Current Classification of Mollusca � Phylum Mollusca
Class Solenogastres Class Caudofoveata
Eumollusca Class Polyplacophora
Conchifera Class Monoplacophora
Ganglioneura Viscelloconcha
Class Gastropoda Class Cephalopoda
Diasoma Class Scaphopoda Class Bivalvia
Cephalopod Characteristic A funnel derived from the molluscan foot or the
molluscan neck region (Shigeno et al., 2007).
Circumoral arms that are derived from the molluscan head (J.Z. Young, 1965) or the molluscan foot (Shigeno et al., 2007).
Chitinous beaks.
Image-forming eyes.
Cephalopod Characteristic A funnel derived from the molluscan foot or the
molluscan neck region (Shigeno et al., 2007).
Cephalopod Characteristic Circumoral arms that are derived from the molluscan
head (J.Z. Young, 1965) or the molluscan foot (Shigeno et al., 2007).
Ontogeny & Phylogeny Spiral cleavage - Discoidal cleavage Larval development - Direct development
→ Lecithophora or Meloblastea Fischer, 1880 As Subphylum for CEPHALOPODA
trochophore
veliger
Gastropoda Cephalopoda
Squid and Octopus Decapodiformes and Octopodiformes � What’s difference?
Sucker morphology Buccal rappet existence
Octopus share what?�Octopodiformes (over 200spp.)� Octopoda Leach, 1818
Cirrata Grimpe, 1916 Incirrata Grimpe, 1916
Vampyromorpha Robson, 1929
Octopus share what?�Octopodiformes (over 200spp.)� True arms II modified or absent Horny rings in suckers absent� Buccal crown absent �
“Order Teuthoidea” Divergent group in genus level 28 Families 71Genera Most of the families are oceanic, mesopelagic
Oegopsida - Myopsida Presence or absence of Cornea � “closed eye” or “open eye”� Coastal or Oceanic�
Family Chtenipterygidae - comb-fin squid with suckers on the buccal membrane. without carpal locking-apparatus on tentacles. with branchial canals in gills.
Family Idiosepiidae
- pygmy squid � Gladius (shell) rudimental but present with an adhesive organ on the dorsal surface of the mantle
Idiosepius pygmaeus (6-8mm ML)
Family Australiteuthidae Lu, 2005 Myopsid eye Spritted fins Feather-shaped chitinous gladius
Australiteuthis aldrichi Lu, 2005 (<30mm ML)
Morphological comparisons of the major taxa within the Decapodiformes
Cornea Branchial Buccal Sucker Tentacle Interstellate canal suckers circular canal support circular pocket connective sucker muscle
Oegopsida No Yes No No No Yes Bathyteuthoidea No Yes Yes No Yes Yes Myopsida Yes Yes Yes/No Yes Yes Yes Idiosepiidae Yes No No No Yes ? Spirulidae No No No No Yes No Sepioidea Yes No Yes/No Yes Yes No
Hypothesis from Morphological and Molecular complex Analysis result �
101 morphological characters mt cytochrom c oxydase subunit I ; nuclear
18S rDNA; D3 expansion fragment of 28S rDNA, Histon H3 �
Cryptic Speciation Coastal species (Loliginids, Sepiids)
Sepioteuthis lessoniana
Western Australia Triantafillos et al. (2005)
Japan Izuka et al. (1996)
Deep-sea Squids - still unexplored field Nektonic species - net avoidance
Difficult to catch adult specimens by sampling gear Still unkown the mature, largest size in most of deep-sea
species Life cycle, life history