The biology of a landlocked form of the normally catadromous salmoniform fish Galaxias maculatus (Jenyns). I. Life cycle and origin

1971 ◽  
Vol 22 (2) ◽  
pp. 91 ◽  
Author(s):  
DA Pollard
Keyword(s):  
Life Cycle ◽  
New Zealand ◽  
River System ◽  
Heavy Rain ◽  
Early Spring ◽  
Ancestral Population ◽  
Late Winter ◽  
Eastern Australia ◽  
Galaxias Maculatus ◽  
Western Victoria

In contrast to most other members of the family Galaxiidae which live and reproduce in fresh water, Galaxias maculatus, the common jollytail of Australia and "whitebait" of New Zealand, is normaIly catadromous throughout its range (south-eastern Australia, New Zealand, and southern South America). In some athalassic inland lakes on the volcanic plains of south-western Victoria, however, a number of populations apparently descended from this species have becomelandlocked. The life cycle of the forminhabiting one of these lakes (the "landlocked jollytail" of Lake Modewarre) may be briefly summarized as follows: Gonadal maturation in the adult fish, which live in the slightly saline landlocked lake, begins around March and is almost completed by about June. The final stage of maturation is not reached, however, until these fish migrate short distances up intermittent inflowing creeks when the latter begin to flow in late winter and spring (July-October). Spawning takes place when the creeks are swollen after heavy rain, the eggs being deposited amongst flooded vegetation in shallow areas of slow-flowing water along the creek banks. Many of the spent fish die after spawning. The eggs, which are stranded when the flood-waters subside, develop amongst the vegetation on the banks above the normal water level. After development is complete reimmersion by the first flood to cover them stimulates hatching. The normal developmental period is probably about 2 weeks, but in the absence of flooding hatching can be delayed up to at least a month after fertilization. The newly hatched larvae are washed downstream into the lake where they feed and grow to maturity. They migrate upstream to spawn in the following late winter-early spring season at an age of approximately 1 year. The fish grow to about 9 cm in their first year, 14 cm in their second, and 17 cm in their third year. The average size of the females is greater than that of the males. The general features of the life history of this landlocked form are compared and contrasted with those of the stream-dwelling species G. maculatus and a number of other salmoniform fishes. The geological origin of the complex of lakes in south-western Victoria inhabited by landlocked galaxiid populations is discussed, and an hypothesis concerning the origin of the Lake Modewarre form from an ancestral population of G. maculatus in the Barwon-Leigh River system is advanced.

Reproduction of Heterodontus portusjacksoni in Victoria, Australia: evidence of two populations and reproductive parameters for the eastern population

2007 ◽  
Vol 58 (10) ◽  
pp. 956 ◽  
Author(s):  
Javier Tovar-Ávila ◽  
Terence I. Walker ◽  
Robert W. Day
Keyword(s):  
Population Analysis ◽  
Sampling Bias ◽  
Early Spring ◽  
Egg Laying ◽  
Late Winter ◽  
Reproductive Parameters ◽  
Breeding Populations ◽  
Eastern Australia ◽  
Western Victoria ◽  
Far Eastern

Significant differences in the length–frequency composition of catch samples, mass–length relationships and length-at-maturity found between Heterodontus portusjacksoni from western and far-eastern Victoria, suggest the presence of at least two separate breeding populations off south-eastern Australia, with some mixing between these regions. In each region females attain a larger size than males, and collectively those sharks in western Victoria are smaller, present higher mass-at-length, and lower length-at-maturity than those in far-eastern Victoria. These regional differences might be a result of sampling bias, length-selective fishing mortality, environmental conditions, or genetic differences. However, tagging evidence from previous studies and the presence of two bio-geographic provinces in the region support the hypothesis of two separate breeding populations. The essential reproductive parameters for H. portusjacksoni population analysis in far-eastern Victoria were determined, using a novel method to estimate fecundity and the ovarian cycle of an egg-laying species. In this region, females have between 6 and 20 pre-ovulatory oocytes (average = 14, n = 29, standard deviation = 3.71) before the reproductive season. The species has an annual reproductive cycle correlated with water temperature, with ovulation starting during late winter to early spring and a ~6 month egg-laying period. The period from the onset of vitellogenesis to ovulation of oocytes is ~18 months.

Leaf spot and dry rot of lettuce caused by Xanthomonas vitians (Brown) Dowson

1963 ◽  
Vol 14 (6) ◽  
pp. 778 ◽  
Author(s):  
DE Harrison
Keyword(s):  
Leaf Spot ◽  
Early Spring ◽  
Late Winter ◽  
Laboratory Studies ◽  
Dry Rot ◽  
Complete Destruction ◽  
Western Victoria ◽  
Valley Area ◽  
North Western

During the late winter and early spring of 1960, and again to a lesser extent in 1961 and 1962, many lettuce crops in the Murray Valley area of north-western Victoria were seriously affected by a disease characterized by blackening, dry rotting, and collapse of the affected leaves. The incidence of disease varied from about 10% up to practically complete destruction of some plantings. A yellow bacterium was consistently isolated from affected plants and proved to be pathogenic to lettuce. Laboratory studies have shown that the organism agrees closely with the recorded description of Xanthomonas vitians (Brown) Dowson, which has not, apparently, been previously studied in Australia.

Pollen vectors and pollination of faba beans in southern Australia

1991 ◽  
Vol 42 (7) ◽  
pp. 1173 ◽  
Author(s):  
FL Stoddard
Keyword(s):  
Vicia Faba ◽  
Mediterranean Climate ◽  
South Australia ◽  
Early Spring ◽  
Late Winter ◽  
Flower Visitors ◽  
Vicia Faba L ◽  
Faba Beans ◽  
Pollen Vectors ◽  
Western Victoria

Commercial crops of faba beans (Vicia faba L.) in South Australia and western Victoria were surveyed for flower visitors and incidence of pollination. Honeybees were the only pollen vectors. The incidence of pollination was never less than 50% and averaged 80%. The effectiveness of honeybees as pollen vectors contrasts with their ineffectiveness in colder climates, partly because in the Mediterranean climate beans flower in late winter and early spring when bees are in search of pollen. It is unlikely that growers of faba beans in Australia will need to provide supplementary hives to ensure adequate pollination.

Seasonality and global public interest in psoriasis: an infodemiology study

2019 ◽  
Vol 96 (1133) ◽  
pp. 139-143 ◽  
Author(s):  
Qian Wu ◽  
Zhiwei Xu ◽  
Yi-Lin Dan ◽  
Chan-Na Zhao ◽  
Yan-Mei Mao ◽  
...  
Keyword(s):  
New Zealand ◽  
Public Interest ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Late Winter ◽  
Search Volume ◽  
Early Autumn ◽  
Search Data ◽  
Google Search

ObjectiveAlthough patients with psoriasis frequently report seasonal changes in their symptoms, the seasonality of psoriasis has rarely been explored. This study aims to investigate the seasonal pattern of and global public interest in psoriasis using Google search data.MethodsInternet search data were collected from Google Trends. Data on the relative search volume (RSV) from January 2004 to December 2018 were retrieved using the term psoriasis. Cosinor analyses were conducted to examine the seasonality of psoriasis using data from two southern hemisphere countries (Australia and New Zealand) and four northern hemisphere countries (USA, Canada, UK and Ireland).ResultsOverall, searches for psoriasis steadily decreased between 2004 and 2010, and then rose from 2011 to 2018. On cosinor analyses, RSV of ‘psoriasis’ displayed a significant seasonal variation worldwide (p<0.025). Further analyses confirmed the seasonality of psoriasis-related RSV in Australia, New Zealand, USA, Canada, UK and Ireland (p<0.025 for all), with peaks in the late winter/early spring months and troughs in the late summer/early autumn months. The top 11 rising topics were calcipotriol/betamethasone dipropionate, ustekinumab, apremilast, shampoo, eczema, guttate psoriasis, seborrhoeic dermatitis, dermatitis, psoriatic arthritis, atopic dermatitis and arthritis.ConclusionThere was a significant seasonal pattern for psoriasis, with peaks in the late winter/early spring and troughs in the late summer/early autumn. Further studies are warranted to confirm the seasonal pattern of psoriasis using clinical data and to explore the underlying mechanisms.

scholarly journals Seasonal Dynamics of Taphrina deformans Inoculum in Peach Orchards

2007 ◽  
Vol 97 (3) ◽  
pp. 352-358 ◽  
Author(s):  
V. Rossi ◽  
M. Bolognesi ◽  
S. Giosuè
Keyword(s):  
Life Cycle ◽  
Relative Humidity ◽  
Early Spring ◽  
The Other ◽  
Late Winter ◽  
Parasitic Stage ◽  
Tree Canopies ◽  
Trap Plants ◽  
Second Period ◽  
Curled Leaves

The dynamics of the inoculum of Taphrina deformans were studied during a 4-year period by (i) inspecting curled leaves for the presence of asci, (ii) placing deposition spore samplers within the tree canopies, and (iii) exposing potted peach plants (trap plants). These three approaches produced consistent results. Four main periods characterized the dynamics of the inoculum: the first period coincides with the parasitic stage of the pathogen's life cycle and the other periods with the saprophytic stage. Mid- to late spring (first period) was characterized by the presence of asci on infected leaves which produced and ejected large quantities of ascospores in 96% of the samplings. Rainfall was not necessary for ascospore dispersal, which was favored by air temperature <20°C and relative humidity ≥80% or wetness duration >8 h. In summer and autumn (second period), blastospores were trapped in 54 and 24% of samplings, respectively, with low spore numbers. In the winter (third period), blasto-spores were trapped in the lowest numbers and in only 6% of samplings. In late winter to early spring (fourth period), blastospores were found in 56% of samples, with increasing numbers. Rainfall significantly influenced blastospore dispersal and temperature was correlated with the seasonality found during the saprophytic stage.

Long-distance movments of juvenile brushtail possums (Trichosurus vulpecula) on farmland, Hawkes Bay, New Zealand

1996 ◽  
Vol 23 (2) ◽  
pp. 237 ◽  
Author(s):  
PE Cowan ◽  
RE Brockie ◽  
GD Ward ◽  
MG Efford
Keyword(s):  
New Zealand ◽  
Early Spring ◽  
Late Winter ◽  
Trichosurus Vulpecula ◽  
Radio Tracking ◽  
Juvenile Male ◽  
Long Distance ◽  
Male And Female ◽  
The Difference ◽  
One Year

Long-distance movements of juvenile male and female brushtail possums (Trichosurus vulpecula) at a farmland site, Hawke's Bay, New Zealand, were studied by radio-tracking. About 20% of radio-tagged possums dispersed more than 2 km, moving up to 11.5 km from their natal area, most in a north-easterly direction. The proportion of males that dispersed was higher than that of females, but the difference was not statistically significant. All juveniles dispersing did so before they were one year old. The bimodal timing of dispersal in summer and late winter to early spring reflected an underlying similar pattern of breeding. Most possums made several moves before settling. A higher proportion of possums dispersed from the lowdensity area of pastoral and cropping land than from the higher-density areas of swamp and willows. A few dispersal records of ear-tagged animals were also obtained; most records were of males from the area of pastoral and cropping land, and movements ranged from 3 to 25 km.

EVALUATION OF CLOVERS ON SANDY COASTAL SOIL

1977 ◽  
pp. 130-138 ◽  
Author(s):  
W.M. Williams ◽  
L.B. Anderson ◽  
B.M. Cooper
Keyword(s):  
New Zealand ◽  
Drought Stress ◽  
Sandy Soil ◽  
White Clover ◽  
Plant Material ◽  
Red Clover ◽  
Early Spring ◽  
Commercial Cultivars ◽  
Mediterranean Origin ◽  
Winter Annual

In evaluations of clover performances on summer-dry Himatangi sandy soil, it was found that none could match lucerne over summer. Emphasis was therefore placed on production in autumn-winter- early spring when lucerne growth was slow. Evaluations of some winter annual clover species suggested that Trifolium spumosum, T. pallidum, T. resupinatum, and T. vesiculosum would justify further investigation, along with T. subterraneum which is already used in pastures on this soil type. Among the perennial clover species, Kenya white clover (7'. semipilosum) showed outstanding recovery from drought and was the only species to produce significantly in autumn. However, it failed to grow in winter-early spring. Within red clover, materials of New Zealand x Moroccan origin substantially outproduced the commercial cultivars. Within white clover, material from Israel, Italy and Lebanon, as well as progeny of a selected New Zealand plant, showed more rapid recovery from drought stress and subsequently better winter growth than New Zealand commercial material ('Grasslands Huia'). The wider use of plant material of Mediterranean origin and of plants collected in New Zealand dryland pastures is advocated in development of clover cultivars for New Zealand dryland situations.

Distribution of the southern brown bandicoot (Isoodon obesulus) in the Portland region of south-western Victoria

2000 ◽  
Vol 27 (5) ◽  
pp. 539 ◽  
Author(s):  
Michael Rees ◽  
David Paull
Keyword(s):  
Local Population ◽  
Historical Records ◽  
Limited Information ◽  
Field Surveys ◽  
Potential Habitat ◽  
Specimen Collection ◽  
Eastern Australia ◽  
Spatial Isolation ◽  
Observational Bias ◽  
Western Victoria

The southern brown bandicoot (Isoodon obesulus) occurs across the periphery of southern and eastern Australia as a series of isolated regional populations. Historical records and recent surveys conducted for I. obesulus indicate that it has disappeared or decreased significantly from many parts of its former range. Vegetation clearance, habitat fragmentation, feral predators and fire have all been implicated in the decline of the species. This paper examines the distribution of I. obesulus in the Portland region of south-western Victoria. Historical records of I. obesulus were compiled from the specimen collection of Museum Victoria, the Atlas of Victorian Wildlife, Portland Field Naturalists’ Club records and anecdotal sources. Field surveys were conducted to determine the current distribution of I. obesulus in the study area based on evidence of its foraging activity. The historical records reveal limited information: most are clustered around centres of human activity, indicating observational bias. The field surveys demonstrate that I. obesulus occurs in the Portland region as a series of local populations. Each local population is associated with a patch of remnant native vegetation separated from neighbouring patches by dispersal barriers. Within these habitat remnants the occurrence of the species is sporadic. Approximately 69% of the potential habitat is managed by the Forests Service, 31% is managed by Parks Victoria, and less than 0.5% is held under other tenures. Spatial isolation of habitat remnants, fires and feral predators are the main threats to I. obesulus in the Portland region.

Seasonal activity and estivation of lumbricid earthworms in the midlands of Tasmania

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1355 ◽  
Author(s):  
RB Garnsey
Keyword(s):  
Soil Moisture ◽  
Adult Development ◽  
Survival Rates ◽  
Soil Surface ◽  
Early Spring ◽  
Lumbricus Rubellus ◽  
Late Winter ◽  
Cocoon Production ◽  
Density And Biomass ◽  
Earthworm Activity

Earthworms have the ability to alleviate many soil degradational problems in Australia. An attempt to optimize this resource requires fundamental understanding of earthworm ecology. This study reports the seasonal changes in earthworm populations in the Midlands of Tasmania (<600 mm rainfall p.a.), and examines, for the first time in Australia, the behaviour and survival rates of aestivating earthworms. Earthworms were sampled from 14 permanent pastures in the Midlands from May 1992 to February 1994. Earthworm activity was significantly correlated with soil moisture; maximum earthworm activity in the surface soil was evident during the wetter months of winter and early spring, followed by aestivation in the surface and subsoils during the drier summer months. The two most abundant earthworm species found in the Midlands were Aporrectodea caliginosa (maximum of 174.8 m-2 or 55.06 g m-2) and A. trapezoides (86 m-2 or 52.03 g m-2), with low numbers of Octolasion cyaneum, Lumbricus rubellus and A. rosea. The phenology of A. caliginosa relating to rainfall contrasted with that of A. trapezoides in this study. A caliginosa was particularly dependent upon rainfall in the Midlands: population density, cocoon production and adult development of A. caliginosa were reduced as rainfall reduced from 600 to 425 mm p.a. In contrast, the density and biomass of A. trapezoides were unaffected by rainfall over the same range: cocoon production and adult development continued regardless of rainfall. The depth of earthworm aestivation during the summers of 1992-94 was similar in each year. Most individuals were in aestivation at a depth of 150-200 mm, regardless of species, soil moisture or texture. Smaller aestivating individuals were located nearer the soil surface, as was shown by an increase in mean mass of aestivating individuals with depth. There was a high mortality associated with summer aestivation of up to 60% for juvenile, and 63% for adult earthworms in 1993 in the Midlands. Cocoons did not survive during the summers of 1992 or 1994, but were recovered in 1993, possibly due to the influence of rainfall during late winter and early spring.

Phenological development and seasonal distribution of the rutherglen bug, Nnysius vinitor Bergroth (Hemiptera: Lygaeidae), on various hosts in Victoria, south-eastern Australia

1988 ◽  
Vol 78 (4) ◽  
pp. 673-682 ◽  
Author(s):  
Garrick McDonald ◽  
A. Mark Smith
Keyword(s):  
Rapid Development ◽  
Early Spring ◽  
Common Source ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Polygonum Aviculare ◽  
Developmental Thresholds ◽  
Eastern Australia ◽  
Weed Hosts ◽  
Maximum Temperatures

AbstractPopulations of Nysius vinitor Bergroth were studied from 1979 to 1982 in two weed hosts, Arctotheca calendula and Polygonum aviculare, and eight irrigated sunflower crops in a summer cropping area of northern Victoria, Australia. The spring generation began with the adults colonizing flowering A.calendula plants in September and concluded with the rapid development of late stage nymphs and an exodus of adults from these plants from mid-November to December. Gradual invasion of sunflowers occurred mostly in late December and reached a peak at flowering, after which nymphs appeared. P. aviculare attracted adults from February and hosted a number of overlapping generations until winter. The weed sustained diminishing numbers of adults through the winter, except in 1982, when a further generation produced an early spring peak. Immigrant populations were regarded as a common source of adults for initiating the spring and summer generations. The rate of development of N. vinitor in spring was more rapid than that predicted by phenological simulation based on ambient temperatures and laboratory-derived day-degree estimates. This was attributed to increased body temperatures through absorption of solar radiation, and the simulation model was adjusted by increasing daily minimum and maximum temperatures by 1·3 and 5·5°C for young and older instars, respectively. This suggested that older nymphs have lower developmental thresholds or are better able to optimize body temperatures.

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