Rurprosjektet
Hovudside for rurprosjektet | Kva går rurprosjektet ut på? | Metodikk
Framgangsmåte for utføring av feltundersøkinga, fyrste år
- Choose a convenient site. Everyone seems to have relatively easy access
to sheltered rather than open coast sites, so I suggest a sheltered but
non-estuarine site (to avoid salinity complications). This will also
minimise problems of people accidentally looking at cthamalids! Please
avoid using sites close to street lighting or other bright lights as this
may inhibit fertilization.Choose sites with plenty of cover of barnacles.
- For this first year, only sample from the middle of the Semibalanus band
(ie not at low water or at the highest distribution on the shore).
- Scrape Semibalanus off the rock surfaces (either singly or in small
groups) with a penknife and inspect the underside of each barnacle with a
handlens. At the start of the season you will see soft, amorphous pale
yellow masses on either side of the barnacle. Use a mounted needle to prod
the masses. Before fertilization they will be fluid to the touch of the
needle, and it will not be possible to remove the masses with the needle.
After fertilization the masses are a little darker in colour, but the main
and very obvious difference is that they become defined rather than
amorphous, and can be flipped out of the barnacle as whole, relatively hard
egg masses.
- Mike Burrows and I estimate that it takes about 20 minutes to investigate
50 barnacles. I feel that the technique is so simple that it can easily be
delegated. I'm certainly going to train a couple of our technicians, so that
sampling can continue if I'm away or ill.
- Stop sampling when all egg masses are hard on two successive sampling
trips.
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