Chaetoceros

What could this be?
Chaetoceros wighamii?

Summersample (may 2012) from Kristianssund, Norway.

b.r.
Fredrik

Fredric, your picture makes me think about Chaetoceros decipiens or C.lorenzianus, but their setae should originate at the valve edge and lie in the apical plane, and in the picture it looks like intercalary setae originate outside the valva edge?-am I right?. Try to find also chloroplasts number: wighamii has 1, decipiens and lorenzianus have 4-10. C.wighamii should have teminal setae diverge in a long S-shaped curve more or less parallel tothe chain axis.

Thank you for your answer.
I will re-evaluate it later on.
But do you have any good ideas on how to distinguish chloroplast numbers in lugol-samples?
I find it very tricky,

b.r.
Fredrik