Genetic and physiological parameters associated with cadmium toxicity in Drosophila melanogaster

Two strains of Drosophila melanogaster represent the extremes in resistance and sensitivity to the lethal effects of CdCl₂. The strain containing the mutations vermilion and brown (v; bw) and the strain Austin had LC₅₀'s of 3.3 and 1.3mm CdCl₂, respectively. The three major chromosomes from these two strains were assorted genetically into the six possible combinations. The measured LC₅₀'s for CdCl₂ for these six genotypes fell into two groups according to the X chromosome; those containing the X chromosome from v; bw had LC₅₀'s 0.5–1.0mm greater than those in which the X chromosome was from Austin. Since the parent strains differed by 2mm, we suggest that the X chromosome is a major, but not the sole, site of genes to produce resistance to CdCl₂. When ¹⁰⁹Cd was in the diet the uptake by v; bw and Austin over 2 days was the same. After 4 days of uptake, the Austin strain excreted the ¹⁰⁹Cd five times faster than v; bw but the six genotypes did not differ appreciably in excretion rate from one another and resembled the sensitive parent Austin more than the resistant one. Thus a second process is indicated that distinguishes resistance to CdCl₂ that apparently is not associated with the X chromosome.This research was sponsored by the Office of Health and Environmental Research, U.S. Department of Energy, under Contract DE-AC05-84OR21400 with Martin Marietta Energy Systems, Inc.     

A New Ichnospecies of Gyrolithes from the Austin Chalk,Upper Cretaceous,Texas, USA

Gyrolithes, a helical marine trace fossil, occurs in beds of the Austin Chalk near Waco, McLennan County, Texas. The new ichnospecies Gyrolithes texanus is characterized by unique morphology and wall construction. This discovery expands the current geographic and environmental range of Gyrolithes, extending this ichnogenus into the chalk-dominated beds of the Cretaceous of Texas. Irregular bedding features from the Gyrolithes locality indicate this section of the Austin Chalk was deposited within a storm-dominated depositional regime, interspersed with periods of quiescence which allow for firm ground formation and colonization by the trace maker. Occurrences of Gyrolithes have been associated by previous publications with marginal marine settings but not associated with storm deposits; therefore, this discovery constitutes an expansion of associated environment for this ichnogenus.     

Evaluation of Spanish Arundo scale Rhizaspidiotus donacis (Hemiptera; Diaspididae) survival and fecundity on three new world genotypes of Arundo donax (Poaceae; Arundinoideae)

A pre-release evaluation of survival and fecundity of the arundo scale, Rhizaspidiotus donacis, was conducted on three invasive genotypes of the riparian weed, Arundo donax. The three A. donax genotypes were collected from Laredo, Austin and Balmorhea, TX, which represented the majority of the genotypic diversity found in Texas watersheds. Although R. donacis developed on all three genotypes of the plant, the Austin A. donax genotype, followed by the Laredo genotype, were the most suitable in terms of the size of first-generation immature and adult scale populations that developed after crawler release. Both the Laredo and Austin genotypes of A. donax are likely to be of Spanish origin and are close genetic matches with scale's original host plant genotype in Alicante, Spain. In comparison, survival was lowest on the phylogenetically distant genotype of A. donax from Balmorhea, TX. Although the population size of settled, immature second-generation scales varied in a manner similar to that of the first generation, the fecundity of isolated first-generation females was not significantly different across the three plant genotypes, suggesting that R. donacis is not a genotype specialist in terms of nutrient assimilation for reproduction. Rather, differences in genotype suitability affect rates of success of crawler settling. These results indicate that selection of scale genotype from the native range may have a moderate influence on the success of R. donacis and ultimately the biological control programme.     

Resource Partitioning among Parasitoids (Hymenoptera: Braconidae) of Phoracantha semipunctata in Their Native Range

The Eucalyptus longhorned borer, Phoracantha semipunctata (F.), is native to Australia, but it has been introduced without its natural enemies into many parts of the world in which its Eucalyptus spp. host has been planted. The beetle has developed large populations in these novel habitats and has been responsible for the mortality of large numbers of trees. Although there is a considerable catalogue of the parasitoids of the beetle in Australia, limited ecological information on the assemblage of parasitoids attacking P. semipunctata is available. We removed bark from 40 felled trees, recorded gallery width and bark thickness over parasitized larvae, and removed all parasitoids. Adult size, sex, and species were recorded when the parasitoid pupae eclosed. Syngaster lepidus Brullè, Jarra phoracantha Austin, Quicke, and Marsh, J. maculipennis Austin, Quicke, and Marsh, and J. painei Austin and Dangerfield were most commonly collected. The solitary parasitoid S. lepidus preferred smaller larvae than did the gregarious Jarra spp. The two species with shorter ovipositors, J. maculipennis and J. painei, parasitized larvae under thinner bark than did the other two species with longer ovipositors. There was a significant positive correlation between host larval size and number of parasitoid pupae of the gregarious species. Also, there was a significant positive correlation between host larval size and parasitoid adult size. The ecological relationships between this assemblage of parasitoids and their beetle host may be useful in establishing an effective biological control program.     

PALMELLOPSIS MURALIS SP. NOV. (CHLOROPHYCEAE,TETRASPORALES, PALMELLACEAE)1

A new member of the chlorophycean, tetrasporalean genus Palmellopsis Korschikov (1953), Palmellopsis muralis Bold and King, is described from limestone in Austin, Texas, U.S.A. Certain details of ultrastructural organization are included.     

Review article

Deciphering the Maya Script. David Humiston Kelley. University of Texas Press, Austin, Texas. 1976. xvii + 334 pp. £19.25.     

THE COPRINOID STATE OF RHACOPHYLLUS LILACINUS

Rhacophyllus lilacinus was obtained in moist chamber from bark collected in Austin, Texas. A perfect state of an undescribed fungus, Coprinus clastophyllus sp. nov., developed in laboratory culture from R. lilacinus. Some morphologic, cultural, cytologic and genetic features of both states are discussed and illustrated.     

Systematics of Old World Odontacolus Kieffer s.l. (Hymenoptera,Platygastridae s.l.): parasitoids?of?spider?eggs

The genera Odontacolus Kieffer and Cyphacolus Priesner are among the most distinctive platygastroid wasps because of their laterally compressed metasomal horn; however, their generic status has remained unclear. We present a morphological phylogenetic analysis comprising all 38 Old World and four Neotropical Odontacolus species and 13 Cyphacolus species, which demonstrates that the latter is monophyletic but nested within a somewhat poorly resolved Odontacolus. Based on these results Cyphacolus syn. n. is placed as a junior synonym of Odontacolus which is here redefined. The taxonomy of Old World Odontacolus s.str. is revised; the previously known species Odontacolus longiceps Kieffer (Seychelles), Odontacolus markadicus Veenakumari (India), Odontacolus spinosus (Dodd) (Australia) and Odontacolus hackeri (Dodd) (Australia) are re-described, and 32 new species are described: Odontacolus africanus Valerio & Austin sp. n. (Congo, Guinea, Kenya, Madagascar, Mozambique, South Africa, Uganda, Zimbabwe), Odontacolus aldrovandii Valerio & Austin sp. n. (Nepal), Odontacolus anningae Valerio & Austin sp. n. (Cameroon), Odontacolus australiensis Valerio & Austin sp. n. (Australia), Odontacolus baeri Valerio & Austin sp. n. (Australia), Odontacolus berryae Valerio & Austin sp. n. (Australia, New Zealand, Norfolk Island), Odontacolus bosei Valerio & Austin sp. n. (India, Malaysia, Sri Lanka), Odontacolus cardaleae Valerio & Austin sp. n. (Australia), Odontacolus darwini Valerio & Austin sp. n. (Thailand), Odontacolus dayi Valerio & Austin sp. n. (Indonesia), Odontacolus gallowayi Valerio & Austin sp. n. (Australia), Odontacolus gentingensis Valerio & Austin sp. n. (Malaysia), Odontacolus guineensis Valerio & Austin sp. n. (Guinea), Odontacolus harveyi Valerio & Austin sp. n. (Australia), Odontacolus heratyi Valerio & Austin sp. n. (Fiji), Odontacolus heydoni Valerio & Austin sp. n. (Malaysia, Thailand), Odontacolus irwini Valerio & Austin sp. n. (Fiji), Odontacolus jacksonae Valerio & Austin sp. n. (Cameroon, Guinea, Madagascar), Odontacolus kiau Valerio & Austin sp. n. (Papua New Guinea), Odontacolus lamarcki Valerio & Austin sp. n. (Thailand), Odontacolus madagascarensis Valerio & Austin sp. n. (Madagascar), Odontacolus mayri Valerio & Austin sp. n. (Indonesia, Thailand), Odontacolus mot Valerio & Austin sp. n. (India), Odontacolus noyesi Valerio & Austin sp. n. (India, Indonesia), Odontacolus pintoi Valerio & Austin sp. n. (Australia, New Zealand, Norfolk Island), Odontacolus schlingeri Valerio & Austin sp. n. (Fiji), Odontacolus sharkeyi Valerio & Austin sp. n. (Thailand), Odontacolus veroae Valerio & Austin sp. n. (Fiji), Odontacolus wallacei Valerio & Austin sp. n. (Australia, Indonesia, Malawi, Papua New Guinea), Odontacolus whitfieldi Valerio & Austin sp. n. (China, India, Indonesia, Sulawesi, Malaysia, Thailand, Vietnam), Odontacolus zborowskii Valerio & Austin sp. n. (Australia), and Odontacolus zimi Valerio & Austin sp. n. (Madagascar). In addition, all species of Cyphacolus are here transferred to Odontacolus: Odontacolus asheri (Valerio, Masner & Austin) comb. n. (Sri Lanka), Odontacolus axfordi (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus bhowaliensis (Mani & Mukerjee) comb. n. (India), Odontacolus bouceki (Austin & Iqbal) comb. n. (Australia), Odontacolus copelandi (Valerio, Masner & Austin) comb. n. (Kenya, Nigeria, Zimbabwe, Thailand), Odontacolus diazae (Valerio, Masner & Austin) comb. n. (Kenya), Odontacolus harteni (Valerio, Masner & Austin) comb. n. (Yemen, Ivory Coast, Paskistan), Odontacolus jenningsi (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus leblanci (Valerio, Masner & Austin) comb. n. (Guinea), Odontacolus lucianae (Valerio, Masner & Austin) comb. n. (Ivory Coast, Madagascar, South Africa, Swaziland, Zimbabwe), Odontacolus normani (Valerio, Masner & Austin) comb. n. (India, United Arab Emirates), Odontacolus sallyae (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus tessae (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus tullyae (Valerio, Masner & Austin) comb. n. (Australia), Odontacolus veniprivus (Priesner) comb. n. (Egypt), and Odontacolus watshami (Valerio, Masner & Austin) comb. n. (Africa, Madagascar). Two species of Odontacolus are transferred to the genus Idris Förster: Idris longispinosus (Girault) comb. n. and Idris amoenus (Kononova) comb. n., and Odontacolus doddi Austin syn. n. is placed as a junior synonym of Odontacolus spinosus (Dodd). Odontacolus markadicus, previously only known from India, is here recorded from Brunei, Malaysia, Sri Lanka, Thailand and Vietnam. The relationships, distribution and biology of Odontacolus are discussed, and a key is provided to identify all species.     

Congo's elusive treasure

A review of The Okapi: Mysterious Animal of Congo‐Zaire, by Susan Lyndaker Lindsey, Mary Neel Green, and Cynthia L. Bennett. Austin, University of Texas Press, 1999, 131 pp, $30.00 hardcover, $17.95 paperback.     

HYBRIDIZATION AND INTROGRESSION IN THE GRASS GENUS ELYMUS

Brown , W. V., and G. A. Pratt . (U. Texas, Austin.) Hybridization and introgression in the grass genus Elymus. Amer. Jour. Bot. 47 (8) : 669–676. Illus. 1960.—The production of artificial F₁ hybrids that produce some seed between E. virginicus and E. canadensis, E. virginicus and E. interruptus, and E. canadensis and E. interruptus proves that similar plants found in nature are true hybrids. The artificial hybrids constituted the basis of comparison in an analysis of natural local populations in the Austin region. Analysis by scatter diagrams indicates that there is introgression of genes of some species into the genomes of others through the development of hybrid swarms. In the area studied the great variability of virginicus is due to the introgression of canadensis and, possibly, interruptus genes. Such hybridization and subsequent introgression have occurred many times and in many places and are still taking place. It is likely that the named varieties of canadensis and virginicus may be introgressant types that are the results of hybridizations between those species and others that occur sympatrically in Eastern United States.     

The international legal regime for navigation

Thomas A. Clingan. The Law of the Sea: Ocean Law and Policy. 1994. San Francisco: Austin and Winfield. 638 pp. ISBN 1–880921–37–5 (hardcover), $89.95. ISBN 1–880921–28–6 (softcover), $69.95     

COMPARATIVE PHYSIOLOGY AND BIOCHEMISTRY AND TAXONOMIC ASSIGNMENT OF THE CHLORELLA (CHLOROPHYCEAE) STRAINS OF THE CULTURE COLLECTION OF THE UNIVERSITY OF TEXAS AT AUSTIN1

The species of the genus Chlorella exhibit considerable biochemical and physiological differences. Therefore, it is important to select for and utilize in research or biotechnology correctly identified strains of the species having the most favorable properties for the respective project. We examined the Chlorella strains of the University of Texas collection at Austin, Texas, according to species-specific chemotaxonomic characters and assigned 58 strains to 10 well-established species (only 17 of these strains were correctly named before).     

Asiaontsira gen. nov., a new tropical genus of the subfamily Doryctinae (Hymenoptera: Braconidae) from Vietnam and South‐East China

A new genus, Asiaontsira gen. nov., and two new species, A. cucphuongi sp. nov. (type species) and A. cantonica sp. nov., are described from tropical and subtropical areas of South‐East China and North Vietnam. This genus is compared to the closely related Australian Ontsirospathius Belokobylskij, Iqbal and Austin, 2004 as well as the similar and almost cosmopolitan genus Ontsira Cameron, 1900. A key to both species of Asiaontsira gen. nov. is provided.     

NATURE OF THE PLANT COMMUNITY. VI. TEXAS GRASSLAND COMMUNITIES UNDER TRANSPLANTED CONDITIONS

Mc Millan , Calvin . (U. Texas, Austin.) Nature of the plant community. VI. Texas grassland communities under transplanted conditions. Amer. Jour. Bot. 48(9): 778–785. Illus. 1961.—Clones of 7 grass taxa, Bouteloua gracilis (H. B. K.) Lag., B. eriopoda (Torr.) Torr., B. curtipendula (Michx.) Torr., Panicum virgatum L., the Andropogon scoparius Michx. complex, the Andropogon gerardi Vitman-hallii Hack. complex, and Sorghastrum nutans (L.) Nash, were transplanted from throughout their distribution in Texas and studied in an experimental garden at Austin. Restricted to western Texas and Panhandle areas, Bouteloua gracilis and B. eriopoda contained similar early-flowering clones throughout their distribution. Less restricted to western sites, B. curtipendula contained later-flowering types from eastern and central areas. In the 4 remaining, widespread taxa, early-flowering potential characterized clones from western sites. These 4 widespread taxa contain the latest-flowering clones from the coast of southern Texas. Clones of Stipa leucotricha Trin. and Rupr. from a broad area in Texas lacked a flowering gradient. Grassland communities of western Texas and the Panhandle, attuned to short growing seasons and low rainfall, were composed of opportunists, the Bouteloua species, and early-flowering variants within the widespread species. Communities of central Texas in habitats of highly unpredictable moisture pattern and a relatively long growing season contained later-flowering variants. Coastal communities attuned to a long growing season contained the latest-flowering variants.     

Influence of host behavior and host size on the success of oviposition ofCotesia urabae andDolichogenidea eucalypti (Hymenoptera: Braconidae)

Behavioral interactions among Cotesia urabaeAustin and Allen, Dolichogenidea eucalyptiAustin and Allen (Hymenoptera: Braconidae), and their host Uraba lugensWalker, the gum leaf skeletonizer (Lepidoptera: Noctuidae), were observed at three host sizes over a 20-min period. These sizes were first instar (small, gregarious), fourth-fifth instar (mid, gregarious), sixth-seventh instar (large, solitary) larvae. Unlike C. urabae, D. eucalyptiused its legs to hold small larvae before ovipositor insertion. D. eucalyptialso visited patches of small larvae more frequently, proceeded less often through patches of mid larvae, and made significantly fewer ovipositions in mid and large larvae. Small larvae responded to both parasitoids by dispersing outward, while mid larvae responded to parasitoids by moving inward to form a denser group. Larvae reared or thrashed after each parasitoid visit, especially mid larvae, and some continued to do so for up to 2h after parasitoid departure. Mid and large larvae occasionally injured parasitoids by biting their appendages. By rearing or thrashing immediately prior to an encounter with a parasitoid, mid and large larvae decreased the likelihood of being parasitized by up to 50%.     

Primary Productivity and Water Balance of Grassland Vegetation on Three Soils in a Continuous CO2 Gradient: Initial Results from the Lysimeter CO2 Gradient Experiment

Field studies of atmospheric CO₂ effects on ecosystems usually include few levels of CO₂ and a single soil type, making it difficult to ascertain the shape of responses to increasing CO₂ or to generalize across soil types. The Lysimeter CO₂ Gradient (LYCOG) chambers were constructed to maintain a linear gradient of atmospheric CO₂ (~250 to 500 μl l⁻¹) on grassland vegetation established on intact soil monoliths from three soil series. The chambers maintained a linear daytime CO₂ gradient from 263 μl l⁻¹ at the subambient end of the gradient to 502 μl l⁻¹ at the superambient end, as well as a linear nighttime CO₂ gradient. Temperature variation within the chambers affected aboveground biomass and evapotranspiration, but the effects of temperature were small compared to the expected effects of CO₂. Aboveground biomass on Austin soils was 40% less than on Bastrop and Houston soils. Biomass differences between soils resulted from variation in biomass of Sorghastrum nutans, Bouteloua curtipendula, Schizachyrium scoparium (C₄ grasses), and Solidago canadensis (C₃ forb), suggesting the CO₂ sensitivity of these species may differ among soils. Evapotranspiration did not differ among the soils, but the CO₂ sensitivity of leaf-level photosynthesis and water use efficiency in S. canadensis was greater on Houston and Bastrop than on Austin soils, whereas the CO₂ sensitivity of soil CO₂ efflux was greater on Bastrop soils than on Austin or Houston soils. The effects of soil type on CO₂ sensitivity may be smaller for some processes that are tightly coupled to microclimate. LYCOG is useful for discerning the effects of soil type on the CO₂ sensitivity of ecosystem function in grasslands. Author Contributions: PF conceived study, analyzed data, and wrote the paper. AK, AP analyzed data. DH, VJ, RJ, HJ, and WP conceived study, and conducted research.     

Diagonal walking in captive infant vervet monkeys

The frequency of use of diagonal walking by three motorically immature vervet monkeys (Cercopithecus aethiops) is discussed. The subjects were housed at The Balcones Research Center (Austin, Texas) and ranged from 15–105 days of age. Mixed longitudinal data taken from film indicated that lateral walknig was the first gait employed by the infant vervets studied, but that diagonal walking completely replaced lateral walking by 81 days of age. These data were compared with those of captive infant Macaca mulatta, and feral infant Papio anubis. General agreement was found regarding onset and frequency of use of diagonal walking in the three genera.     

Relative contribution of exotoxin and micropredation to icthyotoxicity of two strains of Pfiesteria shumwayae (Dinophyceae)

The mechanism by which Pfiesteria shumwayae (Glasgow and Burkholder) kills fish is controversial. Several studies have implicated a Pfiesteria-associated exotoxin in fish mortality while other studies indicate that physical attack of dinoflagellates on fish (micropredation) and not exotoxin is responsible. We examined the ichthyotoxicity of two strains of P. shumwayae (CAAE 101272 and CCMP 2089) in a bioassay system that exposed test fish to the dinoflagellates both with and without direct contact in the same aquarium at the same time. Dinoflagellate-free supernatants from both strains were also tested for toxicity. The results showed that direct contact between P. shumwayae and fish significantly enhanced fish mortality with both strains (P < 0.001). About 87.5% and 100% of fish died when exposed directly to CAAE 101272 and CCMP 2089, respectively. When protected from direct contact with Pfiesteria cells, 19% of the fish exposed to CAAE 101272 and 6% of those exposed to CCMP 2089 died. No deaths were observed in controls. Supernatant killed fish when obtained from cultures of CAAE 101272 but not when obtained from CCMP 2089.Analysis of variance showed that, for both strains, fish mortality in Pfiesteria-inoculated bioassays was significantly higher than control bioassays both with and without direct contact (P < 0.001). Differences between strains were not significant (P = 0.3). These results indicate that both strains are associated with exotoxin production. However, the dominant and most consistent mechanism of fish mortality observed in this study required physical contact between fish and Pfiesteria cells.     

SOME INTERESTING RHODESIAN RECORDS—IV

Austin, G. T. 1979. Pattern and timing of moult in penduline tits (Anthoscopus). Ostrich 49:168-173.

Moult was examined in species of Anthoscopus. Second and subsequent prebasic moults were complete. Primary and rectrix moult was typical of passerines, but secondary moult was some what irregular. Moult was largely non-overlapping with breeding, although some body moult was noted during the breeding season. In southern Africa there was some regional variation in timing of moult. First year birds moulted after adults had largely completed feather replacement. This first prebasic moult was incomplete.     

Biometric relationships between body and otolith measurements in nine demersal fishes from north‐eastern Tasmanian waters,Australia

Relationships between fish and otolith measurements were analyzed in nine demersal fishes from the north‐eastern Tasmanian waters: Foetorepus calauropomus, Trachurus declivis, Parequula melbournensis, Neosebastes scorpaenoides, Platycephalus aurimaculatus, Platycephalus bassensis, Platycephalus conatus, Lepidotrigla mulhalli and Lepidotrigla vanessa. The values of exponent b from the relationships between fish weight and fish total length, total length and otolith length, total length and otolith width, and fish weight and otolith length were estimated. All above relationships were statistically significant. The analysis of covariance (ANCOVA) was used to test the effect of the categorical factor of species in the fish length and otolith length relationship. Significant differences in fish length and otolith length relationship between species were highlighted in both gurnards and flatheads. Results from this study will provide novel information on quantitative biometric relationships between body and otolith measurements of fish species in Australian waters.