Iterative evolution of Middle Jurassic ammonite faunas

The phenomenon of iterative evolution of homeomorphs in identical temporal sequences is exhibited by Aalenian and Bajocian ammonite faunas in the south German depositional basin. Within each evolutionary cycle, inflated, evolute, and ornamented shells with complex suture lines are successively replaced with discoidal, involute, smooth shells with simpler sutures. Three distinct and identical cycles of morphological change occur, and involve ammonites belonging to four different familial/subfamilial groups: the Leioceratinae, Graphoceratinae, Hammatoceratidae, and Sonniniidae. Geometric and statistical analyses of morphological change within each of these higher taxa reveal remarkable iteration in both the pattern and proportion of change with time. The iterative morphological cycles were not driven by orthogenesis or anagenetic transformation within lineages, as has been previously suggested. A clear correlation exists between the successive ammonite faunas and repeated cyclical changes in the physical marine environment of the depositional basin. D Ammonoidea, Aalenian, Bajocian, south Germany, iterative evolution.     

Four New Recent Genera of Foraminiferida

SYNOPSIS. Four new genera of Foraminiferida are described. Phlegeria , type species P. hyalina sp. nov. and Tomaculoides , type species T. lucidum sp. nov. belong to the family Glandulinidae, and both were obtained from the Gulf of Mexico. Francesita , type species Virgulina ? advena Cusbman is found in the North Atlantic and the Gulf of Mexico, and belongs to the Caucasinidae. Montfortella , type species M. bramlettei sp. nov. occurs in Pleistocene strata and is living on the coast of California, and belongs to the Cibicididae.     

Lotus Cell Walls and the Genes Involved in its Synthesis and Modification

The lotus genome (Nelumbo nucifera (Gaertn.)) lacks the paleo-triplication found in other eudicots and has evolved remarkably slowly with fewer nucleotide mutations. It is thought to have greater retention of duplicated genes than other angiosperms. We evaluated the potential genes involved in cell wall synthesis and its modification, and ethylene synthesis and response. In many cell wall transferases and hydrolases families, lotus had fewer members in most families when compared to Arabidopsis. Lotus had similar or fewer members in each family as found in poplar, grape and papaya. The exceptions were in the sialyl and beta-glucuronsyl transferases where similar number were found as in the core eudicots. Lotus had similar numbers of polygalacturonase and pectin methyl esterases as found in Arabidopsis but fewer in all other hydrolases families. For starch degradation, lotus had only two alpha amylases predicted genes versus eight to ten in other eudicots, with similar numbers of beta amylase genes predicted. Lotus also had less than half the number of genes predicted for the enzymes involved in lignin and tannin synthesis compared to Arabidopsis. The stress plant growth regulator ethylene’s synthesis, reception and response predicted genes were fewer in lotus than other eudicots. Only two ethylene receptor genes were predicted in lotus with five reported for Arabidopsis and six for tomato. Our analysis does not supports the conclusion that this species has greater retention of duplicated genes though our data does support the conclusion that lotus split occurred at the base of the eudicots.     

Spores of a New Microsporidan Species Parasitizing Molluscan Neurons

Synopsis.
A new species of Microsporida was observed in neurons of the marine mollusc Aplysia californica and the ultrastructure of its spores was investigated. The spores were ˜ 1.3 m long and had a thick 3-layered coat. An anchoring disc and polar aperture were present. The polaroplast occupied most of the anterior half of the spore. The vesicular portion included lengths of loosely packed lamellar structures as well as the usual vesicular profiles embedded in fibrillar material; it was entirely surrounded by tightly packed, electron-dense lamellae. The polar tube had 5 or 6 coils. In this stage of the life cycle (mature spores), the parasites did not appear to be disturbing the host cells. The organism was named Microsporidium aplysiae sp. n.     

Immunocontraception in Wild Horses: One Inoculation Provides Two Years of Infertility

ABSTRACT ABSTRACT Previous studies reported one year of contraception associated with a 1-injection porcine zona pellucida (PZP) vaccine. We have subsequently determined contraceptive effectiveness of a presumptive 1-injection, 2-year-duration PZP vaccine in free-roaming wild horses (Equus caballus) in Nevada, USA. In January 2000, we captured, freeze-branded, treated, and subsequently released 96 adult females that received 1) a primary dose of vaccine emulsion consisting of aqueous PZP and Freund's Complete Adjuvant, and 2) booster doses of PZP and adjuvant in controlled-release polymer pellets. We determined PZP release characteristics of pellets in vitro, prior to field use. We determined reproductive success in treated and untreated females through October 2004 via measurement of estrone sulfate and progesterone metabolites in fresh feces collected from the ground and by twice-annual foal counts. Among treated females, annual reproductive success from 2001 though 2004 sequentially was 5.9%, 14.0%, 32.0%, and 47.5%. Untreated females showed average reproductive success of 53.8 ± 1.3% across this period. This study revealed that: 1) PZP acted as an effective contraceptive for 2 years posttreatment; 2) some residual contraceptive effect remained in year 3; and 3) fertility returned to control levels by year 4 posttreatment. It appears that controlled-release technology can replace both the second(1-month) and annual booster injection of PZP vaccine, thereby decreasing cost and increasing efficiency of use of this vaccine in wild horse management.     

Identifying Hot Moments in Road-Mortality Risk for Freshwater Turtles

ABSTRACT Risk assessments can be used to identify threats, which vary both in space and time, to declining species. Just as hot spots describe locations where threat processes operate at a higher rate than in surrounding areas, hot moments refer to periods when threat rates are highest. However, the identification of hot moments can be challenging because the temporal complexity of some threat processes makes their effects on population viability difficult to predict. Declining throughout much of their range, Blanding's turtle (Emydoidea blandingii) populations are potentially most vulnerable to road mortality where road densities and traffic volumes are high. The temporal variations in road-mortality risk faced by these and other semiaquatic turtles at the population level are a consequence of several factors, including sex-specific movement characteristics and seasonal changes in traffic volume. We examined these risk factors for Blanding's turtle populations in Maine, USA, by integrating temporally explicit roadkill probabilities with demographic parameters informed by local and range-wide studies. Specifically, we used population simulations to estimate the relative risk for 14 2-week periods during the turtles’ active season. Our analysis clearly identified early summer as a period of elevated risk, with June through mid-July signaling a road-mortality hot moment for Blanding's turtles (for both M and F). These findings provide guidance for the implementation of temporally explicit conservation measures such as cautionary road signage, traffic management, and public outreach that, if timed strategically, could help to mitigate population impacts from road mortality.     

Habitat Value of Intensively Established Pine Plantations for Northern Bobwhite

ABSTRACT Declines in northern bobwhite (Colinus virginianus; bobwhite) populations in the southeastern United States may be partially attributable to loss of early successional plant cover associated with greater use of herbicides in forest management. We tested effects of 5 levels of operational plantation establishment intensity on vegetation communities and structure important for bobwhite in 1–5-year-old loblolly pine (Pinus taeda) plantations (n = 4) in the Outer Coastal Plain Mixed Forest of Mississippi. We compared results with values reported in the literature to calculate usable space for winter food, loafing, nesting, and brood-rearing at 2 levels of spatial resolution. Treatments (k = 5) reflected a range of management intensities and were combinations of mechanical site preparation, chemical site preparation (CSP), and herbaceous weed control (HWC). Coverage of winter food plants in the least intensive treatment was more than double that in the most intensive; however, differences in usable space of winter food cover were negligible due to improved accessibility in more intensive treatments. Although CSP reduced coverage of nonpine woody plants across all years, loafing cover reached adequate levels by year 3 in all treatments. Usable nesting cover was <4% across all years and treatments and was nearly eliminated by the reduction in herbaceous cover and visual screening cover following broadcast HWC. Optimal brood-rearing habitat was virtually absent in all treatments and years due to the lack of conjoint occurrence of bare ground and forb canopy. Although bobwhite habitat may have been promoted by formerly widespread plantation establishment methods that involved wide-scale soil disturbance, those established using newer methods with less soil disturbance are likely inadequate for most bobwhite habitat requirements. Efforts to provide bobwhite habitat in plantation-dominated landscapes may have to rely on management of thinned mid-rotation stands and permanent landscape features such as rights-of-way. The value of young plantations for bobwhite may be increased by reducing management intensity or increasing spacing between planting rows, thus increasing time before crown closure and providing opportunity for understory manipulations.