From Dr. Campbell on Mollusc Interactions With Other Phyla
As suggested by previous
messages ( on Conch-L), it depends on what criteria you use for defining phyla.
If you do not allow one phylum to give rise to another, you will have fewer,
for example. Various extinct forms are considered to possibly represent additional
phyla. Mollusks have interactions with quite a few of the extant animal phyla
(even not considering the high probability that many phyla may eat planktonic
mollusk larvae or mollusks eating their larvae), and even with protists, bacteria,
If you believe the latest
molecular analyses and insist that no phylum can produce another phylum, here
is a list, with molluscan focus:
Many mollusks are commensals; pleurotomariids eat sponges.
- Cnidaria: corals,
jellyfish, etc. Coral reefs provide molluscan habitat, and many gastropods
feed on cnidarians, notably epitoniids and many opisthobranchs.
- Ctenophora: comb jellies.
- Placozoa: obscure
little bunches of cells
- Chaetognatha: arrow
- Echiuran burrows:
some mollusks are commensals in echiuran burrows
- Ectoprocta: bryozoans,
often grow on mollusk shells
- Echinodermata: sea
urchins, starfish, etc. Many starfish eat mollusks, and many mollusks feed
on echinoderms (e.g., cassids), as well as commensal or parasitic forms.
- Hemichordata: acorn
worms, pterobranchs, graptolites
- Chordata: tunicates,
vertebrates. Mollusks provide fascinating years of study to the most advanced
vertebrates, in addition to many vertebrates that feed on mollusks, various
parasites that inhabit both at points in the life cycle, etc.
- Platyhelminthes: flatworms.
Some poorly studied forms may represent additional phyla. Free-living flatworms
are significant predators on oysters; some parasites infest mollusks.
- Gastrotrichia: Tiny,
ciliated; probably eaten by small gastropods.
- Gnathostomulida: Tinier,
in anoxic sediments
- Cycliophora: lives
on lobster lips
- Syndermata: rotifers(wheel
animals), acanthocephalan worms (parasites-not on mollusks)
- Mesozoa: mostly parasitic
in mollusks, especially cephalopods.
- Priapulida: deep-sea
worms, fossil ones ate hyolithids that might have been mollusks
- Kinorhynchia: tiny
- Loricifera: tiny marine
- Nematomorpha: horsehair
- Nematoda: roundworms,
many parasitic, including on mollusks
- Onychophora: velvet
- Tardigrada: water
- Arthropoda (includes
Pentastomida): many prey on mollusks, hermit crabs use their shells
The following phyla appear
relatively closely related to Mollusca:
- Phoronida: phoronid
- Brachiopoda: brachiopods,
often mistaken for bivalves
- Ectoprocta: bryozoan-like,
may live on mollusk shells
- Nemertea: ribbon worms
- Sipuncula: peanut
worms, some live in empty gastropod shells
- Mollusca: many interactions
with other mollusks
- Pogonophora: beardworms,
hot vent worms. Deep-sea Acesta have been found growing on the worm tubes.
- Echiurans: spoonworms
- Annelida: segmented
worms, popular food for many gastropods.
That's 33 if I counted
Dr. David Campbell
Saint Mary's College of Maryland
18952 E. Fisher Road
St. Mary's City, MD 20686-3001 USA
862-0372 Fax: 301 862-0996
"Mollusks murmured 'Morning!'. And salmon chanted 'Evening!'."-Frank
Muir, Oh My Word!