ii i(/(i/ i),s,, 4113 L 201H ly. 61, 13111, [)— - \,—, al"', EXPERIMENTAL BOLBOPHORUS DAMNIFICUS (DIGENEA: BOLBOPHORIDAE) INFECTIONS IN PISCIVOROUS BIRDS

Cynthia M. Doffitt, 1 Linda M. Pote, 13 and D. Tommy King' Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi 39762, USA 2 US Department of Agriculture/Wildlife Services, National Wildlife Research Center, Mississippi State University, Starkville, Mississippi 39762, USA Corresponding author (email: [email protected])

ABSIRAcT In order to cieteriniiie pc)t('Iitial (klInitivt' hosts OF the cligeiii'tic treiiiatole. Bolbop/wr'rts (law?i!flCrl.S, two Anierir'aii \Vhit( , Pelicans (I'rlccairus ('n/tIin>tIuJn(./los ). twi i l)oubli'-crested (oruoiaiits (1'Il(1lac1l)((,,(I.v (lI1I'iIll.S ), tV,'() (;r('at IIne I teri.iiis l.iiI'(f('a IierotItas and two Great Egrets ( 'o/ea (7iba) were captured, treated with )ra/iq!iantel. and [<'ci t'Jiaiincl catfish (Irfalurus puie'tatris) infected \\itli B. (/a !I i c citicII.s illc.'tacercariac. Patent iiih'ctioiis of B. (IaIii?iifirlIs, svhleli developed in lx)tll Aiiierican \\hiite Pelicans at :3 (hLvs postinfec'tioii, were coiifiriiied by the presence of treiciattide ova ill the feces. Mature B. (laIiitiI/i(:u5 treinatod s wer recoered Froui the intestines of both pelicatis at 21 Iass postinfection, fiiithic'r c.'niifirining the estahhishiiieiit of mfc'r'tjon, No evidence of B. Iu,mifuu. mfcctions was nhsei'ved in tile other bird 1vws stitched. This stll(lvpn)vidc's further es idi.'nce that I)oiihle-crested ( oniiorant.s. Uteat Riuc Herons, and Great Egrets do not serve as definitive hosts ['or B. (la)ciIi,fuos. Key tLI)r(/S: ActitciiItiire, AiyIt'a iIlii, .%1(/)'(/ /ti'fl)(/iQS. BOIbO/)1 11)1715 (laiiiiilfu'h's I)igetiea !ctalri,'u.s pillIctalils. Pc'lecaiiivi eilJIhroclli/ il(/W.s Pluilacci,ccicax aricj (ils, piseivoroils birds, trematode.

INTRODUCTION channel c'atlisl i (Sepiilve(la et at.. 1999; Overstreet et al., 2002: Flowers et at., ( oiii ii ierc'ial injitaci titu re oh (1ian nd 2004, Kinsella et al., 2004: Overstreet and catfish (Ictal,i rii.s priiu'tatiLs) is it major Cui'i'an, 2004). Iii the late 1990s , channel industry in the United States, with the Catfish ji'otliic'ers in Mississippi and greatest concentration of proclitetioti Loinsiana first 1 cgali reporting catfish ponds in the northwestern region of' losses, which Welt' jtti'il )llt((l to a treitia- Mississippi (Wellborn, 1988). This imidits- tode tentatively i(ielltifled as BoIbo1.i/wrus try has experienc-ed rapid growth since ti spp. (Avery et al, 2001: Terhiune et al., first coiiiiiierc'ial catfish pond was estab- 2002). Since that time, the results of a lished ill 965 (Wellborn, 1988). The series of inec'tion studies, \vliichI were increase in catfish ponds has beet! cc n fl ri ned by trio] ecu lar at tab sis, have 1)ailied by a stc'adv increase ill t1i!iiil)ers of' estal d isliec I the t rein atoc k' Ba/hop/ia ru.s Pisc'i vol'otls birds in the region (Mott and (lailill ificus as the causative agent of' these Bruiisoii, 1997; Giahii and Ku ig. 2004; losses (Levy et al., 2002; Overstreet et al., (.)verstreet and Currait, 2004). The birds 2002; Yost et a]., 2005). These studies also most often observed feeding oil channel eorifii'ined that One of tile ilehiiitive hosts eatfisit are Aitierican White I'eli('ans f'or this parasite is the American White (Pelecai, 11.5 'iijlh ic)iIt EJHCI W.5 ), Don He- P(lican, the first ntterttiediatc' host is the crested Cormorants (l'lialacrocorax art ri- rains-iiot'n (I'ia)iorbt'ffa trzeolr,$), and (;reat Blue Herons (znIea Iwco(/la.'/ ). the second in terttiediatc' I lost is tire and Great Egrets (Art/ca al/ia; (.flahiii (,i channel catfish (Overstreet et al., 2002: al., 1999, 2000: King and Werner, 2001; Overstreet awl Crirran, 2004). King, 2005). In channel catfish, B. (lalii!lifhli.s' cci'- In addition to predation oh' catfish, these cariae pelteti'ate the skill auth f'ortn pt'odi- birds may also serve as (lehliitive hosts to tttetacet'cai'iae in the snper- digenetic treinatodes that are in k'ctive to ficial layers of tlic' iiitscrulattit'e (Overstreet

684

A DOFFITT ET AL.—BOLBOPHORUS DAMNIFICUS INFECTIONS IN PISCIVOROUS BIRDS 655 et a]., 2002). Hemorrhaging IS often capacity with fresh water every 2-3 days. Pens speciall y designed hr lomig-terni studies associated with cercarial penetration and on 111S('i\ om'nmis birds iiid \Vei'e l(lcllt('d at the inetacercari al cyst development. Iii addi - Mississippi State Universit y College of' Veter- tion, kidiiev tubule necrosis and kidney mars \lediciiie. Birds were led a diet of' inflainniation iiiav occur: however, the specific-pathogemi-free (SPF) channel catfish iile('llillliSIlI of this pathology is unknown daily at approxmiate]v tile following rates: American White Pelicans. 1,500 g: 1)o,dde- (()verstreet et al., 2002: Terliune et a]., crested Cornioraiits, 600 g; Gi'cit l3hii' I Icr- 2002). 1 ugh mortalities are observed in oiis, 400 g: Great Egrets, 400 g. Specific- severel y infected fiiigei'liiig catfish. Larger Pitt] i gelI—free ehtii mu'1 catfish were obtained catfish exhibit less iioi'talitv, hut decreases from enclosed hatch cries at Mississippi Stath in feeding can result in poor growth rates. Univei'sit College of Veterinary Medicine ill Starkville. Mississippi. USA and tile Iliad Additionall y , the meat of ' iiifi'cted catfIsh is (ochiran National \Va]'mml\vater iqmlacumltmmm'e because of damage often umnarkellal )le Center in Stomiesilie, Mississippi, USA. Each caused by eiicvsted nietacercariae (Ter- bird wa.s nhmsei'ved daily for general lie:iftii and mine et al., 2002). body condition. Although the American White Pelican Followin g capture, birds were acchiniateth has been confirmed as a definitive host for for 7 days prior to the iimitiatim,ii of' the infection study (Day 0). (-) it 0, earl i bird was given B. (lanlniflcus. other piscivorolis birds, 26-30 mg/kg hod' weight of the antliehimomithuc \Vhli('hi c011illi011IV feed on conmillerciahly drug pm'a/.i(fmlalltel ( l)romicit ® :34, l3a'er Cor- produced ('atfisil. ('(mid potential lv be poration, Shawnee Mission, Kansas 66201. hosts. Ill to coiitro] the transmission USA). I)umm'ing the acclimation period and coiitinumimug fk)I' the duration of ' t1(' trial, fresh of' B. (lain ni/zeus better, it is necessary to fecal samples \veu ' collected and examiue d identif y all of' tile hosts, especiall y the dail y for the presemle' (I! treumiatnde with definitive hosts, winch call the use of a modification of the FCCILI ti'eiiiatod' eggs into the aquatic environ- sedimentation method ( l"or(-vt, 2001). In ment. This research investigated the order to remove excess feral (fehl'ls. it 0.5-g potential fer Double-crested Corniorai its, hiuiii bogenizeci Sample of ' feral Illatcrial was washed with a 1% soap sointioim amid allowed to Great Blue ilerouis, and Great Egrets to sit undistmim'hed for 5 non before rim lo y al of' serve as definitive hosts for B. ilaniniJi c'ns. the smlpem'mmatIuit. This process was re1a'ated for These were chosen because of 10 cycles, Time kcal sample was th€'im i'iised their frequent association with commercial with , distilled water amid diluted to hO mmii. \f'ter catfish production ponds and their poten- the final water riiisc, the sample was thom'- tial for illti'O(hI icing digenctic treuiiatodes omigliiv inlxe(1 and a i-nil ah(flint of ' this l)l'eh)al'atioil Was quicklyp pipetle(i amid sa'wed into tile population. Nvith a (lissectil ig lulicrosenpe (( )fvn ipmms S'/.60, Olvnmpmis America. Inc., (enter \'alh's. Penn- ill MATERIALS AND METHODS svlva]lia 18034-0610, USA) at .()X order to emi,mniem'ate the treiiiatode eggs. Thu iim umber of' Bird collection and care eggs per gram of feces (e)g) was calculated 'T'\'.'() ildl\'ldIliilS (If (':1(11 bird si 'ics (Anier- according to the following f'orm'nuia: [eggs in i'aii \'Vliitc' Pelican, I )m n ihle-creste I ( 1mb- I imih)(10)]/weightt (g) of feces. m'ant, (;mx'at Blue heron, and Great Egret) Channel catfish were collected f'romu a ill were live-captured from northwestern Missis- coiimmuercial catfish poll(] sippi \\Itii the use of modified padded leg-hold Mississippi that had hi,'emi expermemmeimmg B. traps and methods pr'sk described (King (lalnIn/m('mi.s infections, A sudisamiiple of the et al., 1991"0. Birds 'yen' weighed. marked with channel catfish (ii23) waS cxonimued poor uiiii1ma'iv nmiiiihered hands, amid housed out - to the challenge of the birds with these catfish doors in 3,0X3,0X 1 .5-rn Pullshued with to (1)llfll'Iil t1w presence mid nmimliill'l' of B. outdoor carpet and ou it fitted \V ti i misting (1(1,11 iiiftcmi.s' inetacei'cariae. NI etarm 'm'c:u ia ' f m'011i syst('mns. Pelicans and cormorants were pro- this simhsammiple of Catfish were excised and vided with 1,000-I recirculating filtered water enumerated and a sill (TIC, nietac'e m'earia f'm'oin tanks, and till' herons and egrets were each of the sampled fish) was rznidomn lv provided %vith 110-1 tanks filled to 50% selected for iuioiecmihn analysis ill order to 686 JOURNAL OF WILDLIFE DISEASES, VOL. 45, NO. 3, JULY 2009

T.uii.i: 1. (Thill'iige of birds with live Blhopliorus (Levy et al.. 2002). Cenoinic DNA was isolated (IaIIiifi('rl.s-iIiI&'('tel IiiiiiieI r',itfisli. front individual parasites according to the Ceu.itra Pnrgeoe kit manufacturer's instruc- Estimalrd tiouts (U€'uutrt Svstenis, Inc.,Minneapolis. (II,iItCli.i- Niiiiil,i'r of fish riiuiauen'aiia Minnesota 55441, USA). PCR amplifications Bird period rlii s) i_c iisiiiiii'iI lose1' wen p 'rf On 0( 'c1 in 25- pl reaction volunies composed of 2.0 ph template DNA, 0.625 units A\VPE 1 7 14 182 Takara I lot Start Un l'olyiuucrase (Takara Rio A\VPE 2 7 12 156 Inc.. Japan). 2.5 p1 'Fakara lox PCR huller 1)CCO 1 7 II 143 (Takara Bio Inc., Seta :3-4-1, Otsu, Sluga 520- DCCO 2 7 7 91 219:3, Japan), 200 tiM dNTP mixture (Takara CBIIE 1 5 14 182 Bio), 200 n M forward printer, 200 nM reverse (R11E2 -1 14 182 pruner, and nuclease-free water added quan- ;REG 1 7 12 1511 tum satis to 25 p1. Reactions were performed (REC 2 7 5 65 in a Mt Research FTC- 100 Peltier thermal c'vcler ( Ftio-Rad Laboratories, Inc., Waltham, \\\ I't - ,'\itiericaii Whitu I'fiuti. I)((() I)ouhli- Massachusetts 02451, USA) under the follow- tiI ( riooritnt, (111111: (;ret B1111 , I-tel-on. (;BI'4 - Great Egret. ing conditions: 92 C for 5 mm, followed by :34 cycles of' 94 C for I mm, 58 ( : for I uutimi, 72 C I. mated iiietaccreariai' dose mean number ol staeercariae/fish Xiii iiii6ei' of fish eaten f'or I non, and a final cycle of 72 C for info. The primers used were specific to B. daiiioi- ,fk'ucs' (finvam'd 5 1 -TCA (;T'F TC(; AAC CAT confirm that the catfish were ink'cted with B. CAT CA-3' and reverse S'CCC TCT AC(; (/010 Il iflctis. C71 CCA CC-:3': Levy et al., 2002). Both Seven days following praziquantel treatment positive (known B. (/auouifh.'us moetacercariae) Day 7), the birds were fed live catfish that and negative (nucic'ase-free water) controls were naturally infected with B. dainnificii.s to were used in each I'CFt reaction. The PCR simulate natural infections in these captive products were visualized oil 1.2% agarose birds. The number of fish and inetacercariae gel, which was postst(une(1 with Gelstar consumed by each bird varied based oil nucleic acid stain (Canibrex BioScience Rock- individual feeding rates (Table 1). The infect- land, In(.-., Rockland, ME, USA) and observed ed catfish were led to the birds over a period tinder ultraviolet light. Of' tip to 7 days, with cach bird being fed to Adult tremnatodes were stained in acetocar- satiation each (lay. Attempts to infect the birds mule for 12 hr, destained iii acid alcohol, ceased once they had eaten the preferred close dehydrated il_i a graded alcohol Series (70, 95, of' 14 fish (approximately 182 utctacercai'iae) and 100% ethanol), cleared in Citri-solve or once the 7-day challenge period expired (Omega Laboratories, Inc.. Houston, Texas l)ay 14). After the challenge period expired, 77080. USA), and mounted out slides with all hirds were fed SPF fish for the duration of Permriount (ProSciTech, 'l'hnriuigowa Central the trial. Queensland 4817, Australia). Identifications of Three weeks postchallenge (Day 28), all stained B. daoiiufic'us specimens wem'e based birds were euthanizcd with the use of carbon oil by Overstreet et al. (2002) and dioxide gas and necropsicd. The gastrointesti- I ,evv et al. (2002). One stained si61'n nal tract from the esophagus to the cloaca of Collected from cacti American White Pelican each bird was removed, and opened longitu- was deposited at the US National Parasite dinally, and the intestinal contents were gently Collection in Beltsville, Mar yland, USA rinsed through a No. 200 stainless-steel screen (USNPC 101433.00). aperture = 7.5 gin) with dechlorinated water All procedures used in this study were Pote et al., 1992). All intestinal contents were appm'ovec] liv the US Depam'tmemit of Agrieutl- i nunediately examinedtiocd with the use of a tttu'e/Wilclhife Services (USI)A!WS) National dissecting microscope, and all live parasites \Viklhifo Hesearc'li Center's (N),VRC) lmtstitn- were collected and placed in 70% molecular- tiorial Care and Use Committee under grade ethanol in preparation for staining and/ NWRC QA- l 138. OF molecular analvss.

Identification of trematodes: The molecular RESULTS (let ttific'atiomm of' the eg,gs, mnetacercariae. and ((hull tremrtatodes was based oil The siih)samtiple (n = 23) of channel chain reaction (PCR) with the use of oligouiti- catfish used in the challenge was found ('ll'Oti(h(' primers specific to B. (/U10?llfU'li.i to he infected with all average of 1:3 (u'aui' DOFFITT ET AL.—BOLBOPHORUS DAMNIF/CUS INFECTIONS IN PISCIVOROUS BIRDS 687

0-73) inetacereariae per fish. Eighteen of (hiring the study period. ['he other Great the 23 (78%) sampled catfish were con- Blue Heron (GBI1E 1) shed low numbers firmed to be infected with B. (IalIlnlf,cIIs. of trematorle eggs intermittentl y (Days 2, No nietacercariae were fbund in three of 4. and 6) fbllowing treatment \Nith prazi- the catfish (13%). The two relnainilig qiiai ltd however, based oil both morph in]- sampled catfish (9%) were infcted with ogv and molecular analysis, the eggs were inetaeercariae that were not B. (1001111/ 1- not those of B. (/aI1l1l1fCt1S. (US, but tirelikely to he HiJSt('1'011l()17)llli One adult B. (IaInmflcus was recovered trioha, another larval rligenetic trematode fromi A\VP F 1. It was stained and infecting chantielchannel catfish musculature identified based on its morphology. Five Flollnian, 1999). Given that the ii ietaeer- adult B. (lalIlnificus were recovered from canal closes were based on it sIll)salnple of the intestine of AWPE 2. All adult the channel catfish population used and treinatodcs were ]norpliologicallV identi- that it few of the sampled channel catfish cal. Of these five treinatodes, one was were not infected with inetacercanac or identified based oil two were stained with non—B. clainnificus inetacercariae, all and identified inorphologically, and the data pertaining to 11 letacercanial doses are remaining three were archived in 70% estimations. Although we identified three molecular-grade ethanol. No adult B. catfish as negative fbr oietacercaniae in our (laulnlflcus were found in the intestinal subsample, we may have underestimated contents of either of the Double-erested the iuiiiiher of positive catfish in the Cormorants, Great Blue herons, or Great population, because the detection method Egrets. However, it single gravid adult relies on the microscopic gross examilia- treivatode was recovered front DCCO 1. tion of fish muscle tissue. This tre matode was stained for morpho- Three of the study birds received the full logic comparison and identified as J)repa- close of 182 rnetacercariae ( American ILOCCI)1lt'lllIS spa/hans (Yainaguti, 1958 White Pelican 1 [AWPFJ], Great Blue Rietscliel and \Vencling, 1978 Kostadinova Heron I [GB! IE 1 1, and Great Blue Heron et al. 2002 Jones el al., 2005). 2 [G131IE 2]). Three received nearly the full dose (American \Vliite Pelican 2 DISCUSSION A's\7PE 2], Double-crested Cormorant 1 I 1)(X0 Ii, and Great Egret 1 [GREG 1 I at The two American White Pelicans were 156, 143, and 156 metacercariae, respec- successfully infected with B. (Ia000flcu.s. tively). Because of the individual feeding Both exhibited patent treli iatode infec- rates of the study birds, two of the study tions beginning on Day 10 (3 clays birds received lower closes (Doi tl)l(,-cr(,st(,(l postchallenge) and shed eggs intermittent- Cormorant 2 [DCC() 2] and Great Egret 2 iv until the termination of the trial (l)ay [cItEC 21 at 91 and 65 inetacercariae. 28). This timing of"parasite maturation and respectively Table U. production in the AmericanWhite Both AWPE 1 and AWPE 2 shed B. Pelicans is similar to that of B. (1010 1111 iCu.r (laInnifIcus eggs beginning on Day 10 (:3 in previous studies (Overstreet et al., (lays postchallenge ): A\VP E I ceased 2002). Following necropsv (Day 28), the shedding by Day 15 (8 days postcliallenge. infections were verified by the presence of' Fig. 1), whereas AWPE 2 shed eggs adult B. (laInhL//iClIs in the gastrointestinal intermittentl y until Day 24 (17 days tracts of both pelicans. At necropsy, it postchallenge; Fig. 1). The Double-crest- single adult B. (lamnificus was recovered ccl Cormorants (1)CC() I and l)CCO 2), from A\VPE 1, which had a lower egg GREG 1 and GREG 2, and one Great shedding rate (peak= 1.680 eggs/g kces Blue Heron (CI3HE 2) did not shed [epg]. Fig. 1) for it shorter duration (Days trenlatodle eggs ill the feces at any point 10-15). Conversely, five adult B. (1a111111 fit- 688 JOURNAL OF WILDLIFE DISEASES, VOL. 45, NO. 3, JULY 2009

FIGURE 1. Daily Bolbophorus dmnniJicus egg shedding rates for American \Vhite Pelican (Peh'canus erythrorht1nchos) 1 and 2. Reported as eggs shed per gram of fi'ces (epg). 1=praziquaiitel treatment, C=challenge with live B. datnmmijirus—infected chammmmt'I catfish, N =entlmanasia and mmcernpsv.

Gus were recovered from AWPE 2, which A\VPE I did not exhibit this cyclic pattern. had a higher egg shedding rate (peak= The cyclic nature of egg production 2,840 epg) for a longer duration (Days 10- observed in multiple infections is likely 24; Fig. 1). the effrct of individual trematodes matur- The recovery of a single B. (IallmiJiciIs ing and beginning egg production at adult from AWPE 1 at necropsy may varying rates. provide valuable insight into the life cycle Although neither of the Double-crested of this parasite. Trematode egg counts Cormorants was positive for treinatode obtained from fecal sedimentations of host eggs in the feces, a single gravid adult fecal material, while demonstrating the trematode was recovered from the intes- presence of gravid adults within the avian tine of I)CCO 1 at necropsv. This host, are often confounded by the pres- trematode was identified as IJspafhans, ence of several adult trernatodes. Howev- which has been previously reported from er, the fecal trematode egg data generated this species (Threifidl, 1982; Fedynich et from AWPE I may provide important al., 1997; Flowers et al., 2004). Infections information about the egg output of a by trematodes in the Drepano- single adult trematode. In this and previ- ceplialus have also been reported iii other ous studies (Yost et al., 2005), the fecal egg Plialacrocorax species (Nasir and Marval, data from American White Pelicans in- 1968; Laiiiothe-Argiiinedo and Perez- fected with multiple adult B. (IaliInlficzI.s Ponce de Leon, 1989; Kostadinova et al.. was cyclic with periods of intermittent 2002). Drcpanoceplialii.s' spatliaii.s has not shedding that continued for up to several been reported to infect channel catfish. weeks. However, the fecal egg data from The larval stage of this helminthi has been DOFFITT ET AL—BOLBOPHORUS DAMNIFICUS INFECTIONS IN PISCIVOROUS BIRDS 689

reported in the cichlid fish, Cichlaso,i,a of the study birds (DCCO 2 and GREG 2) feiicstratum (Garcia, 1993; Salgado-Mal- received lower estimated closes of meta- donado et ai., 2005) and Cichiasoina cercariae, three birds (AWPE 1, GBHE 1, o rophthalmus (Salgado-Maldonado and and GBHE 2) received the full estimated Kennedy, 1997). However, the presence dose of 182 metacercariae. The remaining of this treniatode was unexpected because birds (AWPE 2, DCCO 1, and GREG 1) all birds were treated with a dose of received comparable estimated closes praziquantel previously shown to be effi- ranging from 143 to 156 metacercariae cacious against digenetic trernatodes (Table 1). Consequently, at least one (Overstreet et al., 2002 Yost et al., individual of each species studied likely 2005). The presence of D...pathan.s may ingested a metacercariae dose sufficient to indicate that praziquantei is less effective induce an infection, as evidenced by the against this species. Another explanation is successful infection of AWPE 2 with that D. Spat//Gus could be infective to approximately 156 nietacercariae. This channel catfish, despite the flict that it has demonstrates that the lack of B. daionifi- not been previously reporte(l iii channel Gus patent infections in the Double- catfish. No treinatodes were recovered crested Cormorants, Great Blue Herons, from the gastrointestinal tract of DCCO 2. and Great Egrets was not due to an No adult trematodes were recovered insufficient metacercariae dose. from either of the Great Blue Herons at This research provides further confir- necropsy. However, GBHE 1 shed trem- mation that American White Pelicans atocie eggs intermittently kliowing treat- serve as definitive hosts fbr B. (lalnulficus. ment with prazi(1uantel on Days 2, 4, and Additionally, we have demonstrated that 6. These eggs were confirmed to be non— Double-crested Cormorants, Great Blue B. (Ialnn/Jicu.s eggs with the use of Herons, and Great Egrets, when subject- molecular analysis. The absence of eggs ed to the same experimental infection in the feces of GBHE 1 pre- and parameters as the American White Peli- postchallenge indicated a frilure of B. cans, were refractory to B. (lan/n ificus. (lain/nfl cu,s to establish an infrction in this indicating that they are unlikely to serve as host. This was confirmed by the absence natural definitive hosts for this parasite. It of adult tremato(ies in either of the Great is necessary to identify all potential Blue Herons at necropsy. No trematode definitive hosts of B. ilamnzJicu.s iii order eggs were detected in the feces of either of to better understand the life cycle of this the Great Egrets during the study period parasite. This information will be used by and no adult trematodes were recovered researchers and commerciallercial channel cat- from the intestines at necropsy. fish producers to locus control measures Because it has been previously docu- in an effort to reduce the impact of this mented that American White Pelicans parasite on the industry. serve as definitive hosts (Overstreet et It is possible that the failure to infect ai., 2002), their B. (Jamnificus infections Double-crested Cormorants, Great Blue indicate that the metacercariae used br Herons, or Great Egrets with B. (Ia/lu//JI- the challenge were infective and that the G//S was related to experimental design. doses given were sufficient to induce an However, we attempted to mimic the most infection. American White Pelicans efficacious natural conditions for this (AWPE 1 and AWPE 2) were challenged infection to occur in commercial channel with an estimated dose of 182 and 156 catfish production ponds. To that end, live metacercariae, respectivel y (Table 1). channel catfish naturally infected with B. These closes resulted in the maturation clainiuiflcos were used to challenge birds; of one mature adult in A\VPE 1 and five this indicates that our challenge model mature adults in AWPE 2. Although two was valid. Previous studies using this 690 JOURNAL OF WILDLIFE DISEASES, VOL. 45, NO. 3, JULY 2009

nietliod were successful in the establish- Fcoiic:n, A...... 1). B. I'i.:'a:c, .INI) j. F. 13c.:cst:.sx. Ielccticttic cocctcnhinitv structure and pat- ment of patent infections in the American 1997. I tern ill populations of'double-crested White Pelican (Overstreet et a! 2002). and neotropie cormorants. journal of the lie]- Another issue that may have coiifouncicci niinthological Society of Washington 64: 17(i-- our results is the relativel y sinai] avian 182. Sample size. III to maximize our Fi.ossecss, J . B., M. F. Pcsicic .:, J. 1".. Mc I.l.t•:\, (;. I.i:s y . 2004. !)igelleaics ('lcIIectl.'(.i lioni piscis_ results but minimize the number of i>roiis birds iii North Cicrccliiia. U.S.A. ( )lccpitr_ protected birds used iii the stiitiv, we ative Parasilologs 71: 243-211. chose to use two 1)11(15 of each species. II ulEvi, NV. J. 2001. Vctcrinccrv parasitoloi,. refere ccci' Because experimental inflection studies manIac1. Iowa State Uiiiversitv Press, iiiceS. cannot completely mimic natural condi- Iowa, 235 pp c:Aec:IA. NI. I. 1993. I'anica lielnuothcologica de tions, a helminthoiogic survey of gastroin- j. ( ,ielcla'ioctta frcu'sI ?YIllcllt I FOci's: Cichl id,tc ) del testinal trenlatc)de infections in each of 1ago tie ( atc'uiaco. Veracruz. Meicn. ,\ic,lIes del these ('our bird species is currently under ]nstiticto lie Bic)logi:c tJiciversidad Nacioiial way. The data collected in that study will At itonccii IL de Serie Zoologica 64: 75-75. complement the present stud y by docu- Gi,..sccx, J. F., sxo D. T. KIN(;. 2004. Bird depreda- menting all naturally occurring trematode tion . icc Biology and culture of channel cittlisi c. C. S. Tucker and J . A. Ilargreases eds.), infections, including B. claninificus, in Developments ill and fisheries each of these bird species. These two science 34. Elsevier, Aiccstecdaicc. lice Nether- studies, in conjunction, will provide fur- lauds, Pp. 503-529. tiler evidence about the ability of Double- E. S. II ISSIISSEN. T. 'I'oxis s. ' u K. J. crested Cormorants, Great Blue Herons, Pctc:ussi.:it. 1999. Distribution ttiiil relative impact of avian predators at aqoacciitnrc' fan ities ill the and Great Egrets to serve as definitive nortltettsteri c United States. North American hosts for B. (lt'/nUllJiC1I.5. journal of Aq cacc citti re 61: 340-348. 1). S. BEINHoi.u. AND C. A. Si,o.sx. 2000. ACKNOWLEDGMENTS itecen t population trends of' tic ui1 cic-'-crested coi-niorarcts wintering ill the chiLi legion of This research was supported iii part by Mississippi: Rc'spoicses to roost chspeisiii and grants from the U SI )A Southern Regional removal tinder a creel it depredation order. Center (Grant 2002-38500- \Vaterbirds 23: :35-44. 11805), USDA-NM (Grant 2002-35204- 11678), USDA/APHIS (Cooperative Agree- Httc. c. si.s's, C. L. 1999. Parasites of North American freshwater . 2nd Udi tioci . Comstock ])it])- ment 06-7428-0499). the Mississippi Agricul- lishbig Associates. Ithaca, New York. 539 pp. tural and Forestry Experiment Station B A. BHA). .csl I). I. Gicssox. 2005. ys to (MAFES), and Mississippi State University JoNes, A., Ke College of Veterinary Medicine. We thank P. the trtictictceia. Not. 2. CAB International and Fioranelli, K. H ausnn, S. 1 en1n1onS. B. The Nttttcrui I Iistorv Museum,icc. I ,oc dc ccc. 745 pp. Singleton, and S. \Voodrtmff for assistance with KING. 13.1'. 2005. Interactions between the Aicicocaic white pelicaic accd ttqicactdtccrr. ill the s011tice2st- him-d capture. \Ve also thank J. Grady, P. Fioranelli, K. I lauson, S. Lemutuous, K. cr11 United States: Au Os erview. \'catemhimcis 25 Obringer, P. Siefker, B. Singleton, F. Thorn- Special Publication H: 53-56. ton, and S. 'Woodruff for assistance \Sitic ..sxo S. J. \Vl.: llNl:cl. 2001. I)ailv activity animal care. M.Yost and K. Ohringer budgets and pnpciiaticcic size of' American ss lute provided help with trematode egg counts. T. pelicans wiicteriiig ill Iacitisiiiiiii and the Lenarduzzi assisted with bird euthanasia. C. delta region of Mississippi. \Vaterhii it Is 24: 2.5(1- Pamiuska, 1). Milic]ie\V, M. Mauel, and S. 254. Barris assisted with editorial reviews. J . D. PAULSON. D. J. Leiucaxu:, SNI) K. Ifiic i. 1998. Two capture tecictcit1cces for .\cntlicalc vlcite pelicans and great hlcie herons. Colonial LITERATURE CITED Waterhirds 21: 25S-260. Au-,m J . , J . lt•.csici',i-:, I). \Vi',i.:, SNO L. KlIoo. 2001. Kc",sc.:c.ca, J . NI., NI. C. Sc'.-\c.ccNu. AND D. j. New treiciatode ill channel catfish, Iic.td Coch- Foiceesreci. 2004. Parasitic helcccicctIcs of the ran N'tticcictl \ariccwater Aqii.tciiltcire Ceicter American white pelicaic. J'CIINacccc.s eci/(Icrl.c- Fact Sheet No. 004 (revised). Ti cad Cod cal cIcr/ucc/cos. ficcicc . U.S.A. Comparative National \Vartnwater Aquaculture Cent(:'r, Partcsitolog 71: 29-36. Stoneville, MS. Kosrsncxov..s, A.. C. \si:(ccl:s, AND I). I. (4llsoN. DOFFITT El AL—BOLBOPHORUS DAMNIF/CUS INFECTIONS IN PISCIVOROUS BIRDS 691

2002. Flede.sci'iptions (if t\V0 ('ChiflOStOnIes from iif birds f'roni northern ( ilounhit. Zeitsehtrift hir birds ill I LritglIav. With (olIIllIeIItS oil Parasiteiukniide 57: 57-52, I)ietz. 1909 and I'a17J/)/lO-'1(1(II(II (II Dietz, S \I1;-sDo-NI suno'i 500, C., s'o ( R. Ke'.iNEr)i'. 1997. 1909 I)igeoea: EeIiiiiostoitiatidu). .Svsteiiiatk' Ilicliuui'ss aml siuiiilaritv of heloiinth coiliOiiiitities I'ira.Sito1ogv 5:3: 147- 155. In the (11)1)1(111 eichlid fish (7iclilasa,oa I.\\IorIII .'-Ai(cI\III)o, Fl.. AND G. PEIii':'z-Po\ci: i)I' i(/)/itIia/OiU'l 110111 t]t(' YIIC1Ltilll P(hiIutShhla, Mex- I( -,o\. I 1)59. Ireiiiatodos (IC ILV('S Ii. I)CsCri1)Ci(I1 ico. I'arasito1o/ 114: 551-590. dc iiiia espeeie ones -a del geilei-o 1)rcp(mo- H. AI:I lu.su(-..\cull.-sH, C. (:-sa-s-ss-CAlus,sNz..s. cephalus I )ictz. 1909 /Jri'illatoda: Fchiiiostoiii;i- F. So'i'o-C siI-:RA ANuS C. \li:onoz-s-P-si.xii-:uui. 11(111(3 dc I'/ial((cmciiylx Dlii'(lCi'IiS ('11 Tea1)a. 2005 hleluiijiitli jiii't5ite5 iii freshwater fish from Tabasco. NiiaI(s ((('I Iiistitiito de III ilogia 1_Joi- the I'ajaihiiipiii riser basin, Mexico. Parasitology V('rsidlld NaClolilil Atitoiioiitt de NI(sico Sei'ie Research 96: 69-Si). Liii ilogiea 59: 15-20. Si-:uuuai-:o.s, M. S., M. C. Spu,nixc, J . N--I. KINSL-:LLs. Li-:s, M. (., . H. I'i,osviis, NI. F. Pooiic, J F. . -iNn I). J. Foiov------:o, 1999, Parasites of the great N1I,I.i,cN. L. II. k000. L. M. l'o'ri-:, I. I'.-\PEI(NA, R. egret (.-rdea (7llaei ) ill aid a review of' Dzioosi..i. \m) H. W. I .i'i sci.;is. 2002. Morpho- the lid lW tI is reported for the species. Joui'nal logic, 1iatliohigie. .tiid g('ii('tic iI1\'estigatiofls of (if, the I Ielioiothiologieal Societ y of' Washington I/iI/l(i)/.(/ii)('i(A spcies Lffe('tiiig (nitiiied elianiie! 66: 7-13. catfish Iii tlii_' Mississippi Delta. Joiiriial (if 'I'i-:ililuNi-:, J . S., I). J. \Visi.:, -so L. II. K000. 2002. A(Iiiitic Aiiiiii1il I Ieiiltli 14: 2:35-246. 13oII,01i1ni01'i coofiisu'i iof'eetiouis in ehianitel Mori, 1). F., ss o M. W. HIn'Nsox. 1997. A historical cstf'ishi ill northwestern Mississippi and effects pc'rspcctv(' of catfish piodiietioii III the sooth- I_li water tei I iperatti IC Oil Cit tel-gel tCC of cereariae east iii n ']atu iii to asian predation. In Proceed- (coin i ufectei,l siiiuIs. North American Journal of ings iii the Ltstcni \\ iIdlih' I )ainage Nlanagc- Aijuaculttire 64: 70-74. hilt (:1,1 Iei'eiicc 7: 23-..30. W. 19.52. Enchopat-asites iul 110' (101tl(l- N.-ssni, I'., AND I". H. NI soy -sc. 1965. Two 1151101 treioatoc hes. 0iepaooci'p/ia1i olii'aceu.i ii. spe- ci'ested cormorant 3P/ialaci'ocoras' (Ii(citns) il l ('1(5 1111(1 Cafacioouiioio pu/hilt \' ontgnti, 1911, Florida. Proceedings of the I Ieliointltological front \'eneziti'Ia .,,Ncta Itiologica \enei.iielica 6: Society of \\asluington 49: 103-105. 71- 75. \\i-i.i.000N , T. L. 1988. Channel i'itlisIi: I ,if'e Listorv Osi-:i(sTsi-:i-r, II...... si S. S. (Ti im -sN. 200.1. and hiioliigs Siiuithii'rn Regional A9uacultin'e I)(+eatnig iliplostoiooid dangers ill liSt cittf'isli Cculteu' I'uululi'1itiuo \o. 180. Southern Regional aqiiaeiiltiire. I'ohia I'trtsitologica 51: 15:3- 165 Apiacnitnre (cute', Stones ille, Mississippi. L. M. Poii-:, I). T. Kisic, C. K. Yv%im:rn, S. 1958. Svstei na lie! ioittlotm, Vol. I BIrNIN so \\'. I). Gist i'.. 201)2. Bi4bnp/ioiiis Digenetic treivatodes of : Part 1 (I(liiOilfi('iel (Digenea: ll()lhi()phoi'idilcl lntersc'ience Publishers. ho'.. New \ork, (11>111 tIll: challilcl catfish Ictalit nt,s poii c/at us \os'l, NI.. B. S. -5\i) L. M. Po'o-:. 2005, 1111(1 ."hIlieri('liit si llite pelican Fel('('UiOiS en 1/hro- (onhI 'unit ion of Bollouplionis a'anoo/lciei life r/iujuclics in the USA liased iiui hi l'e-cc'le and cycle and chiItrItcterizttioi I (If' all life stages. molecularLu- (hita. S ystematic Parasitology 52: S1- Southeastern Biology 52: 16:3, 96. Ilui-"rsi :001,, C AND B. \Vl';Io)INc, 1975. Treniatodes Ileceii'l'd for pufilicaiion I: Jail hiar?/ 2008.