Host-parasite associations are assumed to be ecologically specialized, tightly coevolved systems driven by mutual modification in which host switching is a rare phenomenon. Ecological fitting, however, increases the probability of host switching, creating incongruences between host and parasite phylogenies, when (1) specialization on a particular host resource is a shared characteristic of distantly related parasites, and (2) the resource being tracked by the parasite is widespread among many host species. We investigated the effect of ecological fitting on structuring the platyhelminth communities of anurans from a temperate forest and grassland in the United States and tropical dry and wet forests in Mexico and Costa Rica. The six communities all exhibit similar structure in terms of the genera and families inhabiting the frogs. Parasite species richness is highly correlated with the amount of time a host spends in association with aquatic habitats, a conservative aspect of both parasite and host natural history, and determined in a proximal sense by host mobility and diet breadth. The pattern of parasite genera and families within host genera across the regions examined is consistent with the prediction that ecological fitting by phylogenetically conservative species, coupled with historical accidents of speciation and dispersal, should be evidenced as a nested-subset structure; the shared requirement for aquatic habitats of tadpoles provides a baseline assemblage to which other parasite taxa are added as a function of adult host association with aquatic habitats. We conclude that parasite communities are structured by both ecological fitting and coevolution (mutual modification), the relative influences of which are expected to vary among different communities and associations.

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Ecological fitting as a determinant of the community structure of platyhelminth parasites of anurans.

Sea turtle products (e.g., meat, adipose tissue, organs, blood, eggs) are common food items for many communities worldwide, despite national regulations in some countries prohibiting such consumption. However, there may be hazards associated with this consumption due to the presence of bacteria, parasites, biotoxins, and environmental contaminants. Reported health effects of consuming sea turtles infected with zoonotic pathogens include diarrhea, vomiting, and extreme dehydration, which occasionally have resulted in hospitalization and death. Levels of heavy metals and organochlorine compounds measured in sea turtle edible tissues exceed international food safety standards and could result in toxic effects including neurotoxicity, kidney disease, liver cancer, and developmental effects in fetuses and children. The health data presented in this review provide information to health care providers and the public concerning the potential hazards associated with sea turtle consumption. Based on past mortality statistics from turtle poisonings, nursing mothers and children should be particularly discouraged from consuming all sea turtle products. We recommend that individuals choose seafood items lower in the food chain that may have a lower contaminant load. Dissemination of this information via a public health campaign may simultaneously improve public health and enhance sea turtle conservation by reducing human consumption of these threatened and endangered species.

Hazards Associated with the Consumption of Sea Turtle Meat and Eggs: A Review for Health Care Workers and the General Public

https://www.otago.ac.nz/parasitegroup/PDF%20papers/Krasnovetal2010-IJP.pdf

Similarity in ectoparasite faunas of Palaearctic rodents as a function of host phylogenetic, geographic or environmental distances: Which matters the most?

Parasites are integral components of marine ecosystems, a general observation accepted by parasitologists, but often considered of trifling significance to the broader community of zoologists. Parasites, however, represent elegant tools to explore the origins, distribution and maintenance of biodiversity. Among these diverse assemblages, host and geographic ranges described by various helminths are structured and historically constrained by genealogical and ecological associations that can be revealed and evaluated using phylogenetic methodologies within the context of frameworks and hypotheses for co-evolution and historical biogeography. Despite over 200 years of sporadic investigations of helminth systematics, knowledge of parasite faunal diversity in chondrichthyan and osteichthyan fishes, seabirds and marine mammals remains to be distilled into a coherent and comprehensive picture that can be assessed using phylogenetic approaches. Phylogenetic studies among complex host-parasite assemblages that encompass varying temporal and geographic scales are the critical context for elucidating biodiversity and faunal structure, and for identifying historical and contemporary determinants of ecological organization and biogeographic patterns across the marine biosphere. Insights from phylogenetic inference indicate (1) the great age of marine parasite faunas; (2) a significant role for colonization in diversification across a taxonomic continuum at deep and relatively recent temporal scales; and (3) a primary role for allopatric speciation. Integration of ecological and phylogenetic knowledge from the study of parasites is synergistic, contributing substantial insights into the history and maintenance of marine systems.

Revealing the faunal tapestry: co-evolution and historical biogeography of hosts and parasites in marine systems.

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1362&context=parasitologyfacpubs

Parasite Systematics in the 21st Century: Opportunities and Obstacles

Description of Heteroplectanum oliveri sp. n. (Monogenea: Diplectanidae) and comments on the helminth fauna of Kyphosus elegans (Perciformes: Kyphosidae) from Chamela Bay, Mexico

Gastrointestinal digenetic trematodes of Olive Ridley's turtle (Lepidochelys olivacea) from Oaxaca, México. Taxonomy and infracommunity structure

Machidatrema n. gen. is proposed to include Neotherletrum frontilatum (Manter, 1969) Gibson and Bray, 1979, Neotheletrum akeh Machida, 1989, Genolinea kyphosi Yamaguti, 1970, and Genolinea chilostoma Machida, 1980. The new genus is characterized by the presence of strong muscles in the anterior part of the body, the hermaphroditic duct divided into 2 sections, prostatic vesicle, and excretory pore in a midventral position. Phylogenetic analysis of the 4 species, based on 14 characters, produced I most parsimonious tree with a consistency index of 0.938. The tree suggests that Machidatrema frontilatum and Machidatrema akeh are sister species: Machidatrema kyphosi is the sister species of the former 2, and Machidatrema chilostoma is the sister species of them all. The genus appears to have originated in the Pacific Ocean, parasitizing fishes belonging to Kyphosus; the common ancestor of M. frontilatum and M. akeh appears to have originated by a host-switching event to fishes belonging to Siganus, and M. frontilatum originated by allopatric speciation involving dispersal to the Indo-Pacific and Australia.

Machidatrema n. gen. (Digenea: Hemiuridae: Bunocotylinae) and phylogenetic analysis of its species.

The phylogenetic analysis of the 16 recognized genera in the Bunocotylinae, based upon 30 morphological trans- formation series, produced 2 most parsimonious trees, each with a consistency index of 0.62. The monophyly of the group is supported by 6 synapomorphies. Ahemiurus, Aphanuroides, Aphanurus, Myosaccium, and Indoderogenes separate independently in the basal part of the tree. Saturnius and Bunocotyle separate next, forming a clade. Machidatrema, Duosphincter, Theletrum, and Monolecithotrema separate independently; and in the most derived part of the tree Opisthadena + Neopisthadena + Mi- trostoma, Genolinea, and Neotheletrum grouped together form a clade. Optimization of hosts and geographic distribution onto the 2 most parsimonious trees suggests that the bunocotylines originated from an ancestor that was host specific to fishes of the Clupeidae and was distributed in the Tethys Sea.

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Phylogenetic analysis of the bunocotylinae dollfus, 1950 (digenea: hemiuridae)

Traditional wisdom, based on assumptions of species-specifi c coevolutionary interactions between hosts and parasites, suggests that pathogens with multi-host life cycles are unlikely to move with their defi nitive hosts because their transmission requirements are so specialized. Ecological fi tting provides a theory of diffuse coevolution, which allows introduced pathogens with complex life cycles to become established and spread rapidly into native hosts if the resource required at each stage of the life cycle is both phylogenetically conservative (distributed among numerous species) and geographically widespread. The external appearance of life cycle complexity does not, therefore, on its own, predict the potential for an organism to become an emerging infectious disease. We apply this concept to explain a potential enigma, the presence of a lung fl uke, Haematoloechus fl oedae, endemic to North American bullfrogs, in Costa Rican leopard frogs, even though there are no bullfrogs extant in the country today, and none ever occurred where the parasite has been discovered. We then discuss how the integration of ecological and life history information within a phylogenetic framework can help biologists move from attempts to manage emerging infectious disease outbreaks to the ability to predict and thus circumvent the outbreak in the fi rst place.

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Phylogeny, ecological fi tting and lung fl ukes: helping solve the problem of emerging infectious diseases Filogenia, fl exibilidad ecológica y digéneos de pulmones: ayudando a resolver la crisis de las enfermedaes infecciosas emergentes

Virginia León-Règagnon

Papers

Description of Heteroplectanum oliveri sp. n. (Monogenea: Diplectanidae) and comments on the helminth fauna of Kyphosus elegans (Perciformes: Kyphosidae) from Chamela Bay, Mexico

Gastrointestinal digenetic trematodes of Olive Ridley's turtle (Lepidochelys olivacea) from Oaxaca, México. Taxonomy and infracommunity structure

Machidatrema n. gen. (Digenea: Hemiuridae: Bunocotylinae) and phylogenetic analysis of its species.

Phylogenetic analysis of the bunocotylinae dollfus, 1950 (digenea: hemiuridae)

Phylogeny, ecological fi tting and lung fl ukes: helping solve the problem of emerging infectious diseases Filogenia, fl exibilidad ecológica y digéneos de pulmones: ayudando a resolver la crisis de las enfermedaes infecciosas emergentes