Fitness components of Drosophila melanogaster developed on a standard laboratory diet or a typical natural food source

Drosophila melanogaster is often used as a model organism in evolutionary biology and ecophysiology to study evolutionary processes and their physiological mechanisms. Diets used to feed Drosophila cultures differ between laboratories and are often nutritious and distinct from food sources in the natural habitat. Here we rear D. melanogaster on a standard diet used in our laboratory and a field diet composed of decomposing apples collected in the field. Flies developed on these two diet compositions are tested for heat, cold, desiccation, and starvation resistance as well as developmental time, dry body mass and fat percentage. The nutritional compositions of the standard and field diets were analyzed, and discussed in relation to the phenotypic observations. Results showed marked differences in phenotype of flies from the two types of diets. Flies reared on the field diet are more starvation resistant and they are smaller, leaner, and have lower heat resistance compared to flies reared on the standard diet. Sex specific effects of diet type are observed for several of the investigated traits and the strong sexual dimorphism usually observed in desiccation resistance in D. melanogaster disappeared when rearing the flies on the field diet. Based on our results we conclude that care should be taken in extrapolating results from one type of diet to another and especially from laboratory to field diets.     

Parasite systematics in the 21st century: opportunities and obstacles

Taxonomic names and phylogenetic hypotheses are indispensable tools for modern biological research, both basic and applied. Like all disciplines, parasitology suffers from the 'taxonomic impediment' - a global shortage of professional taxonomists and systematists. Only a fraction of the species of parasites on this planet have been identified, and the evolutionary relationships of only a minority of those are understood; thus, information on how to manage parasite biodiversity, including known and potential disease agents, is incomplete. A renewal of systematic parasitology has a key role in redefining the relationship between mankind and the organisms whose biology fascinates us so much.     

Comparative morphology of Ostertagia mossi and Ostertagia dikmansi (trichostrongylidae) from Odocoileus virginianus and comments on other Ostertagia spp. from the Cervidae

The synlophes of Ostertagia mossi Dikmans, 1931 and O. dikmansi Becklund & Walker, 1968 were found to be identical supporting recognition of these as the major and minor morphotypes, respectively, of a putative species pair within the Ostertagiinae. The cervical synlophe included three narrowly spaced, continuous, parallel ridges laterally and three parallel but more widely spaced ridges in the dorsal and ventral fields (Type II and Type A patterns, respectively). The disposition of the synlophe in conjunction with a long oesophageo-intestinal valve, and attributes of the genital cone and spicules are characteristics shared among other Ostertagia spp. from cervids in the Holarctic region that allow recognition of a species group morphologically distinct from the Ostertagiinae of domestic ruminants. The morphological similarity of O. mossi/O. dikmansi, O. leptospicularis Assadov, 1953/O. kolchida Popova, 1937 and O. gruehneri Skrjabin, 1929/O. arctica Mitzkewitsch, 1929 is substantial, but these species can be differentiated by small but constant differences in the synlophe and genital complex of males; females cannot be easily distinguished. The morphological similarity of this cryptic complex of species and their relatively restricted distribution among cervids suggests a coevolutionary history for hosts and parasites in the Holarctic region.     

Helminth parasitism in martens (Martes americana) and ermines (Mustela erminea) from Washington, with comments on the distribution of Trichinella spiralis

Helminths are reported for the first time from ermines (Mustela erminea) and martens (Martes americana) in Washington (USA). Among 22 adult ermines, 41% were infected by one or more of five species (Taenia mustelae, Alaria mustelae, Molineus patens, M. mustelae and Trichinella spiralis). Among 78 adult martens from three geographic localities, the prevalence was 83%. Nine species were identified (Mesocestoides sp., T. mustelae and T. martis americana, Euryhelmis squamula, M. patens, Baylisascaris devosi, Physaloptera sp., Soboliphyme baturini and T. spiralis). Trichinella spiralis occurred with a maximum prevalence of 50% in martens, but only occurred in 9% of ermines. Compression and digestion techniques provided a similar estimate of prevalence of T. spiralis, yet neither was entirely accurate in identifying all infected hosts. The species richness of the helminth community of martens in Washington was greater than that reported from other regions of North America.     

Fatal cysticercosis by Taenia crassiceps (Cyclophyllidea: Taeniidae) in a presumed immunocompromised canine host

Cysticercosis in a canine host (Canis familiaris) attributable to the taeniid cestode Taenia crassiceps is reported for the first time in North America. Numerous parent and daughter cysticerci occurred in a massive intrapleural and intraperitoneal infection in an apparently immunocompromised host. The largest cysticerci were ovoid to elongate, 5-9 mm in maximum length, and armed with 32-34 rostellar hooks in 2 rows; small hooks measured 114-143 microm long (x = 124+/-8.2 microm), and large hooks were 156-180 microm (x = 163+/-7.4 microm). Taenia crassiceps is widespread in boreal North America and, like a number of other taeniids, constitutes a potential risk as a zoonotic parasite. The immunological status of the host may be important in determining the outcome of infections for this and other taeniids in atypical hosts.     

Phylogenetic analysis among the families of the Cyclophyllidea (Eucestoda) based on comparative morphology,with new hypotheses for co-evolution in vertebrates

Phylogenetic analysis of the families of the Cyclophyllidea based on comparative morphology revealed support for monophyly of the order. Four equal length trees (CI = 0.71) resulted from analysis of 42 binary and multistate characters. Major conclusions are the following: (1) a basal position for the arostellate groups, with Mesocestoididae + Nematotaeniidae representing the basal subclade; (2) polyphyly for the Anoplocephalidae with sister-group associations postulated respectively for Anoplocephalinae + Thysanosomatinae and Linstowiinae + Inermicapsiferinae; (3) recognition within the rostellate cyclophyllideans of taeniid, dilepidid and davaineid subclades and the Dipylidiidae; (4) designation of Metadilepididae + Paruterinidae as sister taxa; (5) monophyly for the Davaineidae with all inclusive subfamilies; and (6) a close relationship for the Hymenolepididae and acoleate cyclophyllideans. Monophyly for such classically defined groups as the Mesocestoididae, Taeniidae and Davaineidae is corroborated. Polyphyly of the Dilepididae sensu lato, with independence of the Dipylidiidae, Dilepididae sensu Bona (1994), the Metadilepididae + Paruterinidae, and the Gryporhynchidae is confirmed. As presented these constitute testable hypotheses for monophyly and relationships among the families of the Cyclophyllidea. Initial diversification of the cyclophyllideans occurred in mammalian hosts and three independent events of colonisation of avian taxa are postulated. Origins of the cyclophyllideans extend into the Mesozoic or earlier, with extant taxa representing lineages that were persistent across the extinction event that defines the Cretaceous-Tertiary boundary.     

Ending a decade of deception: a valiant failure, a not-so-valiant failure, and a success story

Prior studies involving two methods, Brooks Parsimony Analysis (BPA) and TreeMap, have found BPA to be the more reliable method. Recent criticisms leveled at these studies argue that the tests were unfairly created and biased in favor of BPA. The authors of a recent critique offered new exemplars to demonstrate flaws in BPA, plus a simple fix to correct the flaws found in TreeMap. A re‐evaluation of their exemplars clearly shows that the authors' calculations are incorrect, their understanding of the methods is lacking, and that their simple fix does not work. Additional analyses using TreeMap 2.02 are run to show that TreeMap 2.02, like TreeMap 1.0, cannot adequately deal with widespread parasites, contrary to the claims of its supporters. Furthermore, the exemplars corroborate previous findings that BPA, when calculated correctly, is more reliable than TreeMap1.0 and TreeMap 2.02 and therefore the method of choice in coevolutionary and biogeographic studies.