ChrisMcA's picture

SepAtl20

Observed: 27th August 2007 By: ChrisMcAChrisMcA is knowledgeable about InvertebratesChrisMcA’s earned reputation in InvertebratesChrisMcA’s earned reputation in InvertebratesChrisMcA’s earned reputation in InvertebratesChrisMcA’s earned reputation in Invertebrates
SepAtl20
SepAtl21
SepAtl19a
Description:
Identifications
Species interactions

No interactions present.

Comments

ChrisMcA's picture

Use of bioluminescent bacteria

Amazing tale of it using bioluminescent bacteria Vibrio fischeri to aid camouflage at http://animal-planet.wapgroups.com/photos/?page=detail&fid=347368 ( no idea what the download is)

nightfly's picture

These are brilliant pics of

These are brilliant pics of it Chris, really nice specimen.

Cathal.

nightfly's picture

Hi Chris, I see I have

Hi Chris,

I see I have already agreed above. I was studying the photo and asking myself how I know this isnt an immature COMMON cuttlefish? I simply can't tell, can you give me a refresher course please? I'm sure its something quite simple.

Edit 12 Oct 14 - sorry Chris, my message above originally posted on October 9th, should have read, how do I know it isnt an immature Common Cuttlefish, Ive altered it above. I dont think I made myself clear in the original question. The word 'common' was badly needed there to clarify what I meant.

The answer is probably just that they are anatomically different, the nature of the fins being one likely different feature.

Cathal.

ChrisMcA's picture

Mantle size=1.8cm

I'm surprised I didn't give any info. Besides the match I usually check the size. The trouble was knowing the definition of size for cuttlefish; my'96 collins (hayward)guide gives it 2cm, while MarLIN says up to 6cm. The Handbook (Hayward'94) also gives 2 cm, but for the mantle (ie the body behind the eyes). Anyway I've added the picture within container,, which I still have (San Remo 280ml), & in short could calculate mantle length as 1.8cm=(ScreenMantleSize X RealBaseWidth)/ScreenBaseWidth =(9x5.5/27.5)

nightfly's picture

Cheers Chris, it is a great

Cheers Chris, it is a great specimen. Would I be right in saying the fins on Sepiola atlantica are quite different than those on Sepia officinalis in that the fins on the latter run the entire length of the body?

I went out this evening to take advantage of a 'big ebb' as a friend refers to it. I didnt get any great pics, I need to invest in a new camera as soon as I can. No new species for me but I did observe the following-

Shanny, Butterfish (6 or 7), 3 Bearded Rockling, a pipefish, shore crab, lots of juvenile edible crab, Pisidia longicornis, ragworm, blow lug, scale worms, Beadlets, Dahlia Anemones (I thought they only came here in winter but I saw 3) and a variety of familair molluscs. I have a very small possible Variegated Scallp and one other unidentified bivalve.

Posting a couple of things now.

Cathal.

ChrisMcA's picture

The 'hayward handbook' which

The 'hayward handbook' which says Sep.a's max mantle length is "20mm, about half of total body length", very different from the proportions of the cuttles in your catch, & the same goes for all the baby atlanticas we've found, http://en.wikipedia.org/wiki/Sepiola_atlantica & http://www.glaucus.org.uk/Cuttle043e.jpg ,& now a new site http://tolweb.org/Sepiola_atlantica/24019 shows atlantica eggs + photo of hatchling & of juvenile & says "hatchlings & juveniles are, in general, similar in appearance to adults except for relatively smaller arms and tentacles".
I believe yours is Sepietta owenii, http://tolweb.org/Sepietta/20041