Larval development of estuary perch (Macquaria colonorum) and Australian bass (M. novemaculeata) (Perciformes: Percichthyidae), and comments on their life history

Morphological development of the larvae and small juveniles of estuary perch (Macquaria colonorum) (17 specimens, 4.8−13.5 mm body length) and Australian bass (M. novemaculeata) (38 specimens, 3.3−14.1 mm) (Family Percichthyidae) is described from channel-net and beach-seine collections of both species, and from reared larvae of M. novemaculeata. The larvae of both are characterized by having 24−25 myomeres, a large triangular gut (54−67% of BL) in postflexion larvae, small spines on the preopercle and interopercle, a smooth supraocular ridge, a small to moderate gap between the anus and the origin of the anal fin, and distinctive pigment patterns. The two species can be distinguished most easily by the different distribution of their melanophores. The adults spawn in estuaries and larvae are presumed to remain in estuaries before migrating to adult freshwater habitat. However, larvae of both species were collected as they entered a central New South Wales estuary from the ocean on flood tides; such transport may have consequences for the dispersal of larvae among estuaries. Larval morphology and published genetic evidence supports a reconsideration of the generic arrangement of the four species currently placed in the genus Macquaria.

Phylogenetic analysis of betanodavirus isolates from Australian finfish

In Australia, disease caused by betanodavirus has been reported in an increasing number of cultured finfish since the first report of mortalities in 1990. Partial coat protein gene sequences from the T2 or T4 regions of 8 betanodaviruses from barramundi Lates calcarifer, sleepy cod Oxyeleotris lineolata, striped trumpeter Latris lineata, barramundi cod Cromileptes altivelis, Australian bass Macquaria novemaculata and gold-spotted rockcod Epinephelus coioides from several Australian states were determined. Analysis of the 606 bp nucleotide sequences of the T2 region of 4 isolates demonstrated the close relationship with isolates from the red-spotted grouper nervous necrosis virus (RGNNV) genotype and the Cluster Ia subtype. Comparison of a smaller 289 bp sequence from the T4 region identified 2 distinct groupings of the Australian isolates within the RGNNV genotype. Isolates from barramundi from the Northern Territory, barramundi, sleepy cod, barramundi cod and gold-spotted rockcod from Queensland, and striped trumpeter from Tasmania shared a 96.2 to 99.7%, nucleotide identity with each other. These isolates were most similar to the RGNNV genotype Cluster Ia. Isolates from Australian bass from New South Wales and from barramundi from South Australia shared a 98.6% sequence identity with each other. However, these isolates only shared an 85.8 to 87.9%, identity with the other Australian isolates and representative RGNNV isolates. The closest nucleotide identity to sequences reported in the literature for the New South Wales and South Australian isolates was to an Australian barramundi isolate (Ba94Aus) from 1994. These 2 Australian isolates formed a new subtype within the RGNNV genotype, which is designated as Cluster Ic.

Developments in controlled green-water larval culture technologies for estuarine fishes in Queensland, Australia and elsewhere

Since 1989, researchers with the Department of Primary Industries and Fisheries (DPI&F) in Queensland, Australia, have successfully used controlled low-water exchange green-water cultures to rear the larvae of estuarine fishes and crustaceans through to metamorphosis. High survivals and excellent fry condition have been achieved for several commercially important endemic species produced for various projects. They include barramundi or sea bass, Lates calcarifer, Australian bass, Macquaria novemaculeata, dusky flathead, Platycephalus fuscus, sand whiting, Sillago ciliata, red sea bream or snapper, Pagrus auratus, banana prawn, Fenneropenaeus merguiensis, and others. The consistent success of our standardised and relatively simple approach at different localities has led to it being incorporated into general fingerling production practices at several establishments in Australia. Although post-metamorphosis rearing methods have differed for each species investigated, due to various biological and behavioural traits and project requirements, these larval rearing methods have been successful with few species-specific modifications. Initially modelled on the Taiwanese approach to rearing Penaeids in aerated low-water exchange cultures, the approach similarly appears to rely on a beneficial assemblage of micro-organisms. Conceptually, these micro-organisms may include a mixture of the air-borne primary invaders of pure phytoplankton cultures when exposed to outdoor conditions. Whilst this would vary with different sites, our experiences with these methods have consistently been favourable. Mass microalgal cultures with eco-physiological youth are used to regularly augment larval fish cultures so that rearing conditions simulate an exponential growth-phase microalgal bloom. Moderate to heavy aeration prevents settlement of particulate matter and encourages aerobic bacterial decomposition of wastes. The green-water larval rearing approach described herein has demonstrated high practical utility in research and commercial applications, and has greatly simplified marine finfish hatchery operations whilst generally lifting production capacities for metamorphosed fry in Australia. Its potential uses in areas of aquaculture other than larviculture are also discussed.

An examination of the relationship between emotional intelligence, leadership style and perceived leadership outcomes in Australian educational institutions

In the field of leadership studies transformational leadership theory (e.g., Bass, 1985; Avolio, Bass, & Jung, 1995) has received much attention from researchers in recent years (Hughes, Ginnet, & Curphy, 2009; Hunt, 1999). Many previous studies have found that transformational leadership is related to positive outcomes such as the satisfaction, motivation and performance of followers in organisations (Judge & Piccolo, 2004; Lowe, Kroeck, & Sivasubramaniam, 1996), including in educational institutions (Chin, 2007; Leithwoood & Jantzi, 2005). Hence, it is important to explore constructs that may predict leadership style in order to identify potential transformational leaders in leadership assessment and selection procedures. Several researchers have proposed that emotional intelligence (EI) is one construct that may account for hitherto unexplained variance in transformational leadership (Mayer, 2001; Watkin, 2000). Different models of EI exist (e.g., Goleman, 1995, 2001; Bar-On, 1997; Mayer & Salovey, 1997) but momentum is growing for the Mayer and Salovey (1997) model to be considered the most useful (Ashkanasy & Daus, 2005; Daus & Ashkanasy, 2005). Studies in non-educational settings claim to have found that EI is a useful predictor of leadership style and leader effectiveness (Harms & Crede, 2010; Mills, 2009) but there is a paucity of studies which have examined the Mayer and Salovey (1997) model of EI in educational settings. Furthermore, other predictor variables have rarely been controlled in previous studies and only self-ratings of leadership behaviours, rather than multiple ratings, have usually been obtained. Therefore, more research is required in educational settings to answer the question: to what extent is the Mayer and Salovey (1997) model of EI a useful predictor of leadership style and leadership outcomes? This project, set in Australian educational institutions, was designed to move research in the field forward by: using valid and reliable instruments, controlling for other predictors, obtaining an adequately sized sample of real leaders as participants and obtaining multiple ratings of leadership behaviours. Other variables commonly used to predict leadership behaviours (personality factors and general mental ability) were assessed and controlled in the project. Additionally, integrity was included as another potential predictor of leadership behaviours as it has previously been found to be related to transformational leadership (Parry & Proctor-Thomson, 2002). Multiple ratings of leadership behaviours were obtained from each leader and their supervisors, peers and followers. The following valid and reliable psychological tests were used to operationalise the variables of interest: leadership styles and perceived leadership outcomes (Multifactor Leadership Questionnaire, Avolio et al., 1995), EI (Mayer–Salovey–Caruso Emotional Intelligence Test, Mayer, Salovey, & Caruso, 2002), personality factors (The Big Five Inventory, John, Donahue, & Kentle, 1991), general mental ability (Wonderlic Personnel Test-Quicktest, Wonderlic, 2003) and integrity (Integrity Express, Vangent, 2002). A Pilot Study (N = 25 leaders and 75 raters) made a preliminary examination of the relationship between the variables included in the project. Total EI, the experiential area, and the managing emotions and perceiving emotions branches of EI, were found to be related to transformational leadership which indicated that further research was warranted. In the Main Study, 144 leaders and 432 raters were recruited as participants to assess the discriminant validity of the instruments and examine the usefulness of EI as a predictor of leadership style and perceived leadership outcomes. Scores for each leadership scale across the four rating levels (leaders, supervisors, peers and followers) were aggregated with the exception of the management-by-exception active scale of transactional leadership which had an inadequate level of interrater agreement. In the descriptive and measurement component of the Main Study, the instruments were found to demonstrate adequate discriminant validity. The impact of role and gender on leadership style and EI were also examined, and females were found to be more transformational as leaders than males. Females also engaged in more contingent reward (transactional leadership) behaviours than males, whilst males engaged in more passive/avoidant leadership behaviours than females. In the inferential component of the Main Study, multiple regression procedures were used to examine the usefulness of EI as a predictor of leadership style and perceived leadership outcomes. None of the EI branches were found to be related to transformational leadership or the perceived leadership outcomes variables included in the study. Openness, emotional stability (the inverse of neuroticism) and general mental ability (inversely) each predicted a small amount of variance in transformational leadership. Passive/avoidant leadership was inversely predicted by the understanding emotions branch of EI. Overall, EI was not found to be a useful predictor of leadership style and leadership outcomes in the Main Study of this project. Implications for researchers and human resource practitioners are discussed.

Trans-Bass Strait speciation and trans-Pacific dispersal in the Myoporum thrips (Thysanoptera, Phlaeothripinae)

Molecular and morphological data indicate that the pest thrips damaging Myoporum species in California and Hawai'i, Klambothrips myoporiMound and Morris, originated in Tasmania, Australia. This trans-Pacific dispersal presumably resulted from the international horticultural trade in Myoporum species. The data distinguish the pest from K. adelaideae sp.n. that induces leaf deformation on M. insulare along the coast of mainland Australia that is separated by ∼300km from Tasmania by the Bass Strait. K. myopori is more damaging to its non-native hosts in California and Hawai'i than to M. insulare in Tasmania, and further research is needed to determine if this is the result of release from its natural enemies. However, in certain areas of California, some Myoporum species are invasive weeds, and K. myopori may be considered an example of an accidental but beneficial introduction in this instance because of its detrimental impact on the plant species.

Fish recolonization in temperate Australian rockpools: a quantitative experimental approach

Understanding recolonization processes of intertidal fish assemblages is integral for predicting the consequences of significant natural or anthropogenic impacts on the intertidal zone. Recolonization of experimentally defaunated intertidal rockpools by fishes at Bass Point, New South Wales (NSW), Australia, was assessed quantitatively by using one long-term and two short-term studies. Rockpools of similar size and position at four sites within the intertidal zone were repeatedly defaunated of their fish fauna after one week, one month, and three months during two shortterm studies in spring and autumn (5 months each), and every six months for the long-term study (12 months). Fish assemblages were highly resilient to experimental perturbations—recolonizing to initial fish assemblage structure within 1−3 months. This recolonization was primarily due to subadults (30−40 mm TL) and adults (>40 mm TL) moving in from adjacent rockpools and presumably to abundant species competing for access to vacant habitat. The main recolonizers were those species found in highest numbers in initial samples, such as Bathygobius cocosensis, Enneapterygius rufopileus, and Girella elevata. Defaunation did not affect the size composition of fishes, except during autumn and winter when juveniles (<30 mm TL) recruited to rockpools. It appears that Bass Point rockpool fish assemblages are largely controlled by postrecruitment density-dependent mechanisms that indicate that recolonization may be driven by deterministic mechanisms.

Reconnaissance limnology of Tasmania VI. Biogeographical significance of physicochemical features of coastal lagoons of the islands of Bass Strait

The physicochemical attributes of 66 coastal dune lakes (lagoons) on islands of Bass Strait have been investigated. The full data set is available electronically. Here, selected environmental variables with known ecological significance are presented and, by reference to known sites of floristic richness in Tasmania, the lagoons most likely to harbour endemic freshwater algae are identified, as biogeographical stepping stones between the Tasmanian and mainland Australian microfloras.

Microsatellite DNA analysis of southeast Australian Haliotis laevigata (Donovan) populations - implications for ranching in Port Phillip Bay

The genetic composition of greenlip abalone (Haliotis laevigata) from Point Cook in Port Phillip Bay was examined prior to the aggregation of individuals from this site for ranching. The very thinly distributed natural population at Point Cook was believed to be of low genetic diversity, because the animals all originated from a single spawning event 5 y previously. Animals from Point Cook were compared with other H. laevigata from two sampling sites within Port Phillip Bay, and two sites outside the Bay in Bass Strait, to examine their genetic diversity and origin. Variation was assessed at five microsatellite loci. Deviations from Hardy-Weinberg equilibrium (HWE) were observed at some loci in various populations, but the Point Cook population was in HWE at all five loci. Mean heterozygosity and number of alleles was similar in all populations. Hierarchical analysis of molecular variance indicated significant genetic variation among populations, but did not differentiate Port Phillip Bay from Bass Strait populations. Pairwise comparisons of multilocus F_STand R_ST indicated significant genetic differences between Point Cook and some populations, as well as between other populations, but no consistent spatial pattern of differentiation was observed. There was no significant correlation between genetic and geographic distance. The level of genetic variation observed in the Point Cook individuals was similar to that in individuals from the other four sites, and sufficient to support a ranching program. However, this variation should be monitored to maximize genetic potential, and avoid commercially undesirable effects of inbreeding. Implications of this study in relation to the management of a ranching population in Port Phillip Bay are discussed.

Aspects of the ecology of swamp antechinus (Antechinus minimus maritimus) on a Bass Strait island

The swamp antechinus (Antechinus minimus maritimus) is a small insectivorous marsupial inhabiting closed heath and tussock grassland in south-eastern Australia. The species is considered 'Near Threatened' on the
Australian mainland. Populations persist on coastal islands off Wilsons Promontory, but their current status is unknown. This study investigated the density, diet and reproduction of the swamp antechinus on Kanowna Island.
Data were collected by live trapping in different vegetation types during four trips between August 2003 and January 2004. Higher animal densities (47-129 ha^-1) were found for Kanowna Island than for previously studied mainland populations (1-18 ha^-1). Examination ofscats showed that this species eats a wide variety ofprey types, with moth larvae a major dietary component, particularly during the breeding season. Births were estimated to have occurred between 28 June and 8 August, which is a longer period than reported for other populations of this species. Factors including reduced predation, restricted dispersal and increased food availability may be responsible for supporting this dense population.

Effect of proximity to the shelf edge on the diet of female Australian fur seals

The Australian fur seal Arctocephalus pusillus doriferus is a temperate latitude species with a breeding distribution restricted to Bass Strait, Australia. Recent studies of the foraging behaviour of female Australian fur seals indicated that they feed demersally in the shallow continental shelf waters, a behaviour that is in contrast to the epipelagic foraging of females of most other arctocephaline (Southern Hemisphere fur seals) species and akin to that observed in sea lions. These studies, however, were conducted at one colony (Kanowna Island) located in central northern Bass Strait, and it was suggested that the observed foraging behaviour may have been due to the distance of this colony from the continental shelf edge (180 km), making it inefficient to forage beyond it. Here, the diet of lactating Australian fur seals was compared between 2 colonies to test if differing proximity to the continental shelf edge resulted in differences in foraging behaviour. The 2 breeding colonies studied, Kanowna Island and The Skerries, were 180 and 25 km from the nearest shelf edge, respectively. We analysed a total of 917 scat samples collected at the 2 colonies between 1997 and 2001. From faecal analysis, 45 primarily demersal on-shelf species of fishes and cephalopods were identified. Only 4 species had a frequency of occurrence greater than 10%: redbait Emmelichthys nitidus, jack mackerel Trachurus sp., red rock cod Pseudophycis bachus, and Gould’s squid Nototodarus gouldi. No seasonal, annual or spatial differences were found between the 2 colonies, indicating that proximity to the shelf edge does not influence diet.

Reconnaissance limnology of Tasmania VII. Coastal lagoons of Bass Strait Islands, with reference to endemic microflora and microfauna

Coastal lagoons of the principal islands of Bass Strait, between Australia's mainland and Tasmania, were sampled in two summers. Many, particularly those of low to moderate salinity, contain relatively rich assemblages of microinvertebrates and some endemic Australian freshwater algae. Several species of testate amoebae and rotifers could not be referred to known morphotypes and are probably new species. The presence of certain species on islands of Bass Strait provides a link between populations in mainland Australia and others in Tasmania. Those lagoons are identified that, by virtue of catchments or buffer zones clothed in native vegetation, are favourable for the survival of a native and partly endemic microbiota.