Molluscs

Bivalves (clams, etc.) are the most common molluscs in the deep sediments. Most bivalve species are filter feeders, but some abyssal ones such as the longneck Cuspidarids (below) are carnivorous. They burrow in the mud, and suck in small crustaceans through their siphons. Scaphopods (tusk shells) are the next most common in the sediments. Some actively burrow horizontally through the mud seeking prey. Swimming above the bottom, Cephalopods (squid, octopus, etc.) are also common hunters of the deep. Recently, Johnsen et al. showed in the 11-Mar-99 issue of Nature (p113) that some deep-sea octopods have suckers that emit light, perhaps for communication and/or luring prey.

--Cephalopods in the deep --mainly squids and octopods--are often mysterious. Cirrate octopods and vampire squids have paddle-like fins and webbed legs for swimming. The giant squid and even bigger colossal squid have been found dead many times (washed ashore), but only recently have ones been seen alive. For information on and pictures of the Giant Squid, the bizarre Vampire Squid, see my pictures and links below.

A. California to British Columbia Bathyal and Abyssal (a) = abyssal plain (2300-2850m), (b) = bathyal zone--continental slope (1800-2000m) off Newport, Oregon; (mb) = 1000-3000m in Monterey Bay Canyon; Juan de Fuca ridge off British Columbia (2400m) Click pictures for larger images.
Octopod (a) Benthoctopus canthylus (2000-2800m)	Octopod (b) Benthoctopus yaquinae (1000-3000m)	Longneck clam (a) Cuspidaria sp. (apodema?)	Hydrocarbon-seep clam (b) Vesicomya gigas (1000-3000m) See Methane Seeps for information on its symbiotes	Cockle clam (a)*
Scaphopod (a;mb) Dentalium megathyris (950-4000m)	Gastropod(a) Aforia crebristriata (450-2800m)	Gastropod (mb) with 3 anemones on it! (3000m)	Graneledone from 2000m, Monterey Bay Canyon.	Benthoctopus from 2000m, Monterey Bay Canyon.
Big Squid (a) Moroteuthis robusta	Octopod (a) Graneledone pacifica or Boreopacifica nesis (700-2700m)	Cirrate octopod (a) Cirroteuthis muelleri (400-5000m)	Cirrate octopod (a) Grimpoteuthis bathynectes (2850-3900m)	Octopod/squid's webbing*
A Giant Squid specimen at the Smithsonian in D.C. It is thought to live at 300-700m in the mesopelagic (no larger image)	Unidentified Graneledone species from near the Juan de Fuca ridge (2400m)		Vampire Squid Vampyroteuthis infernalis (mb) These mesopelagic squid-like animals (actually their own category of cephalopod, not quite a true squid) have 2 photophores (light organs) on their back ends, soft hooks instead of suckers, and they "cloak" themselves by folding their black umbrella-like tentacles over their bodies leaving only the glowing back end visible. You can find several videos of this behavior by Googling "vampire squid" and look for video links.
	*Those with "*" are ones we haven't identified at the species level.
Chiroteuthis caly = Glass Squic (mb) with intact feeding arms! These mesopelagic squid have 2 long feeding arms with photophores (light organs) on their tips

California/Oregon Subtidal (er) = Eel River Seeps off Eureka, CA (510-520m) and (hr)- Hydrate Ridge off Newport, OR (500-890m) . See SEEPS & VENTS page for more images and information on some of these species Click pictures for larger images.
Octopod (er) Enteroctopus dofleini?	Cranchiid-type squid seen from Alvin at 880m (hr)	Neptunea humboldtiana or amianta ( er, hr )		"Babysitter Snails"
"Babysitter Snails" These Neptunea lay eggs in a spiral tower, sit on the top, then fall off and die once their jobs are done.		Various squid seen from Alvin at 500 m (er)		Tiny limpets found on carbonate rocks (hr)
Left: Calyptogena (Vesicomya) pacifica (er); has bacterial symbionts; see SEEPS page for more. Right: Acharax spp. (hr); has bacterial symbionts; see Sahling et al. for more on Vesicomya and Acharax		A fairytale scene: The egg towers form extensive surreal scenes of "forests" (er 2001,hr 2006).

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