Dear Olive lover,

It is nice to find secrets in natural history of shells alive in nature!
Olives are not only beautiful but also very interesting from the evolutionary point of view,
though very little has been studied on their ecology. To my knowledge, no study has
been made on reproductive biology of olives, though eggs and veligers of related
Olivella spp. have been described. I wonder what looks like egg masses or capsules of
Olives: do they spawn such capsules under sand? A few years ago, we found some
strange egg capsules that were attached to rhizomes of a seagrass. Unusual veligers
with two prominent lobes emerged from these capsules. I tried to raise them to settlement
and further for identification, but failed after several weeks of culture. By that time, veligers
developed elongated 4-lobed velum and they indicated a long larval life further on.

It occurred to me that the capsules might be those of Olive annulata, because this species
was very common in sand around and inside the seagrass beds. Most strange thing about
the unusual veligers was that they flipped their velum up and down as if they were wings!

Masashi Yamaguchi

-----Original Message-----
From:   Maurizio A. PERINI [SMTP:[log in to unmask]]
Sent:   Wednesday, February 02, 2000 3:35 AM
To:     [log in to unmask]
Subject:        Oliva oliva's behaviour

Tuesday   February 1, 2000   06:50PM

Dear Friends,

I'm just come back from a great three weeks trip to
Philippines looking for Olives and making observation
on their behaviour on their habitat.

About that I would like to share with you three facts
I think probably to be interesting to some of you.

A) The place was Palawan Is., Sulu Sea side and the
species was the common Oliva oliva  Linnaeus, 1758.
Early in the morning at low tide in a tide-pool, where
no track of olives was evident, I put some small peices
of chicken. After about 35 seconds the first oliva appeared.
It came out from the sand about 60 cm from the bait.
After few centimeters it took the right direction to the bait.
The oliva went on with the propodium under the sand and
continually moving its siphon from one side to another.
When it was about two centimeters from the bit of chicken
the propodium came out from the sand. The animal was
very excited. With very fast moviments the propodium made
one or two attempts before to find the meat. With a really
amazing skill the two lateral free ends of the propodium
wrapped the bit. Immediately after the animal rolled on its
left side and the propodium pushed the piece of chicken in
to the pouch at the end of metapodium. Then quickly the
oliva disappeared under the sand.
The whole operation took only few seconds !!
I was able to observe that several times but not all the olives
rolled on one side to put the food in to the pouch. Some of
them simply rose.
At this time I cannot say if the size of the prey cause that
different behaviour. Any idea?
I was able to take some interesting series of pictures.

B) Same place and same species. Only in one occasion I
was able to see two olives united together.
The first one ( a black Oliva oliva ) came out from the sand
attracted by a bait. I was very surprised to see a second
specimen ( a gray zig-zag pattern Oliva oliva ) to come out
immediately behind the first one. But my surprise was greater
when I was able to observe that the second Oliva squeezed
by its propodium the posterior edge of the foot of the first
specimen. Is that a phase of mating ? Any idea?
Unfortunately... no picture !!

C) ... next time.

Kindest regards to all,

Maurizio.

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       Maurizio A. Perini
       Via Pedrazza, 9
       I - 36010 Zane (VI)
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