Lab 7: Mollusca III

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Lab 7 Mollusca III
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Class Bivalvia continued.
Subclass Lamellibranchia Superorder
Eulamellibranchia Order Veneroida Family
Chamidae
Genus Chama sp.
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Family Cardiidae
Genus Laevicardium sp.
Genus Trachycardium sp.
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Family Veneridae
Genus Chione sp.
Genus Tivela sp.
Genus Saxidomus sp.
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Genus Dosinia sp.
Genus Pitar sp.
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Family Tridacnidae
Family Solecurtidae
Genus Tridacna sp.
Genus Tagelus sp.
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Family Solenidae
Family Donacidae
Genus Ensis sp.
Genus Donax sp.
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Order Myoida Family Pholadidae
Family Teredinidae
Genus Pholas sp.
Genus Teredo sp.
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Order Paleoheerodonta Family Unionidae
Genus Anodonta sp.
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Subclass Anomaldesmata
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Class Scaphlopoda (Tusk Shells)
Genus Dentalium sp.

• shell single conical element, open at both ends

• possess a well-developed mantle cavity

• lack ctenidia

• tentacle-like captacula for feeding on diatoms
  and microcrustaceans

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Class Scaphlopoda (Tusk Shells)
radula
captacula
mantle
foot
foot
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Class Cephalopoda(squid, cuttlefish, octopus,
nautilus)

• Great cephalization most complex brain and
  highly developed eyes

• Complex behavior

• 650 living spp.

• Chromatophores pigment cells

• Parental care

• Dorso-ventral body axis

• Prehensile tentacles

• Siphon excurrent pore

• Flourished between Cambrian and Cretaceous
  periods

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Subclass Nautiloidea
Genus Nautilus sp.

• all extinct but this genus

• no suckers on tentacles

• add and release nitrogen gas to control buoyancy

• siphuncle extends throughout the shell through
  holes in each septum

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Subclass Ammonoidea

• became extinct in the Cretaceous period

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Subclass Coleoidea (cuttlefish, squid, octopus
and vampirsqhid)

• internal shells imbedded in mantle or absent

• 8 suckered arms (sometimes 2 additional
  raptorial arms)

• siphon closed tube, single pair of ctenidia and
  nephridia

• Eyes with cornea

• Ink sac

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Order Sepioidea (Cuttlefish)
Genus Sepia sp.
cuttlebone supports mantle
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Order Teuthoidea (Squids)
Genus Loligo sp.
Raptorial arms
mantle
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Wounds inflicted by giant squid.
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Order Octopoda (Octopuses)
Species Octopus bimaculatus Two spot octopus
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Species Octopus digueti
Species Octopus fitchi
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Order Vampyromorpha (Vampire Squids)