Helminth parasites of unisexual and bisexual whiptail lizards (Teiidae) in North America. III. The Chihuahuan spotted whiptail (Cnemidophorus exsanguis)

Twenty-four of 87 (28%) parthenogenetic Chihuahuan spotted whiptails (Cnemidophorus exsanguis) from nine counties of New Mexico and seven counties of Texas were infected with one or more endoparasites. These included a linstowiid cestode (Oochoristica bivitellobata) in seven (8%), a larval spirurid nematode (Physaloptera sp.) in nine (10%) and an oxyurid nematode (Pharyngodon warneri) in 10 (11%). This note, the third in a series of reports on helminths of Cnemidophorus spp., documents parasites in C. exsanguis for the first time.     

Parasites of prairie rattlesnakes (Crotalus viridis viridis) and gopher snakes (Pituophis melanoleucus sayi) from the eastern high plains of New Mexico

Three prairie rattlesnakes (Crotalus viridis viridis) and two gopher snakes (Pituophis melanoleucus sayi) from the eastern high plains of New Mexico (USA) were examined for parasites. One cestode (Oochoristica osheroffi), and two nematode (Kalicephalus inermis and Physoloptera retusa) species were recovered from two infected rattlesnakes. One female gopher snake was infected with two nematode (K. inermis and Rhabdias spp.) and one mite (Entonyssus halli) species.     

Helminth parasites of unisexual and bisexual whiptail lizards (Teiidae) in North America. I. The Colorado checkered whiptail (Cnemidophorus tesselatus)

Eleven of 27 (41%) parthenogenetic Colorado checkered whiptails (Cnemidophorus tesselatus) from four counties of western and southwestern Texas were infected with one or more helminths. These included a linstowiid cestode (Oochoristica sp.), a larval spirurid nematode (Physaloptera sp.) and two species of oxyurid nematodes (Parathelandros texanus and Pharyngodon warneri). This note, the first in a series of reports on helminths of Cnemidophorus spp., represents the first record of parasites from C. tesselatus.     

Eimerians in Harvest Mice, Reithrodontomys spp., from Mexico, California and New Mexico, and Phenotypic Plasticity in Oocysts of Eimeria arizonensis

ABSTRACT Between May 1979 and August 1991, 48.7% (57/117) of the harvest mice ( Reithrodontomys spp.) examined from 10 localities in Mexico, California and New Mexico had coccidian oocysts in their feces. A total of 46.7% (49/105) of the Reithrodontomys megalotis examined were positive for coccidian oocysts; this included samples from five states in Mexico (47.1%, 8/17), three counties in California (66.7%, 4/6) and two counties in New Mexico (45.1%, 37/82); 66.7% (8/12) of the Reithrodontomys montanus from one county in New Mexico also were infected. Only two coccidian species, Eimeria arizonensis and Eimeria langebarteli , were found in these hosts. Oocysts of E. langebarteli were found only in R. megalotis : in all three infected mice from Madera County, California, in the only mouse from San Bernardino County, California, and in 63% (5/8) of the infected mice from four states in Mexico. Oocysts of E. arizonensis were found in R. megalotis in Mexico, California, and New Mexico and in R. montanus from New Mexico. Sporulated oocysts of E. langebarteli differed slightly from those in previously published reports by having wider oocysts and larger sporocysts. Sporulated oocysts of E. arizonensis were variable in size, with those recovered from R. montanus significantly larger in length and width and sporocyst width than those from R. megalotis . The structure of the oocyst residuum was polymorphic, both within and between host species, and within the same mouse; it could appear as one large globule, two globules, several to many smaller globules, or as a compact mass of many small granules. Oocysts with a variable residuum were larger than those with one globule in all oocyst/sporocyst dimensions. Only 9% (5/57) of the infected mice were discharging oocysts of both eimerians when examined.     

Abbreviata terrapenis (Nematoda: Physalopteridae): an accidental parasite of the banded rock rattlesnake (Crotalus lepidus klauberi)

The nematode, Abbreviata terrapenis (Physalopteridae) was found in 16 (6%) of 267 banded rock rattlesnakes (Crotalus lepidus klauberi) from Arizona and New Mexico. Abbreviata terrapenis in C. lepidus represents an accidental parasite in that "infection" was acquired by the ingestion of lizard prey. Feeding captive snakes on wild-caught lizards poses a risk of introducing nematodes to the snakes.     

Helminths of California quail (Callipepla californica) and mountain quail (Oreortyx pictus) in western Oregon

Eighty California quail (Callipepla californica), collected from the E. E. Wilson Wildlife Area near Monmouth, Oregon (USA) during a 22 mo period, were examined for gastrointestinal helminths. Eight birds were infected with three species of nematodes, Heterakis isolonche, Dispharynx nasuta, and Capillaria sp., and two species of cestodes, Rhabdometra odiosa and Davainea sp. Except for D. nasuta, prevalence did not exceed 5% despite mesic conditions in the collection area. Two mountain quail (Oreortyx pictus) were collected from Lane County, Oregon (USA), near Blue River Reservoir; both were infected with the nematode Trichostrongylus tenuis.     

Cystoopsis atractostei n. sp. (Nematoda: Cystoopsidae) from the subcutaneous tissue of the tropical gar,Atractosteus tropicus (Pisces), in Mexico

A new species of parasitic nematode, Cystoopsis atractostei (Trichinelloidea: Cystoopsidae), is described based on female specimens recovered from the subcutaneous tissue of the tropical gar, Atractosteus tropicus Gill (Lepisosteiformes: Lepisosteidae), from 2 localities (Canal Nueva Esperanza and Canal Tabasquillo) of the Pantanos de Centla Biological Reserve, State of Tabasco, southeastern Mexico, collected in April 2001. The total prevalence was 13%, and the mean intensity of infection was 1 nematode per fish. The new species differs from females of the only other adequately described congeneric species, C. acipenseris Wagner, 1867, mainly in possessing a bulbous inflation at the anterior end of the muscular esophagus, the vulva situated well posterior to the nerve ring, smooth cuticle, and in the shape of the posterior vesicular portion of the body (markedly transversely oval) in the largest specimens. Both species also differ in their host types (Lepisosteiformes vs. Acipenseriformes) and in geographical distribution (tropical southern Mexico vs. temperate zones of the Holarctic).     

Phylogeography of the Walnut Twig Beetle,Pityophthorus juglandis,the Vector of Thousand Cankers Disease in North American Walnut Trees

Thousand cankers disease (TCD) of walnut trees (Juglans spp.) results from aggressive feeding in the phloem by the walnut twig beetle (WTB), Pityophthorus juglandis, accompanied by inoculation of its galleries with a pathogenic fungus, Geosmithia morbida. In 1960, WTB was only known from four U.S. counties (in Arizona, California, and New Mexico), but the species has now (2014) invaded over 115 counties, representing much of the western USA, and at least six states in the eastern USA. The eastern expansion places TCD in direct proximity to highly valuable (> $500 billion) native timber stands of eastern black walnut, Juglans nigra. Using mitochondrial DNA sequences, from nearly 1100 individuals, we examined variation among 77 samples of WTB populations across its extended range in the USA, revealing high levels of polymorphism and evidence of two divergent lineages. The highest level of genetic diversity for the different lineages was found in the neighboring Madrean Sky Island and Western New Mexico regions, respectively. Despite their proximity, there was little evidence of mixing between these regions, with only a single migrant detected among 179 beetles tested. Indeed, geographic overlap of the two lineages was only common in parts of Colorado and Utah. Just two haplotypes, from the same lineage, predominated over the vast majority of the recently expanded range. Tests for Wolbachia proved negative suggesting it plays no role in "driving" the spread of particular haplotypes, or in maintaining deep levels of intraspecific divergence in WTB. Genotyping of ribosomal RNA corroborated the mitochondrial lineages, but also revealed evidence of hybridization between them. Hybridization was particularly prevalent in the sympatric areas, also apparent in all invaded areas, but absent from the most haplotype-rich area of each mitochondrial lineage. Hypotheses about the specific status of WTB, its recent expansion, and potential evolutionary origins of TCD are discussed.     

Helminth parasites of unisexual and bisexual whiptail lizards (Teiidae) in North America. V. Mesocestoides sp. tetrathyridia (Cestoidea: Cyclophyllidea) from four species of Cnemidophorus

Two hundred and one whiptail lizards, Cnemidophorus spp., from Texas and Colorado (USA), were examined for Mesocestoides sp. tetrathyridia. Eleven (5%) were infected, including three of 58 (5%) C. dixoni, six of 70 (9%) C. gularis septemvittatus, one of 35 (3%) C. marmoratus, and one of 34 (3%) C. tesselatus; four C. inornatus heptagrammus were not infected. In addition, 41 non-cnemidophorine lizards from the same study area were not infected. Free tetrathyridia were found in the body cavity of lizards and encapsulated tetrathyridia were observed in the heart, liver, stomach, mesenteries, ovaries, intestines, and lungs. None of the Mesocestoides sp. exhibited any evidence of asexual proliferation such as multiple scoleces or buds. This note, the fifth in a series of reports on helminths of Cnemidophorus spp., represents the first time Mesocestoides sp. has been reported from these four taxa, and Colorado is a new geographic locality record for this parasite.     

Seasonality of some Chihuahuan Desert soil oribatid mites (Acari: Cryptostigmata)

1. Reproductive strategies of four species of oribatid mites were investigated in the Chihuahuan Desert from 1981 to 1984.
2. Breeding activity coincided with the summer rainfall period in three of the four cases: Passalozetes neomexicanus, P. californicus and Jornadia larreae. This pattern was not changed by the application of simulated rainfall at other times of the year. The strict seasonality of reproductive behaviour is interpreted as an outcome of strong selection pressure to recruit only when food quality and quantity and microclimate are most favourable.
3. Joshuella striata showed a more flexible pattern which was essentially bimodal. Periods of egg production occurred in winter and also during the summer rainfall period. This pattern is consistent with the known distribution of this species in winter- and summer-rainfall deserts in south-western USA.     

Paracapillaria epinepheli n. sp. (Nematoda: Capillariidae) from the red grouper Epinephelus morio (Pisces) from Mexico

A new nematode species, Paracapillaria epinepheli, is described from the stomach of the marine fish Epinephelus morio (Valenciennes), the red grouper, (Serranidae, Perciformes) from coastal waters of the Gulf of Mexico in Yucatan, southeastern Mexico. It is characterised mainly by its small body (body length of male and female 2.73–3.22 mm and 5.94–6.35 mm, respectively), number (31–36) and structure of the stichocytes, length of the spicule (0.180–0.195 mm), structure of the male caudal bursa (considerably reduced), structure and size of the eggs (size 0.057–0.063 × 0.027–0.030 mm), and by their site within the host. It is the second Paracapillaria species known to occur in the marine and estuarine fishes of the Gulf of Mexico.     

Parasitic infection of the seahorse (Hippocampus erectus)--a case report

This report details the development of a microsporidan infection in a colony of seahorses (Hippocampus erectus) caused by Glugea heraldi. Of 76 animals imported from Florida Bay (USA), two survived. A myxosporidan (Sphaeromyxa sp.) and an unidentified nematode infection were also diagnosed in the same colony, but these infections were not considered important, causative factors in the mortalities.     

Selachohemecus benzi n. sp. (Digenea: Sanguinicolidae) from the blacktip shark Carcharhinus limbatus (Carcharhinidae) in the northern Gulf of Mexico

Selachohemecus benzi Bullard & Overstreet n. sp. infects the heart and kidney of the blacktip shark Carcharhinus limbatus in the northern Gulf of Mexico off Florida and Mississippi, USA. Specimens of S. olsoni Short, 1954, the only congener and only other named blood fluke reported from a chondrichthyan in the Gulf of Mexico, were collected from the heart of the Atlantic sharpnose shark Rhizoprionodon terraenovae from two new localities, Apalachicola Bay, Florida, and Mississippi Sound, Mississippi, USA. The new species differs from S. olsoni by having a larger body (1.4-3.8 mm long), robust tegumental body spines numbering 51-63 along each lateral body margin, a testis extending from the posterior caeca to the ovary, and a medial ovary with lobes. We amend the diagnosis of Selachohemecus Short, 1954 to accommodate it and provide a diagnostic key for all named chondrichthyan blood flukes.     

Venom variability and envenoming severity outcomes of the Crotalus scutulatus scutulatus (Mojave rattlesnake) from Southern Arizona

Twenty-one Mojave rattlesnakes, Crotalus scutulatus scutulatus (C. s. scutulatus), were collected from Arizona and New Mexico U.S.A. Venom proteome of each specimen was analyzed using reverse-phase HPLC and SDS-PAGE. The toxicity of venoms was analyzed using lethal dose 50 (LD(50)). Health severity outcomes between two Arizona counties U.S.A., Pima and Cochise, were determined by retrospective chart review of the Arizona Poison and Drug Information Center (APDIC) database between the years of 2002 and 2009. Six phenotypes (A-F) were identified based on three venom protein families; Mojave toxin, snake venom metalloproteinases PI and PIII (SVMP), and myotoxin-A. Venom changed geographically from SVMP-rich to Mojave toxin-rich phenotypes as you move from south central to southeastern Arizona. Phenotypes containing myotoxin-A were only found in the transitional zone between the SVMP and Mojave toxin phenotypes. Venom samples containing the largest amounts of SVMP or Mojave toxin had the highest and lowest LD(50s), respectively. There was a significant difference when comparing the presence of neurotoxic effects between Pima and Cochise counties (p=0.001). No significant difference was found when comparing severity (p=0.32), number of antivenom vials administered (p=0.17), days spent in a health care facility (p=0.23) or envenomation per 100,000 population (p=0.06). Although not part of the original data to be collected, death and intubations, were also noted. There is a 10× increased risk of death and a 50× increased risk of intubations if envenomated in Cochise County.     

Phylogeography of the dusky shrew, Sorex monticolus (Insectivora, Soricidae): insight into deep and shallow history in northwestern North America

Phylogenetic relationships among the dusky shrew (Sorexmonticolus) and eight related species (S. bairdi, S. bendirii, S. neomexicanus, S.ornatus, S. pacificus, S. palustris, S. sonomae and S.vagrans) were assessed using sequences from the mitochondrial cytochrome b gene (801 bp). Analyses using parsimony and maximum likelihood revealed significant molecular variation not reflected in previous morphological studies of these species. Conversely, three morphologically defined species (S.bairdi, S.neomexicanus and S.pacificus) were poorly differentiated. Sorexornatus and S.vagrans represented basal taxa for a more inclusive group that included: (i) a widespread Continental clade containing S.monticolus (Arizona to Alaska, including S. neomexicanus); (ii) a Coastal clade containing S.monticolus (Oregon to south-east Alaska, including S. bairdi and S. pacificus); (iii) the semiaquatic species (S. bendirii and S. palustris); and (iv) S.sonomae. Additional subdivision was observed within the Continental clade corresponding to populations from the northern and southern Rocky Mountains. Average uncorrected sequence divergence between the Coastal and Continental clades was 5.3% (range 4.5-6.2%), which exceeds many interspecific comparisons within this species complex and within the genus Sorex. Lack of resolution of internal nodes within topologies suggests a deep history of rapid diversification within this group. Late Pleistocene/Holocene glacial perturbations are reflected in the shallow phylogeographic structure within these clades in western North America. Our results suggest also that S. monticolus is not monophyletic under current taxonomic nomenclature. This perspective on phylogeographic history was developed within a growing comparative framework for other organisms in western North America.     

A Continent-Wide Migratory Divide in North American Breeding Barn Swallows (Hirundo rustica)

Populations of most North American aerial insectivores have undergone steep population declines over the past 40 years but the relative importance of factors operating on breeding, wintering, or stopover sites remains unknown. We used archival light-level geolocators to track the phenology, movements and winter locations of barn swallows (Hirdundo rustica; n = 27) from populations across North America to determine their migratory connectivity. We identified an east-west continental migratory divide for barn swallows with birds from western regions (Washington State, USA (n = 8) and Saskatchewan, Canada (n = 5)) traveling shorter distances to wintering areas ranging from Oregon to northern Colombia than eastern populations (Ontario (n = 3) and New Brunswick (n = 10), Canada) which wintered in South America south of the Amazon basin. A single swallow from a stable population in Alabama shared a similar migration route to eastern barn swallows but wintered farther north in northeast Brazil indicating a potential leap frog pattern migratory among eastern birds. Six of 9 (67%) birds from the two eastern populations and Alabama underwent a loop migration west of fall migration routes including around the Gulf of Mexico travelling a mean of 2,224 km and 722 km longer on spring migration, respectively. Longer migration distances, including the requirement to cross the Caribbean Sea and Gulf of Mexico and subsequent shorter sedentary wintering periods, may exacerbate declines for populations breeding in northeastern North America.     

Spinitectus mexicanus n. sp. (Nematoda : Cystidicolidae) from the intestine of the freshwater fish Heterandria bimaculata in Mexico

A new nematode, Spinitectus mexicanus n. sp., is described on the basis of the specimens recovered from the intestine of Heterandria bimaculata (Heckel) (Poeciliidae, Cyprinodontiformes) from 3 rivers of the Papaloapan River basin (type locality La Basura River), Los Tuxtlas, Veracruz State, Mexico. It differs from its congeners mainly in having the spination of the cuticle separated into 4 longitudinal sectors, each with posteriorly diminishing numbers of larger spines at the anterior part of body. It is the first species of Spinitectus described from a poeciliid fish and the second reported from freshwater fishes in Mexico.     

Trichinella infection in wildlife of the southwestern United States.

Several potential mammalian reservoirs of sylvatic species of Trichinella were examined from Texas, New Mexico, and Arizona. During 1998-99, tongues were collected from a black bear (Ursus americanus) in Arizona; from 9 black bears, a coyote (Canis latrans), and a mountain lion (Felis concolor) in New Mexico; and from 154 coyotes, 32 raccoons (Procyon lotor), 13 opossums (Didelphis marsupialis), 4 ocelots (Leopardus pardalis), 3 bobcats (Lynx rufus), and 5 feral hogs (Sus scrofa) in southern Texas. Larvae of Trichinella murrelli were identified by a multiple-polymerase chain reaction analysis in 1 black bear (11.1%) from New Mexico and in 7 coyotes (4.5%) of Texas, whereas Trichinella spiralis larvae were detected in the black bear of Arizona. This is the first report of Trichinella infection in wildlife of New Mexico and Texas and extends the distribution of T. murrelli into the southwestern United States near the border of Mexico.     

Genetic differences within and between species of deep-sea crabs (chaceon) from the North Atlantic Ocean

The deep-sea red crab Chaceon quinquedens is a commercially important crustacean on the Atlantic continental shelf and slope of North America. To assess genetic subdivision in C. quinquedens, we examined the nucleotide sequence of the mitochondrial 16S rDNA gene and the internal transcribed spacers (ITS) of the nuclear ribosomal repeat in samples from southern New England and the Gulf of Mexico. We compared those data to sequences from two congeners, a sympatric species from the Florida coast, C. fenneri, and an allopatric eastern Atlantic species, C. affinis. The 16S rDNA data consisted of 379 aligned nucleotides obtained from 37 individuals. The greatest genetic difference among geographical groups or nominal species was between C. quinquedens from southern New England and C. quinquedens from the Gulf of Mexico. Haplotypes from these two groups had a minimum of 10 differences. All 11 C. fenneri samples matched the most common haplotype found in C. quinquedens from the Gulf of Mexico, and this haplotype was not detected in C. quinquedens from southern New England. The three haplotypes of C. affinis were unique to that recognized species, but those haplotypes differed only slightly from those of C. fenneri and C. quinquedens from the Gulf of Mexico. Based on 16S rDNA and ITS data, genetic differences between C. quinquedens from southern New England and the Gulf of Mexico are large enough to conclude that these are different fishery stocks. Our results also indicate that the designation of morphological species within the commercially important genus Chaceon is not congruent with evolutionary history. The genetic similarity of C. affinis from the eastern Atlantic and C. quinquedens from the Gulf of Mexico suggests these trans-Atlantic taxa share a more recent common history than the two populations of "C. quinquedens" that we examined.