bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproductive dynamics of broadbill swordfish, Xiphias gladius, in the domestic longline fishery off eastern Australia
Authors: Young Jock , Drake Anita , Brickhill Michael , Farley Jessica , Carter Thor
Published: August 2003

The reproductive ecology of broadbill swordfish, Xiphias gladius, was evaluated based on 1437 fish (size range 50–300 cm orbital fork length [OFL]) caught in the domestic longline fisheries off eastern Australia and New Zealand between May 1999 and March 2001. Reproductive activity was assessed using histology, a gonadosomatic index, and maximum oocyte size. Males were significantly smaller than females and represented less than one third of the sampled fish. Sex ratio differed significantly with respect to fish size and time of year. Females began maturing at 150-cm OFL and spawned from September to March, with the greatest activity from December to February. Males matured at 90-cm OFL; ripe males were found from January to March, but also in May and October, suggesting an extended reproductive period. During the spawning period the proportion of spawning to inactive mature sized females was significantly higher in waters west of longitude 158°E than in waters to the east. Further to the east, samples taken from the New Zealand fishery showed no actively spawning fish during the main spawning period. Females were increasingly reproductively active as water temperature increased beyond 24°C and sea surface chlorophyll a decreased below 0.2 μg L–1. Batch fecundity was linearly related to fish length with a mean batch fecundity of 1.66 million oocytes for females ranging in size from 173- to 232-cm OFL. The presence of hydrated oocytes and post-ovulatory follicles (POFs) in the same ovaries indicated multiple spawnings. Depending on the time taken for POFs to degrade, these may have been daily at the height of the spawning season.
Interpretation of otolith microstructure in the early life history stages of two temperate reef wrasses (Labridae)
Authors: Welsford Dirk C.
Published: August 2003

Notolabrus fucicola and N. tetricus larvae were reared in the laboratory at a constant temperature of 11°C; both species hatched after 4 days. Mortality was high throughout the post-hatching stage, with no N. tetricus surviving beyond 24 hours post-hatching. Notolabrus fucicola late yolk sac larvae showed no clear incremental structure in their sagittal otoliths up to 9 days post-hatch. The radius of the sagittae of these late yolk sac larvae corresponded with the radius of a non-incremental region around the primordium of sagittae taken from post-settlement juveniles of both species captured in the wild. Therefore, it is likely that the first increment is formed at or near yolk sac absorption in these species. Post-settlement juveniles of both species were exposed to oxytetracycline (OTC) and held in aquaria for up to 33 days. Post-OTC increment counts showed that increments were formed daily in the sagittae of both species.
Asynchronous patterns of reproduction for the sympatric scallops Chlamys bifrons and Chlamys asperrima (Bivalvia: Pectinidae) in South Australia
Authors: Styan C. A. , Butler A. J.
Published: August 2003

Patterns of spawning activity were assessed by monitoring gonad states over 2.5 years for Chlamys asperrima and Chlamys bifrons at two sites in Gulf St Vincent, South Australia. Chlamys asperrima appeared to have a minor spawning in June, followed by a major spawning starting in late August. In contrast, the gonads of C. bifrons were regressed only during winter and it appeared that C. bifrons spawned for a long period, from late spring (September) until early autumn (March). At one site where sampling was frequent, there was evidence of three series of C. bifrons spawning events during the summer of 1994/95 and at least two series of events during 1995/96. Build-up and decrease in gonad weight was quick, but there was strong evidence of serial spawning for both species. Subsequently, we once observed C. asperrima spawning in situ at Edithburgh Jetty, at a time when gonad weights had been decreasing in previous years, but also long after the time when peak gonad weights had usually occurred. Only patches within the population were seen spawning, with scallops not spawning observed less than 100 m away from those that were. Indirect sampling of gonad condition also suggested that spawning in C. bifrons at Largs Bay was not always synchronous among patches of scallops within a population, nor always between sexes within patches.
Formation and annual periodicity of opaque zones in sagittal otoliths of Mugil cephalus (Pisces: Mugilidae)
Authors: Smith Kimberley A. , Deguara Kerrie
Published: August 2003

The present study used a variety of methods to validate the annual periodicity and to determine the timing of formation of opaque and translucent zones in the sagittal otoliths of sea mullet (Mugil cephalus) from south-eastern Australia. Otoliths of captive juvenile fish were sampled regularly to determine timing of formation of the first opaque zone and ‘marginal increment analysis’ was used to infer timing of formation of subsequent zones. Otoliths of tagged (oxytetracycline injected) and recaptured fish also provided direct observations about the timing and periodicity of otolith zone formation. An ‘increment’ was defined as a translucent zone followed by an opaque zone. The first opaque zone was typically completed in February–March, at an age of 22–23 months. Subsequent opaque zones were completed between November and March, but typically in December. Opaque zones were associated with periods of slow otolith growth during winter and spring. Otoliths of fish aged between 0 and 11 years were examined during the study. Otoliths were sampled from two locations on the south-eastern Australian coast, separated by 5.5° latitude. The transition between opaque and translucent zones appeared more distinct in otoliths from the higher latitude, resulting in greater precision of age estimates at this location. Precision of age estimation was also found to vary with time of year. It is recommended that sampling of otoliths for age determination of Mugil cephalus in south-eastern Australia occur from April to October. Sampling at these times would avoid months in which otolith increments are most difficult to interpret and when the stage of completion of increments is most variable.
Global overview of the major constituent-based billfish tagging programs and their results since 1954
Authors: Ortiz Mauricio , Prince Eric D. , Serafy Joseph E. , Holts David B. , Davy Kay B. , Pepperell Julian G. , Lowry Michael B. , Holdsworth John C.
Published: August 2003

Release and recovery files from the world's five major constituent-based billfish (Istiophoridae) tagging programs were assembled into a single composite database. Data sources included the National Marine Fisheries Service's (NMFS) Cooperative Tagging Center (MIA) in the Atlantic Ocean, the NMFS's Cooperative Billfish Tagging Program (LJA) in the Pacific and Indian Oceans, the Australian Cooperative Tagging Program in the Pacific and Indian Oceans, the New Zealand Cooperative Game Fish Tagging Program in the Pacific Ocean, and The Billfish Foundation's (TBF) tagging program in the Atlantic, Pacific and Indian Oceans. Results for the main target species, including black marlin (Makaira indica), blue marlin (Makaira nigricans), white marlin (Tetrapturus albidus), striped marlin (Tetrapturus audax) and sailfish (Istiophorus platypterus) were compared and contrasted based on species, ocean body and tagging program. A total of over 317 000 billfish have been tagged and released, and 4122 have been recovered since 1954. Tag recovery percentages were generally higher for a recently developed double-barb nylon anchor tag compared with the typically used stainless steel dart tag. Greatest distances moved were largest for blue marlin and black marlin, followed by striped marlin, white marlin and sailfish. The TBF program had the highest tag recovery percentages for white marlin (2.4%) and blue marlin (1.7%), whereas the MIA program had the highest percentage recovery for sailfish (1.8%). The LJA program had the highest recovery percentages for black marlin (1.9%) and striped marlin (1.4%). The annual number of releases and recoveries for each target species tended to increase over the time series, particularly during the last decade. Cyclic annual movement patterns and/or seasonal site fidelity were evident for black marlin and white marlin. The data suggest that tag recovery percentages can be affected by tag type, reporting rate, localized fishing activities, outreach activities, and a variety of logistical issues indirectly related to size of ocean body. The efficiencies of the tagging programs are compared and recommendations are made to improve the programs. The composite tagging database provides the opportunity for a more comprehensive evaluation of the data and tagging programs than has previously been possible by examining the individual programs in isolation. The main advantage of constituent-based tagging programs is that large numbers of billfish can be tagged at a minimum cost. The main drawbacks are a lack of control over the tagging event and return of recovery data. Constituent-based tagging programs provide essential data on billfish movement and biology, and should be expanded and improved to meet the increasing need for this information.
Isotopic (δ13C) evidence for the autochthonous origin of sediment organic matter in the small and acidic Lake Katanuma, Japan
Authors: Doi Hideyuki , Kikuchi Eisuke , Hino Shuji , Itoh Takeru , Takagi Shigeto , Shikano Shuichi
Published: August 2003

Sources of sediment organic matter from the strongly acidic Lake Katanuma (0.14 km2; average pH 2.2), in Japan, were determined from an analysis of carbon stable isotope ratios (δ13C). Organic carbon was derived mainly from the benthic diatom, Pinnularia braunii, and particulate organic matter (POM) primarily from the phytoplankton, Chlamydomonas acidophila, and not from emergent or terrestrial C3 plants such as Phragmites australis, Sasa kurilensis or Fagus crenata. Although the sediment organic matter of most small lakes, especially strongly acidic lakes, is commonly thought to be of allochthonous origin, the sources of sediment organic matter in the small and acidic Lake Katanuma were clearly autochthonous.
Early development and growth of the eastern rainbowfish, Melanotaenia splendida splendida (Peters). I. Morphogenesis and ontogeny
Authors: Humphrey Craig , Klumpp David W. , Pearson Richard
Published: August 2003

This paper describes the ontogeny and morphogenesis of the eastern rainbowfish, Melanotaenia splendida splendida, including details on reproduction and the conditions required for laboratory breeding and rearing. M. s. splendida is easily bred under standard laboratory conditions using readily available commercial foods. Aquaria with two males and three females can produce between 40 and 200 eggs daily. They can be induced to spawn daily throughout the year through manipulation of light and temperature conditions. The eggs, which ranged in size from 0.93 to 1.20 mm, had a homogeneous yolk and a clear, uniform chorion, making observation of developmental stages possible. Development was telolecithical and division was meroblastic. Development of M. s. splendida was similar to that of other Melanotaenia species. At 28°C, hatching occurred between 4 and 8 days, with an average larval length of 3.7 mm standard length. Growth was rapid and the fish reached sexual maturity within approximately 90 days. Knowledge of the developmental stages of M. s. splendida is important in enabling further work, such as bioassays and environmental monitoring, to be carried out, investigating the ways in which changes in the environment, such as pollution, will impact on Australia's freshwater fishes. Melanotaenia splendida splendida is an ideal species for this purpose in the north-eastern tropics of Australia.
Early development and growth of the eastern rainbowfish, Melanotaenia splendida splendida (Peters). II. Otolith development, increment validation and larval growth
Authors: Humphrey Craig , Klumpp David W. , Pearson Richard G.
Published: August 2003

A method of preparing and interpreting the microstructure of otoliths of the eastern rainbowfish, Melanotaenia splendida splendida, was developed and used to validate the periodicity of increment formation. Otoliths were collected from laboratory-reared M. s. splendida of known age. The sagittal otolith was preferred for ageing because resolving the earliest increments was easier than in the lapillus during an early slow-growth period, up to 15 days after hatching. Increments formed in the sagittae before hatching, and a distinct discontinuity was visible in the otolith sections at a time corresponding to hatching. Another discontinuity occurred at the time of yolk-sac absorption, when larvae became completely reliant on exogenous feeding. After this, increments were clear, regularly spaced and easily resolved. Linear relationships were found between fish size and sagittal length, breadth and perimeter. Observations of the otolith sections confirmed that the increments in sagittae of M. s. splendida were laid down daily. The information provided here enables growth and mortality rates of M. s. splendida to be measured, providing a useful tool for monitoring the impacts of contaminants in tropical Australian waters.
Differences in fish assemblages from different reef habitats at Hamelin Bay, south-western Australia
Authors: Harman Nicole , Harvey Euan S. , Kendrick Gary A.
Published: August 2003

Differences in the diversity of fish species between granite and limestone reefs, as well as high- and low-relief limestone reefs, were investigated at Hamelin Bay, south-western Australia. It was found that there were significant differences in the presence and abundance of fish species between granite reefs and limestone reefs. Granite reefs were characterized by greater numbers of Coris auricularis (western king wrasse) and Parma mccullochi (common scalyfin), whereas limestone reefs had greater numbers of the fish species Odax cyanomelas (herring cale), Pempheris klunzingeri (rough bullseye) and Kyphosus sydneyanus (common buffalo bream). A significant difference in fish diversity was also found between high-relief and low-relief limestone reefs in the same area. More species were found on the high-relief reefs than low-relief reefs. Complementing differences in fish assemblages, significant differences were found in algal assemblages from the different habitats. This was mainly owing to a dominance of Ecklonia radiata on low-relief limestone reefs. Ecklonia radiata was less dominant on granite reefs and on high-relief limestone reefs, where there was a lower overall algal biomass and a higher total number of species.
Importance of the riparian zone to the conservation and management of freshwater fish: a review
Authors: Pusey Bradley J. , Arthington Angela H.
Published: August 2003

The relationship between freshwater fish and the integrity of the riparian zone is reviewed with special emphasis on the fauna of northern Australia. Linkages between freshwater fish and riparian zone processes are diverse and important. The riparian zone occurs at the interface between terrestrial and aquatic ecosystems and it may, therefore, regulate the transfer of energy and material between these systems, as well as regulating the transmission of solar energy into the aquatic ecosystem. Riparian influences on light quantity, quality and shade in streams are discussed and predictions are made about the likely impacts associated with changes in light quality. Increased rates of transfer of thermal energy between the atmosphere and the aquatic environment in the absence of an intact riparian zone may potentially disrupt reproduction by desynchronizing the thermal regimen from regional factors, such as the flow regimen, as well as having direct effects on mortality rates, body morphology, disease resistance and metabolic rates. Impacts associated with changes in light quality range from increased egg and larval mortality due to increased ultraviolet (UV) B irradiation and a decreased ability to discriminate between potential mates to increased conspicuousness to predators. Increased insolation and proliferation of exotic pasture grasses, an increasing threat in northern Australia, are shown to have a range of impacts, including changes in habitat structure, food-web structure and the facilitation of invasion by exotic fish species. The interception of terrestrial sediments and nutrients by the riparian zone has important consequences for stream fish, maintaining habitat structure, water clarity and food-web structure. Coarse organic matter donated to the aquatic environment by the riparian zones has a large range of influences on stream habitat, which, in turn, affect biodiversity and a range of process, such as fish reproduction and predation. Terrestrial matter is also consumed directly by fish and may be a very important source of energy in some Australian systems and under certain circumstances. Attention to the linkages between fish and riparian systems is essential in efforts to rehabilitate degraded stream environments and to prevent further deterioration in freshwater fish populations in northern Australia.
Bubbler design for reservoir destratification
Authors: Sahoo Goloka Behari , Luketina David
Published: August 2003

Two important bubbler-performance criteria, the mechanical efficiency, ηmech, and the destratification time, Γ, were analysed as functions of two dimensionless parameters, G, the strength of stratification, and M, the source strength. Equations to estimate the optimum airflow rate (via M) and corresponding ηmech and Γ for a known linear stratification G in a reservoir were derived. Owing to difficulties in accurately determining the actual G, it was demonstrated that it is appropriate practice to reduce the design G value by around 10%. It was shown that the equivalent linear stratification method might lead to sub-optimal design for stratification profiles that deviate substantially from a linear profile. Rather, a bubble-plume model should be applied. Finally, the effects of incorporating changes in bubble radius in a bubble-plume model were examined. ηmech and Γ were found to be relatively insensitive to bubble radius; however, the ideal bubble size for maintaining a suitable oxygen dissolution efficiency is 1 mm.
Biogeochemical processes and labile composition of settling particulate organic matter in the south-west Pacific Ocean
Authors: Gupta Lallan Prasad , Kawahata Hodaka
Published: August 2003

Settling particles collected by sediment traps deployed for approximately 1 year in the Coral Sea and Tasman Sea were analysed to understand the biogeochemical processes controlling the cycling and flux of particulate organic matter (POM) in the south-west Pacific. Samples were analysed for 20 amino acids (AA) and two hexosamines (HA) and the data were interpreted together with already published data on opal (biogenic silica), organic carbon and total nitrogen contents. Mean fluxes of labile carbon and nitrogen at one site were significantly different (P < 0.04, t-test; n = 14–18) from those at other sites. The southernmost trap recorded the highest concentrations of AA, HA and organic carbon normalized AA. At a site in the south, POM was more degraded in the deep trap than in the shallow trap. Occasionally, higher fluxes were also recorded at the deep trap relative to the shallow trap. The C/Natomic ratio coupled with AA- and HA-based parameters clearly suggested contribution of POM through resuspension as well as lateral advection at the more southern site, whereas a strong influence of zooplankton on total mass flux was revealed at the northern site during the period August–September 1995. It is evident from the data that higher flux of particles having higher labile contents (AA and HA) is more prevalent in the Tasman Sea than in the Coral Sea.
ICCAT stock assessments of Atlantic billfish
Authors: Restrepo Victor , Prince Eric D. , Scott Gerry P. , Uozumi Yuji
Published: August 2003

This paper presents a historical overview of the assessments of the Atlantic stocks of blue marlin (Makaira nigricans), white marlin (Tetrapturus albidus) and sailfish (Istiophorus platypterus) that have been conducted by the International Commission for the Conservation of Atlantic Tunas between 1977 and 2000. Details are presented on the data sets used and the models applied, noting the strengths and weaknesses of the assessments. The major causes of uncertainty in the current perception of the status of the stocks are related to some of the data used and to their interpretation, especially historical trends in catch per unit effort. In particular, there are uncertainties about historical catch data, including discards, and about the degree to which longline fishing effort overlaps with billfish habitat. The paper concludes with an account of the efforts that should be made to reduce these uncertainties.
Dynamics of a cyanobacterial bloom in a hypereutrophic, stratified weir pool
Authors: Thompson P. A. , Waite A. M. , McMahon K.
Published: August 2003

In summer 1997–1998, a bloom of the cyanobacteria Anabaena circinalis (Rabenhorst) and Anabaena spiroides (Klebahn) contaminated the Canning River (Perth, WA), forcing its closure to the public for swimming and fishing. We investigated the major nutrient fluctuations before, during and after the bloom. The river was persistently temperature stratified at least 1 month prior to the bloom. The surface and bottom layers of water had distinctly different nutrient concentrations, which meant that biomass and growth rates of the phytoplankton within each layer were limited by different nutrients. At the peak of the bloom, in the bottom waters growth rates were light limited and biomass was nitrogen limited, whereas in the surface waters biomass was controlled by phosphorus (P) availability and growth rates were probably limited by the lack of dissolved inorganic carbon. Another consequence of stratification was that, at the peak of the bloom (0.25 mg chlorophyll L−1), the mostly buoyant cyanobacteria could not access 83% of the P released from sediments during the summer period of anoxia. In this situation, the injection of oxygenated water, tested as a remediation measure for algal blooms, is likely to exacerbate a bloom by providing more of the limiting nutrient to the surface layer. However, aeration prior to the bloom may reduce P release from the sediments by preventing anoxia.
Effects of specific purine and pyrimidine compounds on the ingestion of test diets by the abalone Haliotis discus and the oriental weatherfish Misgurnus anguillicaudatus
Authors: Miyasaki Taiko , Harada Katsuhiko
Published: August 2003

To improve the feed ingestion of cultured fish and shellfish, 26 purine and pyrimidine compounds were examined as dietary supplements at a concentration of 1.0 mmol kg–1 (or L–1) of diet. For the black abalone Haliotis discus, feeding was significantly (P < 0.05) increased by thymidine, adenosine-5�-monophosphate, adenosine- 5�-diphosphate (ADP), adenosine-5�-triphosphate, guanosine-5�-monophosphate (GMP), inosine-5- monophosphate (IMP) and 2�-deoxycytidine-5�-monophosphate. For the oriental weatherfish Misgurnus anguillicaudatus, feeding was significantly (P < 0.05) increased by thymidine, ADP, IMP and thymidine-5�-monophosphate (TMP). At one-tenth of the initial concentration, ADP, GMP and IMP were effective for the abalone and thymidine and TMP were effective for the weatherfish. None of the compounds inhibited feeding of either species.
A perspective on billfish biological research and recommendations for the future
Authors: Holland Kim N.
Published: August 2003

A review of papers published on billfish biological research since the 1988 Billfish Symposium highlights the important role these symposia play in disseminating billfish research results and also shows that progress since 1988 has been slow, especially when compared with tuna and other pelagic fishes. One reason for the disparity is that marlin have not yet been successfully held in captivity. Progress has been made in elucidating the trophic biology of billfish and these data are helping to build models of pelagic ecosystem dynamics. The deployment of several types of electronic tags has expedited advances in understanding the short-term movements and depth distribution of billfish, but long-term tracks remain elusive. In part, this may be because insufficient effort has been directed at developing methods for restraining marlin for tag attachment or implantation. Light-based geolocation techniques show great promise for elucidating billfish movements, but appropriate scientific rigour must be applied to the publication of these data. Several suggestions for advancing billfish research are presented.
Modification of sediment redox potential by three contrasting macrophytes: implications for phosphorus adsorption/desorption
Authors: Aldridge Kane T. , Ganf George G.
Published: August 2003

Freshwater macrophytes may increase sediment redox potential and the affinity of sediments for phosphorus through radial oxygen loss from their below-ground biomass. This study demonstrated that the ability to alter sediment redox potential differs between macrophytes, according to their capacity to transport oxygen. Of the emergent macrophytes, Typha domingensis increased sediment redox potential (218 mV above bare sediment) to a greater extent than Bolboschoenus caldwellii (41 mV above bare sediment). However, the inhibition of convective flow in T. domingensis reduced its oxidizing ability by 78 mV. In contrast, Potamogeton crispus, a submerged macrophyte, had no influence on sediment redox potential. The presence of T. domingensis also increased phosphorus uptake from the water column by 0.88 mg P m−2 day−1, above that of bare sediments. In addition, inundation predictably decreased sediment redox potential from 175 mV to −176 mV over a 42-day period. Similarly, the addition of cellulose (10 mg L−1) decreased sediment redox potential by 42 mV. Consequently, deposition of organic debris may counteract the oxidizing effects of macrophytes that have a limited capacity to transport oxygen, such as P. crispus. Results suggest that macrophytes play an important role in facilitating the restoration of freshwater systems.
Shrinkage of 0+ carp (Cyprinus carpio L.) after preservation in ethanol
Authors: Smith Benjamin B. , Walker Keith F.
Published: August 2003

Changes in the length and weight of 240 larval and juvenile carp (standard length 10–45 mm) were monitored over 180 days after preservation in 70% and 95% ethanol. Shrinkage varied with initial (pre-preservation) size and ethanol concentration, but was stable after 1 day. Absolute shrinkage was directly proportional to initial body size, but per cent shrinkage was inversely proportional to initial size. Length shrinkage peaked at about 14% and weight shrinkage peaked at about 75%. Weight loss in 95% ethanol was almost twice that in 70% ethanol. The initial length and weight of specimens preserved in 70% or 95% ethanol may be estimated by regression equations provided here.
Summer flow event induces a cyanobacterial bloom in a seasonal Western Australian estuary
Authors: Robson Barbara J. , Hamilton David P.
Published: August 2003

In January 2000, record rainfall led to the first recorded bloom of Microcystis aeruginosa in the Swan River estuary. A simple model is used to examine the bloom dynamics and the unusual conditions that produced it. Laboratory trials were conducted to determine the response to salinity of M. aeruginosa, while other parameters for the model were obtained from the literature. Growth was found to be optimal at salinities up to 4, and declined to zero at 25. The unseasonable summer rainfall flushed brackish and marine water from the estuary and produced a surface mixed layer with low salinity. The model simulations show that the hydrological conditions, in combination with high concentrations of inorganic nutrients (dissolved inorganic nitrogen >1.2 mg L–1, filterable reactive phosphorus >0.02 mg L–1) in river inflows, high water temperature and high daily insolation, promoted rapid phytoplankton growth, favouring dominance by M. aeruginosa. Doubling rates during the bloom were around 0.35 day–1 and cell counts exceeded 105 cells mL–1 within three weeks of the inflow event. Although this doubling rate ultimately determined the total bloom biomass, local concentrations were strongly influenced by physical processes that concentrated M. aeruginosa cells both vertically and horizontally, and advected a seed population from the upper estuary into the lower basin.
Spatial and temporal dynamics of temperate Australian rockpool ichthyofaunas
Authors: Griffiths Shane P.
Published: August 2003

Spatial and temporal variation, and factors influencing the structure of intertidal rockpool fish assemblages were quantitatively investigated at three large rocky headlands in south-eastern New South Wales, Australia. A total of 5244 fish from 46 species, mainly permanent intertidal residents from the families Clinidae, Blenniidae, Tripterygiidae, Gobiidae, Gobiesocidae and Girellidae, was caught in the rockpools. Numbers of species and individuals and dominance patterns of species showed significant variability within locations, possibly in response to variations in rockpool tidal height and volume, or environmental variables, such as temperature and dissolved oxygen. Species composition also differed among locations, probably as a result of availability of different habitats at each location, which may be preferred by different species. Fish assemblage structure was stable and persistent through time, presumably because rockpools are colonized only by species suitably adapted to the dynamic intertidal environment. Temporal variability in the abundance of some common species occurred during summer and autumn, mainly owing to recruitment of resident fishes. Directions for future research are given, which may contribute to an understanding of the processes that underpin these patterns.
Embryonic development of southern calamary (Sepioteuthis australis) within the constraints of an aggregated egg mass
Authors: Steer M. A. , Moltschaniwskyj N. A. , Jordan A. R.
Published: August 2003

A post-cleavage embryological scheme was established for southern calamary Sepioteuthis australis. Using this developmental scheme, intra- and interspecific comparisons were made. Sepioteuthis australis development most closely resembled that of its tropical congeneric species, S. lessoniana, with only a few subtle heterochronies. The greatest developmental difference was observed when comparisons were made with Loligo pealei. These differences were attributed to developmental duration and respective egg sizes. Within S. australis, variation in developmental rates among embryos was associated with the size of the egg mass, with less variation evident in smaller egg masses. Embryos located on the periphery of the egg mass and at the distal or unattached end of an individual egg strand developed significantly faster than those located deep within the egg mass. On average, embryos in small egg masses, consisting of five individual egg strands, developed significantly faster than those in dense aggregations (>100 strands).
The effects of Produced Formation Water (PFW) on coral and isolated symbiotic dinoflagellates of coral
Authors: Jones Ross J. , Heyward Andrew J.
Published: August 2003

There is concern of the effects of Produced Formation Water (PFW, an effluent of the offshore oil and gas industry) on temperate/tropical marine organisms of the North West Shelf (NWS) of Australia. Little is known of the effects of PFW on tropical marine organisms, especially keystone species. Exposing the coral Plesiastrea versipora to a range (3–50% v/v) of PFW from Harriet A oil platform resulted in a reduction in photochemical efficiency of the symbiotic dinoflagellate algae in hospite (in the coral tissues), assessed as a decrease in the ratio of variable fluorescence (Fv) to maximal fluorescence (Fm) measured using chlorophyll fluorescence techniques. Significant differences were noted at PFW concentrations >12.5% (v/v). In corals where Fv/Fm was significantly lowered by PFW exposure, significant discolouration of the tissues occurred in a subsequent 4-day observation period. The discolouration (coral bleaching) was caused by a loss of the symbiotic dinoflagellates from the tissues, a known sublethal stress response of corals. PFW caused a significant decrease in Fv/Fm in symbiotic dinoflagellates freshly isolated from the coral Heliofungia actiniformis at 6.25% PFW, slightly lower than the studies in hospite. Corals exposed to lower PFW concentrations (range 0.1%–10% PFW v/v) for longer periods (8 days) showed no decrease in Fv/Fm, discolouration, loss of symbiotic dinoflagellates or changes in gross photosynthesis or respiration (measured using O2 exchange techniques). The study demonstrates minor toxicity of PFW from Harriet A oil platform to corals and their symbiotic algae.
Temporal and spatial variation in recruitment and growth of medusae of the jellyfish, Catostylus mosaicus (Scyphozoa : Rhizostomeae)
Authors: Pitt Kylie A. , Kingsford Michael J.
Published: August 2003

The timing of recruitment and growth of medusae of the commercially harvested jellyfish, Catostylus mosaicus (Scyphozoa), was examined over a period of 8 years at Botany Bay and 2.5 years at Lake Illawarra in New South Wales, Australia. Recruitment events occurred sporadically during December and between March and July at Botany Bay and between February and July at Lake Illawarra. Recruitment did not occur during late winter or spring at either location, although small numbers of recruit medusae could potentially occur during any time of year. Despite anecdotal observations that recruitment sometimes occurred after periods of heavy rain, we found no correlation between the timing of recruitment and rainfall in Botany Bay over a period of 8 years. Cohort analyses indicated growth of small medusae was very rapid (max. 4.81 mm day–1), with growth rates decreasing as medusae grew larger. Medusae appeared to grow faster at Botany Bay than Lake Illawarra. A conservative estimate indicated medusae of C. mosaicus can live for up to 13 months.
New sensitivity grades for Australian river macroinvertebrates
Authors: Chessman Bruce C.
Published: August 2003

The SIGNAL biotic index for river macroinvertebrates, originally developed and tested in eastern Australia, was revised for application to the entire continent. Macroinvertebrate survey data from the National River Health Program were used to set grade numbers between 1 and 10 to represent the water-quality sensitivities of 210 taxa. Grades were assigned at the taxonomic levels customarily used by government agencies (predominantly family level) and by community groups (mainly order). A new index version using these grades, SIGNAL2, was correlated with water temperature, turbidity, electrical conductivity, alkalinity, pH, dissolved oxygen, total nitrogen and total phosphorus. Because of natural spatial variation in water quality, index scores need to be interpreted in a local context or against site-specific predictions generated by the Australian River Assessment System (AUSRIVAS).
Retinal specializations in the blue marlin: eyes designed for sensitivity to low light levels
Authors: Fritsches Kerstin A. , Marshall N. Justin , Warrant Eric J.
Published: August 2003

The large eyes and well-developed visual system of billfishes suggest that vision is an important sense for the detection and interception of prey and lures. Investigations of visual abilities in these large pelagic fishes are difficult, however anatomical studies of billfish eyes and retinas allow prediction of a number of visual capabilities. From the density of ganglion cells in the blue marlin (Makaira nigricans) retina, visual acuities of less than 10 cycles per degree were derived, a surprisingly low visual resolution given the absolute size of the marlin eye. Cone photoreceptors, on the other hand, were present in high densities, resulting in a presumed summation of cones to ganglion cells at a ratio of 40 : 1, even in the area of best vision. The optical sensitivity of the marlin eye was high owing to the large dimensions of the cone photoreceptors. These results indicate that the marlin eye is specifically adapted to cope with the low light levels encountered during diving. Since the marlin is likely to use its vision at depth, it is suggested that this line of research could help estimate the limits of vertical distribution based on light level.
Genetic population structure of mangrove jack, Lutjanus argentimaculatus (Forsskål)
Authors: Ovenden Jennifer R. , Street Raewyn
Published: August 2003

Translocations of mangrove jack, Lutjanus argentimaculatus (Forsskål 1775), to increase angling opportunities in artificial impoundments are foreshadowed in Queensland. To evaluate genetic population structure before translocations occur, mangrove jack were collected from three sites on the Queensland coast and from one site on the north-western coast of Western Australia. Allelic variation at four dinucleotide microsatellite loci was high: gene diversity (heterozygosity) ranged from 0.602 to 0.930 and allelic counts from 10 to 24. Genetic differentiation among collection sites was weak: estimates of FST were 0.002 for all four sites, and less (FST = 0.001) across a major biogeographical boundary (the Torres Strait region). Nucleotide sequence from two mitochondrial regions (control, 375 base pairs, and ATPase, 415 base pairs) was obtained from a subset of the Australian and additional Indo-Pacific (Indonesian and Samoan) mangrove jack. Haplotype diversity was high (control region, 33 haplotypes for 34 fish; ATPase region, 13 haplotypes for 56 fish). Phylogenetic analysis of mitochondrial DNA sequence data could not discern a relationship between tree topology and geography. These results suggest that mangrove jack in Queensland, and possibly throughout Australia, experience high levels of gene flow. The artificial gene flow caused by permitted translocations is unlikely to exceed natural levels. Fine-scale ecological matching between donor and recipient populations may increase stocking success, and is important if translocation is needed as a species recovery tool in the future.
Changes in biological parameters of Atlantic sharpnose shark Rhizoprionodon terraenovae in the Gulf of Mexico: evidence for density-dependent growth and maturity?
Authors: Carlson John K. , Baremore Ivy E.
Published: August 2003

Biological parameters of the Atlantic sharpnose shark Rhizoprionodon terraenovae in the northern Gulf of Mexico were re-examined to test for potential changes due to density dependent responses. Biological data from published studies in the Gulf of Mexico collected during the period 1979–1984 were compared with data collected during the period 1998–2001. For combined sexes, the von Bertalanffy growth parameters were L∞ = 110.8 cm total length, K = 0.39 year–1 and to = –0.86 year during 1984 and L∞ = 94.0 cm total length, K = 0.73 year–1 and to = –0.88 year during 1998–2001. Median size for males and females at maturity decreased from approximately 78.3 and 80.2�cm total length (TL), respectively, in 1979–1980 to 72.6 and 75.8 cm TL, respectively, in 1998–2001. Age at maturity for combined sexes also decreased from 2.3 years in 1979–1980 to 1.4 years in 1998–2001. Litter size was similar between periods (5.0 embryos), as was the average size of embryos close to parturition (32 cm TL; 130–150�g). Growth rates using observed mean size-at-age data were higher from 1998–2001 for early ages (0–2.5 years). The observed decrease in maturity and increased growth rate lends support to the hypothesis of a compensatory response, although it could not be fully determined whether the response was due to differences in methodology among studies, anthropogenic influences or natural causes.
Nutrient response to soil and litter metabolic activity in a transect across a seasonal wetland
Authors: Qiu S. , McComb A. J. , Bell R. W. , Davis J. A.
Published: August 2003

Many wetlands in the interdunal depression of coastal sand dunes of the Swan Coastal Plain are surrounded by partially vegetated catchments. Although litter can be an important source of nutrients, little is known about litter related microbial activity in these catchments, especially its role in regulating nutrient concentrations in soils during the wet season. Heterotrophic microbial activity and phosphorus (P) dynamics were monitored before and after the onset of the wet season along transects from a vegetated catchment to the lakebed in Thomsons Lake, south-western Australia. Microbial activity was measured in the field as CO2 efflux (range from 47 to 176 mg CO2 m–2 h–1) and in the laboratory as substrate-induced-respiration (SIR; range from 11 to 133 μg g–1 h–1). Substrate-induced-respiration was positively correlated with soil organic content, and was concentrated in surface soils. In contrast, in the exposed lakebed most microbial biomass was below the surface, in the 10–30 cm depth zone. There were significant changes in nutrient dynamics in response to soil microbial activity. Before rain, P extracted by anion exchange membrane (PAEM) was well correlated with site litter and plant debris (r2 = 0.90, P�<�0.001), suggesting that PAEM in soils was litter-sourced. This relationship was modified during the wet season: there was an overall increase in microbial biomass P (PMB; from average 7.5 μg g–1 to 21.6 μg g–1), and a decrease in PAEM : PMB in surface soils. Along the study transect, the assimilation index PAEM : PMB declined towards the wetland, where soils were more silty and organic, and CO2 production was significantly higher. Our data suggest that heterotrophic microbial activity has a significant role in regulating P flux from catchment litter during the wet season, which would affect the mobility of litter-sourced P from catchment to the wetland.
Short-term movement and behaviour of black marlin Makaira indica in the Coral Sea as determined through a pop-up satellite archival tagging experiment
Authors: Gunn John S. , Patterson Toby A. , Pepperell Julian G.
Published: August 2003

Pop-up satellite tags were deployed on seven black marlin, Makaira indica,in the north-western Coral Sea, to examine movement, post-capture mortality and habitat preferences. Five of these tags popped up and transmitted positions, and detailed data on diving behaviour, ambient water temperature and daily movement were received via ARGOS transmission from two tags. One tag was later found on a beach, allowing a complete archival data set to be downloaded and geolocation estimates provided by software on-board the pop-up tags and those based on the complete archival tag data sets to be compared. The tags indicated rapid movement away from release sites; three south-easterly displacements (222 km (120 nm), 222 km (120 nm), and 1185.3 km (640 nm) net) appeared to be associated with the East Australian Current, one moved 555.6 km (300 nm) directly east, and the last tag moved offshore and then back towards the coast over a 2-month period for a net displacement of 384 km (207 nm). Based on displacement speeds and diving behaviour, it was concluded that five of the seven fish survived capture and handling for periods ranging from 3 to 64 days. The fate of the other two is unknown. Estimates of longitude made on board the pop-up tag were very similar to the best estimates that could be made using the complete archival data set; however, pop-up tag latitude estimates were significantly more variable than those using the archival data. In the two cases in which pop-up tags were scheduled to stay on the marlin for more than 3 months, the tags detached prematurely, after 39 and 64 days. Temperature and depth data indicated a preference for waters of the mixed layer (20–120 m) and temperatures warmer than 24°C.
Review: Mechanisms of anoxia tolerance in plants. I. Growth, survival and anaerobic catabolism
Authors: Gibbs Jane , Greenway Hank
Published: August 2003

Anoxia can be one consequence of waterlogging and submergence of plants. Anoxia in plant tissues reduces the rate of energy production by 65–97% compared with the rate in air. Thus, adaptation to anoxia always includes coping with an energy crisis. Tolerance to anoxia is relevant to wetland species, rice cultivation and transient waterlogging of other agricultural and horticultural crops. This perspective, in two parts, examines mechanisms of anoxia tolerance in plants. Part 1 covers anoxia tolerance in terms of growth and survival, the interaction of anoxia tolerance with other environmental factors, and the development of anoxic cores within plant tissues. Equally importantly, Part 1 also examines anaerobic carbohydrate catabolism (principally ethanolic fermentation in plants) and its regulation. We put forward two modes of anoxia tolerance, one based on reduced rates of anaerobic carbohydrate catabolism and the other on accelerated rates (Pasteur effect). Further, Part 1 examines mechanisms of post-anoxic injury. In Part 2 (Greenway and Gibbs, manuscript in preparation) we consider flow of the limited amount of energy produced under anoxia to processes essential for cell survival. We show that acclimation to anoxia in plants involves integration of a set of sophisticated characteristics, as a consequence of which the habitat within the anoxic cell is a very different world to that of the aerobic cell.
In vitro and ex vivo green fluorescent protein expression in alveolar mammary epithelial cells and mammary glands driven by the distal 5´-regulative sequence and intron 1 of the goat β-casein gene
Authors: Wu Hsi-Tien , Lin Chich-Sheng , Huang Mu-Chiou
Published: August 2003

The 5′-regulative sequence and intron 1 of the goat β-casein gene from −4044 to +2123 bp was cloned and fused with the reporter gene of green fluorescent protein (GFP) to create a plasmid termed pGB562/GFP. To detect GFP expression, pGB562/GFP was transfected in vitro via liposomes into the mammary epithelial cell line NMuMG. Cells could not express GFP unless the transfected NMuMG cells lined up to create functional alveoli. These functional cells were cultured with lactogenic hormones, including insulin, dexamethasone and prolactin, and were grown on a layer of the extracellular matrix Matrigel. Green fluorescent protein expression levels in NMuMG cells were 25-, 55- and 42-fold those in the control group at 24, 48, and 72 h after pGB562/GFP transfection respectively. In addition, pGB562/GFP was transfected ex vivo by electroporation into mammary gland fragments and cells were then cultured in vitro with a supplement of lactogenic hormones. Strong GFP expression localized in fragments of the mammary gland was observed 24 h after gene transfer. The novel strategy of ex vivo gene transfer into mammary tissue using GFP as a reporter gene to detect the function of a tissue-specific promoter is efficient and convenient. The data obtained herein reveal that the 5′-regulative sequence and intron 1 of the 6.2 kb goat β-casein gene can enhance the efficiency of transgene expression. Thus, the GB562 sequence may act as a good promoter and effectively elevate the production of exogenous protein in mammary glands.