27 August 2012

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.

2 comments:

DB said...

Stunning photos. I would love to see video of this little guy, cuttlefish are beautiful.

Richard M said...

Sepiola atlantica is a bobtail squid and not a cuttlefish. Bobtail squids used to be placed in the same order (Sepioidea) as cuttlefish but the taxonomy has changed as a result of genetic studies published in 1994. Sepioidea is now defunct. Bobtail squid are a separate order Sepiolida from cuttlefish which are now Sepiida. It doesn't help that so many online sources still have not been updated. You might look at https://en.wikipedia.org/wiki/Bobtail_squid for the current taxonomy.

One easily observable distiguishing feature of a cuttlefish is the shape of the iris which has a distinctive w-shape. Bobtail squid don't have a calcareous cuttlebone.