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Auckland Shell Club |
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Auckland Shell Club |
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August Meeting
Members brought in so many trays of displays and so many items for sale or giveaway that the room was a little cramped. Most of the display trays contained exquisite Cypraeidae, and we had never seen so many in one place - not even in Shell Shows. There were Cypraeidae from specific countries, variations of one species, melanistic and rostrate species, Cypraeidae found in NZ, mature big/small pairs, and many other themes.
Mike Bressolles started off the Cypraeidae discussion with an explanation of how they colour their shells.
The application of pigment varies greatly amongst the species, but damage of the animal's mantle will cause more pigmentation to be applied. The delicate mantle never recovers from injury, and the scar tissue then makes black pigment. Mike showed examples of this on some of his shells.
Melanistic (dark coloured) shells commonly occur when the animal lives in an environment (Eg. a muddy area) that causes irritation to the mantle. Other factors affecting shell colouration are diet, water temperature and chemistry, and predation.
After depositing pigmentation the animal applies very hard layers of transparent enamel. Entirely white shells occur due to an absence of pigment.
Mike also displayed a Cypraea tigris that he had (with much difficulty) sawn in half. One half he had then boiled in peanut oil, and this caused the dark blotches to turn red/orange. He explained that this colour change occurs when the protein keratin is broken down by heat. A similar colour change occurs when you boil a lobster.
Michael Barlow spoke about his many years of Cypraeidae collecting in Niue.
As a child he had lived there for many years, and since then he returns once or twice every year.
He described Niue Island as essentially a rock in the deep ocean - not your typical tropical island with palm trees and white sand. It is surrounded by a small fringe reef, a rocky platform that is quite difficult to get onto.
59 species of cowrie can be found there, and he had brought in an impressive tray of 57.5 of these species (many quite small) that he had personally collected.
Niue Island has a rough side and a lee side, and many of the Cypraeidae species inhabit specific and sometimes very small areas.
Night-time is the best time to go collecting, and most species can simply be found exposed on the reef at low tide. However, the best collecting areas are now marine reserves, and it is also illegal to take shells using scuba.
Some Cypraeidae species appear to be seasonal, and have only been seen by Michael in numbers one time. Others appear in cycles - possibly due to the impact of storms, or to changes in their food supply. Some species that were common in the past are now very rare.
Heather then gave us an interesting slideshow of ...
. Underwater images of live cowries, showing the huge variety of mantles which give no indication of the identity of the shell they cover. Interestingly the mantle of the entirely white Ovula ovum is entirely black.
. Zoila specimens, some of which are very valuable - up to AUS$10,000 for a single specimen. One photo was of a tray estimated to contain about AUS$42,000 worth of Zoilas.
. Cypraeidae collecting trips in Niue, Florida, and the Great Barrier Reef where Heather normally goes every year. Every reef she encounters is different, and there was a photo of one which is completely covered in staghorn coral.
. Jill Hayward and her magnificent shell collection. Jill started collecting in the 70's, and all her shells are displayed in glass fronted cabinets covering the walls.
. Video of live Cypraeidae off the Andaman Islands. They have amazing mantles, and move very fast. There were also photos of their coiled egg masses.
Unfortunately we did not have time for Doug Snooks talk, so that has been held over to the next meeting.
Rae Sneddon
Members will be saddened to learn that Rae Sneddon passed away on August 10, 2012.
Rae was a member of the Shell Club from the 1970s to 2004, being the clubs librarian for much of this time. Her large collection consisted of both New Zealand and overseas shells, with a special fondness for Cypraeidae. This was auctioned by the club in 2004 when Rae moved into a retirement home.
She volunteered between 1992 and 2004 working with Peggy Town to identify and update molluscs in the Marine Department of Auckland Museum. They also made a significant contribution during the development of the Oceans gallery.
Our present-day library is testament to Rae's care and commitment.
Next Meeting – Tuesday 11th of September
Epsom Community Centre, 202 Gillies Avenue, Epsom at 7:30pm (doors open 7pm).
Doug Snook will speak about worldwide Cypraeidae, and we will also have some videos of seabed life.
Please bring in any shells that you are unable to identify.
Shell Auction - Albany Hall, Saturday 27th October 2012
Our annual Shell Auction will again be held at the Albany Hall, 3-21 Library Lane, Albany.
The lot list is included with this newsletter.
Due to the size of this year's auction (~300 lots) we will again commence at midday, with viewing from 10am.
Proxy bids should be emailed to Peter Poortman at petermwp@gmail.com or posted to 26 Pendlebury Street, Green Bay, Auckland 0604.
New Zealand Shell Show 2013
This will again be held at Te Tuhi Center for the Arts in Pakuranga, Auckland, on 3rd - 5th May 2013.
A schedule will be sent to all members in early November, if not sooner.
Peter Poortman (petermwp@gmail.com or 09 817 1397) is the contact for this.
Poirieria Magazine
We welcome contributions to our club magazine "Poirieria".
Anything related to shells or collecting would be greatly appreciated - Eg. shelling trips/finds, personal observations/tips, scientific research, historic anecdotes, a notable washup, etc.
Please email articles to Peter Poortman at petermwp@gmail.com, or post to 26 Pendlebury Street, Green Bay, Auckland 0604.
Club Library
We have an extensive collection of books, magazines, and scientific publications available, as well as a biological microscope.
Luen, our librarian, is currently doing a stocktake. Can members please return any library books/videos/etc that they may have, or just let him know what you have. IE. The book name, the club id number on it, and if possible the year of publication.
Luens contact details are: wildhoney@slingshot.co.nz or (09) 834 5195 (after hours).
Your club needs you!
Volunteers are required for some of the clubs more active positions - in particular the roles of President, Newsletter Editor, & Porieria Editor.
If you have the time and the skills for any of these positions then we would like to hear from you.
Please contact Peter Poortman at petermwp@gmail.com or (09) 817 1397.
Items of Interest
. As part of a wider study of the genus Cominella, Hamish Spencer requires some ethanol preserved live taken specimens of the Norfolk Island endemic species Cominella norfolkensis. If you are going to Norfolk Island and would be willing to collect these whelks, please contact Hamish at h.spencer@otago.ac.nz. He will send you the details, including collection materials and the necessary documentation.
. Items of interest for the monthly newsletter are always welcome - email to petermwp@gmail.com, or post to Peter Poortman, 26 Pendlebury Street, Green Bay, Auckland 0604.
