Why study molluscs?

Because they are very interesting, cool and some even taste great…

Detail from a Sailors Valentine by Bill Jordan

Most of us are familiar with at least a few species of mollusc (Phylum Mollusca), mostly as food like oysters and clams, or as garden pests like snails and slugs. Molluscs have long been important to humans, with solid evidence of man’s use of molluscs as food, tools and ornamentation extending back to the Middle Stone Age (127,000 years ago) in Africa and Eurasia ^{[1, 2]}. Today molluscs remain a very important global food source (in excess of 16 million metrics tons of protein) worth in excess of $15 billion ^[3]. Just as shells provided our ancestors with a trade medium (shell beads) and canvas for art, today the trade (legal and illegal) of sea shells and pearls continues, as does use of shells in art and as inspiration.

Of all the animals, the Mollusca have the second largest number of present day species with 200,000+ species. There are in excess of 130,000 described species of mollusc alive today and conservative estimates put the number of undiscovered or un-described living species at 70,000 or more ^[4]. The fossil record for Mollusca includes about 70,000 described extinct species and extends back at least to the Cambrian (543 to 490 Million years ago) and possibly to the Neoproterozoic (~543 – 1000 million years ago) if Kimberella proves to be a mollusc^[5].

A sub-adult Mesonychoteuthis hamiltoni being prepared for study in New Zealand

Aside from sheer numbers of extant and extinct species, the molluscs are also one of the most diverse groups of animals, with 8 classes of living organisms and at least two additional classes from the fossil record. Shelled molluscs range in size from less than 1mm (Omalogyra fusca^[6]) to the giant clam (Tridacna gigas) at well over a 1.25 meters^[7]. While most molluscs are shelled, shell-less molluscs also vary immensely in size (and shape) from 1mm long eyeless worm-like members of the Aplacophora class, which are found living between grains of sand, to the the colossal squid (Mesonychoteuthis hamiltoni), a well-named deep-sea predator which reaches total lengths of at least 14 meters (~46 feet – the length of a bus!) with a dinner plate sized eye that rivals ours in complexity.

Molluscs are an extremely diverse and important group of animals (evolutionarily, ecologically, economically and gastronomically), which makes them both fun and challenging to study. They are found in just about every ecosystem in the world. Often they function as ecosystem engineers, like oysters and other bivalves, which filter the water and can form large reefs. Although there are may molluscs in freshwater and on land, most molluscs are marine. Molluscs have adopted a wide variety of feeding modes including scraping detritus and diatoms from rocks, filter feeding, herbivory and carnivory. There are molluscs with gills and molluscs with lungs, molluscs with and without eyes (and just about every type of eye in-between!), molluscs with a radula (a rasping tongue like organ found only in molluscs) and molluscs without. Some molluscs have very simple brains, others are extremely complex (very intelligent those cephalopods!).

Why mollusc cards?

Unfortunately what makes them fun and challenging to study can also sometimes make it difficult to explain, especially to all age groups and often in a very limited time frame. There is no “All molluscs have….” rule for molluscs as there are with most other animal groups. Any simplification risks over-simplifying, yet we rarely have time – or attention span – to go into a great deal of detail. We wanted to have an outreach product that we could use with a wide range of ages and education levels as a fun reinforcement tool that focuses attention on the diversity of marine molluscs . We wanted something that could augment our other outreach activities during presentations, but that could also be left with a class and continue to educate curious minds. We wanted something kids and adults could, and would, pick up and use to play the card games they already know, but then be able to see and read about molluscs at the same time. Thus the Mollusc Playing Cards were born.

@article{Steele-2008,
  Author = {Steele, T.E. and Klein, R.G.},
  Date-Added = {2011-12-18 07:13:29 +0000},
  Date-Modified = {2011-12-18 07:16:01 +0000},
  Journal = {Archaeofauna},
  Keywords = {mollusc, tool, SHELLFISH, LIMPETS, SOUTH AFRICA, MIDDLE STONE AGE, LATER STONE AGE, HUMAN POPULATION DENSITY, MODERN HUMAN ORIGINS},
  Pages = {63-76},
  Title = {Intertidal shellfish use during the Middle and Later Stone Age of South Africa},
  Volume = {17},
  Year = {2008}}

[2] Kuhn, S., Stiner, M., Reese, D. & Gülecc, E. (2001) Ornaments of the earliest Upper Paleolithic: New insights from the Levant. IN Proceedings of the National Academy of Sciences, 98.7641-7646.
[Bibtex]

@article{Kuhn-2001,
  Abstract = {{Two sites located on the northern Levantine coast, \"{U}\c{c}a\u{g}{\i}zl{\i} Cave (Turkey) and Ksar 'Akil (Lebanon) have yielded numerous marine shell beads in association with early Upper Paleolithic stone tools. Accelerator mass spectrometry (AMS) radiocarbon dates indicate ages between 39,000 and 41,000 radiocarbon years (roughly 41,000--43,000 calendar years) for the oldest ornament-bearing levels in \"{U}\c{c}a\u{g}{\i}zl{\i} Cave. Based on stratigraphic evidence, the earliest shell beads from Ksar 'Akil may be even older. These artifacts provide some of the earliest evidence for traditions of personal ornament manufacture by Upper Paleolithic humans in western Asia, comparable in age to similar objects from Eastern Europe and Africa. The new data show that the initial appearance of Upper Paleolithic ornament technologies was essentially simultaneous on three continents. The early appearance and proliferation of ornament technologies appears to have been contingent on variable demographic or social conditions.}},
  Author = {Kuhn, Steven L. and Stiner, Mary C. and Reese, David S. and G\"{u}le\c{c}, Erksin},
  Citeulike-Article-Id = {10139211},
  Citeulike-Linkout-0 = {http://dx.doi.org/10.1073/pnas.121590798},
  Citeulike-Linkout-1 = {http://www.pnas.org/cgi/content/abstract/98/13/7641},
  Citeulike-Linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/11390976},
  Citeulike-Linkout-3 = {http://www.hubmed.org/display.cgi?uids=11390976},
  Date-Added = {2011-12-18 04:19:09 +0000},
  Date-Modified = {2011-12-18 04:19:54 +0000},
  Day = {19},
  Doi = {10.1073/pnas.121590798},
  Journal = {Proceedings of the National Academy of Sciences},
  Keywords = {archeology, mollusca, paleolithic},
  Month = jun,
  Number = {13},
  Pages = {7641--7646},
  Pmid = {11390976},
  Posted-At = {2011-12-18 04:17:32},
  Priority = {2},
  Title = {{Ornaments of the earliest Upper Paleolithic: New insights from the Levant}},
  Url = {http://dx.doi.org/10.1073/pnas.121590798},
  Volume = {98},
  Year = {2001},
  Bdsk-Url-1 = {http://dx.doi.org/10.1073/pnas.121590798}}

[3] Cooley, S., Lucey, N., Kite-Powell, H. & Doney, S. (2011) Nutrition and income from molluscs today imply vulnerability to ocean acidification tomorrow. IN Fish and Fisheries, .no.
[Bibtex]

@article{Cooley-2011,
    abstract = {{Atmospheric carbon dioxide (CO2) emissions from human industrial activities are causing a progressive alteration of seawater chemistry, termed ocean acidification, which has decreased seawater pH and carbonate ion concentration markedly since the Industrial Revolution. Many marine organisms, like molluscs and corals, build hard shells and skeletons using carbonate ions, and they exhibit negative overall responses to ocean acidification. This adds to other chronic and acute environmental pressures and promotes shifts away from calcifier-rich communities. In this study, we examine the possible implications of ocean acidification on mollusc harvests worldwide by examining present production, consumption and export and by relating those data to present and future surface ocean chemistry forecast by a coupled climate-ocean model (Community Climate System 3.1; CCSM3). We identify the 'transition decade' when future ocean chemistry will distinctly differ from that of today (2010), and when mollusc harvest levels similar to those of the present cannot be guaranteed if present ocean chemistry is a significant determinant of today's mollusc production. We assess nations' vulnerability to ocean acidification-driven decreases in mollusc harvests by comparing nutritional and economic dependences on mollusc harvests, overall societal adaptability, and the amount of time until the transition decade. Projected transition decades for individual countries will occur 10–50 years after 2010. Countries with low adaptability, high nutritional or economic dependence on molluscs, rapidly approaching transition decades or rapidly growing populations will therefore be most vulnerable to ocean acidification-driven mollusc harvest decreases. These transition decades suggest how soon nations should implement strategies, such as increased aquaculture of resilient species, to help maintain current per capita mollusc harvests.}},
    author = {Cooley, Sarah R. and Lucey, Noelle and Kite-Powell, Hauke and Doney, Scott C.},
    citeulike-article-id = {10139546},
    citeulike-linkout-0 = {http://dx.doi.org/10.1111/j.1467-2979.2011.00424.x},
    doi = {10.1111/j.1467-2979.2011.00424.x},
    journal = {Fish and Fisheries},
    keywords = {acidification, change, climate},
    pages = {no},
    posted-at = {2011-12-18 05:20:52},
    priority = {2},
    publisher = {Blackwell Publishing Ltd},
    title = {{Nutrition and income from molluscs today imply vulnerability to ocean acidification tomorrow}},
    url = {http://dx.doi.org/10.1111/j.1467-2979.2011.00424.x},
    year = {2011}
}

@book{Ponder-2008,
  Address = {Berkeley and Los Angeles},
  Citeulike-Article-Id = {10137583},
  Date-Added = {2011-12-17 20:50:27 +0000},
  Date-Modified = {2011-12-17 20:52:47 +0000},
  Author = {Ponder, W. F. and Lindberg, D. R.},
  Keywords = {mollusca},
  Posted-At = {2011-12-17 20:33:35},
  Priority = {2},
  Publisher = {University of California Press},
  Title = {{Phylogeny and evolution of the Mollusca}},
  Year = {2008}}

[5] Fedonkin, Simonetta & Ivantsov (2007) New data on Kimberella, the Vendian mollusc-like organism (White Sea region, Russia): palaeoecological and evolutionary implications. IN Geological Society, London, Special Publications, 286.157-179.
[Bibtex]

@article{Fedonkin-2007,
  Abstract = {The taphonomic varieties of over 800 specimens of Kimberella (collected from the Vendian rocks of the White Sea region) provide new evidence of the animal's anatomy such as: shell morphology, proboscis, mantle, possibly respiratory folds and possibly musculature, stomach and glands. Feeding tracks, crawling trails and, presumably, escape structures preserved along with the body imprint provide insights on the mode of locomotion and feeding of this animal. The shield-like dorsal shell reached up to 15 cm in length, 5--7 cm in width, and 3--4 cm in height. The shell was stiff but flexible. Evidence of dorso-ventral musculature and fine transverse ventral musculature suggests arrangement in a metameric pattern. Locomotion may have been by means of peristaltic waves, both within the sediment and over the surface of the sea floor, by means of a foot resembling that of monoplacophorans. Respiration may have been through a circumpedal folded strip (possibly an extension of the mantle). Feeding was accomplished by a retractable proboscis bearing terminal hook-like organs and provided with a pair of structures interpreted here as glands. Whilst feeding, Kimberella moved backwards. The structural complexity of Kimberella poses questions about the time of origin of the triploblastic metazoans.},
  Author = {Fedonkin, M. A. and Simonetta, A. and Ivantsov, A. Y.},
  Date-Added = {2011-12-18 02:23:59 +0000},
  Date-Modified = {2011-12-18 02:24:55 +0000},
  Doi = {10.1144/SP286.12},
  Eprint = {http://sp.lyellcollection.org/content/286/1/157.full.pdf+html},
  Journal = {Geological Society, London, Special Publications},
  Keywords = {mollusca, precambrian},
  Number = {1},
  Pages = {157-179},
  Title = {New data on Kimberella, the Vendian mollusc-like organism (White Sea region, Russia): palaeoecological and evolutionary implications},
  Url = {http://sp.lyellcollection.org/content/286/1/157.abstract},
  Volume = {286},
  Year = {2007},
  Bdsk-Url-1 = {http://sp.lyellcollection.org/content/286/1/157.abstract},
  Bdsk-Url-2 = {http://dx.doi.org/10.1144/SP286.12}}

@book{Powell-1979,
  Address = {Auckland},
  Author = {Powell, A.W.B.},
  Date-Added = {2011-12-18 07:02:27 +0000},
  Date-Modified = {2011-12-18 07:04:28 +0000},
  Keywords = {New Zealand, Mollusca},
  Publisher = {Collins},
  Pages = {500 (p120)},
  page = {120},
  Title = {New Zealand Mollusca: Marine, Land and Freshwater Shells},
  Year = {1979}}

@book{Spalding-2001,
  Address = {Berkeley},
  Author = {Spalding, M.D. and Ravilious, C. and Green, E.P. },
  Date-Added = {2011-12-18 16:25:40 +0000},
  Date-Modified = {2011-12-18 16:27:55 +0000},
  Keywords = {coral reef},
  Publisher = {University of California Press},
  Title = {World Atlas of Coral Reefs},
  Year = {2001}}

The winning hand from a round of "Pass the Clam!"

Players:up to 13 (more if two or more decks are used)

Deck: four cards, all of same rank, for each player in the game. For example, three players would need 12 cards: perhaps the four cephalopods (Aces), four hard clams (Kings) and four scallops (Queens).

Deal: Any player is chosen to shuffle the cards then the player to their left deals four cards, one at a time, in rotation, to each player.

One of the student play-testers for "Pass the Clam!"

Play:After the deal, all players look at their hands. Every player then selects one card and simultaneously passes it, face down, to the left. Picking up the card passed from the right, play is repeated until any player gets four cards of one rank. When a player does get four of one rank they silently stop passing or picking up cards and places their index finger to the side of their nose and leaves it there. As soon as any player sees another player’s finger beside his nose, she can also touch her finger to the side of her nose and leave it, without having to have four cards of the same rank. The last player to place his finger to his nose loses the hand. Each player gets one “life” for each letter in the name of the mollusc, so for Pass the Clams it would be 5 lives. Pass the Abalone would be 7 lives, etc. Score can be kept by assigning the letters of the animal’s name to each loss. So in Pass the Clam if a player loses a hand he gets a ‘C’. If he loses another hand he gets an ‘L’, etc. Once a player has lost all his lives, he become the Clam and drop out of the game. When a player drops out of the game his set of four cards (all of same rank) is removed from play. For a shorter game, each player only has one life and drops out upon losing her first hand. Players who have been knocked out of play can talk to remaining players or otherwise distract them to try and force them to out. The winner is the last player left surviving.

Thanks: Maria, Dane, Evan, Melissa and Roni, Johann, Tammy and all the students who helped play test this game with the Mollusc cards.

The Molluscan Diversity Playing Cards were developed to be a flexible tool to learn about the phylum Mollusca in general, with a focus on the diversity of marine molluscs. We developed it to be an educational outreach tool we could use and enjoy in our work with all ages. On top of that it’s fun and will fit in a shirt pocket!

Each card has a unique mollusc on its face (along with the standard poker pips) with detailed information about the animal such as range, habitat, feeding method, class and order, reproductive strategy, fisheries and endangered status.The deck features 52 different animals with each rank being assigned to one group of animals (see the Table below).

Each card is information rich, but in practice, use of the card’s information can be tailored to the audience level. Each card includes the animal’s common name, scientific name, an image of the animal, and the class and order it belongs to. A set of symbols provide information on common life history traits (all have: feeding mode, edible, commercial, and reproduction mode; some also have: endangered status or danger). Range, habitat and interesting notes are described in the text area on the bottom half of the card.

The price for each deck is $12.99, which allows us to give one deck to a high poverty school for every two we sell, plus shipping and handling. For continental United States orders shipping is $2.00 for the first deck, $0.50 additional each deck after that, free ground shipping any order over $50. Please contact us for the best rates possible to your location.