The habitat value of Gorse Ulex europaeus L. and Hawthorn Crataegus monogyna Jacq. for birds in Quarry Hills Bushland Park, Victoria

Weeds are one of the primary threats to biodiversity; however, their impacts on wildlife can vary. This research investigated the habitat value of Gorse <i>Ulex europaeus i>L. and Hawthorn <i>Crataegus monogyna i>Jacq. and the impacts of its removal on birds in a bushland park in Victoria. The area search method was used to survey birds in vegetation dominated by these two weeds, in native vegetation and in areas where a weed removal program was undertaken; this included revegetated areas. The highest bird species richness and abundance was found in sites dominated by the weeds. At sites where the weed removal program was in the early stages, a much lower species richness and abundance occurred. The final stage of the weed removal program, where revegetated areas were older than five years, supported high richness and abundance of birds, but not as high as that of sites dominated by the weeds; nor was the composition the same. Thus, even after five years, revegetation may not provide for the bird community that was originally supported by weeds. This is an important weed management consideration in this park, and should be for weed removal projects elsewhere

Crystal structure of (4-bromonaphthalen-2-yl) acetonitrile, C12H8BrN

C_I2H₈BrN, monoclinic, <i>Pi>l2₁/<i>ci>l (No. 14), <i>ai> = 7.555(6) &Aring;, <i>bi> =7.727(3) &Aring;, <i>c i>=16.643(2) &Aring;, β =98.95(2)°, <i>Vi> =959.8 &Aring;³ , Z =4, R_<i>gti>(<i>Fi>) =0.033, wRref(F²) =0.097, <i>Ti> =173 K.

Some morphometric and biochemical features of ready-to-migrate silver and pre-migratory yellow stages of the shortfin eel of south-eastern Australian waters

The mean total length (<i>L</i>_T), mass and age of ready to migrate female silver shortfin eels <i>Anguilla australisi> from the Hopkins River estuary and the mouth of the Merri River in south-eastern Australia, were 83&middot;2 &plusmn; 1&middot;2 cm, 1051 &plusmn; 51 g, and 17&middot;2 &plusmn; 1&middot;79 years, respectively. The eye index (<i>I</i>_E) of the silver shortfin eels was &lt; 5&middot;2 (mean 7&middot;64 &plusmn; 0&middot;29) and differed significantly from that of the yellow shortfin eels collected from two other sites. The <i>I</i>_E increased with <i>L</i>_T (mm) and was related by log <i>I</i>_E= 2&middot;656 log <i>L</i>_T6&middot;925. The per cent moisture, protein and ash content of the liver of silver shortfin eels was significantly lower than in yellow shortfin eels, but lipid content was significantly higher in the former (35&middot;5 &plusmn; 2&middot;0%). The mean mass μg mg lipid &oline;) of saturates (230&middot;4 &plusmn; 2&middot;6 v. 181&middot;7 &plusmn;2&middot;6), monoenes (367&middot;4 &plusmn; 6&middot;3 v. 290&middot;8 &plusmn; 8&middot;9) and PUFA (177&middot;3 &plusmn; 5&middot;3 v. 159&middot;7 &plusmn; 4&middot;6) in muscle was significantly higher, and the great majority of individual fatty acids was found also in higher quantities in silver shortfin eels. In the liver, the PUFA found in the highest quantity was 22:6n-3, except in shortfin eels from Hopkins River estuary, and the amount of 18:2n-6 in the liver of silver shortfin eels was significantly higher than that in yellow shortfin eels but the reverse was true of 20:4n-6. In both muscle and liver tissues the saturate 16:0 and the monoene 18:ln-9 collectively accounted for >50% of all the fatty acids in the lipid.

Spawning season, fecundity and proximate composition of the gonads of wild-caught blacklip abalone (Haliotis rubra) from Port Fairy waters, south eastern Australia

This study was based on wild-caught blacklip abalone <i>Haliotis rubrai> L., from Port Fairy waters, south eastern Australia (142°15&prime;E; 38°21&prime;S), from July  1998 to November 1999, and was initiated to evaluate the spawning season and other aspects of its reproductive biology. The shell length and body weight of female and male abalone sampled ranged from 12.0 to 18.6 and 12 to 15 cm, and 137 to 529 and 148 to 585 g, respectively. The sex ratio did not vary significantly from 1:1 through the year. The gonadosomatic index (GSI) ranged from 3.0% to 8.4% in males, and 2.5% to 14.1% for females, and the highest GSI as well as the highest proportion of mature animals were recorded from September to October. During these months the hepatosomatic index (HSI) was low, and an inverse correlation between GSI and HSI (<i>Pi> &lt; 0.05) was evident. Fecundity of blacklip abalone ranged from 1.09 to 7.5 million eggs for females of 12–14.5 cm in length, and 115–487 g in total body weight, respectively. The lipid content of the female gonad increased significantly from about July to November, and an opposite trend was observed for lipid content of the digestive gland. Seasonal changes in the protein and ash contents of the gonad and/or the digestive gland were not always significant.

Description of loxocythere (novoloxocythere) pelius subgen. sp. nov. (ostracoda) from the cenozoic of S.E. Australia with comments on species of antarctiloxoconcha hartmann, 1986 and loxoreticulatum benson, 1964 from Australian and Antarctic marine waters

<i>Loxocythere (Novoloxocythere) peliusi> subgen. et sp. nov. is described from Upper Miocene strata of the Port Phillip and Western Port Basins. Victoria. It has its acme in shallow open marine facies of latest Miocene (Cheltenhamian) age. This species, along with <i>Loxocytherei>le="font-style: italic;"> <i>(Novoloxocythere) kerryswansoni</i> Yassini and Jones, 1995, forms a discrete group of rotund Australian <i>Loxocytherei> species that possess posterior extremities in both valves that are positioned well above mid carapace height (i.e. adjacent to dorsal margin). This feature along with a sub-triangular inner margin outline, defines a carapace shape that is distinct from that of rotund species of <i>Loxocythere (loxocythere)i> Hornibrook, 1952 andle="font-style: italic;"> <i>Antarctiloxoconchai> Hartmann, 1986. The type species of <i>Antarctiloxoconcha – A.frigidai> (Neale. 1967), possesses internal carapace features that are very similar to the type species of <i>Loxocythere - L. crassai> Hornibrook, 1952. Both have relatively short carapaces and sub-quadrate inner margin outlines with posterior extremities in both valves positioned below mid carapace height. Species of <i>Loxocythere (Novoloxocythere)i>, in particular <i>L. (N.) kerryswansoni</i>, have a carapace shape that is transitional betweenle="font-style: italic;"> <i>Loxocytherei> and <i>Loxoreticulatumi> Benson, 1964. Species of <i>Loxoreticulatumi> generally possess a sub-parallelogram shaped carapace/inner margin and arched median hinge element. The latter feature is distinct from the mostly straight median hinge elements of <i>Loxocythere (Loxocythere)i> andle="font-style: italic;"> <i>Loxocythere (Novoloxocythere)i> species. Species of <i>Loxocythere (Novoloxocythere)i> are also readily distinguishable from relatively elongate species of <i>Loxocytherei>, such as <i>L. (L.) hornibrooki</i> McKenzie, 1967, as the latter possess long (for genus), sub-rectangular shaped carapaces/inner margin outlines and posterior extremities below mid height.

Evaluation of fixed sample-size plans for Plutella xylostella (Lepidoptera: Plutellidae) on broccoli crops in Australia

Fixed sample-size plans for monitoring <i>Plutella xylostellai> (L.) (Lepidoptera: Plutellidae) on broccoli and other <i>Brassica i>vegetable crops are popular in Australia for their simplicity and ease of application. But the sample sizes used are often small, ≈10–25 plants per crop, and it may be that they fail to provide sufficient information upon which to base pest control decisions. We tested the performance of seven fixed sample-size plans (10, 15, 20, 30, 35, 40, and 45 plants) by resampling a large data set on <i>P. i><i>xylostella i>in commercial broccoli crops. For each sample size, enumerative and presence-absence plans were assessed. The precision of the plans was assessed in terms of the ratio of the standard error to the mean; and at least 45 and 35 samples were necessary for the enumerative and presence-absence plans, respectively, to attain the generally accepted benchmark of &le;0.3. Sample sizes of 10–20 were highly imprecise. We also assessed the consequences of classifications based on action thresholds (ATs) of 0.2 and 0.8 larvae per plant for the enumerative case, and 0.15 and 0.45 proportion of plants of infested for the presence-absence case. Operating characteristic curves and investigations of the frequency of correct decisions suggest improvements in the performance of plans with increased sample size. In both the enumerative and presence-absence cases, the proportion of incorrect decisions was much higher for the lower of the two ATs assessed, and type II errors (i.e., failure to suggest pest control upon the AT is exceeded) generally accounted for the majority of this error. Type II errors are the most significant from a producer’s standpoint. Further consideration is necessary to determine what is an acceptable type II error rate.

Surface bands on deepwater squalid dorsal-fin spines : an alternative method for ageing centroselachus crepidater

Bands on the external surface of the second dorsal-fin spine proved to be a novel method of estimating the age and growth of <i>Centroselachus crepidateri>. Bands that followed the shape of the spine base were enhanced with an alizarin red derivative. Internal bands in spine cross sections were also examined. The number of both external and internal bands increased with animal size, although most spines had more external than internal bands. External bands were more reliable and were assumed to be annuli. The rate of band formation differed after five bands had been formed, and internal bands ceased forming after 30 years. Females to 54 years old and males to 34 years old were examined. Maturity occurred over a wide age range, with estimates of 20 years for females and 9 years for males. The youngest pregnant female was 27 years old. The Francis reparameterized von Bertalanffy growth model found similar growth for males and females, and the von Bertalanffy equations were <i>L<span style="display: none;" id="1226274043527S"> i>_{<i>t i>}= 96.12^{(1 – e(–0.072(<i>ti>+6.13))}) for females and<i> L<sub>t i>= 73.22(1 – e^{(–0.141(<i>ti>+2.99))}) for males.

The molecular systematics of Leiopotherapon unicolor (Günther, 1859): testing for cryptic speciation in Australia’s most widespread freshwater fish

<i>Leiopotherapon unicolori> is the most widespread freshwater fish species in Australia. A comprehensive allozyme and mitochondrial DNA 16S rRNA data set was assembled from 141 specimens of <i>L. unicolori> collected Australia-wide in order to test for cryptic speciation in this far-ranging species. Surprisingly, little genetic diversity was observed within <i>L. unicolori> and provided no evidence for the existence of cryptic species within this lineage. In contrast, a small sample set of <i>L. aheneusi> used as the outgroup showed two highly divergent haplotypes strongly suggestive of cryptic speciation. <i>L. unicolori> has a number of ecological and life history attributes that may explain the lack of significant genetic divergence over substantial geographical distances. The occurrence of other widespread fish and crustacean species that also display only limited genetic diversity indicate that climate conditions more favourable to dispersal across central and northern Australia than is suggested by the extent of present-day aridity have occurred in the relatively recent geological past.

Plant natriuretic peptide active site determination and effects on cGMP and cell volume regulation

Natriuretic peptides (NP) were first identified in animals where they play a role in the regulation of salt and water balance. This regulation is partly mediated by intracellular changes in cyclic GMP (cGMP). NP immunoanalogues occur in many plants and have been isolated, with two NP encoding genes characterised in <i>Arabidopsis thalianai> L. (<i>AtPNP-Ai> and <i>AtPNP-Bi>). Part of AtPNP-A contains the region with homology to human atrial (A)NP. We report here on the effects of recombinant AtPNP-A and smaller synthetic peptides within the ANP-homologous region with a view to identifying the biologically active domain of the molecule. Furthermore, we investigated interactions between AtPNP-A and the hormone, abscisic acid (ABA). ABA does not significantly affect <i>Arabidopsis i>mesophyll protoplast volume regulation, whereas AtPNP-A and synthetic peptides promote water uptake into the protoplasts causing swelling. This effect is promoted by the membrane permeable cGMP analogue, 8-Br-cGMP, and inhibited by guanylate cyclase inhibitors indicating that increases in cGMP are an essential component of the plant natriuretic peptides (PNP) signalling cascade. ABA does not induce cGMP transients and does not affect AtPNP-A dependent cGMP increases, hence the two regulators differ in their second messenger signatures. Interestingly, AtPNP-A significantly delays and reduces the extent of ABA stimulated stomatal closure that is also based on cell volume regulation. We conclude that a complex interplay between observed PNP effects (stomatal opening and protoplast swelling) and ABA is likely to be cell type specific.

Development and application of polymerase chain reaction-based assays for Rathayibacter Toxicus and a Bacteriophage associated with annual ryegrass (Lolium Rigidum) toxicity

Annual ryegrass toxicity (ARGT) is responsible for significant stock losses in South Australia and Western Australia. The toxicity is caused by corynetoxins produced by the bacterium <i>Rathayibacter toxicusi> (with the possible involvement of a bacteriophage), which infects annual ryegrass (<i>Loliumi> <i>rigidumi>). Polymerase chain reaction (PCR)-based assays, compatible with an existing enzyme-linked immunosorbent assay for the corynetoxins, have been developed and used to screen <i>L. rigidumi> for both the presence of <i>Ri>. <i>toxicusi> and for the bacteriophage isolate NCPPB 3778. The results from analysing bacterially infected galls from toxic grain screenings showed a positive correlation between the presence of the bacterium and corynetoxins but not with the bacteriophage. Analysis of pasture-derived samples of annual ryegrass showed about a 50% correlation of corynetoxins with bacterial presence and about a 5% correlation of phage with the presence of the bacterium. These observations support the potential application of the PCR-based assays in providing a useful, complementary tool in the assessment of the likelihood of pasture and feed to cause ARGT and to enable a better understanding of the complex aetiology of ARGT.

Effect of cage colour and light environment on the skin colour of Australian Snapper Pagrus auratus (Bloch & Schneider, 1801)

A two-factor experiment was performed to evaluate the effects of cage colour (black or white 0.5 m³ experiment cages) and light environment (natural sunlight or reduced level of natural sunlight) on the skin colour of darkened Australian snapper. Each treatment was replicated four times and each replicate cage was stocked with five snapper (mean weight=351 g). Snapper exposed to natural sunlight were held in experimental cages located in outdoor tanks. An approximately 70% reduction in natural sunlight (measured as <i>PARi>) was established by holding snapper in experimental cages that were housed inside a 'shade-house' enclosure. The skin colour of anaesthetized fish was measured at stocking and after a 2-, 7- and 14-day exposure using a digital chroma-meter (Minolta CR-10) that quantified skin colour according to the <i>L</i>*<i>ai>*<i>bi>* colour space. At the conclusion of the experiment, fish were killed in salt water ice slurry and post-mortem skin colour was quantified after 0.75, 6 and 22 h respectively. In addition to these trials, an <i>ad hoci> market appraisal of chilled snapper (mean weight=409 g) that had been held in either white or in black cages was conducted at two local fish markets. Irrespective of the sampling time, skin lightness (<i>L</i>*) was significantly affected by cage colour (<i>Pi>&lt;0.05), with fish in white cages having much higher <i>L</i>* values (<i>L</i>*≈64) than fish held in black cages (<i>L</i>*≈49). However, the value of <i>L</i>* was not significantly affected by the light environment or the interaction between cage colour and the light environment. In general, the <i>L</i>* values of anaesthetized snapper were sustained post mortem, but there were linear reductions in the <i>ai>* (red) and <i>bi>* (yellow) skin colour values of chilled snapper over time. According to the commercial buyers interviewed, chilled snapper that had been reared for a short period of time in white cages could demand a premium of 10–50% above the prices paid for similar-sized snapper reared in black cages. Our results demonstrate that short-term use of white cages can reduce the dark skin colour of farmed snapper, potentially improving the profitability of snapper farming.

Crystal structure of (13S*,13aR*)-2,3-dimethoxy-13-hydroxy-13a-methyl-8-oxo-5,6,13,13a-tetrahydro-8H-dibenzo[a,g]quinolizine, C20H21NO4

C₂₀H₂₁N0_4, monoclinic, <i>Pi>12₁/<i>ci>l (No. 14), <i>ai> = 7.521(2) &Aring;,
<i>b i>= 23.257(2) &Aring;<i> c i>= 9.784(2) &Aring;, &szlig;= 95.57(2)°, <i>Vi> = 1703.3 &Aring;³,
<i>Z i>= 4, R_gt(<i>Fi>) = 0.060, <i>wi>R_ref(F²) = 0.183, <i>Ti> = 293 K.

Culture-based fisheries in non-perennial reservoirs in Sri Lanka: production and relative performance of stocked species

In Sri Lanka, there is a great potential for the development of culture-based fisheries because of the availability of around 12 000 non-perennial reservoirs in the dry zone (&lt;187 cm annual rainfall) of the island. These reservoirs fill during the north-east monsoonal period in October to December and almost completely dry up during August to October. As these non-perennial reservoirs are highly productive, hatchery-reared fish fingerlings can be stocked to develop culture-based fisheries during the water retention period of 7–9 months. The present study was conducted in 32 non-perennial reservoirs in five administrative districts in Sri Lanka. These reservoirs were stocked with fingerlings of Indian (catla <i>Catla catlai> Hamilton and rohu <i>Labeo rohitai> Hamilton) and Chinese (bighead carp <i>Aristichthys nobilisi> Richardson) major carps, common carp Cyprinus carpio L., genetically improved farmed tilapia (GIFT) strain of Nile tilapia, <i>Oreochromis niloticusi> (L.) and post-larvae of giant freshwater prawn, <i>Macrobrachium rosenbergiii> De Man, at three different species combinations and overall stocking densities (SD) ranging from 218 to 3902 fingerlings ha^&minus;1, during the 2002–2003 culture cycle. Of the 32 reservoirs stocked, reliable data on harvest were obtained from 25 reservoirs. Fish yield ranged from 53 to 1801 kg ha^&minus;1 and the yields of non-perennial reservoirs in southern region were significantly (<i>P i>&lt; 0.05) higher than those in the northern region. Naturally-recruited snakehead species contributed the catches in northern reservoirs. Fish yield was curvilinearly related to reservoir area (<i>Pi> &lt; 0.05), and a negative second order relationship was evident between SD and yield (<i>Pi> &lt; 0.05). Chlorophyll-a and fish yield exhibited a positive second order relationship (<i>Pi> &lt; 0.01). Bighead carp yield impacted positively on the total yield (<i>Pi> &lt; 0.05), whereas snakehead yield impact was negative. Bighead carp, common carp and rohu appear suitable for poly-culture in non-perennial reservoirs. GIFT strain<i> O. niloticusi> had the lowest specific growth rate among stocked species and freshwater prawn had a low return.

Culture-based fisheries in non-perennial reservoirs of Sri Lanka: influence of reservoir morphometry and stocking density on yield

Culture-based fish yield in non-perennial reservoirs of Sri Lanka was related to reservoir morphometry and stocking density. The reservoirs were stocked mainly with fingerlings of one Chinese and three Indian major carp species, common carp, <i>Cyprinus carpioi> L., and the genetically improved farmed tilapia strain of Nile tilapia, <i>Oreochromis niloticusi> (L.), at four pre-determined species combinations and a range of stocking densities [<i>SDi> (fingerlings ha^&minus;1)]. Twenty-three reservoirs were harvested successfully at the end of the culture period of 2002–2003. Basic limnological and morphometric parameters, including shoreline development (D_L) and shoreline area ratio (RLA), were estimated for each of the 23 reservoirs. Bray–Curtis similarity and non-metric multidimensional scaling using mean values of limnological data revealed that reservoirs could be ordinated into two major clusters, one with intact sample distribution due to similar trophic characteristics and the other with scattered sample distribution. Reservoirs in the cluster with similar trophic characteristics showed significant correlation (<i>Pi> &lt; 0.05) between RLA and total fish yield (<i>Yi>). A multiple regression equation, <i>Yi> = &minus;693 + 4810 RLA + 0.484 <i>SDi>, was generated to estimate fish harvest in relation to <i>SDi>.</sub>

Comparison of the color stability and lipid oxidative stability of fresh vacuum packaged lamb muscle containing elevated omega-3 and omega-6 fatty acid levels from dietary manipulation

A series of three experiments were conducted with second cross ([Merino&times;Border Leicester]&times;Poll Dorset) wether lambs to evaluate the effects of dietary treatments on manipulation of muscle long-chain (LC) omega-3 fatty acids (FA) on the color stability and oxidative stability of fresh and vacuum packaged lamb. At the end of 7-, 6- and 6-week experimental periods for experiments (Exp.) 1–3 respectively, lambs were slaughtered at a commercial abattoir. At 24 h post-mortem, muscle longissimus lumborum (LL) and longissimus thoracis (LT) were removed and evaluated for color and lipid oxidative stability under specified commercial storage and display condition. Of the dietary supplements used, fish meal and fish oil moderately (<i>Pi>&lt;0.01) and markedly (<i>Pi>&lt;0.001) increased muscle omega-3 FA content, while both protected canola seed (<i>Pi>&lt;0.001) and protected sunflower meal protein significantly (<i>Pi>&lt;0.02) increased muscle omega-6 FA content or ratio of omega-6/omega-3 of the longissimus muscle. In all experiments, the substantial increase (<i>Pi>&lt;0.001) in muscle LC omega-3 and omega-6 FA had no consistent significant effect on color values (redness (<i>a*i>), yellowness (<i>b*i>) and lightness (<i>L*i>)) for fresh and vacuum packaged lamb over a 6-day display period. Lipid oxidation, determined by the levels of thiobarbituric acid reactive substances (TBARS) indicated the enrichment of muscle polyunsaturated fatty acid (PUFA) levels in lambs did not produce significant differences resulting either from main treatment effects or for treatment&times;day&times;type interactions (where type was fresh and vacuum packaged). Present results demonstrated the color and lipid oxidative stability of lamb longissimus muscle during refrigerated display was not affected by enhanced levels of omega-3 and omega-6 FA due to dietary treatments.