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Click to edit Master subtitle style9/14/10Lec 14 - DOF 3,14Otocephala Part 1:
9/14/10Otocephala(Teleostei)
9/14/10OtocephalaHerrings and minnow-like fishesOnce thought to be separate groups, havebeen places in the Otocephala based onrecent phylogenetic work
9/14/10Clupeomorpha(Teleostei:Otocephala)364 spp.The herring and their kin.Most in two families Clupeidae (herrings) orEngraulidae (anchovies) but also includesthree other familiesClupeomorphaClupeidae(herrings)Engraulidae(anchovies)PristigasteridaeDenticipitidaeChirocentridae
9/14/10Clupeomorpha(Teleostei:Otocephala)All adapted to living in well-lighted surface water,where most species school and feed on plankton.Why does it help to be silvery in well lit areas?Almost all are open water, pelagic schoolingforms, 80% marine.
9/14/10Clupeomorpha(Teleostei:Otocephala)Have conspicuous silvery scales, acompressed often keeled bodies.Some with ventral and dorsal scutesSilvery scales and compressed body functionin reducing the visibility of the fish, scalesscatter light coming from above, while thecompressed body reduced the profile visiblefrom below.
9/14/10ClupeomorphaHave a connection betweenthe swim bladder and innerear by means of a narrowdiverticulum of the bladder.The latter structure givesclupeids a sense of hearingthat is among the most acutein fishes.Synapomorphy – gas bladderextends anteriorly up into thebraincase and contacts theutriculus of the inner ear andGrande and diPinna 2004
9/14/10Clupeomorpha(Teleostei:Otocephala)Condition termed, Otophysic -“ear-to-gas-bladder”Increases the hearing ability by increasingsensitivity to low frequency sounds (1-1000Hz)Tail beats of other fish 3-20 Hz can beheard.Why would this be useful?
9/14/10Clupeomorpha(Teleostei:Otocephala)Have a flexible mouth and gill rakers forplankton feeding.Advancements from the Elopomorphcondition includes:a modified joint at the posterior angle of thejaw (angular fused to articular rather than theretroarticular)Caudal skeleton reduction (reduced first uralcentrum and reduction to six in the numberof hypural bones)F –retroarticular
9/14/10Clupeomorpha(Teleostei:Otocephala)Clupeomorphsare specialized planktonfeeders with relatively few species butextraordinary high numbers.Total world fish catch in 1991 was 70million tons of fish, 1/3 of those wereclupeomorphs
9/14/10Clupeidae(Otocephala:Clupeomorpha)Herrings, shads, sardines,alewives, menhaden, andother clupeid fishes (188spp.) can be easilyrecognized by their keeled(sawtooth) bellies andsilvery deciduous scales.Often very abundantmembers of the food weband feed on zooplanktonand phytoplankton.Important commercial
9/14/10Clupeidae(Otocephala:Clupeomorpha)Best known fossil fish,KnightiaFreshwater Eocene herring from the GreenRiver shale formations of Wyoming
9/14/10Clupeidae(Otocephala:Clupeomorpha)Herring Hazard VideoFished like madhttp-//

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Term
Fall
Professor
Chakrabarty
Tags
Ichthyology, Gill, Clupeomorpha

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