Geologic youth of galapagos islands confirmed by marine stratigraphy and paleontology

Six distinctive types of fossiliferous marine deposits occur on the Galádpagos Islands that provide evidence for the age of emergence of the islands above sea level and hence a maximum age for the islands' terrestrial biota. These subtidal to supratidal deposits include (i) volcanic tuffs with fossils, (ii) limestones and sandstones interbedded with basalt, (iii) terrace deposits, (iv) beach rock, (v) supratidal talus deposits, and (vi) recently uplifted tidal and subtidal rocks and sand. With the exception of (vi), the deposits were previously assigned ages varying from Miocene to Pleistocene, but all are less than about 2 million years old. This age, together with independently determined geologic ages, indicate that the islands emerged from the sea relatively recently and that all evolution of the islands' unique terrestrial biota occurred within the past 3 to 4 million years.     

Experimental rearing of juvenile New Zealand turbot Colistium nudipinnis (Waite 1910): a potential new aquaculture species

Investigations into factors affecting the growth of the first hatchery-produced juvenile New Zealand turbot Colistium nudipinnis (Waite 1910) showed that this endemic flatfish can be reared in raceways and tanks. After initial high mortality (> 60%) in the post-weaning period (to 120 days post-hatch), the juveniles showed high survival over the grow-out period. Growth of the juveniles was better at lower (16–18 °C) than at higher (> 20 °C) water temperatures, and better in a deep tank than in shallow raceways. Under the experimental rearing conditions, growth (to mean weight of 0.2 kg in 20 months) was relatively slow and food conversion (FCRs > 1.4) relatively high, both factors being related to the feeding behaviour of this species. C. nudipinnis feeds directly from the bottom, and this behavioural characteristic influences aspects of fish farming practice, such as stocking density and feeding strategy, that are critical to its economic viability. There is potential to improve the growth by optimizing the rearing conditions, so that it may not be unrealistic to achieve the maximum growth reached in these trials commercially and produce marketable farmed turbot, of over 400 g weight, within 2 years.     

Pollination by ants: a low-energy system

Polygonum cascadense, a small, apparently self-incompatible, annual plant, is regularly cross-pollinated by the ant Formica argentea. Comparison of other purported ant-pollinated plants with traits favoring such pollination suggests that some, but not all, may be ant pollinated. Ant-pollination interactions are characterized by low expenditure of energy by both ant and plant.     

Combining Glyphosate With Burning or Mowing Improves Control of Yellow Bluestem (Bothriochloa ischaemum)

The invasive yellow bluestem (Bothriochloa ischaemum [L.] Keng) threatens native biodiversity, and its control is of interest to land managers involved in restoration of invaded grasslands. We used single, double, and triple applications of glyphosate (2.125 kg ai · ha^?1 · application^?1) over the course of one growing season in combinations at different timings (early, middle, late season) with and without a mechanical treatment of mowing or burning to determine the most effective control method. One year after treatment, burning and mowing prior to a mid-season single or double early, middle, and/or late season herbicide application resulted in a similar level of control of yellow bluestem relative to a triple herbicide application, all of which had greater control relative to herbicide treatment alone. Reproductive tiller density and visual obstruction increased 2 yr after treatment with two herbicide treatments applied either early and middle season or early and late season, but it was prevented with burning and mowing prior to herbicide application. With the exception of three herbicide applications, combining burning or mowing with herbicide applications provided more effective control of yellow bluestem than any individual herbicide applications. Burning or mowing likely improves glyphosate effectiveness by altering the invasive grass structure so that plants are clear of standing dead and have shorter, active regrowth to enhance herbicide effectiveness. During restoration projects requiring control of invasive yellow bluestem, an effective management option is a combination of mechanical and chemical control.     

Effect of ovine granulocyte-macrophage colony-stimulating factor on bovine in vitro embryo development and blastocyst interferon-τ secretion

This experiment examined the effects of including recombinant ovine granulocyte-macrophage colony-stimulating factor (GMCSF) in in vitro culture on secretion of interferon-τ (IFNT) by bovine blastocysts. At 32 h post-insemination (p.i.), cleaved bovine zygotes were selected and incubated with or without GMCSF for either 48 h only (between 32 and 80 h p.i., Early) or until day 9 p.i. (Throughout). Concentrations of GMCSF (ng/ml) examined were as follows: Experiment 1: 2, 5, 10 and 50 (Early only); Experiment 2: 50 (Early and Throughout); Experiment 3: 2 and 10 (Early and Throughout). In none of the experiments did GMCSF have an effect (p > 0.05) on the numbers of blastocysts formed or blastocyst characteristics as assessed by cell number, proportion of apoptotic cells or oxidation of pyruvate. When GMCSF was included in culture medium between 32 and 80 h p.i. (Early), IFNT concentrations were lower (in media drops recovered after culture of groups of embryos for 48 h between days 7 and 9 p.i. and normalized by the numbers of blastocysts developing within each drop) compared to no inclusion of GMCSF or GMCSF present Throughout culture (Experiment 2, p > 0.05; Experiment 3, p = 0.038). IFNT was present in media drops in which groups of embryos had been incubated between days 7 and 9 p.i. but in which no blastocysts had developed. Experimental treatment did not influence (p > 0.05) IFNT secretion by blastocysts incubated individually for 24 h. However, during the 24-h individual culture, blastocysts recovered on day 7 secreted less IFNT than blastocysts recovered on day 8 (mean ± SE; 15 ± 1.3 v 30 ± 3.6 pg/ml; p < 0.001). In conclusion, in contrast to previous studies in the ovine, GMCSF did not increase IFNT secretion but in agreement with the ovine did not affect bovine blastocyst development.