Validation of the formation and appearance of annual marks in the otoliths of yellowtail (Trachurus novaezelandiae) and blue mackerel (Scomber australasicus) in New South Wales

1999 ◽  
Vol 50 (5) ◽  
pp. 389 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell ◽  
Neil L. Andrew
Keyword(s):  
Growth Rate ◽  
Age Estimation ◽  
New South ◽  
New South Wales ◽  
Early Summer ◽  
Age Class ◽  
South Wales ◽  
In Captivity

Yellowtail (Trachurus novaezelandiae) and blue mackerel (Scomber australasicus) were captured off the coast of New South Wales, marked with oxytetracycline, and kept in captivity for 1 year. The fish were periodically sampled to validate the use of their otoliths for age estimation. Opaque marks were formed during the year in the otoliths of yellowtail apparently aged 0 to 7 years and in apparently 1-year-old blue mackerel. These marks were formed in winter for both species, but did not become visible until early summer in some fish. There was an association between the growth rate of the otolith and the detection of opaque marks. Within an age class, fish with the fastest growing otoliths tended to have their most recently formed opaque marks visible earliest. These relationships between growth rate and the probability of correctly assigning an age class have important implications for ageing fish. Extra keyword: ageing

Seasonal variation in reproductive performance of Merino ewes in northern New South Wales

1962 ◽  
Vol 2 (4) ◽  
pp. 69 ◽  
Author(s):  
JF Barrett ◽  
TF Reardon ◽  
LJ Lambourne
Keyword(s):  
Seasonal Variation ◽  
Birth Weight ◽  
Reproductive Performance ◽  
New South ◽  
New South Wales ◽  
Early Summer ◽  
The Other ◽  
South Wales ◽  
Group A

Two groups of Merino ewes were observed for five years to determine the variation within years and to make comparisons between years in the numbers of ewes exhibiting oestrus, in fertility, and in lamb birth weights. A group of 35 ewes (continuous), was run constantly with vasectomized rams and services were recorded. From the other (changing) group, a fresh sub-group of 15 ewes was joined with fertile rams every four to six weeks; services were recorded, together with lambing performance and lamb birth weights.Distinct breeding and anoestrous seasons similar to those shown by other workers were observed in both groups of ewes. However, the onset of oestrous activity was a month earlier in the changing ewes than in the continuous ewes.Fertility was low during spring and early summer and reached a maximum in autumn.The birth weight of the lambs appeared to be predominantly influenced by the ewes' nutrition during pregnancy.

Studies on Age, Growth, and Life History of the Pilchard, Sardinops neopilchardus (Steindachner), in Southern and Western Australia

1950 ◽  
Vol 1 (2) ◽  
pp. 221 ◽  
Author(s):  
JM Blackburn
Keyword(s):  
Growth Rate ◽  
Western Australia ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
The Body ◽  
Fish Length ◽  
Linear Type ◽  
Spawning Period ◽  
South Wales

The biology of the unexploited Australian pilchard, Sardinops neopilchardus (Steindachner), was studied from a limited material available from Victorian, Tasmanian, South Australian, and Western Australian waters. This completes the preliminary study of the species over almost the whole of its sub-continental range. In Victorian waters, the surface shoaling season is spring and summer, in South Australia, summer and autumn, and in southern Western Australia, autumn and winter; these are the spawning seasons for the respective areas. In New South Wales and Queensland waters, the shoaling season is autumn to spring, which is again a spawning period. The situation in Tasmania, where the species is rare, is probably similar to that in Victoria. On the west coast of Australia, where the species extends northward to the Tropic of Capricorn (as it also does in the east) the seasonal distribution is not clear. In all these areas pilchard occurrences are virtually limited to the bay and neritic waters. Victorian pilchards attain mean standard lengths of about 8.0, 10.5, 12.5, 14.0, and 15.5 cm. at the ages of one, two, three, four, and five years respectively. This growth rate is considerably lower than that in New South Wales. In southern Western Australia the growth rate is intermediate between the other two, but in South Australia it was not established. The average size of pilchards in the seasonal shoals appears to be greater in Western Australia than elsewhere, but no fish over 19.5 cm. standard length (9.0 in. total length) has been encountered in any of the current Australian investigations. Sexual maturity occurs earlier in Victoria than in New South Wales, sometimes at one year of age. The ring pattern of Australian pilchard scales is complex, involving yearly, spawning, and secondary rings. A hypothesis to account for the formation of spawning rings is outlined, and an earlier hypothesis relating to yearly rings is abandoned. Secondary rings occur on most scales from the same fish. In all waters the season of ring formation coincides with that of surface availability of fish, but in Victoria it is also the growing season, which makes age determination particularly difficult. The fish-length/scale-length relationship for Victorian material is of the same linear type as for New South Wales, but there are differences in the size of scales taken from the same area of the body. The possible influences of distribution, size, and condition of fish on future economic exploitation are discussed.

A new record extending the Southerly distribution of the Shark Ray (Rhina ancylostomus), and notes on the behaviour of the specimen in captivity

1992 ◽  
Vol 43 (1) ◽  
pp. 319 ◽  
Author(s):  
I Gordon
Keyword(s):  
New Record ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
In Captivity ◽  
Live Specimen

A live specimen of Rhina ancylostomus was collected off Forster, New South Wales, Australia (32�10'S, 152�45'E), some 600 km farther south than the species has previously been recorded. The specimen has been maintained live at the Manly Oceanarium, where information has been gained on some basic behavioural attributes of this rare elasmobranch.

Performance of Hereford and crossbred Hereford cattle in the subtropics of New South Wales: growth of first-cross calves to weaning

1978 ◽  
Vol 29 (6) ◽  
pp. 1313 ◽  
Author(s):  
R Barlow ◽  
GH O'Neill
Keyword(s):  
Growth Rate ◽  
Birth Weight ◽  
New South ◽  
New South Wales ◽  
Gestation Length ◽  
Body Dimensions ◽  
South Wales ◽  
Hereford Cattle

Thirty-one Simmental (S), 33 Friesian (F), 27 Brahman (B) and 30 Hereford (H) sires were mated to Hereford (H) females over 3 years at Grafton to evaluate the performance of first-cross calves in the subtropics of New South Wales. An average of four calves was produced by each sire. Gestation lengths of B x H and S x H calves were 8 and 3 days longer and those of F x H calves were 2 days shorter than in H x H calves. There was a significant genotype x sex interaction for birth weight. Among male calves B x H were heaviest at birth, while S x H were heavier than H x H. There were no significant differences between genotypes among female calves. When adjusted to a constant gestation length B x H males were still heavier at birth. Crossbred calves grew faster to weaning than Hereford calves. Advantages in liveweight at weaning were 12.4 kg (B x H), 15.1 kg (S x H) and 16.3 kg (F x H), when a common conception day was assumed. Crossbred calves had greater body dimensions at birth, and generally had greater increases in body dimensions between birth and weaning. Differences in body dimensions were not entirely accounted for by differences in weight. Brahman x H calves had approximately twice as much eyelid pigmentation as calves of other genotypes. Male calves had 1.4 days longer gestation length, 2.2 kg heavier birth weight (genotype x sex interaction significant), and 60 g day-1 faster growth rate to weaning than females.

A Biological Study of the Anchovy, Engraulis australis in Australian Waters

1950 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
M Blackburn
Keyword(s):  
Growth Rate ◽  
Life History ◽  
New South ◽  
New South Wales ◽  
Border Region ◽  
Biological Study ◽  
Fish Length ◽  
Slight Variation ◽  
Scale Reading ◽  
South Wales

A biological study was made of the common Australian anchovy, Engraulis australis (White), which occurs in coastal waters south of the Tropic of Capricorn. The occurrences in Victorian waters, where the only fishery exists, were those most fully investigated. There are three subspecies which are easily recognized by their mean vertebra numbers, in combination with the region of occurrence. E. a. australis (White) occurs in Queensland and in all but the southernmost waters of New South Wales. E a antipodum Gunther ranges from the border region of New South Wales through Victorian, Tasmanian, and South Australian waters. E. a. fraseri n, subsp. occurs in Western Australia. Each subspecies is further divided into local populations which intergrade. The subspecies antipodtim grows to about 2.3, 2.9, 3.5, 4.2, and 4.7 inches of total length (mean sizes) at 1/2, 1 1/2, 2 1/2, 3 1/2:, and 4 1/2: years respectively, The greatest known length is 6.2 inches. Sexual maturity is usually attained at 1 year. Spawning occurs mainly in the inlets, in summer. The fish inhabit principally the inlet waters, but as they become older they tend to move out to sea in winter and return in spring. n'ithin the inlets, the younger fish are usually found furthest from the sea. There is a special brackish-water population in the rivers entering the Gippsland Lakes. The growth rate of the subspecies australis is similar to that of antipodum, but the life history ppears to differ in many ways, although the full facts are not clear. There is more spawning in the colder months, and it takes place mainly at sea. The subspecies fraseri occurs both in inlets and at sea, but the data are insufficient to establish the life history. The growth rate is approximately the same as elsewhere. Anchovies occur in large numbers in certain inlets, where they can be caught easily with haul seines. In Port Phillip Bay there are proficient anchovy fishermen who cannot dispose of much of the fish they are able to catch. The fish would be suitable for canning whole, for fish paste (for which a little is used now) and for live-bait for tuna fishing. They would not be suitable for oil reduction. The scale-reading (age) studies yielded some results of general academic interest. The fish-length/scale-length relationship is not the same in all regions, and this affects calculations of gvowth rate. There is slight variation in growth rate between localities, and possibly between year classes and sexes; and apparent but not real variation between age-groups, and between different sizes in each age-group.

Mild congenital goitre increases lamb mortality in southern New South Wales

2008 ◽  
Vol 48 (7) ◽  
pp. 995 ◽  
Author(s):  
S. M. Robertson ◽  
M. A. Friend ◽  
B. J. King
Keyword(s):  
Growth Rate ◽  
Iodine Deficiency ◽  
New South ◽  
New South Wales ◽  
Small Degree ◽  
Wagga Wagga ◽  
South Wales ◽  
High Incidence

Congenital goitre, symptomatic of iodine deficiency, can be associated with elevated levels of lamb mortality. This study details an outbreak east of Wagga Wagga in southern NSW, where goitre has previously not been documented. Measurements were taken on flocks at two sites near Ladysmith. Up to 82% of dead lambs had thyroid : weight ratios of more than 0.4 g/kg bodyweight, potentially large enough to affect survival. Up to 16% of lambs surviving to marking had enlarged thyroids (i.e. estimated by palpation). Lambs with enlarged thyroids may be more prone to dystocia, with ewes requiring assistance at delivery. Sex and birthweight were not related to thyroid size, but of lambs surviving to marking, a greater proportion of Merino than crossbred lambs had enlarged thyroids. At the second site, growth rate from birth to marking but not to weaning was reduced in lambs with higher thyroid scores. The high incidence of goitre in these flocks suggests that iodine deficiency may be an important factor in lamb mortality in some years in this region, but is unlikely to be detected due to the relatively small degree of thyroid enlargement.

Nematode parasite control in weaner cattle on the Northern Tablelands of New South Wales

1979 ◽  
Vol 19 (98) ◽  
pp. 269 ◽  
Author(s):  
FL Bowen
Keyword(s):  
Growth Rate ◽  
New South ◽  
Early Summer ◽  
Parasite Infection ◽  
Parasite Control ◽  
Regular Treatment ◽  
South Wales ◽  
Two Factors ◽  
Parasite Infections ◽  
Production Losses

An indication of the extent to which parasite infection can limit production in yearling cattle was studied by comparing a monthly treatment with cambendazole with non-treated control cattle. In the same experiment the technique of limiting parasite infections by alternate grazing of pastures by sheep and cattle was studied. Growth rate of monthly treated cattle (0.667 kg day-1) was significantly (P < 0.05) greater than for untreated cattle (0.421 kg day-1) over the 12-month period of the trial. The mortality of 12.5% in untreated animals was avoided by regular treatment. These two factors resulted in a marked financial advantage to monthly treated cattle. Ostertagia ostertagi, as the major nematode involved, produced production losses primarily in the spring and early summer periods. The alternation of sheep and cattle grazing gave an advantage over set stocked cattle in both liveweight gain and financial returns, but did not prevent mortalities in untreated cattle.

Adaptation of pearl millet (Pennisetum typhoides) to coastal New South Wales. 1. Preliminary evaluation

1973 ◽  
Vol 13 (65) ◽  
pp. 685 ◽  
Author(s):  
R Ferraris ◽  
MJT Norman ◽  
AC Andrews
Keyword(s):  
Growth Rate ◽  
Pearl Millet ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Performance Criteria ◽  
Forage Crop ◽  
Pennisetum Typhoides ◽  
South Wales ◽  
Commercial Cultivars

The adaptation of pearl millet (Pennisetum typhoides) as a summer forage crop to coastal New South Wales was assessed at Camden (latitude 34�S). Spaced plants of 20 strains, including openpollinated and hybrid types, commercial cultivars and advanced breeding lines, were grown in a time of planting-time of harvest experiment. Only data from the five commercial cultivars are presented. The growth pattern and productivity of three of these cultivars were measured in a second experiment at normal plant spacing. In experiment 1, with planting dates from November 23 to February 14, all cultivars showed a reduction in time to early flowering with later planting. Two maturity groups were recognised: mid-season (cultivars Tamworth, Yates Hybrid and Mx 001) and late-season (Ingrid Pearl and Katherine Pearl). The late cultivars did not differ in yielding ability from the mid-season cultivars, but had fewer tillers, higher leaf content and slightly higher protein content in both experiments. In experiment 1, later planting reduced dry matter yield and tiller number. Relative growth rate in the early reproductive phase of later types, but not that of midseason types, was positively related to length of day. In experiment 2, sown January 25 in 0.5 m rows, Katherine Pearl, Ingrid Pearl and Tamworth all yielded approximately 12,000 kg ha-1 dry matter at 12 weeks from sowing. A maximum growth rate of 37.9 g m - 2 day-1, representing 8.1 per cent utilisation of visible radiation, was achieved with Tamworth between six and eight weeks from sowing. From these preliminary experiments it was concluded that pearl millet satisfied basic performance criteria and justified further study as a potential forage crop for the region.

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