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 (L_T), mass and age of ready to migrate female silver shortfin eels Anguilla australis from the Hopkins River estuary and the mouth of the Merri River in south-eastern Australia, were 83·2 ± 1·2 cm, 1051 ± 51 g, and 17·2 ± 1·79 years, respectively. The eye index (I_E) of the silver shortfin eels was < 5·2 (mean 7·64 ± 0·29) and differed significantly from that of the yellow shortfin eels collected from two other sites. The I_E increased with L_T (mm) and was related by log I_E= 2·656 log L_T6·925. 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 (35·5 ± 2·0%). The mean mass μg mg lipid ‾) of saturates (230·4 ± 2·6 v. 181·7 ±2·6), monoenes (367·4 ± 6·3 v. 290·8 ± 8·9) and PUFA (177·3 ± 5·3 v. 159·7 ± 4·6) 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.

Distribution and habitat requirements of the Yellow-Footed Antechinus Antechinus flavipes at multiple scales: a review

This review synthesises present knowledge of the distribution patterns and habitat requirements of the Yellow-footed Antechinus Antechinus flavipes. Factors influencing the distribution of A. flavipes are examined at several spatial scales ranging from the broad climatic conditions prevalent over the species’ entire range to the characteristics of nest sites used by individual animals. Analysis of the literature suggests that: 1) at the broad-scale, A. flavipes distribution is largely determined by warm, dry climatic conditions, the distribution of dry forests and woodlands and competition with closely related species; 2) at the landscape-scale the determinants of A. flavipes distribution are largely unknown, although initial investigations suggest some tolerance of fragmented landscapes; and 3) at a local-scale the distribution of A. flavipes is largely determined by the presence of large diameter trees, tree hollows, coarse woody debris, rocky crevices and leaf-litter. Directions for future research are suggested throughout the review.

Biometrics and sexing criteria of the yellow-faced honeyeater lichenostomus chrysops

Morphometric data on 99 adult and 13 juvenile Yellow-faced Honeyeaters Lichenostomus chrysops that were independently sexed using molecular techniques were analysed to investigate size dimorphism between the sexes. Our results support previous studies that have demonstrated Yellow-faced Honeyeaters are sexually dimorphic in size, with males being the larger sex. Discriminant analyses of morphometric data were used to develop a simple method for sexing adult Yellow-faced Honeyeaters in the hand. As five observers collected the measurements our sexing criteria are conservative and should have wide application for field ornithologists working on the species.

Methods for aging and sexing the Black-eared Miner, Manorina melanotis, and Yellow-throated Miner, M. flavigula

Morphometric data on 92 Black-eared Miners and 47 Yellow-throated Miners that had been independently sexed using molecular techniques were analysed to investigate size dimorphism between the sexes. We found that both species are sexually dimorphic in size, with males being the larger sex. Discriminant analyses of morphometric data were used to develop a simple method for sexing both species in the hand. Additionally, alula shape was consistent with other methods that we applied for ageing individuals. Sex-specific size differences between Black-eared and Yellow-throated Miners detected here add further support to the contention that they represent different taxa. The application of these sexing and ageing techniques for both species of mallee miner will improve ongoing field management of the endangered Black-eared Miner.

Habitat requirements of the yellow-footed antechinus (Antechinus flavipes) in box–ironbark forest, Victoria, Australia

Understanding the habitat requirements of a species is critical for effective conservation-based management. In this study, we investigated the influence of forest structure on the distribution of the yellow-footed antechinus (Antechinus flavipes), a small dasyurid marsupial characteristic of dry forests on the inland side of the Great Dividing Range, Australia. Hair-sampling tubes were used to determine the occurrence of A. flavipes at 60 sites stratified across one of the largest remaining tracts of dry box–ironbark forest in south-eastern Australia. We considered the role of six potential explanatory variables: large trees, hollow-bearing trees, coppice hollows, logs, rock cover and litter. Logistic regression models were examined using an information-theoretic approach to determine the variables that best explained the presence or absence of the species. Hierarchical partitioning was employed to further explore relationships between occurrence of A. flavipes and explanatory variables. Forest structure accounted for a substantial proportion of the variation in occurrence of A. flavipes between sites. The strongest influence on the presence of A. flavipes was the cover of litter at survey sites. The density of hollow-bearing trees and rock cover were also positive influences. The conservation of A. flavipes will be enhanced by retention of habitat components that ensure a structurally complex environment in box–ironbark forests. This will also benefit the conservation of several threatened species in this dry forest ecosystem.

Afternoon T : Testosterone level is higher in red than yellow male polychromatic lizards

Recent work on within-species polymorphism across a broad range of taxa has renewed and considerably increased the attention to this classic evolutionary area, notably in lizard species where colors covary with reproductive strategies. We demonstrate elsewhere that red-headed males beat yellow-headed males in staged contests for females in the Australian painted dragon lizard Ctenophorus pictus. This morph difference in behaviour is linked to what appears to be a convention of red dominance in male–male interactions set very early in ontogeny, long before coloration has developed. In the current note, we investigate the relationship between time of day, which is directly linked to vigilance time in territorial males, and plasma levels of testosterone and corticosterone. We show that red males have higher testosterone levels in late afternoon following a day of territory patrolling and a non-significant trend in plasma corticosterone levels that decline with time of day. In conclusion, there are significant differences in testosterone profile between the two color morphs, providing a potential proximate link to the behavioural differences between them.

Cracking and distortion of water jackets in engine blocks

This thesis investigated the cracking and distortion of water jackets in engine blocks. The Taguchi method was utilized to improve production process and in doing so, reducing the scrap of water jacket cores by over 60%. Further, by altering core material and pouring temperature, casting distortion was improved.

Transcriptomics-based analysis using RNA-Seq of the coconut (Cocos nucifera) leaf in response to yellow decline phytoplasma infection

Invasive phytoplasmas wreak havoc on coconut palms worldwide, leading to high loss of income, food insecurity and extreme poverty of farmers in producing countries. Phytoplasmas as strictly biotrophic insect-transmitted bacterial pathogens instigate distinct changes in developmental processes and defence responses of the infected plants and manipulate plants to their own advantage; however, little is known about the cellular and molecular mechanisms underlying host–phytoplasma interactions. Further, phytoplasma-mediated transcriptional alterations in coconut palm genes have not yet been identified. This study evaluated the whole transcriptome profiles of naturally infected leaves of Cocos nucifera ecotype Malayan Red Dwarf in response to yellow decline phytoplasma from group 16SrXIV, using RNA-Seq technique. Transcriptomics-based analysis reported here identified genes involved in coconut innate immunity. The number of down-regulated genes in response to phytoplasma infection exceeded the number of genes up-regulated. Of the 39,873 differentially expressed unigenes, 21,860 unigenes were suppressed and 18,013 were induced following infection. Comparative analysis revealed that genes associated with defence signalling against biotic stimuli were significantly overexpressed in phytoplasma-infected leaves versus healthy coconut leaves. Genes involving cell rescue and defence, cellular transport, oxidative stress, hormone stimulus and metabolism, photosynthesis reduction, transcription and biosynthesis of secondary metabolites were differentially represented. Our transcriptome analysis unveiled a core set of genes associated with defence of coconut in response to phytoplasma attack, although several novel defence response candidate genes with unknown function have also been identified. This study constitutes valuable sequence resource for uncovering the resistance genes and/or susceptibility genes which can be used as genetic tools in disease resistance breeding.