Comparative life history for populations of the Sceloporus grammicus complex (Squamata: Phrynosomatidae)

A Teotihuacán population of the Sceloporus grammicus complex was compared with other previously studied populations (Parque Nacional Zoquiapan [PNZ], Monte Alegre Ajusco [MAA], Pedregal San Angel [PSA], Cantimplora [CA], Capulín, Laguna, Paredon, Michilia, and south Texas) for variations in several life history characteristics (SVL at sexual maturity, reproductive period, ovulation and gestation time, and litter size). Mean body size at sexual maturity of females from Teotihuacán was larger than PNZ, MAA, CA, and Capulín. Reproductive period (vitellogenesis, ovulation, gestation, and birth) for the Teotihuacán population was the shortest of all populations. In the Teotihuacán population, gestation time was similar to the Capulínand MAA populations but was shorter than all other populations except the Michilia population. Embryonic development at ovulation varied among populations, with Teotihuacán and Capulín showing earlier stages (stages 1) at ovulation than all other populations. Teotihuacán, PSA, PNZ, and Texas all showed similar litter size, which were larger than Laguna, Paredon, MAA, Capulín, and CA populations. Differences in reproductive characteristics of these populations could indicate phylogenetically constrained, reproductively isolated populations, or they may be explained as merely responses to different environments.     

Reproductive cycle of the lizard Sceloporus mucronatus with comments on intraspecific geographic variation

Sceloporus mucronatus is a viviparous lizard that inhabits high altitudes in central México. Lizards from Tecocomulco, Hidalgo, México, were collected monthly at 2500 m throughout one year. Macro- and microscopic evidence of gonads showed that both sexes reproduce synchronously during the fall. In males, after a short testicular quiescence in December, the recrudescence begins in winter (January) and continues through spring and summer (July), with maximum activity occurring from late summer to early fall (August–September). Regression takes place simultaneously with copulation during the fall (October–November). In females, vitellogenesis occurs during summer and fall (August–November), with ovulation in the fall (November–December). Gravid females were found throughout the winter, and parturition occurs during spring (May). Litter size was correlated with female snout–vent length. Female reproductive phenology of viviparous Sceloporus species seems to be highly conservative at different altitudes, but male reproductive phenology shifts between spring–summer (in populations higher than 2500 m) and summer–fall (in populations 2500 m or lower), as in the present study. The longer period of testicular recrudescence (January–July) in the studied population from Tecocomulco suggests plasticity in testicular activity.     

Thermal ecology and activity patterns of the short-horned lizard ( Phrynosoma douglassi ) and the sagebrush lizard ( Sceloporus graciosus ) in southeastern Idaho

A mark - recapture study of the short - horned lizard ( Phrynosoma douglassi ) and the sagebrush lizard ( Sceloporus graciosus ) was performed from 1976 to 1977 in southeastern Idaho. Both species had mean cloacal temperatures of approximately 33 C. However, P. douglassi had more variable cloacal temperatures, particularly during morning and evening periods. This was caused by differences in sleeping sites chosen by the two species. Adults of both species were active from mid - April through late August, with peak activity in June. Juvenile P. douglassi displayed a seasonal activity pattern similar to that of adults. Juvenile S. graciosus were most active later in the year (August), when adults were disappearing. In both species, young - of - the - year appeared in early to mid - August. Adult and juvenile P. douglassi were active during all daylight hours and displayed no activity peaks, whereas young - of - the - year displayed a bimodal activity pattern. Adult and juvenile S. graciosus were active over all daylight hours but had peak activity between 1200 and 1500 h. Ants ( Pogonomyrmex ) were the lizard's principle prey. However, only young - of - the - year P. douglassi had activity patterns that paralleled that of ants on their mounds.         

Two aberrant karyotypes in the sagebrush lizard ( Sceloporus graciosus ): triploidy and a "supernumerary" oddity

Widespread karyotypic sampling in the lizard Sceloporus graciosus Baird & Girard has confirmed previous reports of chromosomal monotypy. Most individuals throughout the range have a diploid karyotype of 2N = 30 consisting of 12 biarmed macrochromosomes and 18 microchromosomes. A single female karyotyped from the vicinity of Riverside, California, was unmistakably triploid, showing 3N = 45 with 18 macrochromosomes and 27 microchromosomes. This female appeared phenotypically normal but appeared reproductively incompetent. A male from Zion National Park, Utah, showed an extra bivalent in some diakinesis arrays, which apparently represents a supernumerary chromosome.     

Food habits of the western whiptail lizard ( Cnemidophorus tigris ) in southeastern New Mexico

This study presents the first food habit assessment for the western whiptail lizard ( Cnemidophorus tigris ) in the shinnery oak – mesquite habitat ( Quercus havardii – Prosopis glandulosa ) of southeastern New Mexico. Short-horned grasshoppers, termites, antlions, beetles, and spiders formed the major portion of the diet during the four-year study. Discriminant analyses were used to evaluate annual, seasonal (monthly), and sexual variation. Incidental food categories were responsible for most of the annual and seasonal variation. Dominant foods varied little between months and years. Sexual variation was more evident; it may act to reduce intraspecific competition for food resources and may be associated with secondary sexual size dimorphism.         

Morphological and genetic variation among populations of the rare Kachina daisy ( Erigeron kachinensis ) from southeastern Utah

Erigeron kachinensis , the Kachina daisy, is a rare species restricted to canyons in southeastern Utah. The species is known to exhibit low fecundity due to low percent fertilization of ovules and high percent abortion of fertilized ovules. Previous reproductive studies suggest that low fecundity is a consequence of small population size and inbreeding depression. This study examines genetic diversity within and among populations of E. kachinensis in Natural Bridges National Monument using enzyme electrophoresis. Field populations are found to have significantly different morphologies. However, morphological differences were less pronounced among populations grown in the greenhouse. The Kachina daisy exhibits levels of genetic variability in its populations similar to that of other outcrossed species. Genetic diversity statistics demonstrate that only 22.8% of genetic variation is distributed among populations. Genetic distance could not be correlated with geographic distance. Most of the populations showed significant deviation of fixation indices from zero for multiple loci. Observation of genotype frequencies demonstrates that populations are fixing on different genotypes and may be experiencing initial stages of genetic drift. Mean observed heterozygosity was 0.166 and was found to increase with increasing size and/or age in populations.     

The pattern of esterase variation in the Mimulus glabratus complex (Scrophulariaceae)

Disc gel electrophoretic assays of Mimulus plants showed young stems to contain at least 15 esterase bands. The 6 bands in the center of the gels were highly reproducible. Eighty-one populations representative of all the cytotaxonomic groups and of the Western Hemisphere geographic range of the Mimulus glabratus complex were assayed for those 6 bands. There was no apparent correlation between the distribution of the esterase bands and important environmental parameters such as elevation and latitude. Hence, their distribution did not appear to reflect environmental adaptive values. Each population was monophonic for its particular combination and intensity of esterase bands which is consistent with our previous suggestion that genetic drift is a strong component of the evolutionary pattern of the complex.     

The effect of elevation on the distribution of sibling species in the Simulium arcticum complex (Diptera: Simuliidae)

At least 5 sibling species and an additional 11 cytotypes of the Simulium arcticum complex occur in Montana. Consequently, this speciose complex might allow study of environmental correlates with genetic differentiation. We used conventional methods of collection and cytogenetic analysis to study 1128 male larvae of the Simulium arcticum complex at 15 sites within 5 drainages in western Montana to test the hypothesis that distribution of siblings is associated with elevation. We sampled at the mouth, at the headwaters, and at an intermediate site to span the range of elevations within each drainage. We restricted our analyses to the most abundant taxa of the S. arcticum complex within our study area and observed a statistically significant presence of S. apricarium at low-elevation sites. Simulium arcticum IIL-18 appeared more frequently than expected at high elevation sites. Simulium brevicercum and S. arcticum sensu strictu appeared to be distributed randomly. We suggest potential causal reasons for these distributions including differential use of habitats along these elevational gradients.     

Life history variation in recently established populations of western mosquitofish ( Gambusia affinis )

We report life history characteristics for 4 recently established populations of western mosquitofish ( Gambusia affinis ). Mosquitofish from thermally stable habitats, Bonham and Garrett, were characterized by maturity at large sizes, high fat reserves, and large embryos. In contrast, females from a thermally unstable habitat, Wabuska, matured at small sizes and had low fat reserves and small embryos. Females from Parker, a site with no appreciable thermal input, matured at intermediate sizes and had low fat reserves as well as large embryos. These populations shared a common ancestor in 1937; therefore, these results suggest either phenotypic plasticity or rapid evolution.     

Chromosomal relationships among three species of jackrabbits ( Lepus : Leporidae) from Mexico

We studied differentially stained karyotypes of the leporids Lepus californicus, L. callotis, and L. flavigularis and described their banding patterns of euchromatin to decide whether results fit expectations of chromosomal rearrangements leading to the karyotypic evolution ancestral of the L. californicus--L. callotis--L. flavigularis lineage. Results confirmed previous findings on numbers of chromosomes (2 n 's) and fundamental numbers (FNs; except for L. californicus ). Homologous G-banding patterns allowed identification of chromosome rearrangements such as pericentric inversions and addition and deletion of euchromatin. Chromosomal rearrangements that we deduced mostly support hypotheses on karyotypic changes in the chromosomal evolution of the Lepus ancestral lineage that we examined. The karyotypic pattern coincides with patterns of geographic variation and distribution of the species examined.     

Effects of fragmentation on genetic variation in populations of the terrestrial earthworm Drawida japonica Michaelsen, 1892 (Oligochaeta,Moniligastridae) in Shandong and Liaodong peninsulas,China

Earthworms are excellent indicators of landscape fragmentation due to their widespread distribution and poor dispersal abilities over water. Based on field studies conducted in the Shandong and Liaodong peninsulas and their associated islands during summer 2009, we analysed the genetic variation of Drawida japonica Michaelsen, 1892 (Oligochaeta, Moniligastridae) using DNA sequences of the 16S and 28S ribosomal genes in samples obtained from 13 localities, 12 of which were islands, one artificially connected to the mainland by man (Yangma SC). We identified 55 haplotypes among 79 samples, based on 1094 bp, including 47 unique haplotypes. The phylogenetic tree topologies showed two distinct clades. A multiple-apex Poisson distribution using a mismatch analysis of nucleotides was also detected. Results of a Tajima D neutral test were not significant (p > 0.05). Genetic divergence among populations was much larger than within populations. A positive relationship between genetic diversity and island area was revealed, but no significant correlation between genetic diversity and distance to the nearest larger landmass was found. These results indicate that the intraspecific genetic diversity of D. japonica has been influenced by geographic isolation (i.e. island habitat). Passive transport via anthropogenic activities or nonhuman vertebrates (birds or mammals) may also play a key role in dispersal.     

Observations on the behaviour of the Cape girdled lizard Cordylus cordylus (Reptilia: Cordylidae)

Cape girdled lizards Cordylus cordylus are social and territorial. Behaviour observed in captivity revealed at least 24 distinct postures and displays. Thermoregulatory behaviour was the most frequent of all behaviours observed (66·7%). Of the social behaviours, aggression was observed most frequently (72·1%). Six behavioural postures are not known to have been described before. This species has no bright colours or contrasting markings to use in displays to conspecifics.     

Taxonomy and variation of the Lopidea nigridia complex of western North America (Heteroptera: Miridae, Orthotylinae)

External morphological variation in the Lopidea nigridia "complex" of western North America was examined using principal component analysis and showed continuous variation among populations in most characters. External morphology did not parallel paramere structure and did not substantiate previously recognized species. There was little correlation between dorsal coloration and paramere structure. Cluster analysis (UPGMA) using paramere and color characters failed to group populations coded as the same species and also failed to group all specimens of any one population. The variation in structure of the parameres and vesicae among populations of the nigridia complex was no greater than the interpopulational variation of these structures structures in the congeneric species marginata Uhler. Lopidea nigridia Uhler is treated as a polytypic species comprising three subspecies: Lopidea nigridia nigridia Uhler, a fuscous-white form from the sagebrush steppe of the Great Basin and the chaparral of southern California; Lopidea nigridia serica Knight, a solid red form from the eastern slopes of the Rocky Mountains from Alberta to Colorado and east across the Northern Great Plains to southern Manitoba; Lopidea nigridia aculeata Van Duzee, a polymorphic form varying from solid red to fuscous red and white from the Cascade Mountains and eastern slopes of the coastal ranges of British Columbia, Washington, and Oregon, the Blue and Wallawa mountains of Oregon and Washington, and throughout the Coastal and Sierra Nevada ranges of California. The following new synonymies are created: Lopidea nigridia Uhler -- Lopidea raineri Knight, Lopidea scullent Knight, Lopidea rolfsi Knight, and Lopidea wilcoxi Knight; Lopidea nigridia aculeata Van Duzee -- Lopidea nigridia hirta Van Duzee, Lopidea usingeri Van Duzee, Lopidea discreta Van Duzee, Lopidea fallax Knight, Lopidea Yakima Knight, Lopidea audeni Knight, Lopidea eriogoni Knight, Lopidea calcaria Knight, Lopidea chamberlini Knight, Lopidea angustata Knight, Lopidea rubrofusca Knight, and Lopidea flavicostata Knight and Schaffner; Lopidea nigridia serica Knight -- Lopidea medleri Akingbohungbe.     

Effects of islanding on the genetics of Niviventer confucianus (Mamalia: Rodentia: Muridae) populations in the Thousand Island Lake region

The impact of islanding on the genetics of the dominant species, Niviventer confucianus, was analysed using 13 microsatellite markers. All 16 populations are of high genetic diversity with a total of 134 alleles. The average number of effective alleles (Ne) is 6; the average expected heterozygosity (H_E) and polymorphic information content (PIC) are 0.823 and 0.763, respectively. Landscape fragmentation might contribute to weak genetic differentiation among 13 island populations. Values of F_ST simulated by Structure 2.3.4 implied that the 16 populations could be assigned into three clusters, from which we postulated the possible dispersion history. Pairwise F_ST tests showed that genetic differences mainly occurred between small island populations and others. Currently, habitat area appears to be the main factor affecting the genetics of Niviventer confucianus, and not the distances between islands. Hence we suggest that more attention should be paid to habitat area in the future.     

A new genus of Dicrocoeliidae (Digenea) from the lizard Gallotia atlantica (Sauria: Lacertidae) from the Canary Islands (Spain)

A helminthological investigation was carried out on the lacertid lizard, Gallotia atlantica (Peters and Doria, 1882) (Reptilia: Lacertidae) from Lanzarote, Canary Islands (Spain). One hundred and three digenean trematodes were found in the small intestine. Based on morphological and morphometric analysis of 35 specimens, it is concluded to be a new species which is here named Pseudoparadistomum yaizaensis gen. et sp. nov. referring to the locality where the hosts were caught. Pseudoparadistomum n.g. most closely resembles members of Paradistomum and Paradistomoidella, but is characterized by a V-shaped excretory vesicle, a spined tegument, and the position of the ovary relative to the testes.     

Records of the yellow-nosed cotton rat ( Sigmodon ochrognathus ) in southwestern New Mexico

The yellow-nosed cotton rat ( Sigmodon ochrognathus ) previously was known only from extreme southwestern New Mexico in the Peloncillo and Animas mountains. Here I document S. ochrognathus at 3 localities from the Big Burro and Mogollon mountains in southwestern New Mexico. My northernmost capture represents an extra-limital record of 160 km north of prior records in southern New Mexico and represents the northernmost occurrence in North America. Lack of intensive mammalian surveys in the region render it difficult to interpret my recent captures, but the most parsimonious explanation is that captures likely represent overlooked populations. I captured S. ochrognathus in grassy areas ungrazed by domestic livestock along the Gila River. Understanding the use of limited grassland habitats along arid rivers by terrestrial vertebrates in the region is important because many of these grasslands have been converted to agricultural lands or are grazed by livestock.     

Revision of the Phlox austromontana (Polemoniaceae) complex in Utah

The taxa centering around Phlox austromontana Coville are revised. Named as a new variety is P. austromontana var. lutescens Welsh from eastern Garfield County, Utah. A new combination is provided as P. austromontana var.  jonesii (Wherry) Welsh.          

The parasitoid complex attacking coexisting Spanish populations of Euphydryas aurinia and Euphydryas desfontainii (Lepidoptera: Nymphalidae,Melitaeini)

We report on a five‐year investigation of the complex of parasitoids associated with coexisting populations of Euphydryas aurinia and Euphydryas desfontainii at a Spanish site. A sample of over 7000 eggs, 1000 larvae and 200 pupae (the last of these in part having been experimentally placed) revealed the existence of no egg parasitoids, of three primary larval parasitoids and of five primary pupal parasitoids, plus 13 secondary and facultatively tertiary parasitoids associated with the cocoons of the main larval parasitoid, the specialist Cotesia sp. D. The most abundant secondary parasitoid, Neochrysocharis albiscapus, entirely escaped tertiary parasitism by being gregarious. The mortality induced by parasitoids on the butterfly populations, although heavy, was clearly partially minimized by secondary parasitoids acting on Cotesia sp. D. The striking coincidence of the parasitoid complexes attacking the two Euphydryas species suggests a good system for investigating apparent competition between hosts sharing common natural enemies.     

First records of parasitoidism by Sarcophagidae flies (Diptera) on three amphibian species in Mexico

ABSTRACT

Myiasis of amphibians is one example of parasitoidism in which the body of these vertebrates is infested by fly larvae. Only four families of Diptera have species reported as myiasigenous of amphibians: Chloropidae, Muscidae, Calliphoridae and Sarcophagidae. The latter is the only family for which cases of myiasis have been reported for the Neotropics, with observations from Nicaragua to Argentina. As part of a project to evaluate the conservation status of amphibian species in Mexico, five cases of myiasis were recorded in three frog species belonging to the families Hylidae, Ranidae and Craugastoridae. This study presents the first records of myiasis by a sarcophagid in Mexico, expands the geographical distribution of Lepidodexia (Notochaeta) bufonivora, reports new amphibian hosts for this parasitoid fly, and provides new details of both sarcophagid larvae and females.