Helminths of Freshwater Fishes from the Metztitlán Canyon Reserve of the Biosphere, Hidalgo, Mexico

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    Helminths of Freshwater Fishes from the Metztitln CanyonReserve of the Biosphere, Hidalgo, MexicoAuthor(s): Scott Monks , Vctor Rafael Zrate-Ramrez , Griselda Pulido-FloresSource: Comparative Parasitology, 72(2):212-219. 2005.Published By: The Helminthological Society of WashingtonDOI: http://dx.doi.org/10.1654/4139URL: http://www.bioone.org/doi/full/10.1654/4139

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  • Helminths of Freshwater Fishes from the Metztitlan Canyon Reserveof the Biosphere, Hidalgo, Mexico

    SCOTT MONKS,1,3 VICTOR RAFAEL ZARATE-RAMIREZ,2 AND GRISELDA PULIDO-FLORES1

    1 Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones Biologicas, Ciudad Universitaria,

    Apdo. Postal 1-69, Pachuca, CP 42001, Hidalgo, Mexico (e-mail: smonks@uaeh.edu.mx; gpulido@uaeh.edu.mx) and2 El Colegio de la Frontera Sur-Unidad Chetumal, Avenida Centario Km. 5.5,

    CP 77001, Chetumal, Quintana Roo, Mexico

    ABSTRACT: The occurrence of 6 species of helminth parasites (Clinostomum complanatum, Diplostomidae gen. sp.,

    Posthodiplostomum minimum, Bothriocephalus acheilognathi, Glossocercus sp., Contracaecum sp.) is reported from

    7 species of freshwater fishes (Chirostoma jordani, Astyanax mexicanus, Herichthys labridens, Oreochromis niloticusniloticus, Abramis brama, Cyprinus carpio carpio, and Poeciliopsis gracilis) in Metztitlan Lake (Laguna de Metztitlan),

    Reserva de la Biosfera Barranca de Metztitlan, Hidalgo, Mexico. Fish were collected between July 2002 and June 2003. The

    helminth fauna of H. labridens, an endangered species of Cichlidae, is described for the first time. Migratory birds of the

    families Ardeidae and Phalacrocoracidae appear to play an important role in the helminth species composition of fishes from

    Metztitlan Lake. All helminth species represent new records for this federally protected area of Hidalgo.

    KEY WORDS: Digenea, Cestoda, Nematoda, Poeciliidae, Cyprinidae, Cichlidae, Characidae, Atherinidae, Clinostomum

    complanatum, Posthodiplostomum minimum, Bothriocephalus acheilognathi, Glossocercus, Contracaecum, Chirostoma

    jordani, Astyanax mexicanus, Herichthys labridens, Oreochromis niloticus niloticus, Abramis brama, Cyprinus carpiocarpio, Poeciliopsis gracilis, zoonosis, Hidalgo, Mexico.

    The Biosphere Reserve projects combine conser-

    vation with human development in a context of

    sustainable development and scientific investigation.

    The Metztitlan Canyon (Barranca de Metztitlan)

    Reserve of the Biosphere, in the northern part of the

    centrally located state of Hidalgo, Mexico, has a high

    level of endemism in plants and animals (SEMAR-

    NAP, 1999) because of its geomorphologic origin.

    No extensive survey of fish parasites has been con-

    ducted in Hidalgo.

    Metztitlan Lake (Laguna de Metztitlan; Lugar de

    la Luna) is located in the northwest end of an

    enclosed basin or endorreic and has a surface area of

    3,230 km2. The lake was formed naturally when

    a prehistoric rockslide closed off the exit for the

    outflow of Metztitlan River, which today still feeds

    the lake. The local fishery has an ancient history, and

    the catch of native species of fishes has had a large

    economic and nutritional impact on indigenous

    people. Water level in the lake fluctuates greatly

    depending on the season and rainfall within the

    watershed, and the lake has been known to

    completely dry up at least twice in recent times. In

    the past, native species from rivers and streams that

    feed the lake have repopulated the lake after its

    return. In the past decade, the Mexican government

    began extensive introductions of exotic Cichlidae,

    tilapia, and Cyprinidae carpas (Ibanes-Aguirre

    et al., 2002) before efforts were successful in getting

    the area recognized as a reserve. The full consequen-

    ces of these introductions of exotic species on the

    survival of native fauna are not known, although it is

    expected that the cointroduced helminths will have

    negative effects (Osorio-Sarabia et al., 1986; Sal-

    gado-Maldonado et al., 1986). Also, Metztitlan Lake

    is visited by migratory birds (mainly Ardeidae and

    Phalacrocoracidae), and the potential is high for the

    spread of introduced helminths, mainly digeneans

    and nematodes, to other Mexican localities (Lamothe-

    Argumedo and Perez-Ponce de Leon, 1986; Ramos-

    Ramos, 1995). This article represents the first report

    of helminth parasites of freshwater fish from this

    protected area of Hidalgo, Mexico, many of which

    are new reports for fishes from the Panuco River

    Basin.

    MATERIALS AND METHODS

    This study focused on fish from Metztitlan Lake (locatedbetween 988239000 and 988579080W and between 208149150and 208459260 N), municipio of Metztitlan, Hidalgo,Mexico. Monthly collections were made from July 2002 toJune 2003, and 366 fishes were obtained, mostly with thehelp of a local fisherman. All species of fish that are knownto inhabit the lake were collected. The majority of fish weretransported live to the laboratory in containers of lake water,but when the number of fish was large, some fish were keptin plastic bags and chilled on ice; fish were examined within48 hr of capture. Fish were identified using the study of3 Corresponding author.

    Comp. Parasitol.72(2), 2005, pp. 212219

    212

  • Alvarez (1950) and by comparison with previouslyidentified voucher specimens. Voucher specimens of eachspecies are deposited in the Coleccion de Helmintos, Centrode Investigacion Biologicas, Universidad Autonoma delEstado de Hidalgo, Hidalgo, Mexico. External surface,internal visceral organs, eyes, and gills of each fish wereexamined using a dissecting microscope and standardparasitological techniques (Pritchard and Kruse, 1982).Live parasites were held briefly in saline, cleaned, andkilled by rapid immersion in hot water, warm Alchohol-Formalin-Acetic acid (AFA), or Berland solution (forNematoda). Platyhelminths were flattened under slightcoverslip pressure and fixed with AFA, subsequentlytransferred to 70% ethanol, stained with Gomori trichrome,Mayer carmalum, or Ehrlich hematoxylin, dehydrated in analcohol series, cleared in methyl salicilate, and mounted inCanada balsam. Nematodes were stored in 70% ethanol,cleared in a mixture of glycerin and ethanol by evaporation,and examined in temporary glycerin mounts. Voucherspecimens of helminths were deposited in the ColeccionNacional de Helmintos (CNHE), Universidad Autonoma deMexico, D. F., Mexico; the Harold W. Manter Laboratory ofParasitology, University of Nebraska Lincoln, Lincoln,Nebraska, U.S.A.; and the Coleccion de Helmintos,(CHE), Hidalgo, Mexico. Infection parameters follow thestudy of Margolis et al. (1982).

    RESULTS

    During the 12-mo study period, 366 fish were

    necropsied as follows: Atherinidae, Chirostomajordani Woolman, 1894 (n 87); Characidae,Astyanax mexicanus (De Filippi, 1853) (n 64);Cichlidae, Herichthys labridens (Pellegrin, 1903) (n 47) and Oreochromis niloticus niloticus Linnaeus,1758 (n 48); Cyprinidae, Abramis brama Linnaeus,1758 (n 10) and Cyprinus carpio carpio Linnaeus,1758 (n 46); and Poecilidae, Poeciliopsis gracilisHeckel, 1848 (n 64). Members of Cyprinidae andCichlidae were the most abundant, with 2 species

    from each family. Three native species were collected

    (Ast. mexicanus, H. labridens, and P. gracilis), 3exotic species (O. n. niloticus, Abr. brama, and C. c.carpio), and 1 species probably translocated fromanother Mexican state (Ch. jordani). Six parasitichelminth taxa (Clinostomum complanatum [Rudol-phi, 1814], Diplostomidae gen. sp., Posthodiplosto-mum minimum [MacCallum, 1921], Bothriocephalusacheilognathi [Yamaguti, 1934], Glossocercus sp.,and Contracaecum sp., Figs. 18) were collectedfrom the 7 species of fish.

    Larval forms

    DigeneaDiplostomidae gen. sp.

    Metacercariae that could only be identified as

    being a member of the Diplostomidae were collected

    from Ast. mexicanus, Ch. jordani, O. n. niloticus, andP. gracilis. These specimens resemble those collectedby Vidal-Martnez et al. (2001) from native cichlids

    of Southeastern Mexico in general characteristics, but

    these specimens have the cecum surrounding the

    tribocytic organ (Fig. 1). The specimens collected

    most resemble a species of Austradiplostomum Szidatand Nani, 1951, but have a well-developed muscular

    acetabulum, almost equal in size to that of the oral

    sucker, in contrast to members of Austradiplosto-mum, which lack the acetabulum. They also some-what resemble Diplostomum compactum (Lutz,1928), a parasite of c