Monogeneans of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula, Mexico.

During a survey of the parasites of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula the following species of monogeneans were found on cichlid, pimelodid, characid and poeciliid fishes: Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther) (type host), Cichlasoma friedrichsthali (Heckel), Cichlasoma octofasciatum (Regan), and Cichlasoma synspilum Hubbs, all new host records; Sciadicleithrum meekii Mendoza-Franco, Scholz et Vidal-Martínez, 1997 from Cichlasoma meeki (Brind); Urocleidoides chavarriai (Price, 1938) and Urocleidoides travassosi (Price, 1938) from Rhamdia guatemalensis (Günther); Urocleidoides costaricensis (Price et Bussing, 1967), Urocleidoides heteroancistrium (Price et Bussing, 1968), Urocleidoides anops Kritsky et Thatcher, 1974, Anacanthocotyle anacanthocotyle Kritsky et Fritts, 1970, and Gyrodactylus neotropicalis Kritsky et Fritts, 1970 from Astyanax fasciatus; and Gyrodactylus sp. from Gambusia yucatana Regan. Urocleidoides chavarriai, U. travassosi, U. costaricensis, U. heteroancistrium, U. anops, Anacanthocotyle anacanthocotyle and Gyrodactylus neotropicalis are reported from North America (Mexico) for the first time. These findings support the idea about the dispersion of freshwater fishes and their monogenean parasites from South America through Central America to southeastern Mexico, following the emergence of the Panamanian isthmus between 2 and 5 million years ago.

Fish as paratenic hosts of Serpinema trispinosum (Leidy, 1852) (Nematoda: Camallanidae).

Third-stage larvae of the nematode Serpinema trispinosum (Leidy, 1852) were collected from the intestine of the freshwater cichlid, Cichlasoma urophthalmus (Günther), from a small lake in Yucatan, Mexico. This is the first record of Serpinema larvae from fishes, and their presence may reflect the importance of fishes as paratenic hosts of turtle parasites in this genus.

Helminth parasites of Epinephelus morio (Pisces: Serranidae) of the Yucatan Peninsula, southeastern Mexico.

The present paper comprises a systematic survey of helminths from 202 red groupers, Epinephelus morio (Valenciennes) (Pisces: Serranidae), the most important commercial marine fish in the region, collected from ten localities off the Yucatan Peninsula in the Gulf of Mexico during 1994-1996; two more helminth species were recorded from E. morio earlier. Thirty species of helminths were found: Monogenea 1, Cestoda 3, Trematoda 17, Nematoda 8, Acanthocephala 1. Of them, 15 species were adults, whereas 15 species were larval stages parasitizing piscivorous elasmobranch and teleostean fishes, birds and marine mammals as adults. A new didymozoid trematode, Allonematobothrium yucatanense sp. n., is described from the fins of this host. Most findings represent new host- and geographical records. Philometra margolisi, a nematode parasitizing the gonads, is undoubtedly the most important parasite affecting the reproduction of the host, endangering E. morio in aquaculture. Larval anisakid nematodes (Anisakis, Pseudoterranova, Hysterothylacium) recorded from the red grouper in the region of the southern Gulf of Mexico are important from the viewpoint of public health.

Ascarophis mexicana n. sp. (Nematoda: Cystidicolidae) from two species of Epinephelus (Pisces) from the Gulf of Mexico in southeastern Mexico.

A new cystidicolid nematode, Ascarophis mexicana n. sp., is described from the stomach of 2 species of the genus Epinephelus, E. morio and E. adscensionis (Pisces: Serranidae), from the Gulf of Mexico, southeastern Mexico (states of Yucatan and Veracruz). It is distinguished mainly by small body measurements (body length of male and female 3.39-4.18 mm and 5.94-6.23 mm, respectively), a conspicuously long left spicule (1.58-2.05 mm), length ratio of spicules (1:10-12), and by eggs provided with 2 filaments on 1 pole. Ascarophis mexicana is the second Ascarophis species known to parasitize fishes of the genus Epinephelus (groupers).

Redescription of the male and first description of the female of Capillaria carioca Freitas et Lent, 1935 (Nematoda: Capillariidae), a parasite of the marine fish Sphoeroides testudineus.

A redescription of the male and the first description of the female of the intestinal nematode Capillaria carioca Freitas et Lent, 1935 are presented on the basis of specimens collected from the type host, the marine fish Sphoeroides testudineus (Linnaeus) (Teleostei, Tetraodontoidei), from the Lagoon of Yucalpetén in the northern coast of Yucatan (Gulf of Mexico), Mexico. This species is characterized by a well-sclerotized spicule and by the presence of two large ventrolateral lobe-like papillae on the male caudal end and, therefore, is assigned to the subgenus Neocapillaria Moravec, 1987. C. carioca is reported from Mexico for the first time.

Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 1. Adults.

The present paper comprises a systematic survey of adult nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southeastern Mexico, in 1993-1994. Examinations of a total of 533 fishes (17 species) originating from 39 cenotes from the Mexican states of Yucatan and Quintana Roo revealed the presence of the following nine nematode species: Rhabdochona (Rhabdochona) kidderi, Procamallanus (Spirocamallanus) rebecae, P. (S.) neocaballeroi, Philometroides caudata, Hysterothylacium cenotue. Pseudocapillaria yucatanensis, Paracapillaria rhamdiae, P. teixerafreitasi and Capillostrongyloides sp. (only females). Four species (R. kidderi, P. rebecae, P. neocaballeroi and Capillostrongyloides sp.) are briefly described and illustrated and some problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Taxonomic changes include Procamallanus (Spirocamallanus) neocaballeroi (Caballero-Deloya. 1977) comb. n. and Procamallanus (Spirocamallanus) rebecae (Andrade-Salas, Pineda-López et García-Magaña, 1994) comb. n. The nematode fauna of fishes in cenotes of the Yucatan Peninsula shows its appurtenance to the Neotropical fauna with close affinities with that of fish nematodes from South America, but with a considerable degree of endemism.

Nematodes parasitic in fishes of cenotes (= sinkholes) of the Peninsula of Yucatan, Mexico. Part 2. Larvae.

This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexalatus, Acuariidae gen. sp., Spiroxys sp., Falcaustra sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts.

Cenotes (sinkholes) of the Yucatan Peninsula, Mexico, as a habitat of adult trematodes of fish.

Examination of a total of 581 fish specimens of 15 species from 39 cenotes (sinkholes) in the Yucatan Peninsula, southeastern Mexico, revealed the presence of 10 species of adult trematodes. These were as follows: Saccocoelioides sogandaresi Lumsden, 1963, Saccocoelioides sp. (family Haploporidae), Cichlasotrema ujati Pineda et Andrade, 1989 (Angiodictyidae), Crassicutis cichlasomae Manter, 1936 (Homalometridae), Magnivitellinum simplex Kloss, 1966 (Macroderoididae), Stunkardiella minima (Stunkard, 1938) (Acanthostomidae), Oligogonotylus manteri Watson, 1976 (Cryptogonimidae), Genarchella tropica (Manter, 1936), G. astyanactis (Watson, 1976), and G. isabellae (Lamothe-Argumedo, 1977) (Derogenidae). Saccocoelioides sogandaresi is reported from Mexico for the first time. Poecilia velifera and P. latipunctata for S. sogandaresi, Cichlasoma octofasciatum for C. cichlasomae, Cichlasoma friedrichstahli and C. meeki for O. manteri, and C. meeki, C. octofasciatum and Gobiomorus dormitor for G. isabellae represent new host records. Most species found are described and figured and their host range and distribution are discussed.

Pseudocapillaria yucatanensis sp. n. (Nematoda: Capillariidae) from the bagre Rhamdia guatemalensis (Pisces) from cenotes in Yucatan, Mexico.

A new nematode species, Pseudocapillaria yucatanensis sp. n., is described from the intestine of the freshwater pimelodid catfish Rhamdia guatemalensis (Günther) from cenotes (= sinkholes) in Yucatan, Mexico. It differs from other three related species parasitizing freshwater fishes mainly in possessing the spicule with a simple rim of its proximal end and a non-expanded distal end, in the length of the spicule (0.218-0.295 mm), and the size (0.050-0.060 x 0.025-0.030 mm), shape and structure of eggs, and also in the host types and geographical distribution. Pseudocapillaria yucatanensis is the first known autochtonous species of Pseudocapillaria parasitizing freshwater fishes in Mexico.