A decline in the abundance and condition of a native bivalve associated with Caulerpa taxifolia invasion

2007 ◽  
Vol 58 (3) ◽  
pp. 263 ◽  
Author(s):  
Jeffrey T. Wright ◽  
Louise A. McKenzie ◽  
Paul E. Gribben

Caulerpa taxifolia is a fast-spreading invasive seaweed that threatens biodiversity in temperate Australian estuaries. To date, little is known about its effects on infauna. In the present study, we describe variation in demographic and life-history traits of the abundant infaunal bivalve, Anadara trapezia, in C. taxifolia and uninvaded habitats (seagrass and unvegetated sediments) at multiple sites across three estuaries in south-eastern New South Wales. Densities of A. trapezia were always lower in C. taxifolia than on unvegetated sediment, and lower in C. taxifolia than in seagrass at three out of four sites where they were compared. Dry tissue weight of A. trapezia was also lower in C. taxifolia than on unvegetated sediment at most sites, but was only lower in C. taxifolia than in seagrass at one of four sites. Populations were dominated by larger individuals (>45 mm length), but smaller individuals (35–45 mm length) were more common in C. taxifolia and seagrass. A. trapezia shell weight and morphology was variable and appeared weakly affected by invasion. Generally, our findings are consistent with the hypothesis that A. trapezia is negatively affected by C. taxifolia. However, C. taxifolia invasion appears complex and, at some places, its effects may not differ from those of native seagrass. There is a need for manipulative studies to understand the mechanisms underlying the effects of C. taxifolia on infauna.

2012 ◽  
Vol 63 (3) ◽  
pp. 246 ◽  
Author(s):  
Jeffrey T. Wright ◽  
James E. Byers ◽  
Loni P. Koukoumaftsis ◽  
Paul E. Gribben

Invasive habitat-forming species cause large changes to the abiotic environment, which may lead to lethal and sublethal effects on native fauna. In this study, we tested whether morphological anti-predator traits of an infaunal bivalve, Anadara trapezia, differed between areas invaded by the habitat-forming seaweed Caulerpa taxifolia and uninvaded habitats in estuaries in New South Wales, Australia. Caulerpa changes the abiotic environment in ways that may affect traits of native species. In particular, there is lower water flow, lower dissolved oxygen in the water and sediments are more silty and anoxic than in unvegetated habitat. To test our hypotheses, we collected Anadara from Caulerpa and uninvaded habitats and measured shell thickness, shell strength and resistance to opening of valves. We found that all three traits were reduced in Anadara from Caulerpa habitat compared with Anadara from uninvaded habitats. These findings are consistent with the idea that trait modifications in native fauna in response to invasive habitat-forming species can potentially increase susceptibility to predation.


2000 ◽  
Vol 48 (1) ◽  
pp. 21 ◽  
Author(s):  
Hugh A. Ford ◽  
Steve Trémont

Most endemic Australian passerines that have been studied display long breeding seasons, multiple nesting attempts, small clutches, low annual productivity, high longevity and a high incidence of cooperative breeding. We compare the life histories of two large endemic honeyeaters (Meliphagidae) near Armidale, New South Wales. Red wattlebirds, Anthochaera carunculata, have a long breeding season, with many nesting attempts and clutches of two eggs, similar to other honeyeaters whose breeding biology has been studied. Noisy friarbirds, Philemon corniculatus, which are spring and summer visitors to the study area, have shorter breeding seasons, usually making one attempt and have a modal clutch size of three. Both species had incubation and nestling periods of about 16 days. Friarbirds apparently have a laying interval of 24 hours, the same as other honeyeaters, but unlike some other endemic passerines, which have laying intervals of 48 hours. Breeding success did not differ between the species, with young fledging from 32.7% of wattlebird nests and 40.9% of friarbird nests. The reproductive strategy of the noisy friarbird thus differs quantitatively from the apparent norm for other honeyeaters and many other Australian endemic passerines.


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.


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.


2016 ◽  
Vol 67 (10) ◽  
pp. 1546 ◽  
Author(s):  
Cassandra L. Rigby ◽  
Ross K. Daley ◽  
Colin A. Simpfendorfer

Deep-water sharks have low biological productivity and are vulnerable to exploitation with species-specific regional life history required to enable effective management. The present study describes the life history of two squalids collected from Australia: (1) the piked spurdog (Squalus megalops) from the tropical Great Barrier Reef; and (2) the Philippine spurdog (S. montalbani) from New South Wales. Maximum observed ages for males and females were 18 and 25 years for S. megalops and 28 and 27 years for S. montalbani. Multiple growth models were all well supported and indicated very slow growth rates for both species. The tropical S. megalops population was smaller and older at maturity than previously reported temperate populations. Males were mature at 352-mm stretched total length (LST) and 12.6 years, whereas females were mature at 422mm LST and 19.1 years. Squalus montalbani males were mature at 700mm LST and 21.8 years, whereas females were mature at 800mm LST and 26 years. Fecundity was lower for S. megalops than S. montalbani with two to three compared with nine to 16 embryos. Both species have a conservative life history, although in the event of overfishing the longer-lived, later-maturing and deeper-dwelling S. montalbani is likely to take longer to recover than S. megalops.


1982 ◽  
Vol 30 (3) ◽  
pp. 461 ◽  
Author(s):  
JA Friend

Descriptions of two new genera including five new species of Australian landhoppers are presented. Two new species are recorded from south-west Western Australia (Austrotroides pectinalis and A. occidentalis) and one each from the Adelaide area (A. crenatus), southern Victoria (Agilestia hyperocha) and southern Queensland-northern New South Wales (A. hylaea). Notes on the life history of Austrotoides crenatus are provided.


1986 ◽  
Vol 37 (3) ◽  
pp. 385 ◽  
Author(s):  
LELM Crowley ◽  
W Ivantsoff ◽  
GR Allen

In recent literature, the crimson-spotted rainbowfish from eastern Australia, M. fluviatilis, is recognized as a single species or subspecies. The present paper includes a study of early life-history stages, which shows that two species are represented: M. duboulayi (Castelnau) from eastern or coastal drainage systems of northern New South Wales and southern Queensland, and M. fluviatilis (Castelnau) of the inland Murray-Darling system.


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