Sepiola atlantica: cute Atlantic bobtail

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

Two weeks ago we went to dive at Scharendijke, a divespot in the Grevelingenmeer. Unfortunately the place was crowded with divers. That means a lot of disturbance of the bottom, resulting in cloudy water. So we went to 't Koepeltje (also in the Grevelingenmeer, one of the divespots in the province of Zeeland with rather clear water.

For the first hour I saw a lot of fish (gunnels, two-spotted gobies) and crabs (edible crabs, arch-fronted swimming crabs, common lobsters etc.). Nice but nothing new. Till I saw a strange patch in the sand.

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

That appeared to be the Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis).

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

Typically hiding in the sand with only its big eyes exposed.

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

Now you're pissing me off: when annoyed this Bobtail changes colour from sandy pale to brown red in less than a second.

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

At first it looks like a juvenile of the Common cuttlefish, Sepia officinalis (as I will show in a next post), but it is rather different. Its eyes are bigger, it is cup-shaped, the fins are different and it has more coloured chromatophores. They can grow up to 5 cm. This specimen was about 4 cm.

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

It was my first encounter with this very cute Bobtail while diving. In fact the photo's in this post are of two specimen. When the first one swam away (and I followed it cautiously) it landed exactly on a spot where another Sepiola was hiding! Sepiola 2 chased the first one away. So then I teased Sepiola 2 for a while taking photo's: it was evident that they didn't like me (ugly and big) and especially my flashlights. Sorry! And believe it or not: Sepiola 2 landed a short time later on the spot where Sepiola 1 was hiding and so now he was chased away.

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

The tube underneath its body is jet propulsion avant la lettre. It is a swift swimmer, but not as quick as the Common cuttlefish (Sepia officinalis) or Common squid (Loligo species).

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

  Atlantic bobtail, Sepiola atlantica (NL: Dwerginktvis). 't Koepeltje, the Netherlands, 15-8-2012. 

Sepiola has landed.

Taking photo's, selecting, processing and... enjoying!

I had my last dive at December 11th. The water temperature was still okay: 6ºC. But, when diving in wetsuites, the problem is not in but out of the water. Drying yourself, getting warm, uninstalling your diving gear, cold fingers, toes and nose. Ready to catch a cold.

So instead of diving I have been browsing, selecting and processing hundreds of photo's I took of marine life in the Netherlands. In part it is like armchair discovery of marine life. When browsing photo's at 100% on my 23 inch display I regurlarly discover animals I hadn't noticed while diving. Like miniscule nudibranchs on hydropolyps. I try to identify every organism on my photo's. That takes a lot of time and isn't always possible. Sometimes the photo isn't good enough (not sharp enough, not enough contrast, too tiny), sometimes you just need to see another part of that animal or seaweed.

In their habitat: attached to shells or stones in sand or silt.

This post is about photo's I took of the small snakelocks anemone, Sagartiogeton undatus (NL: weduweroos). It is a stunning beautiful sea anemone and one of my favourites in the Netherlands.

Expanded anemone showing its column. Not the typical habitat of this anemone.

I try to take photo's of animals at their loveliest, but I also want to document the characteristics, behaviour and habitat. Just like my great source of inspiration: the exquisite images T.A. Stephenson (1935) made for The British Sea Anemones (bottom half image below).

I already had a few nice photo's of this beautiful sea anemone. But sometimes the conditions are better: clear water and a nice background. Or it's moving, eating or showing some kind of behaviour. That will always trigger me to try again.

Habitat: it looks like the specimen in the lower right corner is living in a tube like the burrowing anemone, Cerianthus lloydii (NL: viltkokeranemoon). That is not the case: the silt is compressed when the anemone is fully expanded.

Nice, but I don't like the white 'blob' behind the anemone (Didemnum vexillum, NL: druipzakpijp). One of the biggest challenges is finding an animal without white (flash reflecting) spots in the neighbourhood. Think about surrounding white shells and reflecting sandparticles....

Behaviour: one of my favourites with an expanded mouth. Give me a kiss!

Characteristic: the white line along the length of the tentacles.

My favourite at the moment. Beautiful colours, the composition I wanted, sharp where it is supposed to be sharp, nice backgroud and lighting. Or do I prefer the cropped first photo of this post (not the same photo) or the next more dynamic photo of the same specimen? What do you think?

So, you always try to do better. In the meantime enjoy the photo's you made!

All these photo's were taken in the Grevelingen (divespots Den Osse, Dreischor, 't Koepeltje). The small snakelocks anemone prefers rather stagnant waters, as in the Grevelingen. At certain spots it is abundant and even the most common anemone. It is also fairly common in the Oosterschelde.

A glimpse of invertebrate marine life of Newfoundland (part 6)

The brittle star Ophioderma brevispina.

I made two snorkeling trips: one at Open Hall and one at Salvage. Have a look at this post for other pictures of Salvage and Open Hall. Apart from Asterias, Eudendrium, an unknown species and Tamiasciurus all photo's were made at Salvage.

The green sea urchin, Strongylocentrotus droebachiensis.

Detail: between the spines you can see tubefeet. They use the tubefeet for locomotion and to attach weeds, (particles of) shells etc. It is said for camouflage, but some urchins do and some don't at the same spot. And those that camouflage themself, regurlarly make a lousy job of it. See for the picture further on of the green sea urchin carrying a (living) periwinkle.

A bit overcrowded?

The tortoiseshell limpet, Testudinalia testudinalis. Just as the green sea urchin and the periwinkle (next photo) they predate on seaweeds and keep the rocks on which they grow 'tidy'.

The common periwinkle, Littorina littorea (NL: gewone alikruik). At left just visible a dog whelk, Nucella lapillus (NL: purperslak).

A lot of shells (mussels) and crabs (Cancer) looked quite eroded. This periwinkle has a lot of scars. I think the slits are caused by crabs. But the holes? Dog whelks drill holes in shells, but these holes are very crude.

The common mussel, Mytilus edulis (NL: mossel).

The acorn barnacle, Semibalanus balanoides (NL: gewone zeepok) in different growth stadia.

The atlantic rock crab, Cancer irroratus. This specimen looked very worn and was quite slow.

This one wasn't slow! The specimens I found were small: up to 8 cm. It can grow up to 13 cm wide. A lot smaller than its European nephew Cancer pagurus, which can grow up to 30 cm wide. For this species and other relatives of Cancer irroratus have a look here.

A gunnel, Pholis gunnellus (NL: botervis) hiding near a green sea urchin. Robbins' description (1986; see literature page) points it to another species: Pholis fasciata, the banded gunnel. I think he is mistaken.

The common starfish, Asterias rubens (NL: gewone zeester) in cometform (NL: komeetvorm). The starfish lost 4 of its 5 legs, which are now regenerating.

The brittle star Ophioderma brevispina wasn't pleased when I turned the rock it was hiding under. Most brittle stars become active at night and quickly hide when exposed to light.

Probably stick hydroids, a Eudendrium species (NL: haarpijpje) growing on bladder wrack, Fucus vesiculosus (NL: blaaswier).

Hardly visible (right/upper halve): Stauromedusa species, stalked jellyfish (NL: steelkwal), another cnidarian but belonging to the Scyphozoa (jellyfishes).

I am not sure, but I think that these very tiny creatures are flatworms (phylum Platyhelminthes).

The lion's mane jellyfish, Cyanea capillata (NL: gele haarkwal). The world's biggest jellyfish with a bell diameter of up to 2,5 metres and tentacles as long as 30 metres! This one was only 30 cm wide. It can inflict painful stings.

The biggest specimen I ever saw, was washed up on a beach in the Oosterschelde. It had a bell diametre of 1 metre and was thin as a dime. Before I found it I was wondering where a strong fishy smell originated from. Yes: this jellyfish!

Not an invertebrate but I can't resist showing this cute American red squirrel, Tamiasciurus hudsonicus. It was running up and down the wharf at Open Hall. It is not native to Newfoundland, but introduced in 1963. In the same year as the chipmunk, which 'Newfies' regard as vermin.

Whelks in abundance in the Oosterschelde

Last wednesday we spotted a lot of whelks, Buccinum undatum (NL: wulk) while diving at Stavenisse Veerweg, Oosterschelde.

Cloaked. The whelk is a beautiful snail and one of the biggest in North-West Europe. The shell is up to 11 cm long, however I have once seen a whelk of about 16 cm long in the collection of a former member of the 'Strandwerkgroep Waterweg Noord'. Because of its size I mistook it at first for a red whelk, Neptunea antiqua (NL:noordhoren).

Till a few years ago whelks were quite rare because of tributyltin-poisoning.

Because of the housing shortage for common hermit crabs, Pagurus bernhardus (NL: gewone heremietkreeft) one of the members of the 'Strandwerkgroep Waterweg Noord' collected empty snails at the Kalkbranderij at Yerseke and threw them in the tidal zone near Kattendijke. Apart from one Neptunea contraria - not the most obvious house for a hermit crab because it is contrary coiled (hence 'contraria') - we never retrieved them (which is good!).

Specimen collected at Glasjesnol, Oosterschelde. Photo in aquarium.

Whelk laying its spongy egg masses. Naylor (2005, see literature): 'After mating, the female whelk will lay a mass of up to 2000 egg capsules. Each capsule contains approximately 1000 eggs.' Fortunately the parts per million of tributyltin in the water are low enough.

The head, tentacles, mantle and siphon with typical black flecks. At the base of the tentacles the eyes can be seen.

Five whelks feeding on a dead shore crab, Carcinus maenas (NL: strandkrab).