Integration of the Electrosense with Other Senses: Implications for Communication Stefan Schuster Illstitut fiit Z..l.:tie U, Ll !1td.sität E rr.üt Niihl struLttrtL c..-i e,,,,ii;',,,ä,,,i,Äi;,:i:;l;;,ii,;:l:i::;:,"i',:;:b''3' s' D elt)s' L r'!dt ABSTRACT The outstnndinA ctecbonoro. and elc.trosetrsoN,biliries ,seücdt, oI.lecbi. tish enablc thcn to exchanSe nNüges n,". u.t.n,n"t rt,.,ti, r,_ ..., ,,,.r inn.."ss,Lrr€ r. most oth., animals. llut ",.]j ' 1 .,1 rr.a:.ö\.1..,\ .rd..F.r,.m olerr., ""'': r,h p",r , rr!r LF\.u'1,.".,.,'. ..,,: ..,f,b",,;". ,:'1":.:- \rstrinI,: s rurcri.nrtän!l ., i,,i''' Dr.b.rtrh."','., rr ""ll"iii"i i1,..' " 1",i _i-, 1","f ä, J. l. ,.,, i,il;l i": t-, inrr.(.ur,Jr., I .Lt, i..,*.h.o.rI L,t,; p,*F'., ,.r,.,n" ,n,-.,1.. i,1. ,,"r ,,8,," . ._ a-.i.,-,;",; el€.tric tsn conl.l r",: ,.";; ..;g*Lren.tit fron uritizins morc dran.n o-,.. ,ig,'r.. -po.r.,;;; ä",fi11: prnicrl..llcnd ;,: ä;:*ä ;lj.",:l;l'::':l::J:: ;:,: orsisn.ts s€nr snnuttan.ous\, icrcss se,crar a..*r.. rÄ" rdnrblr nt p.+ *-,rJ U...iir." ble hb,ia!!. rr"o,. r,"l *nna ,n, Pr . "o de r' ll i'l\P'rf i' hc'e r Jr'..',\ ToJ,t ro,.r.t.n,h. J"r..r b or mu,.*n. "'-"""""v'ommrnicarion svst'ms ivitrin a *"rr a+i,,., "*.*,r,i,r.gi.ir;;:;k. K€yho'd\:\lt,r',r,.'..rt.oi ,,.V.i,r, sN, H...,.r t,rrd,.,1 .,,,,.,tr,r,,-.rLi-.r.,: ',' Ir'tr1 t'- kr tßh 782 Comn nicntion in Fishes photoreceptor bundl( 1.. INTRODUCTION al. (1997)suggestihai between 520 and 540 eleÜromolor l^ hv -tu.lv hcanr!. and \ ii'rn in ele' rr:( lr'h s I o-e absorbs long waveler "ulstJndrnB ' o\ e- ,""'"i", ii'-."-..i,t,'rr' ie' , n.role thLm to e\( h rnßc mes'ag+ +' erl\ and co-workers now clo:er loJl rt lhe c' nsh arnF as .haffcl rrr.,.. es'ible l. m,*l olher 'in;m?l'l A device to collect mr " r".,*.'.trricatrinsh"h-rhdt(le' tri' rr-h Pro\iJeinrere'rin8 about 600 rods, 25 rhJl '-r.'"i.',i.iil,'," h"w .rn:m rl' c'rn beierit r-om Jrrrr/inq mor( anangement (Ulbrich ."f "'pr,-F eh'l :c{i'hdo on,.!eri-err ä lrne. fir\l ., nrr.rry to'omLUlder'r*umPrions is not optimized for ci lhe'n logelher trr|r otl,er b(ll tun,lr(,n:ng.Fnsor) .\"lem. rr d rr-e presently do not unde ",^-e* (omm h :rh ü"' i".i'. s".""J ,r,.^ limirä r'or ' rn rni'ärrns in oul understandint """..' "* 'ri"l' h) .,PProrri.'rFr\ .'g".r. rhur ,he ri-h 'mendrrrg "i"lt,'..i".i'.".'i.r' $;rlr :r' orher 'en'ur) rb:lrt:c' I wilr ärcue thar TeyssädreandM( ,'n,1..'tantlne,het,v'rrwhthPlecirkfr'hu"car:nteractionol'l'errtänouc'.",'." see by using the fish' ;;:;.,:'; i.:i",..;;bitirrer in 'pc.'rrccomn'uni'dtrol rer(vJIrr ra-r '(ourd an indicator. This stu{ ;",;;::;'-h,; ,." LJ'.g u. ra t" 'ruot murti"en'ort intesrdtrnn rn a $err 1x), the fish no longe ..,?."i',r.r, ,r ;on,,\t crrrririS uP rnrere-I in c''mmen'irg uPon were Luüble to percr "",-"Jrh- encle;r nr r:- the"" n'J:n pL'posc or s rihnB lhi' chJP'er 5e\ eral .rPn+s siripes. Moller et a]. ( gererdted br'ad t,, f,n. "f rhe nortr^l-<u'n nd retir'ä h rte dlreädv importani role in c, '"r"ri"n ,;;;*'f," ."."""'inn h:ol"gi"t' new in'ight' s irl äl-'I Provide dn electrocommunicati( juveniles. cxciting"i;;ä inPut;o the st;dy of electrosensory Performarlce This studyr of C. t.turs,i plays a r also likely to contribu OF 2. NON-ELECTRIC SENSORY AND MOTOR ABILITIES and B]eckmann,1998) ELECTRIC FISH ptoxnnity to shelters Despite its bw r pattenls (Schusteranr and Visual Signals 2.1 Vision to very lowambientlj aimosiblind' living in Eleciric fish are noctürnal and often described asbeing two paticms dcierior abilitv t0 ;;;ti-;;i";"-^"J ..-Pensatins their lack of vision with their absent at around l0( .i."*r.."," .r'a"t i" ,ire dark. öngonrg research' mostlv on the mormyrid limite.l bpaitemsth; d n'h hdve ;-,,;;;;,,.;;;;;;i;: r, p'"u,crc' i .r;äerent Pictun M'rmv- that puts Grdtlro,rc,, ,; -11:T be.iur,rul m.,vdb'e eyL' wtrh d tullv in d i c' ul'ioror ]wdb::l-1; (Süthe$, 1966). Evid( änd hrgrly o"8an'/eu 1987r lhe IIorm\_rd et'nr r'.rn e'r'emely regulir designed for. Yci, ih€ -'"'"^'*t"t prrn'iplL'"ndbehivroril rercvJr'etre"r(onry sto.e and recognize \ "r*""esrsr o\eare* rerif in ;;;;;*il';* t.,"a,.-u^ä \'4o;mvrrd ri-h po--e"'r power: templäte tnat ;n DUnd rF- I N4' Ls dn' la38: *r.*r. if,. 4,,ng,'"d r, Jrrd . onF- 'rre sroLrpeä experimenis, a fish vi 'd- cells Meldnin ä'"ll .'"zt rhe.F bundle- dre Fnshcäihed rn prqment vantage point and wa cr rn hsh.rhar hJve :;::;;;;;'."'"i "r. ,. ;';,äre bFthLcn th' Pn.rore(ertor- e\ patterns (say A). Afte rhe morT) r'd. l err'LiIt1er b-;ghr illumrn.rtion indr!irrnts rhdr was 'transfer{ested' \ been (rvrcrwd'r'::lna i .. ,.,r.i" aaruJne lo d:llerenl do'olule le\ cl- ol llumrnJhon properties the fish hä "t on üe oPtumotor läi.I"iu ---^'-,,r"" ,arces $ irh b, h"\ i.r.rr restrh' borh rcsults of these transf rhe {;'h dbil t\ to 1"i"""'"1r."""J," .'"; Molrer' loR2) d' w(rl r' on ' strategy kno$'n to be 2002' Ld-8e ämoLni'.or ;,i,.'.' i''.^*' and cmr'rcrd Collett, 1983, Could, srthin rhe ;;";;;;;;":.ä;;.,Ji;,; i;;;t;;;;, .err' rer,'ct unab'orbcd Photons '......- phororccepl^r bundle{\.4.twä,r.io18)dncJmd)rrdcji,ntiBtrtvi.ir,.,C;är er al. (1.)q7l ,uBtse-r 1t.,,, bp" de" I p,,rph1 rop.in p.gmenr r.U_oiL,inq," auetenein, b, rhcen 5ZU .rnd 540 nm). dl t,.J.r onF ,,,1her \ ijudt pigm"rr L pre,errin.rL :b,:rb. long w,rr,,cnrrh- ,b.\.e b00 nm. A dera ,eJ .iud1 br li".*"u";h dn.r , o ( orler\ now reve,.,s rhnt lhF morm) nJ r.trra i. fai more rh.rn rLr,L a de\ rce ro colhLr.. mu, h tighr d. po.-ibte fa.,rph,,toreceprorL,unJb.;;;,.: dbuul 600 rod-. ,,ls.one".rnd rt MLi.ter ce,t. in a triqhtl ,randrr,ji,,eJ dl'dnßpre t/U'bri, h,etrt.,20L, rj Rer, h(rb..t .p",...on],ntriur,_um.i_u-eir. r- nut ont ri,/eo ror..rh hir.B photons bui rathe;..,."ln_,,,."rr Pre.erll) don^, Lr,rd, htdnd. ßecon-ingyen..t\ Itdetini,ct\ D^,vrcte"urDn\.\".,,;;.;";: m ^Lrr Jrder.,.'nJirB ot the -trü,h c.rnd rL.n,ri,u or rr.e mo.-u.in ",.,,,r änd Moller .Teyssidre 0 982) demonsh.ai€d that Crdrroxcr,rs could äcrua y -eF b\ ucins th. fjsh . opr.r.otor fotjos i 8 rc_por{e to a mov rg Brätirg a. dn indrcdror Thi. -rud) .rt5.,.howcd tt-.ä, .rr h I er tighr .n,cn iti(, (;bov&0 l\). lhe h,,qe..hor"ed l;.h no op,,,mor,,r rc.oon.e: rndic.rrinB ih.r the ri,h were Jndlrie to pL-ce,\c th- conlrJ_r br t{cel ihc mo\ing bt.;t rnd ahrre siripes. Moller et (1982) al. were the firsr to demonstrate th"at vistun ptays an important roi€ in communjcation in clectrjc fish, acft1s tosetiler;ith cle,lr,,commun,c.,uon In o,oer r,, resutrrF s.oLrn.oh".;n r?-.,r,..ii"" |l.\ enrlc-. 1'ri--lUd\m.rdeitpt.ru.ibtprh. he_u,,inrrrerrirr,doublebandini ,lL, p,/, iip'.r!. rol,..r..r , rsudt .rgnrt n-o,idt.,.mmüqiLdrio,,.Vr5ion; al.olil,l\ loc,,lltrrL'utF ,,l et.,rdpirtssucce_s.fCrn,r,,,,ar,,:rrorderfrnde drro brccrmd'r',. tuq6t dr.,J hd. r. entl) be,n ,h^h n to hslp thc fi_h n ,rtntdinrnp Pm\imi'\ l^.helrcr, rM,,||er 2002. R,,rd.,\nJ \,4,, er. )002/. De.pitF ir: lol\ re5.t\ rnd power C,trtlnrt, ttt. (rn Ji.c"im,ndle !irual pattems (Schusterand paftern Amtsfetd,2002)_ recognition is, however,limfted to very low ambienr lighr levels ofabolrr 10Ix. A lcainect abilitv to <liscriminate lv\o pdllLrn- rrcanrrl deterior.rted .iqn at 40 r\ rnd'h.r_ comDterel; dbjsnt ä' "trc.rdy rround t000 t\. Mo1\,ver.:ucce,_rut pdrrefir di"rrimLnar w,rs lrnl tcd {,. pdrrern- llür -ubtentJcd r i.r.rt anghs gre.,r"l., t-r" ., d"8;;..;"n tl.al Dü1, C;rrl/1, r.,,.,. .1,,-p ro cn^t',er n,,ct;firdt ani ndt. r,ie hrr Vr,or,,"rt,; (Suihers, 1966)- Evidently, spatial resotution is not what the normvrid eve is de.igned for. \rr thr fr.h doe. h.rve ar rt. di,po.rr .r *.v \tor..,nd ,i.or.1r"i"* ,,, recoSnr/e ri-udt p.,ltF,ns rhrr .pe1,, to iit rt. tol^ _prt;r ._iii.g power: iemplatc matching (Schnster änd Amisfeld, 2002). Li the respectiv! experiments, a fish viewed rwo diaferenr visual pafterns A and B from'a fixecl vantage poini and ra,as rrained io receive food a;ft äpproäctred one of rhe two patterns (sayA).