03750naa a2200181 a 450000100080000000500110000800800410001910000160006024501400007626000090021652031070022565000220333265000190335470000160337370000160338970000170340577301460342211328272022-12-02       2022    bl uuuu     u00u1 u    #d1 aRUPP, G. S.  aA rare specimen of bifurcated Holothuria (Halodeima) grisea (EchinodermatabHolothuroidea) from southern Brazil.h[electronic resource]  c2022  aHolothurians    are     echinoderms     with    fusiform        and     elongated       bodies  along   the     oralaboral      axis.   The     anterior         region  presents        a       crown   of       tentacles      around   the    mouth,   followed        by      the     pharynx,        surrounded      by      a       calcareous      ring,   the     esophagus,      and     the      digestive        tract. Holothuria      (Halodeima) grisea Selenka,     1867    is      a       common  species  in       intertidal      regions         along   the     Brazilian       coast,  with    the     southern        limit   of      distribution    in      the     State   of      Santa   Catarina,       Brazil. Between 2019    and     2022,   samples  of      this    species were    inspected as    part    of      a       populational    and     reproductive    study   in       Santa   Catarina.       In      this    period, 2,574   specimens       were    observed,       and     one     stood   out      for     presenting       the    anterior        part    of       the    body    bifurcated,     with     two     tentacle       crowns   and     two     mouths. This    organism        was     collected       at      Arma????o       do      Itapocor??i,        Penha,  on       February        24,     2021,   and      taken   to      the    laboratory,     where   it      was     kept    alive    for     three   weeks    for    observations    of      its      functional     anatomy and     behavior.       Subsequently,    the     organism         was     anesthetized    with    7%      magnesium       chloride        and     fixed   in      10%     formalin        for     further analysis.       The     specimen,       when    contracted,     had     a       length  of      11.6     cm,      a       width   of      3.6     cm      in      the     median  region,         and     a       weight  of      70.86   g       after   the     elimination      of      the     internal        liquid.         The     width   of      the     anterior        region  (withdrawn      tentacles)      was     3.75    cm.     It      was     found   that    the     tentacles       of      both    crowns  (25     peltate  tentacles        each    crown)  were    functional      and     active  in      capturing       food    particles,      driving  them    to      the     mouths,         and     frequently      adhering        to      the     surface         of      the     container.       Images  were    recorded        through         digital         photos  and     videos.         This    is      probably         the     first   in      vivo observation        of      a       bifurcated      holothurian,    a       rare    phenomenon      in      Holothuroidea.  Preliminary     analyses        of      the     internal        anatomy using    micro-computed  tomography      revealed        two     complete        calcareous      rings,  and     further  studies will    elucidate       whether other   parts   of      the     digestive       system  are     duplicated.  aHolothuria grisea  apepinos-do-mar1 aMARTINS, L.1 aMARENZI, A.1 aCOSTA, R. C.  tIn: CONGRESO LATINOAMERICANO DE EQUINODERMOS, 5., 2022, Argentina. Res??menes... Argentina: Rede Latinoamericana de Equinodremos, 2022. p. 27