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The parasite communities of marine fish in the tropical Pacific remain poorly studied. We did an initial study of the metazoan parasite communities of striped bonito Sarda orientalis from the Pacific coast of Mexico. Two hundred thirty individuals from two locations were collected between April 2017 and March 2018. Twenty-two metazoan parasite taxa (20 helminths and two Crustacea) were identified: one species of Monogenea, twelve of Digenea, one of Acanthocephala, two of Cestoda, four of Nematoda, one of Copepoda, and one of Isopoda. Didymozoid digeneans (six species) were the most frequent and abundant parasite species at both sampling locations. Parasite species richness at the component community level was similar in both locations (16–17 species). However, parasite community structure and species composition varied between them. Local fluctuations in some biotic (e.g. host feeding behaviour and body size) and abiotic environmental factors were probably responsible for these variations. [ABSTRACT FROM AUTHOR]

Seventy-four representatives of 8 species of whiptail lizards ( Aspidoscelis ssp.), from Mexico were examined for helminths: Aspidoscelis calidipes ( n = 8), A. communis ( n = 10), A. cozumelae ( n = 9), A. gularis ( n = 10), A. lineattissima ( n = 9), A. motaguae ( n = 11), A. parvisocia ( n = 9), and A. sackii ( n = 8). We found one species of Cestoda, Oochoristica scelopori, and 7 species of Nematoda, including Abbreviata terrapenis, Parapharyngodon alvarengai, Pharyngodon warneri, Spauligodon garciaprietoi, Spinicauda spinicauda, Thubunaea cnemidophorus, and Physaloptera sp. Mean helminth diversity per lizard species was 3.1 (SD 1.8). Spauligodon garciaprietoi was present in 6 of 8 (75%) of the lizard species. The specimens we examined were infected by an aggregate of helminths that were either characteristic of Aspidoscelis spp. from the United States (North America: O. scelopori, T. cnemidophorus, A. terrapenis, P. warneri) or characteristic of Aspidoscelis spp. from Mexico (Mesoamerica: S. garciaprietoi, P. alvarengai, S. spinicauda). Twentytwo new host records are reported. [ABSTRACT FROM AUTHOR]

In order to draw patterns in helminth parasite composition and species richness in Mexican freshwater fishes we analyse a presence-absence matrix representing every species of adult helminth parasites of freshwater fishes from 23 Mexican hydrological basins. We examine the distributional patterns of the helminth parasites with regard to the main hydrological basins of the country, and in doing so we identify areas of high diversity and point out the biotic similarities and differences among drainage basins. Our dataset allows us to evaluate the relationships among drainage basins in terms of helminth diversity. This paper shows that the helminth fauna of freshwater fishes of Mexico can characterise hydrological basins the same way as fish families do, and that the basins of south-eastern Mexico are home to a rich, predominantly Neotropical, helminth fauna whereas the basins of the Mexican Highland Plateau and the Nearctic area of Mexico harbour a less diverse Nearctic fauna, following the same pattern of distribution of their fish host families. The composition of the helminth fauna of each particular basin depends on the structure of the fish community rather than on the limnological characteristics and geographical position of the basin itself. This work shows distance decay of similarity and a clear linkage between host and parasite distributions. [ABSTRACT FROM AUTHOR]

The Oriental Basin is located in part of the states of Puebla, Tlaxcala and Veracruz, inside of the Trans-Mexican Volcanic Axis; so far, only two helminth species have been recorded (Caballerolecythus ibunami and Lamotheoxyuris ackerti) and three siphonapterans (Anomiopsyllus perotensis, Stenistomera alpina and Echidnophaga gallinacea). Two sampling visits to the area were carried out in June of 2007 and July of 2008, including five localities in the region; eight helminth and nine flea taxa were collected from Liomys irroratus, Dipodomys phillipsii, Peromyscus difficilis, P. maniculatus and Reithrodontomys megalotis. New hosts and localities records for seven helminths and one taxa for fleas were found. [ABSTRACT FROM AUTHOR]

To uncover and describe patterns of biogeography of helminth parasites in freshwater fishes of Mexico, and to understand processes that determine them. Three predictions about host-specificity, faunal exchange in transitional areas, and the biogeographical‘core’ fauna, are evaluated, all of which follow from a fundamental hypothesis: that parasites show characteristic associations with particular host clades. The parasite fauna of the southern Mexican cichlids and of the fishes of the Mesa Central are examined as case studies that reflect Neotropical and Nearctic historical influences.The region covered in this study includes most of Mexico, with emphasis on six biogeographical areas: the Yucatán Peninsula (area 1), the Grijalva-Usumacinta drainage (area 2), the Papaloapan and Pánuco drainages (area 3), the Balsas drainage (area 4), the Lerma-Santiago drainage (area 5), and the Bravo drainage (area 6).A parasite data base containing all the records of helminth parasites of freshwater fishes of Mexico was filtered to extract records of adult helminth parasites in freshwater fishes from the six biogeographical areas designated in this study. Jaccard's similarity coefficients and cluster analyses (usingupgma) were used to analyse the extent of faunal similarity between the designated biogeographical areas and between host (fish) families. Taxonomic composition of parasite assemblages in different host groups was also qualitatively compared from summary data. These data were used to test the three main predictions.To date, 184 species of helminths (120 as adults) have been recorded from 127 freshwater fishes in Mexico (almost 33% of the total fish diversity of Mexico). Of these parasite species, 69 are digenetic flukes, 51 are nematodes, 33 are monogeneans, 25 are tapeworms, and only six are acanthocephalans. The data and analyses from the six biogeographical areas corroborate the predictions that: (1) the adult parasite fauna is largely circumscribed by higher levels of monophyletic host taxa (families, orders, etc.), and that this pattern is independent of areas; (2) areas within a certain biogeographical region, and consequently with similar fish composition (e.g. areas 1, 2 and 3) have more similar parasite faunas compared to areas with less similar fish faunal composition; and (3)‘core’ parasite faunas persist to some extent in transitional areas with limited host-sharing.Helminth biodiversity in Mexican freshwater fishes is determined by the historical and contemporary biogeography of their hosts. Host lineage specificity, mainly at the level of the host family, appears to be an important factor in the distribution of the parasites. Most fish families (Characidae, Cichlidae, Pimelodidae, Ictaluridae, Catsotomidae, Goodeidae, Atherinidae) possess their own characteristic‘core’ helminth fauna, with limited host-sharing in transitional areas (e.g. areas 3 and 4). A re-evaluation of the helminth fauna of Mexican cichlids questions the hypothesis that cichlids lost parasites during the colonization of Mexico from South America. The evidence supports the idea that they acquired new parasites by host switching, possibly from marine or brackish-water percomorphs. In contrast, the parasite fauna of the Mesa Central remains enigmatic and reflects the region's history of endemicity with historical marine and Nearctic connections. [ABSTRACT FROM AUTHOR]

Examines the presence of some endohelminths in freshwater turtle Trachemys scripta in Yucatan, Mexico. Parasites known to occur in local fishes and serve as paratenic hosts; Description of species of helminths; Discussion of problems concerning the morphology, taxonomy and geographical distribution of helminths.