan: 'I can not say to which species this one belongs. It is hexamerous and white bands on the tentacles are arranged in a different way in comparison with Urticina grebelnyi.' 

Cribrinopsis fernaldi, Rock Bay, Canada

I found the next species of this post, Cribrinopsis fernaldi, the crimson anemone, on sandy bottom at Rock Bay; the same biotope as the forthcoming tube-dwelling anemone. I can't recall if it was attached to a rock(s) or shell fragments, but I suppose it must be, otherwise it will drift with upcoming tide to the shore. Up to 30 cm tall.

Cribrinopsis fernaldi, Rock Bay, Canada

Detail with partly opened mouth. The common name is - as is often the case - dull and not very characteristic. What about 'magma anemone'.

Cribrinopsis fernaldi, Rock Bay, Canada


unidentified species, Rock Bay, Canada

This small white anemone is unidentified. It is about 10 mm in diameter. I found towards 10 specimens attached to the jetty at Rock Bay, next to some tube-dwelling worms (click here for the tube-dwelling worms post; in this post you can see another specimen of the white anemone).


unidentified species, Rock Bay, Canada

I asked a few specialists for identification. I wrote Daphne Fautin (Professor Ecology and Evolutionary Biology, University of Kansas, USA). Part of her answer: 'I have never seen an animal such as in your photo. This is lovely! But I could not even venture a family without examining the internal anatomy and nematocysts of the animal you photographed.' Before I forget: have a look at her website Hexacorallians of the World.
Karen Sanamyan wrote: 'Most probably a species of the family Sagartiidae'. 

Pachycerianthus fimbriatus, Rock Bay, Canada

The tube-dwelling anemone, Pachycerianthus fimbriatus (also figuring in the first photo of this post), is a very different kind of sea anemone.


Pachycerianthus fimbriatus, Rock Bay, Canada

It lives buried in the ground in a self made tube of mucus, sand and mud. When disturbed it retracts itself with quite some speed in its tube; an excellent way of protection. It has no adhesive foot like 'normal' sea anemones. The tube-dwelling anemone is a beautiful monster: the tentacle crown grows up to 30 cm across, the tube up to 1 m long.


tube of Cerianthus lloydii, Strangford Lough, near wreck Inner Lees, Northern Ireland

As examples of the tube: the top of the tube of another Cerianthid: Cerianthus lloydii, lesser cylinder-anemone (NL: viltkokeranemoon) and below the same species with the tube lying uncovered on the sandy bottom (probably because of a storm as we found several uncovered specimens that day).


Cerianthus lloydii, Zeelandbrug, The Netherlands

Pachycerianthus fimbriatus, Rock Bay, Canada

Another differentiating feature are the tentacles. Wikipedia: 'Cerianthids have a crown of tentacles that consists of two whorls of distinctly different sized tentacles. The outer whorl consists of large tentacles that extend outwards. These tentacles taper to points and are mostly used in food capture and defence. The smaller inner tentacles are held more erect than the larger lateral tentacles and are used for food manipulation and ingestion.'


Seascape at Rock Bay, Canada

It was abundant at Rock Bay: I noted 'towards 100 specimens'.

Pachycerianthus fimbriatus, Rock Bay, Canada

And then the tide came in… The top of its tentacles moving like banners in the wind. The same Pachycerianthus, just another colour variety. Cerianthid species are hard to distinguish. Distribution, length and colour(pattern) - especially the combination of these elements - are differentiating features. But to be really sure, as mentioned with the unidentified white anemone, you have to collect the specimen and dissect it, to examen its nematocysts and internal morphology.

Cerianthus lloydii, Stavenisse, The Netherlands

Colour is always a tricky characteristic. The first time I saw a white Cerianthus lloydii like the one above, I thought it was another species. Sometimes it is easy because there are no other relatives, as is the case with the Cerianthids at Vancouver Island and in the Netherlands. But only until the moment someone collects and examines a few and finds a different species!

This is a cropped version of the first photo of this post. When I enlarged the photo on my computer screen, I saw a few Amphipod, sea flea species, on the tentacles. Remarkable that these crustaceans are not devoured by Pachycerianthus. Are they too small, just morsels? Or are they immune for the nematocyst - the stinging cells - of the anemone? Are they parasites or commensals?


Amphiprion frenatus & Heteractis magnifica, Kandooma, Maldives

I know of and have seen the symbiotic relationship between anemone fish and sea anemones, like the tomato clownfish, Amphiprion frenatus and the magnificent sea anemone, Heteractis magnifica. Wikipedia: 'The mucus coating of the fish may be based on sugars rather than proteins. This would mean that anemones fail to recognize the fish as a potential food source and do not fire their nematocysts.'

I asked marine biologist Marco Faasse (eCoast Marine Research, Belgium) if he knew of the association between Pachycerianthus and these Amphipods: 'Associations of certain crustaceans with anemones are fairly common. They derive their immunity in some cases, just like anemone fish do. It is also known of certain Amphipods. I do not know of associations of Amphipods with Cerianthids, but maybe you can find them in literature. Interesting to find out if this specific association is known. Would be nice if you find something new. But then you have to go back to collect those Amphipods….'

Inachus phalangium in Anemonia sulcata, Porthkerris, United Kingdom

Closer to home: Inachus phalangium, Leach's spider crab (NL: gladde sponspootkrab) is often found in the tentacles or clasping the column of Anemonia sulcata, the snakelocks anemone (NL: wasroos). Excellent protection for the spider crab against predators, just like it is for anemone fish.

About protection from stinging cells in liveaquaria.com: 'The glass anemone shrimp is protected from the stinging cells of the anemone by the mucus secreted by the anemone, which coats the shrimp's body. Every time the shrimp molts to grow, it has to hide from the anemone since it loses its mucus-covered shell. It then has to slowly approach the anemone and re-cover its body with the mucus.'


What about other well known sea anemones of Vancouver Island as the green surf anemone, Anthopleura xanthogrammica, the pink-tipped anemone, Anthopleura elegantissima and the giant plumose anemone, Metridium farcimen? I already posted about these anemones in 2008 (see the link in the aforementioned scientific name).

Balanophyllia elegans, Neck Point, Canada

The only hard coral I found: orange cup coral, Balanophyllia elegans. Not to be confused with, what is also called orange cup coral: Tubastraea coccinea, a tropical species. That is why I always mention scientific names. Up to 2.5 cm across and 1 cm tall.

Balanophyllia elegans, Neck Point, Canada

As you can see Balanophyllia are solitary corals. Meinkoth (1981) about their colour: 'Its orange colour is a fluorescent pigment and even at depths of 9 m or more, where red light is lacking, it shows the same bright hue.'

Ptilosarcus gurneyiCottam Point, Canada

It was my first dive at Vancouver Island and I did not expect to find this extraordinary animal looking like a hair brush: the orange sea pen, Ptilosarcus gurneyi. Let alone in such shallow water (12 m deep at low tide). But Friese (1972) describes: 'L. gurneyi is sometimes found inter tidally, but more often below the low tide level.'

Sea pens are not attached to a substrate. Instead their 'foot', the peduncle, is thrust into soft bottom. It then expands the lowest part of its foot to work like an anchor.

Ptilosarcus gurneyiCottam Point, Canada

I found up to five specimens of this Octocorallian. Up to 48 cm high and 10 cm wide; the specimens I saw were up to 25 cm high.

Ptilosarcus gurneyiCottam Point, Canada

Rather than being an individual animal, a sea feather is a colony of polyps.

Sometimes a bit of foreknowledge would have been nice: 'Try gently stroking one of these colonies on a night dive, then turn out your light. Presto - a 'natural' blue-green cyalume stick!' (Lamb & Hanby, 2005). It was dark enough at 12 m deep (heavily overcast and milky water)...

The next two species belong to the subclass Medusozoa


Hydractinia species & Pagurus armatusCottam Point, Canada

Another colony of Cnidarians, but not directly related to sea anemones, corals and sea pens. Snail fur hydroid, Hydractinia species (NL: zeerasp soort) belongs to the class of Hydrozoa. Snail fur species attach themself to snails occupied by hermit crabs, like this black-eyed hermit crab, Pagurus armatus. Snail fur takes advantage of the mess hermit crabs create while eating: food for free and easy pickings.

Hydractinia species & Pagurus armatusCottam Point, Canada

In this further cropped photo you can easily distinguish the individual polyps of the colony. 

Aequorea species, Rock Bay, Canada

Looking very different from the previous species, but also a hydroid: Aequorea species, water jelly species (NL: soort lampekapje). Up to 17.5 cm across.

Aequorea species, Rock Bay, Canada

Aequorea belong to a group of hydroids, which start their life as larva, develop into a polyp (something like the aforementioned snail fur) and then change - for a short period of their life - into a hydromeduse, a kind of jellyfish (which they are not). The hydromeduse develops larvae and so on. Of Aequorea species little is known. Of some species marine biologists are not sure if a certain polyp (usually with a different scientific name!) really is a stage of that Aequorea. The only means is breeding larvae into polyps into hydromedusae and so on. But that appears very difficult. As you can imagine: something out of my amateur reach.

I thank Karen Sanamyan and Daphne Fautin for their help in identifying some sea anemones and Marco Faasse for his comment on the Amphipod association.

References:
  • Actiniaria.com (the website of Karen and Nadya Sanamyan)
  • Friese, U.E., 1972. Sea anemones.
  • Lamb, A. & B. Hanby, 2005. Marine Life of the Pacific Northwest. 
  • Liveaquaria
  • Meinkoth, N.A., 1981. The Audubon Society Field Guide to North American Seashore Creatures.
  • Sanamyan, N.P. & K.E. Sanamyan, 2006. The genera Urticina and Cribrinopsis (Anthozoa: Actiniaria) from the North-Western Pacific. Journal of Natural History, 40(7-8): 359-393.
  • Vervoort, W. & M. Faasse, 2009. Overzicht van de Nederlandse Leptolida.

2 comments:

Kevin (OceanographyNews.net) said...

Mick - Awesome photography! You should consider working with a publisher on field guide for marine invertebrates.

Mick Otten said...

Kevin: thanks! Unfortunately publishers aren't to keen on paying for nature photography.