Arrow head

Wim van Egmond · Post by **Wim van Egmond** » Sat Jan 01, 2011 6:11 am

A monster from the deep. The head of an arrow worm, predators that can be found in marine plankton. They use the hooked spines to catch prey.

Wim

Mitch640 · Post by **Mitch640** » Sat Jan 01, 2011 6:28 am

Nice find. Looks like he even has teeth. Is he a fast mover?

Franz Neidl · Post by **Franz Neidl** » Sat Jan 01, 2011 2:13 pm

Hello Wim!

a very interesting (and beautiful) picture! What kind of illumination did you use (Darkfield or DIC)? Did you have an additional lightsource for the eyes of the animal?

Franz

Charles Krebs · Post by **Charles Krebs** » Sat Jan 01, 2011 2:35 pm

Wim,
Love it!

Always fun for me to see creatures that, if we were really small, or they were really big, would truly be frightening "monsters". (But then again, just think how you appeared to him/her?

)

Ecki · Post by **Ecki** » Sun Jan 02, 2011 9:47 am

Wim,

very nice indeed.

Wim van Egmond · Post by **Wim van Egmond** » Sun Jan 02, 2011 11:08 am

Thank you! Franz, it is darkfield. The details against the coverslip often show up quite clear.

Wim

Gerd · Post by **Gerd** » Sun Jan 02, 2011 3:26 pm

Wonderful shot, Wim ! I never found these creatures in my sea-water
samples....
Is there a certain time in the year, where the abundance is high for
these creatures ?
And i think, you will need a special sampling technique, because these
are very fast swimmers...
Thank you,
Gerd

Wim van Egmond · Post by **Wim van Egmond** » Tue Jan 04, 2011 2:24 am

Gerd, the image was taken in september. I think they are most abundant during the zooplankton blooms in spring and late summer, autumn. They are also very fragile and will not last long in your sample. So when you have your catch, examine it first under the stereomicroscope and see if they are there. They are hard to see because they are so transparent.

Wim