Temporal and spatial variation in recruitment and growth of medusae of the jellyfish, Catostylus mosaicus (Scyphozoa : Rhizostomeae)

2003 ◽  
Vol 54 (2) ◽  
pp. 117 ◽  
Author(s):  
Kylie A. Pitt ◽  
Michael J. Kingsford

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.

1988 ◽  
Vol 39 (6) ◽  
pp. 709 ◽  
Author(s):  
JJ Burchmore ◽  
DA Pollard ◽  
MJ Middleton ◽  
JD Bell ◽  
BC Pease

Four species of whiting (Family Sillaginidae) were collected from Botany Bay, New South Wales, between 1977 and 1979: Sillago ciliata (sand whiting), S. maculata maculata (trumpeter whiting), S. robusta (stout whiting) and S. bassensis flindersi (eastern school whiting). Sillago ciliata was the most abundant species over-all. Sillago ciliata was caught in greatest numbers in Zostera seagrass and shallow sandy habitats, whereas S. m. maculata, S. robusta and S. b. flindersi were most abundant over deeper muddy and sandy habitats. Sillago ciliata and S. b. flindersi were present mainly as juveniles. Gonosomatic indices and gonadal maturity stages of S. ciliata and S. m. maculata peaked around February. These species probably spawn within the Bay. Length to caudal fork at first maturity was 24 cm for male and female S. ciliata, 19 cm for male and female S. m. maculata, 17 cm for male and 18 cm for female S. robusta, and 14 cm for male and female S. b. flindersi. Although all species fed mainly on polychaetes and crustaceans, there was little overlap in specific dietary items between species. Variations observed in diet were due to fish size and temporal and spatial habitat differences within and among species.


2006 ◽  
Vol 21 (2) ◽  
pp. 217 ◽  
Author(s):  
Bryan E. Chenhall ◽  
Brian G. Jones ◽  
Craig R. Sloss ◽  
Mark O'Donnell ◽  
Marrack Payne ◽  
...  

2006 ◽  
Vol 21 (2) ◽  
pp. 228 ◽  
Author(s):  
Paul L. Brown ◽  
Vincent J. Carolan ◽  
Deborah J. Hafey ◽  
Machiko Iko ◽  
Scott J. Markich ◽  
...  

1985 ◽  
Vol 25 (4) ◽  
pp. 758 ◽  
Author(s):  
DG Hall ◽  
EC Wolfe ◽  
BR Cullis

Pasture production, ewe and lamb growth, ewe wool production and diet quality were studied on lucerne-subterranean clover pastures at Wagga Wagga, New South Wales. Lucerne was sown at rates of 0.75 to 3.0 kg/ha, and the pastures were rotationally grazed with Border Leicester x Merino ewes at 9.6 or 12.7 sheep/ha, the ewes lambing in August- September. Lucerne density declined by 45% over the 3 years on all treatments. The clover cultivar sown, Woogenellup, had low persistence, particularly at 12.7 sheep/ha. The density of lucerne had little effect on annual wool and lamb production, although the ewes grew faster on the denser lucerne in summer and the sparser lucerne in winter. At 12- 7 sheep/ha, there was an extra 19% total lamb weight by the end of November and an extra 22% of finer wool (1 �m) annually, but the fleeces had a higher proportion of wool tenderness. The major limitations of the lucerne-subterranean clover pastures to sheep production were the low quality of the diet in early summer, and low pasture production in late winter. In early summer the lucerne was rapidly consumed, leaving only moderate quality clover and grass residues, which limited lamb growth, while in winter pregnancy toxaemia occurred, fleeces were tender and wool growth was low, particularly during a drought in 1976.


1982 ◽  
Vol 33 (6) ◽  
pp. 945 ◽  
Author(s):  
IG Eliot ◽  
DJ Clarke

A 5-year set of profile data from Warilla Beach, N.S.W., measured fortnightly, has been statistically analysed by using Fourier transform, least-squares, and empirical orthogonal function (eigenfunction or EOF) techniques to identify characteristic patterns of temporal and spatial variation in the sediment volume of the subaerial beach. Least-squares analysis enabled separation of the variation in the subaerial beach at Warilla into a 5-year trend, periodic fluctuations and aperiodic events. The periodic fluctuations are dominated by biennial and annual components. The biennial component accounts for 40% of the sediment budget of the subaerial beach, the annual component 30%, 13% is due to the long-term trend over the 5 years, and about 20% is estimated as aperiodic fluctuations mainly related to changes in the wave regime. Phase differences were identified for periodic oscillations on adjacent beach segments and a chronology of change in sediment volume deduced from the phase differences. The results show that variation in the sediment volume of the subaerial beach is determined by interaction between the biennial and seasonal exchanges although the resulting pattern of exchange may be obscured by higher-frequency beach changes. In alternate years the focus of onshore-offshore sediment exchange shifts from the centre of the beach to the exposed, northern sector. The major depositional zone associated with this exchange is located on the southern+entral sector of the beach and the major erosion zone is on the northern part of the beach. The pattern of alongshore sediment exchange was more closely investigated by EOF analysis. The method facilitated separation of onshore-offshore and alongshore modes of sediment transfer and identification of the patterns of alongshore sediment exchange. The first four EOF's for the data on the subaerial beach at Warilla contain 95.3% of the total variance. The fundamental pattern of sediment movement identified in the EOF analysis involves an onshore-offshore transfer of sediment in biennial, seasonal and 6-monthly cycles. The transfer accounts for 61.7% of the variance for the sediment store of the subaerial beach. The amplitude spectrum of the associated time series for this eigenfunction mode shows that the biennial component is dominant. This result supports the results from the least-squares analysis. It could not have been anticipated from previous studies of beach change from New South Wales or elsewhere and is the subject of ongoing investigation. Subsequent eigenfunction modes identify alongshore movements, with three patterns accounting for a further 33.8% of the remaining variance. They are associated with the prevailing system of inshore water circulation and identify major, recurrent rip and bar locations. Time series associated with the eigenfunction modes confirm the dominance of biennial, annual, and biannual sediment transfers occurring on Warilla Beach.


1967 ◽  
Vol 15 (6) ◽  
pp. 1163 ◽  
Author(s):  
WH Ewers

A morph-frequency cline and a size cline are described for the snail Velacumantus australis. The frequency of a white-banded form decreases clinally with latitude South. Living populations from Queensland and northern New South Wales have frequencies between 7 and 18% whereas all populations from southern New South Wales and eastern Victoria, except those from Lake Illawarra, have frequencies between 2 and 5%. The frequency in Port Phillip Bay is less than 0.1%. The frequency in a sample from Swan River, Western Australia, was 9.1% about the same as in samples from localities of the same latitude on the eastern coast of Australia. The frequency in most fossil samples was similar to that in nearby living populations. The mean length of populations from the eastern states increases clinally with increase in latitude South, although there are some irregular fluctuations between adjacent populations which are probably influenced by population density.


1981 ◽  
Vol 29 (2) ◽  
pp. 121 ◽  
Author(s):  
GM Lodge

Emergence and survival of the seedlings of warm-season native perennial grasses Aristida ramosa R.Br., Bothriochloa macra (Steud.) S . T. Blake, Dichanthium sericeum (R.Br.) Camus, Sporobolus elongatus R.Br., Eragvostis leptostachya Steud. and Chloris truncata R.Br. and the cool-season species Stipa variabilis Hughes and Danthonia linkii Kunth were studied in both native pastures and sown monospecific plots on the north- west slopes of New South Wales. The most favourable period for the successful emergence and establishment of warm-season grasses was from mid summer to early autumn. Cool-season native perennial grasses established best from seedlings that appeared from mid autumn to late winter. Few seedlings were observed to germinate in spring, probably as a result of large variations in temperature, low minimum temperatures or intra and interspecific competition. Seedlings growing in native pasture spent long periods in the vegetative phase compared to the early flowering of seedlings in the sown plots. In the pasture studied only two seedlings flowered over 700 days after emergence, and many others after persisting for up to 2 years died without producing seed. These findings indicate that the seedlings in these native pastures were under considerable stress and that the adult populations of the species examined were relatively stable and little recruitment occurred.


2002 ◽  
Vol 42 (8) ◽  
pp. 1087 ◽  
Author(s):  
C. R. Kidd ◽  
G. M. Murray ◽  
J. E. Pratley ◽  
A. R. Leys

Winter cleaning is the removal of grasses from pasture using selective herbicides applied during winter. We compared the effectiveness of an early (June) and late (July) winter cleaning with an early spring herbicide fallow (September), spring (October) herbicide and no disturbance of the pasture on development of the root disease take-all in the subsequent wheat crop. Experiments were done at 5 sites in the eastern Riverina of New South Wales in 1990 and 1991. The winter clean treatments reduced soil inoculum of Gaeumannomyces graminis var. tritici (Ggt) compared with the other treatments at all sites as measured by a bioassay, with reductions from the undisturbed treatments of 52–79% over 5 sites. The winter clean treatments also significantly reduced the amount of take-all that developed in the subsequent wheat crop by between 52 and 83%. The early and late winter clean treatments increased the number of heads/m2 at 3 and 1 sites, respectively. Dry matter at anthesis was increased by the winter clean treatments at 3 sites. Grain yield was increased by the winter cleaning treatments over the other treatments at the 4 sites harvested, with yield increases of the early winter clean over the undisturbed treatment from 13 to 56%. The autumn bioassay of Ggt was positively correlated with spring take-all and negatively correlated with grain yield of the subsequent wheat crop at each site. However, there was a significant site and site × bioassay interaction so that the autumn bioassay could not be used to predict the amount of take-all that would develop.


1987 ◽  
Vol 38 (6) ◽  
pp. 795 ◽  
Author(s):  
I Yassini ◽  
BG Jones

Major controls of the distribution pattern and abundance of living ostracod populations in Lake Illawarra, a coastal lagoon south of Wollongong, New South Wales, are salinity and the benthic flora. The biocenotic ostracod assemblage from the intertidal zone around Windang Island is a typical, diverse, upper sublittoral, open ocean fauna. The lake entrance channel, which is a transport corridor for marine sediments into the lagoon, has a restricted ostracod biocenose (14 species) but contains an additional 72 species in the diverse thanatocenose resulting from the mixing of estuarine and marine species. Within the lagoon, the benthic flora influences the ostracod distribution pattern with the most diverse assemblage (13 species) occurring in areas covered by seagrasses. Seagrass distribution is, in turn, controlled by water depth, circulation, turbidity and substrate. Estuarine ostracods associated with the seagrass beds can tolerate florally induced fluctuations in pH from 7 to 10 and in dissolved oxygen from 1 mg l-1 to 14 mg l-1. In the deeper parts of the lagoon with a predominantly mud substrate, the ostracod assemblage is dominated by Osticythere reticulata. Most samples retrieved from the most polluted part of the lagoon contained no ostracods. A total of 90 ostracod species and subspecies belonging to 50 genera has been identified; nine species: Cytheralison cosmetics, Callistocythere janiceburrowsae, Callistocythere windangensis, Neocytherideis anneclarkeae, Actinocythereis robustus, Bradleya rectangulata, Procythereis jonesi, Hemicytherura windangensis and Cytheropteron wrighti; and one subspecies, Callistocythere dorsotuberculata paucicostata, are described as new to science.


1978 ◽  
Vol 29 (6) ◽  
pp. 803 ◽  
Author(s):  
BD Scott

The changes in the concentrations of nitrate, phosphate and silicate in a marine-dominated estuarine basin are described and related to the changes in the physical properties of the water and the primary production. The consumption of oxygen and nutrient regeneration in the lower water column were directly related to density differences in the lower water column, and to the primary production. The regeneration of nutrients was related to the consumption of oxygen, with seasonal differences in the regeneration of nitrate and silicate. Increased rates of nutrient regeneration during salinity stratification after heavy rain were attributed to increased sedimentation rates.


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