Waders and Other Aquatic Birds on the Swan River Estuary, Western Australia

1938 ◽  
Vol 38 (1) ◽  
pp. 18-29 ◽  
Author(s):  
D. L. Serventy
Keyword(s):  
Western Australia ◽  
River Estuary ◽  
Aquatic Birds ◽  
Swan River

scholarly journals Reproductive biology of Rhabdosargus sarba (Sparidae) in Western Australian waters, in which it is a rudimentary hermaphrodite

2003 ◽  
Vol 83 (6) ◽  
pp. 1333-1346 ◽  
Author(s):  
S. Alex Hesp ◽  
Ian C. Potter
Keyword(s):  
Reproductive Biology ◽  
Western Australia ◽  
River Estuary ◽  
Marine Waters ◽  
Spawning Period ◽  
Shark Bay ◽  
Males And Females ◽  
First Maturity ◽  
Swan River ◽  
Western Australian

The reproductive biology of the tarwhine Rhabdosargus sarba has been studied in three very different environments in Western Australia, namely the lower reaches of the Swan River Estuary and marine waters at the same latitude, i.e. ≈32°S, and a large subtropical marine embayment (Shark Bay) approximately 800 km further north. A macroscopic and histological examination of the gonads demonstrated that R. sarba is typically a rudimentary hermaphrodite in Western Australian waters, i.e. the juveniles develop into either a male or female in which the ovarian and testicular zones of the gonads, respectively, are macroscopically undetectable. This contrasts with the situation in the waters off Hong Kong and South Africa where R. sarba is reported to be a protandrous hermaphrodite. Although R. sarba spawns between mid-late winter and late spring in each water body, the onset of spawning in the estuary is delayed until salinities have risen well above their winter minima. Although males and females attain sexual maturity at very similar lengths in the Swan River Estuary and Shark Bay, i.e. each L50 for first maturity lies between 170 and 177 mm total length (TL), they typically reach maturity at an earlier age in the former environment, i.e. 2 vs 3 years old. During the spawning period, only 25 and 12% of the males and females, respectively, that were caught between 180 and 260 mm TL in nearshore marine waters were mature, whereas 94 and 92% of the males and females, respectively, that were collected in this length-range over reefs, were mature. This indicates that R. sarba tends to move offshore when it has become ‘physiologically’ ready to mature. The L50s at first maturity indicate that the minimum legal length in Western Australia (230 mm TL) is appropriate for managing this species.

Flushing of dense, hypoxic water from a cavity of the Swan River estuary, Western Australia

Estuaries ◽  
2002 ◽  
Vol 25 (5) ◽  
pp. 908-915 ◽  
Author(s):  
Rajendra G. Kurup ◽  
David P. Hamilton
Keyword(s):  
Western Australia ◽  
River Estuary ◽  
Hypoxic Water ◽  
Swan River

Morphological and electrophoretic studies of the palaemonidae (Crustacea) of the Perth Region, Western Australia

1984 ◽  
Vol 35 (6) ◽  
pp. 769 ◽  
Author(s):  
AJ Boulton ◽  
B Knott
Keyword(s):  
Nova Scotia ◽  
Western Australia ◽  
River Estuary ◽  
Morphological Characters ◽  
Present System ◽  
Swan River

A reappraisal of the morphological characters currently used to separate the genera Palaemon, Palaemonetes and Macrobrachium reveals that the present system of classification is inadequate to differentiate the species of these genera occurring in the Swan River Estuary, W.A. Since separation on morphological grounds proved to be unreliable, an electrophoretic survey of 17 enzymes at 24 loci was carried out. The results suggest that Palaemonetes australis may be congeneric with Macrobrachium intermedium. The species of Palaemonetes from the Swan River Estuary are genetically dissimilar to P. vulgaris from Nova Scotia, which appears to be phylogenetically closer to Palaemon afinis. A discussion of the affinities and likely oilgins of these species, with emphasis on the anomalous occurrence of Palaemonetes australis in south-western Australia is presented.

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