phylum mollusca
DESCRIPTION
PHYLUM MOLLUSCA. PHYLUM MOLLUSCA. Invertebrates Freshwater, marine, & terrestrial Largest marine phylum 23 % of named marine species Mantle Radula Ventral foot. CLASS CEPHALOPODA. Squids, octopods, cuttlefish, Nautiloidea Bilateral symmetry Marine Arms or tentacles. - PowerPoint PPT PresentationTRANSCRIPT
PHYLUM MOLLUSCA
PHYLUM MOLLUSCAInvertebratesFreshwater, marine, & terrestrial Largest marine phylum
23% of named marine species
Mantle Radula Ventral foot
CLASS CEPHALOPODASquids, octopods, cuttlefish, NautiloideaBilateral symmetryMarineArms or tentacles
ORDER TEUTHIDA – SQUIDS 8 arms in pairs of 22 tentacles (usually longer)Largest eye-to-body ratio
FAMILY LOLIGINIDAE“pencil squids”Body tapers to a pointArms are partially retractableBuccal membrane has 7 lappets
Sepioteuthis sepioideaCaribbean reef squid
Cigar-shaped bodyArms shorter than body10-20 cm longFins extend almost whole length of body
Undulate rapidly as they swim
Sepioteuthis sepioideaUnique behaviors
Pointing bodies upward prior to striking preyCurling upward during territorial disputesPointing head-down when approached by predators
Found in Caribbean sea and off the coast of Florida
Young congregate in turtle grassesDie after reproducing
(like other cephalopods)First squid to be observed “flying”?
Squid Flight
ORDER OCTOPODA8 armsNo shell
FAMILY OCTOPODIDAEMajority of know octopods Bottom-dwelling Suckers in one or two seriesOne arm modified as open sperm groove in
males
Octopus briareusCaribbean reef octopus“Chunky” body compared to arms40 – 60 cm long, up to 1.5 kgDark ring around eyeNo dark borders on suckers
Octopus briareusCannibalistic when confined in small tanks
with othersNocturnal huntersReflective skin is easy to see at nightUses chromatophores for camouflage
Disguise themselves as other species or objectsOne of the most intelligent invertebratesVery little sexual dimorphismAlso die after reproducing
Females live long enough to guard eggs