Lecture 5 - Molluscs and Anthropods Flashcards
Body structures for Mollusca
Head (with mouth and feeding structures/radula)
Foot
Visceral mass
Mantle
Marine Snails
C. Gastropoda
O Neogastropoda
Nudibranchs
No deep sea
Thecosomata and Gymnosomata
Foot in 2 wings
Thecosomata - smaller with shells
Gymnosomata - larger, predatory, no shells
Bivalves are abundant where?
In deep sea sediments
Characteristics of Solemyidae
Bivalves that live at great depths and have bacterial symbioses in their gills (`800m)
Mussels
O. Filibranchia in C. Bivalvia
Use gills for feeding and specialize on enrichment/small habitats (sunken wood, whales, ect)
C. Cephalopoda
up to 5000 m All marine squids/octopi Modified foot with tentacles Shell reduced or absent Well-developed nervous system and vision Jet propulsion Close circulatory system chromatophores ink sac semelparous (single repro event for females) Short lived
Jet propulsion effectiveness
1/2 as effective as fins
Nautilus
up to 700 m
shelled
multichambered for buoyancy
Spirulida
C. Cephalopoda
up to 1000 m
internal spiraled shell
True squids
down to 1000 m O. Teuthoidea 8 arms, 2 tentacles that can retract all pelagic suckers or hooks
How do deeper squids carry eggs?
gelatinous material
In some true squids, what changes with depth?
Go deeper as they mature
eye structure changes with depth
Deep sea squids have been recorded as low as …
5000 m
Which true squid has one large and one small eye?
f. Histioteuthidae (also has vertical migration)
Largest squid
Colossal squid
Two subOs of O. Octopoda
subO. Incirrata (no fins)
subO. Cirrata (fins)
subO. Cirrata go as deep as …
> 5000 m, near bottom of pelagic
Movement in deeper pelagic cephalopods (squid, octopi)
Reduce use of jet propulsion
Use fins for rowing/flying or arms/webbing for jellylike movement
Vampire squid
O. Vampyromorpha 800-1000 m at low O2 Only cephalopod to eat non-living food No suckers Have luminescence on tentacles Trailing filaments stick to food
