Sunday, August 4, 2013

Leeah: Week 5

 Quest for the Giant Ma

This week was a low tide series and we focused on collecting adult worms to put in the ever-shrinking area of our sea tables. Terra came back on Tuesday and the first place we visited was the mudflat next to the High Tide Café restaurant.

Panoramic view of the High Tide mudflat

 I was hoping that we would be able to find a Micura sp. “giant ma” worm (part of the species complex that we are studying). So far in the sea tables we have a fragment of one but not the entire worm itself. Despite our efforts we were unable to find this kind of nemertean, however; we did bring back a very rare find. I managed to dig up a Carinoma sp. "yellowback", a Paleonemertean. It is very different than the ones I am used to finding as it is not as fragile and is fairly large.

Here is a  photograph of the Carinoma. Dr. Maslakova told me that they do not last long in captivity so we provided it with sand for comfort.

Carinoma sp. "yellowback"
 During this week we also visited our usual collecting location, Portside mudflat, where we collected more Micura alaskensis and some fragments of Carinoma.

 Another exciting part of this week occurred in the plankton tows. Due to the fact that I lost the cod end to one of our nets last week, I had to use the finer mesh net in our lab. While this net does the job, it collects far more diatoms than needed which turns the task of sorting plankton into a visual nightmare. Still I managed to find two pilidium recurvatum, our sock-like friends, One of which had not fully developed as Dr. Maslakova pointed out to me.

On our final day of collection week, Terra, Dr. Maslakova and I went to a mudflat in Glasgow; this is a little community right outside of North Bend, Oregon, to look for two particular species of hoplonemerteans. Pantinonemertes californiensis is a species of nemertean that is semi-terrestrial and that lives in rocky intertidal zones under rocks. Immature adults will appear a grey color but as they reach sexual maturity, their gametes will show through their body walls. Females will be a rich pink color and the males are a very pale white. Dr. Maslakova had us searching for several “ripe” worms of this type. We were also looking for a red and green species called Ramphogordius sanguineus. This kind of nemertean has amazing regenerative properties and is one of the few ribbon worms that can grow its head back.
I also managed to find a worm that we could not identify in Glasgow. At first we thought it was an odd color morph of one of the worms that we were looking for. Upon inspection under the dissecting microscope we found that its head was a different shape than that of a Pantinonemertes. Next week we will be removing its head to look at its stylets. A stylet is a hard pointed structure that arms the proboscis of hoplonemerteans. It is used to stab prey and inject toxins into the prey. We will also be fixing a tissue sample in order to send it for DNA sequencing which will tell us if we have found a new species of nemertean.

Here is a picture of the hoplonemertean we will be dissecting next week:

And here are my sketches for this week:

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