Peteiro dos cefalópodos

O peteiro ou rostro (rostrum) que teñen todos os cefalópodos existentes é unha estrutura dividida en dúas partes, situada na masa bucal e rodeado dos apéndices cefálicos (brazos) musculares. As dúas pezas que forman o peteiro, moitas veces denominadas mandíbulas,Tanabe, K., Y. Hikida & Y. Iba (2006). Two coleoid jaws from the Upper Cretaceous of Hokkaido, Japan. Journal of Paleontology 80(1): 138–145.  son a mandíbula dorsal e a inferior, que encaixan funcionando a modo de tesoira.Young, R.E., M. Vecchione & K.M. Mangold (1999). Cephalopoda Glossary . Tree of Life Web Project.Young, R.E., M. Vecchione & K.M. Mangold (2000). Cephalopod Beak Terminology . Tree of Life Web Project. Está composto principalmente de quitina e proteínas con enlaces cruzados,Saunders, W.B., C. Spinosa, C. Teichert & R.C. Banks (1978). The jaw apparatus of Recent Nautilus and its palaeontological implications.  Palaeontology 21(1): 129–141.Hunt, S. & M. Nixon (1981). A comparative study of protein composition in the chitin-protein complexes of the beak, pen, sucker disc, radula and oesophageal cuticle of cephalopods. Comparative Biochemistry and Physiology Part B: Comparative Biochemistry 68(4): 535–546. Miserez, A., Y. Li, J.H. Waite & F. Zok (2007). Jumbo squid beaks: Inspiration for design of robust organic composites.  Acta Biomaterialia 3(1): 139–149. Organic composite is exceptionally robust: jumbo squid . Ask Nature. polo que os peteiros son case indixeribles e a miúdo son os únicos restos identificables dos cefalópodos que se encontran nos estómagos de especies predadoras coma os cachalotes.Clarke, M.R. (1986). A Handbook for the Identification of Cephalopod Beaks. Oxford University Press, Oxford. Poden utilizarse para estimar a lonxitude do manto e o peso total do corpo do animal orixinal así como a biomasa inxerida total da especie.Clarke, M.R. (1962). The identification of cephalopod "beaks" and the relationship between beak size and total body weight. Bulletin of the British Museum (Natural History), Zoology 8(10): 419–480.Wolff, G.A. (1981). A beak key for eight eastern tropical Pacific cephalopod species with relationships between their beak dimensions and size. Fishery Bulletin 80(2): 357–370.Wolff, G.A. (1984). Identification and estimation of size from the beaks of 18 species of cephalopods from the Pacific Ocean.  NOAA Technical Report NMFS 17, NOAA/National Marine Fisheries Service.Jackson, G.D. (1995). The use of beaks as tools for biomass estimation in the deepwater squid Moroteuthis ingens (Cephalopoda: Onychoteuthidae) in New Zealand waters. Polar Biology 15(1): 9–14. Jackson, G.D. & J.F. McKinnon (1996). Beak length analysis of arrow squid Nototodarus sloanii (Cephalopoda: Ommastrephidae) in southern New Zealand waters. Polar Biology 16(3): 227–230. Jackson, G.D., N.G. Buxton & M.J.A. George (1997). Beak length analysis of Moroteuthis ingens (Cephalopoda: Onychoteuthidae) from the Falkland Islands region of the Patagonian Shelf. Journal of the Marine Biological Association of the United Kingdom 77(4): 1235–1238. Gröger, J., U. Piatkowski & H. Heinemann (2000). Beak length analysis of the Southern Ocean squid Psychroteuthis glacialis (Cephalopoda: Psychroteuthidae) and its use for size and biomass estimation. Polar Biology 23(1): 70–74.  Os peteiros dos cefalópodos fanse gradualmente menos ríxidos a medida que nos movemos desde o extremo á base, un gradiente que resulta da composición química diferente das distintas zonas. Nos peteiros hidratados das luras de Humboldt (Dosidicus gigas) este gradiente de rixidez abrangue dúas ordes de magnitude.Miserez, A., T. Schneberk, C. Sun, F.W. Zok & J.H. Waite (2008). The transition from stiff to compliant materials in squid beaks. Science 319(5871): 1816–1819. 

Coñécense restos fosilizados dos peteiros de varios grupos de cefalópodos, tanto extintos coma aínda existentes, incluíndo luras, polbos, belemnitas, e vampiromorfos.Zakharov, Y.D. & T.A. Lominadze (1983). New data on the jaw apparatus of fossil cephalopods. Lethaia 16(1): 67–78. Kanie, Y. (1998). New vampyromorph (Coleoidea: Cephalopoda) jaw apparatuses from the Late Cretaceous of Japan. Bulletin of Gumma Museum of Natural History 2: 23–34.Tanabe, K. & N.H. Landman (2002). Morphological diversity of the jaws of Cretaceous Ammonoidea. Abhandlungen der Geologischen Bundesanstalt, Wien 57: 157–165.Tanabe, K., P. Trask, R. Ross & Y. Hikida (2008). Late Cretaceous octobrachiate coleoid lower jaws from the north Pacific regions. Journal of Paleontology 82(2): 398–408. Klug, C., G. Schweigert, D. Fuchs & G. Dietl (2010). First record of a belemnite preserved with beaks, arms and ink sac from the Nusplingen Lithographic Limestone (Kimmeridgian, SW Germany). Lethaia 43(4): 445–456. Tanabe, K. (2012). Comparative morphology of modern and fossil coleoid jaw apparatuses. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 266(1): 9–18.  Os ápticos, estruturas en forma de placas que se encontran nos ammonites, poderían tamén ser elementos das mandíbulas.Morton, N. (1981). Aptychi: the myth of the ammonite operculum. Lethaia 14(1): 57–61. Morton, N. & M. Nixon (1987). Size and function of ammonite aptychi in comparison with buccal masses of modem cephalopods. Lethaia 20(3): 231–238. Lehmann, U. & C. Kulicki (1990). Double function of aptychi (Ammonoidea) as jaw elements and opercula. Lethaia 23: 325–331. Seilacher, A. (1993). Ammonite aptychi; how to transform a jaw into an operculum? American Journal of Science 293: 20–32. 

Nas ilustracións móstranse os termos utilizados para referirse ás distintas partes do peteiro dos cefalópodos.

 Medidas 
miniatura|Peteiro de lura xigante e músculos asociados coa man como comparación de escala.
En teutoloxía utilízanse comunmente como medidas do peteiro a lonxitude rostral inferior (lower rostral length, LRL) e a lonxitude rostral superior (upper rostral length, URL), respectivamente. Estas son as medidas estándar da medida do peteiro nos Decapodiformes, mentres que a lonxitude da cuberta (hood length) é a preferida para os Octopodiformes.

 Notas 

 Véxase tamén 
 Bibliografía 
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 Bolstad, K.S. (2006). Sexual dimorphism in the beaks of Moroteuthis ingens Smith, 1881 (Cephalopoda: Oegopsida: Onychoteuthidae). New Zealand Journal of Zoology 33(4): 317–327. 
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 Clarke, M.R. & L. Maddock (1988). Beaks of living coleoid Cephalopoda. In: M.R. Clarke & E.R. Trueman (eds.) The Mollusca. Volume 12. Paleontology and Neontology of Cephalopods. Academic Press, San Diego. pp. 121–131.
 Clarke, M.R. & R.E. Young (1998). Description and analysis of cephalopod beaks from stomachs of six species of odontocete cetaceans stranded on Hawaiian shores. Journal of the Marine Biological Association of the United Kingdom 78(2): 623–641. 
 Hernańdez-García, V., U. Piatkowski & M.R. Clarke (1998). Development of the darkening of Todarodes sagittatus beaks and its relation to growth and reproduction. South African Journal of Marine Science 20(1): 363–373. 
 Hernández-López, J.L. & J.J. Castro-Hernández (2001). Age determined from the daily deposition of concentric rings on common octopus (Octopus vulgaris) beaks. Fishery Bulletin 99(4): 679–684.
 Hobson, K.A. & Y. Cherel (2006). Isotopic reconstruction of marine food webs using cephalopod beaks: new insight from captively raised Sepia officinalis. Canadian Journal of Zoology 84(5): 766–770. 
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 Lefkaditou E. & P. Bekas (2004). Analysis of beak morphometry of the horned octopus Eledone cirrhosa (Cephalopoda: Octopoda) in the Thracian Sea (NE Mediterranean). Mediterranean Marine Science 5(1): 143–149.
 Lu, C.C. & R. Ickeringill (2002). Cephalopod beak identification and biomass estimation techniques: tools for dietary studies of southern Australian finfishes. Museum Victoria Science Reports 6: 1–65.
 Martínez, P., A. Sanjuan & Á. Guerra (2002). Identification of Illex coindetii, I. illecebrosus and I. argentinus (Cephalopoda: Ommastrephidae) throughout the Atlantic Ocean; by body and beak characters. Marine Biology 141(1): 131–143. 
 Ogden, R.S., A.L. Allcock, P.C. Watts & J.P. Thorpe (1998). The role of beak shape in octopodid taxonomy. South African Journal of Marine Science 20(1): 29–36. 
 Roeleveld, M.A.C. (2000). Giant squid beaks: implications for systematics. Journal of the Marine Biological Association of the UK 80(1): 185–187. 
 Uchikawa, K., M. Sakai, T. Wakabayashi & T. Ichii (2009). The relationship between paralarval feeding and morphological changes in the proboscis and beaks of the neon flying squid Ommastrephes bartramii. Fisheries Science 75(2): 317–323. 
 Xavier, J.C., M.R. Clarke, M.C. Magalhães, G. Stowasser, C. Blanco & Y. Cherel (2007). Current status of using beaks to identify cephalopods: III International Workshop and training course on cephalopod beaks, Faial Island, Azores, April 2007. Arquipélago: Life and Marine Sciences 24: 41–48.
 Xavier, J.C. & Y. Cherel (2009). Cephalopod Beak Guide for the Southern Ocean. British Antarctic Survey, Cambridge. 129 pp.
 Xavier, J.C., R.A. Phillips & Y. Cherel (2011). Cephalopods in marine predator diet assessments: why identifying upper and lower beaks is important. ICES Journal of Marine Science 68(9): 1857–1864. 

 Ligazóns externas 

Categoría:Cefalópodos