the Cephalopoda
the Cephalopoda
the Cephalopoda
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Recent Aedvances in<br />
Cephalopod Systematics<br />
Kotaro TSUCHIYA<br />
Lab. Invertebrate Zoology<br />
What’ <strong>the</strong> <strong>Cephalopoda</strong>
Squid<br />
Octopus<br />
!"#$%&'#'()*!<br />
Cuttlefish<br />
+,-.(*&%/(./0*./*1%#%/!<br />
Vampire squid<br />
Bobtil squid
Molluscan Characters!<br />
Current Classification of Mollusca!<br />
!! Phylum Mollusca<br />
Class Solenogastres<br />
Class Caudofoveata<br />
!! Eumollusca<br />
Class Polyplacophora<br />
!! Conchifera<br />
Class Monoplacophora<br />
!! Ganglioneura<br />
!! Viscelloconcha<br />
Class Gastropoda<br />
Class <strong>Cephalopoda</strong><br />
!! Diasoma<br />
Class Scaphopoda<br />
Class Bivalvia
Bivalvia<br />
+.)2"3*43'-#*'5*!"#$%&'#'(%!<br />
Diasoma<br />
Scaphopoda <strong>Cephalopoda</strong><br />
Gastropoda<br />
Viscelloconcha<br />
Cephalopod Characteristic<br />
!! A funnel derived from <strong>the</strong> molluscan foot or <strong>the</strong><br />
molluscan neck region (Shigeno et al., 2007).<br />
!! Circumoral arms that are derived from <strong>the</strong> molluscan<br />
head (J.Z. Young, 1965) or <strong>the</strong> molluscan foot<br />
(Shigeno et al., 2007).<br />
!! Chitinous beaks.<br />
!! Image-forming eyes.
Cephalopod Characteristic<br />
!! A funnel derived from <strong>the</strong> molluscan foot or <strong>the</strong><br />
molluscan neck region (Shigeno et al., 2007).<br />
Cephalopod Characteristic<br />
!! Circumoral arms that are derived from <strong>the</strong> molluscan<br />
head (J.Z. Young, 1965) or <strong>the</strong> molluscan foot<br />
(Shigeno et al., 2007).
Cephalopod Characteristic<br />
!! Chitinous beaks.<br />
Upper beak Buccal mass<br />
Cephalopod Characteristic<br />
!! Image-forming eyes.
Ontogeny & Phylogeny<br />
!! Spiral cleavage - Discoidal cleavage<br />
!! Larval development - Direct development<br />
trochophore<br />
!! ! Lecithophora or Meloblastea Fischer, 1880<br />
veliger<br />
As Subphylum for CEPHALOPODA<br />
Current Classification of <strong>Cephalopoda</strong><br />
Based on morphological character
Squid and Octopus<br />
Decapodiformes and Octopodiformes!<br />
!! What’s difference?<br />
!! Sucker morphology<br />
!! Buccal rappet existence<br />
Squid and Octopus<br />
!! What’s difference?<br />
!! Modification of <strong>the</strong> fourth pair of arms as tentacles!
672'#-)*)$%3"*8$%29!<br />
672'#'(.5'3:")***;'
H'3"7-&%3*I/%&E).)!<br />
;A%F-:.E%*"2*%&?*=>>J@!<br />
H'3"7-&%3*I/%&E).)!<br />
;K'F'C'3.*"2*%&?*=>>L@!<br />
16s rDNA<br />
12s rDNA<br />
CO I<br />
Mitochondria genome structure
!-33"/2*!&%)).5.7%2.'/!<br />
!! Clarke (1988) Morphological base<br />
“Order Teuthidea”<br />
!! Divergent group in genus level<br />
!! 28 Families 71Genera<br />
!! Most of <strong>the</strong> families are oceanic, mesopelagic
Oegopsida - Myopsida<br />
Family Chtenipterygidae<br />
- comb-fin squid<br />
!! with suckers on <strong>the</strong> buccal membrane.<br />
!! without carpal locking-apparatus on tentacles.<br />
!! with branchial canals in gills.
Family Idiosepiidae<br />
!! Gladius (shell) rudimental but present<br />
- pygmy squid*!<br />
!! with an adhesive organ on <strong>the</strong> dorsal surface of <strong>the</strong> mantle<br />
Idiosepius pygmaeus (6-8mm ML)<br />
Family Australiteuthidae Lu, 2005<br />
!! Myopsid eye<br />
!! Spritted fins<br />
!! Fea<strong>the</strong>r-shaped chitinous gladius<br />
Australiteuthis aldrichi Lu, 2005 (
Classification Updated<br />
Young (2008)<br />
Morphological comparisons of <strong>the</strong> major taxa<br />
within <strong>the</strong> Decapodiformes<br />
Cornea Branchial Buccal Sucker Tentacle Interstellate<br />
canal support circular pocket connective<br />
sucker muscle<br />
Oegopsida No Yes No No No Yes<br />
Bathyteuthoidea No Yes Yes No Yes Yes<br />
Myopsida Yes Yes Yes/No Yes Yes Yes<br />
Idiosepiidae Yes No No No Yes ?<br />
Spirulidae No No No No Yes No<br />
Sepioidea Yes No Yes/No Yes Yes No
Recent Systematic Hypo<strong>the</strong>sis<br />
""""""""""M Molecular base<br />
Morecular Analysis<br />
(Akasaki et al. 2006)!<br />
mtDNA genome structure
Hypo<strong>the</strong>sis from Morecular Analysis<br />
(Akasaki et al. 2006)!<br />
mtDNA genome structure<br />
Hypo<strong>the</strong>sis from Morphological and Molecular<br />
complex Analysis result!<br />
101 morphological characters<br />
mt cytochrom c oxydase subunit I ; nuclear<br />
18S rDNA; D3 expansion fragment of<br />
28S rDNA, Histon H3**!
"Species-level Taxonomy<br />
!! Only 700 species are known from World<br />
Ocean<br />
Cryptic Speciation<br />
Coastal species (Loliginids, Sepiids)<br />
Japan<br />
Izuka et al. (1996)<br />
Sepioteuthis lessoniana<br />
Western Australia<br />
Triantafillos et al. (2005)
Deep-sea Squids<br />
- still unexplored field<br />
!! Nektonic species - net avoidance<br />
!! Difficult to catch adult specimens by sampling gear<br />
!! Still unkown <strong>the</strong> mature, largest size in most of deep-sea<br />
species<br />
!! Life cycle, life history<br />
Octopus - Labyrinth of Taxonomy<br />
!! Scarce of hard tissue in octopus body<br />
!! Absence of stable key taxonomic character<br />
!! Need to evaluate useful taxonomical information from living animals
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