Trematodes of the family Heterophyidae (Digenea) in Mexico: a review of species and new host and geographical records Scholz, T. Aguirre-Macedo, M. L. Salgado-Maldonado, G. Journal of Natural History 2001 2001-12-31 35 12 1733 1772 8SWQT Price, 1935 Price 1935 [310,830,603,627] Trematoda Heterophyidae Ascocotyle Animalia Plagiorchiida 7 1738 Platyhelminthes species tenuicollis Ascocotyle   Metacercaria  Morphology. Aguirre-Macedo and GarcõÂa-MaganÄa (1994: 17; ®gure 7a, b), Scholz et al. (1995: 179; ®gure 3A, C±E) and Scholz et al. (1997a: 163; ®gure 1E±G, I) provided detailed descriptions of metacercariae that can easily be distinguished from those of other  Ascocotylespeciesby combination of the following features: cyst spherical, thin-walled; body pyriform; preoral lobe prominent; posterior appendage long, curved to convoluted, reaching to pharynx or overlapping it; oral sucker with 32 circumoral spines forming two complete rows of 16 spines each; intestinal caeca short, very wide, sacciform, preacetabular, containing discoidal corpuscles; excretory bladder voluminous, ®lled with large lipoid droplets.  FIG. 2.  Ascocotyle( Ascocotyle) tenuicollis. Adults from the intestine of  Casmerodius albus, PaÂtzcuaro Lake, MichoacaÂn, misidenti®ed as  Ascocotyle leighi(CNHE 1532). (A) Total view, ventrally; (B) anterior end (spines of the posterior row on the dorsal side not ®gured); (C, D) detail of the terminal genitalia, ventral and lateral views, respectively. Abbreviations: ed, ejaculatory duct; eg, eggs; g, gonotyl; gp, genital pore; ic, intestinal caecum; mvs, mouth of ventrogenital sac; oe, oesophagus; ph, pharynx; sv, seminal vesicle; u, uterus; vf, vitelline follicles; vs, ventral sucker.  Second intermediate hosts.  Astyanax fasciatus(Cuvier),  Bramocharax caballeroiContreras-Balderas and Rivera-Teillery (Characidae);  Poecilia catemaconisMiller,  P. latipunctataMeek,  P. mexicanaSteindachner,  P. petenensis(GuÈnther),  P. velifera(Regan),  Poeciliopsis catemacoMiller (Poeciliidae);  Cichlasoma argenteaAllgayer,  C. aureum(GuÈnther),  C. fenestratum(GuÈnther),  C. friedrichstahli(Heckel),  C. geddesi(Regan),  C. helleri(Steindachner),  C. intermedium(GuÈnther),  C. lentiginosum(Steindachner),  C. managuense(GuÈnther),  C. nourissati(Allgayer),  C. octofasci- atum(Regan),  C. pearsei(Hubbs),  C. salvini(GuÈnther),  C. synspilumHubbs,  C. urophthalmus(GuÈnther),  Cichlasomasp.,  Petenia splendida(GuÈnther) (Cichlidae);  Ophisternon aenigmaticumRosen and Greenwood (Synbranchidae).   Siteof infection. Heart, exceptionally gill arches.  Distribution. Campeche(El Vapor, El Viento, La Pera, Palizada, Rancho II, Santa Gertrudis); Chiapas(Cedros, LacanjaÂ); Quintana Roo(Bacalar, Box Toro, CabanÄas, Cenote Azul, Escondido, FramboyaÂn, La UnioÂn, Laguna Paiyegua, Mahahual, Ramonal, Raudales, RõÂo Hondo); Tabasco(Camellones Chontales, El Espino, Puyacatengo, Santa Anita, Tucta, YumkaÂ); Veracruz(Catemaco, Los TuxtlasÐBalzapote, La Palma, Las MaÂquinas); YucataÂn (CelestuÂn, Chaamac, Chen-haÂ, DzibilchaltuÂn, Mitza, Noc-choncunchey, Sahkaba).  References from Mexico. Aguirre-Macedo and GarcõÂa-MaganÄa (1994); Scholz et al. (1995, 1997a); Salgado-Maldonad o et al.(1997); Scholz and Vargas-VaÂzquez (1998); Vidal-MartõÂnez et al. (2000); present study.  Specimens deposited. CHCM-137, IPCAS D-345.  Adult  Morphology. Scholz et al.(1997a: 163and 165; ®gure 1A±D, H) described adults from naturally and experimentally infected de®nitive hosts. The adult of  A. ( A.) tenuicollisfrom the intestine of  Casmerodius albusLinnaeusfrom PaÂtzcuaro Lake (MichoacaÂn), previously misidenti®ed as  A. leighi(CNHE 1532Ðsee Comments), is illustrated in ®gure 2.  DeW nitive hosts.  Ardea herodias,  Casmerodius albus,  Buteogallus anthracinus(Deppe), Phalacrocora x  olivaceus(Humboldt).   Siteof infection. Intestine.  Distribution. Jalisco( Salinasde Careyes), MichoacaÂn (PaÂtzcuaro), YucataÂn (CelestuÂn).  References from Mexico. Aguirre-Macedo and GarcõÂa-MaganÄa (1994); Scholz et al. (1997a); present study.  Specimens deposited. CHCM-361, IPCAS D-344.  Comments. Cichlids are the most suitable second intermediate hosts but ®sh of other families may also harbour metacercariae that are normally encysted within the bulbus of the heart ( Scholz et al., 1997a). Adults have been found in four species of ®sh-eating birds in Mexico, two of which (  A. herodiasand  P. olivaceus) are new de®nitive hosts of this parasite. SepuÂlveda et al. (1999) found  A.( A.) tenuicollisto belong to the most frequent (prevalence 54%) and numerous (mean intensity of infection 112 specimens; range 1±1260) helminth parasites of  Casmerodius albusin Florida.