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

1950 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
M Blackburn

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.

1950 ◽  
Vol 1 (2) ◽  
pp. 221 ◽  
Author(s):  
JM Blackburn

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.


1993 ◽  
Vol 44 (5) ◽  
pp. 709 ◽  
Author(s):  
KML Perera

Fifteen (or sixteen) species of ectoparasites-6 monogeneans, 4 (or 5) trematodes, 2 copepods, 1 isopod, 1 cestode, and unidentified cysts -were collected from 428 Scomber australasicus individuals caught at Eden, New South Wales, Australia, between November 1988 and June 1992. Neither common nor rare parasites of slimy mackerel showed seasonal variation in abundance or prevalence. Only the copepod Brachiella magna occurred more frequently on larger (older) fish than smaller (younger fish). Two monogeneans (Kuhnia scombri, Pseudokuhnia minor), 2 didymozoids, and unidentified cysts occurred more frequently on smaller than larger fish. The intensities of the remaining monogeneans (Kuhnia scombercolias, Kuhnia sprostonae and Grubea australis), 1 didymozoid, 1 copepod (Peniculus sp.), the isopod (Ceratothoa imbricata) and a trypanorhynch cestode were not significantly correlated with fish length.


1999 ◽  
Vol 50 (5) ◽  
pp. 389 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell ◽  
Neil L. Andrew

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


PEDIATRICS ◽  
1964 ◽  
Vol 33 (5) ◽  
pp. 805-805
Author(s):  
CLEMENT A. SMITH

For the pediatrician curious enough to pursue the life history of his patient into its prenatal phase or the obstetrician interested in more than one of his two patients, this small book will be of great usefulness. Of the twenty-one chapters, twelve are by Australian or New Zealand workers, the Editor, a Professor of Obstetrics and Gynaecology at the University of New South Wales, among them. The international flavor is augmented by Swedish, German, and Scottish contributors.


1979 ◽  
Vol 30 (2) ◽  
pp. 265 ◽  
Author(s):  
H Paxton

Australian beachworms, recognized by specialists as one species Onuphis teres (Ehlers 1868), and by fishermen as a number of forms, were studied to determine whether more than one species was involved. Monthly sampling at a study site (Narrabeen, New South Wales) and collections from other localities were undertaken to study the morphology of beachworms, electrophoretic mobility of glucosephosphate isomerase and aspects of their life history. Three forms of beachworms-slimy, stumpy and kingworm-occur at the study site. Stumpies were found to be young kingworms, while slimy represents a separate species. The two species belong to Americonuphis Orensanz, 1974; the name is preoccupied and is replaced with Australonuphis. The holotype of A. teres is a kingworm and the closely related slimy is described as A. Parateres, sp. nov. Four other forms of beachworms were collected from northern New South Wales and Queensland: stripey, giant, wiry and white-headed wiry. These forms are referred to Onuphis. Stripey and giant are morphologically distinct and are described as O. taeniata, sp. nov., and O. gygis, sp. nov., respectively. Wiry and white-headed wiry belong to a polymorphic species described as O, mariahirsuta, sp. nov.


2021 ◽  
Vol 13 (18) ◽  
pp. 10207
Author(s):  
Fahim Ullah ◽  
Sara Imran Khan ◽  
Hafiz Suliman Munawar ◽  
Zakria Qadir ◽  
Siddra Qayyum

Bushfires have been a key concern for countries such as Australia for a long time. These must be mitigated to eradicate the associated harmful effects on the climate and to have a sustainable and healthy environment for wildlife. The current study investigates the 2019–2020 bushfires in New South Wales (NSW) Australia. The bush fires are mapped using Geographical Information Systems (GIS) and remote sensing, the hotpots are monitored, and damage is assessed. Further, an Unmanned Aerial Vehicles (UAV)-based bushfire mitigation framework is presented where the bushfires can be mapped and monitored instantly using UAV swarms. For the GIS and remote sensing, datasets of the Australian Bureau of Meteorology and VIIRS fire data products are used, whereas the paths of UAVs are optimized using the Particle Swarm Optimization (PSO) algorithm. The mapping results of 2019–2020 NSW bushfires show that 50% of the national parks of NSW were impacted by the fires, resulting in damage to 2.5 million hectares of land. The fires are highly clustered towards the north and southeastern cities of NSW and its border region with Victoria. The hotspots are in the Deua, Kosciu Sako, Wollemi, and Yengo National Parks. The current study is the first step towards addressing a key issue of bushfire disasters, in the Australian context, that can be adopted by its Rural Fire Service (RFS), before the next fire season, to instantly map, assess, and subsequently mitigate the bushfire disasters. This will help move towards a smart and sustainable environment.


1978 ◽  
Vol 29 (6) ◽  
pp. 1313 ◽  
Author(s):  
R Barlow ◽  
GH O'Neill

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.


1985 ◽  
Vol 36 (2) ◽  
pp. 235 ◽  
Author(s):  
JH Harris

The age of M. novemaculeata from the Hawkesbury River and other streams in the Sydney Basin, New South Wales, was determined by using otoliths. Annuli were counted after simple sectioning of otoliths and intensification of the growth-check pattern by a two-stage burning technique. Age determinations were validated by the use of fish of known age; an error of + 1 year occurred in 17% of determinations. Ages of older fish (14+ to 18+ years) were not overestimated by more than 2-4 years, if at all. Progression of year-classes, and the annual nature of growth-check formation, further validated age determinations. Scale-reading seriously underestimated the age of bass. M. novemaculeata is a long-lived species. The oldest fish was 22+ years, and the mean age of the sample (n = 607) was 4.9 years. There are significant differences in longevity between the sexes; fewer males reach the older age-groups. About 10% of juvenlle fish deposited a growth-check in their otoliths during their upstream recruitment migration. The frequency of this 'migration check' was increased to 20% by capture and relocation of juveniles to isolated waters. A procedure was designed to identify migration checks in wild fish.


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