Diversity of the genus Daphniopsis in the saline waters of Australia

2000 ◽  
Vol 78 (5) ◽  
pp. 794-808 ◽  
Author(s):  
Paul DN Hebert ◽  
Christopher C Wilson
Keyword(s):  
Reproductive Biology ◽  
Western Australia ◽  
Saline Lakes ◽  
Inland Waters ◽  
Allozyme Analysis ◽  
Asexual Population ◽  
Cyclic Parthenogenesis ◽  
Saline Waters ◽  
Group D

Although members of the cladoceran genus Daphniopsis form a dominant element of the fauna in the saline inland waters of Australia, their taxonomy has been in flux. In this study allozyme analysis was employed to examine the diversity, distributions, and reproductive biology of species in this genus. The results establish that D. pusilla, a species formerly thought to be widespread, is restricted to Western Australia, while a newly described species, D. truncata, which shares the attribute of producing a one-egged ephippium, is broadly distributed. The results of this study verify the taxonomic validity of the three recognized species of Daphniopsis, which produce two-egged ephippia, but another member of this group, D. wardi, is described from Western Australia. All populations were found to reproduce by cyclic parthenogenesis, except for one obligately asexual population of D. pusilla × D. truncata hybrids. No other case of hybridization was detected, although two species co-occurred in 15% of habitats. The six species of Daphniopsis now known from Australia appear to represent another example of an endemic radiation in the saline lakes of this continent.

The Distribution of Chaetognatha in the Gulf of Alaska in 1954 and 1956

1959 ◽  
Vol 16 (3) ◽  
pp. 351-361 ◽  
Author(s):  
Paul N. Sund
Keyword(s):  
Coastal Region ◽  
Gulf Of Alaska ◽  
Inland Waters ◽  
San Juan ◽  
Frequency Of Occurrence ◽  
Subarctic Region ◽  
Saline Waters ◽  
Hydrographic Features

Zooplankton collections from two cruises to the Gulf of Alaska during 1954 and 1956 were studied to determine the species of Chaetognatha present, to establish their distribution within those waters, and to consider the distribution of the species with regard to certain general hydrographic features prevalent in the region at the time the collections were made. Also considered were a few collections made during the summer of 1958 in the waters surrounding San Juan Island in the San Juan Archipelago, Washington.The general oceanographic features of the Gulf of Alaska are described. The distributions and frequency of occurrence of 3 species of 2 genera of chaetognatha are described and discussed. Eukrohnia hamata is found at most off-shore stations, diminishing in number nearer the coast in less saline waters. Sagitta elegans is apparently cosmopolitan in the areas studied. S. lyra an oceanic form, was found in regions influenced by waters of the Subarctic Region and the American Coastal Region. The presence of S. lyra in inland waters of the San Juan Archipelago during the summer of 1958 is considered to be an indication of the shoreward movement of oceanic waters.

Aspects of the chemical variability of some Tasmanian inland waters

1976 ◽  
Vol 27 (3) ◽  
pp. 351 ◽  
Author(s):  
RT Buckney
Keyword(s):  
Total Concentration ◽  
Inland Waters ◽  
Morphometric Characters ◽  
Fresh Waters ◽  
Ionic Concentrations ◽  
Geological Conditions ◽  
Chemical Variability ◽  
Saline Waters ◽  
The Mean ◽  
Standard Deviations

Variability of total concentration and of ionic concentrations (measured as the standard deviations) is proportional to a power of the mean concentrations in 25 Tasmanian waters. Stoichiometric variability is low in saline waters and can be high in fresh waters. Climate is recognized as being of primary importance in affecting variability, although morphometric characters exert an influence. Geological conditions are an important factor in determining stoichiometric variability.

A study of the reproductive biology of blue-flowered Conospermum species (Proteaceae)

2006 ◽  
Vol 54 (6) ◽  
pp. 543 ◽  
Author(s):  
Lynley M. Stone ◽  
Kevin A. Seaton ◽  
Margaret Byrne ◽  
Jen A. McComb
Keyword(s):  
Genetic Analysis ◽  
Reproductive Biology ◽  
Western Australia ◽  
Pollen Tubes ◽  
Wild Plants ◽  
Seed Progeny ◽  
Stigma Receptivity ◽  
Open Set ◽  
Hand Pollination ◽  
Insect Pollinators

Blue-flowered Conospermum species are endemic to Western Australia, and are highly sought after in the horticulture industry. Aspects of the reproductive biology of several species were investigated. The paniculate inflorescences of Conospermum eatoniae E.Pritz. contain 6–10 florets; however, the uppermost two or three florets never open and only the basal one or two florets in an inflorescence set seed. When insect pollinators are excluded, flowers do not self-pollinate and set seed. Stigma receptivity occurred for up to 6 days following triggering of the style and was variable between C. eatoniae, C. amoenum Meisn. subsp. amoenum, C. caeruleum R.Br. and C. brownii Meisn. Hand-pollination with 10 pollen genotypes and two maternal C. eatoniae parents showed that although pollen tubes were observed in the style, no seed was set. Genetic analysis of open-set seed progeny showed that C. eatoniae outcrossed infrequently when grown in clonal rows in a plantation, but outcrossing was common in wild plants. This study demonstrates that the reproductive biology of blue-flowered Conospermum is complex and requires further investigation if the species are to be widely cultivated for horticulture.

Biology of Fire Ephemerals of the Sandplains of the Kwongan of South-Western Australia

1985 ◽  
Vol 12 (6) ◽  
pp. 641 ◽  
Author(s):  
JS Pate ◽  
NE Casson ◽  
J Rullo ◽  
J Kuo
Keyword(s):  
Life Cycle ◽  
Reproductive Biology ◽  
Seedling Growth ◽  
Western Australia ◽  
Growth Rates ◽  
Dry Matter ◽  
Dry Weight ◽  
Growing Season ◽  
Adaptive Significance ◽  
Sexually Dimorphic

The growth, longevity, mineral relationships and reproductive biology of 18 species of fire ephemerals were examined in sclerophyllous shrubland, located mainly within the Jurien : Badgingarra region of the Northern Sandplains of the kwongan of SW. Australia. Ten of the species were monocarpic, completing their life cycle within the 6-8 month winter growing season after a summer or autumn fire. The remaining species were polycarpic, commencing reproduction in their second season and surviving and reproducing for a further two to eight seasons (depending on species). Detailed study was made of growth and dry matter allocation in the dioecious, sexually dimorphic, polycarpic species Tersonia brevipes (Gyrostemonaceae). Monocarpic species tended to produce smaller seeds, and exhibited greater seed output per unit biomass and higher harvest indices for dry matter and minerals than polycarpic species. Certain monocarpic species showed great plasticity in final dry weight, e.g. a 2700-fold difference between largest and smallest individuals in a sample of 250 plants of Stipa elegantissima (Poaceae), and a 180-fold range in a similarly sized sample of Macarthuria apetala (Aizoaceae). The fire ephemerals studied generally exhibited faster seedling growth rates, greater concentrations of P and N (but not of Ca, Mg and K) in seedling dry matter, but usually lesser concentrations of P and N (but not of Ca, Mg and K) in seed dry matter than in cohabiting obligate seeder or sprouter species with potential life spans exceeding 15 years. The above-mentioned features of fire ephemerals are suggested to be of special adaptive significance within the context of exploitation of transiently non-limiting habitat resources immediately following fire.

scholarly journals Reproductive biology is alive and well in the west

2020 ◽  
Vol 32 (4) ◽  
pp. 439
Author(s):  
Jim Cummins
Keyword(s):  
Reproductive Biology ◽  
Western Australia ◽  
The West ◽  
Recent Meeting

This report describes a recent meeting of the Endocrine and Reproductive Biology Society of Western Australia (ERBSWA) on 23 July 2019, and summarises the research presented and the prizes awarded.

Faunal assemblages of some saline lakes near Marchagee, Western Australia

1981 ◽  
Vol 32 (1) ◽  
pp. 133 ◽  
Author(s):  
SA Halse
Keyword(s):  
Western Australia ◽  
Saline Lakes ◽  
Salt Lake ◽  
Total Dissolved Solids ◽  
Dissolved Solids ◽  
Faunal Assemblages ◽  
Invertebrate Species ◽  
Solids Concentration ◽  
Eastern Australia

Five saline lakes near Marchagee. with salinities ranging from 10-71‰, were sampled every two months between March and September 1979. The lakes contained faunal assemblages of 6-13 invertebrate species; only two species were common to all lakes. Fish (Pseudogobius olorum) were found in one salt lake. Austrochiltonia subtenuis was recorded at a salinity of 71‰ twice the salinity it was previously thought to tolerate. Pseudogobius olorum was collected at a salinity of 55‰ and is the second species of fish to be collected from highly saline Australian lakes. Mytilocypris mytiloides was collected at a total dissolved solids concentration of 45‰ a much higher level of salinity than it tolerates in eastern Australia. Necterosoma pensillatus was found at a salinity of 10.5‰ the lowest yet recorded for the species.

Chemistry of salt lakes and other water of the sub-humid regions of Tasmania

1976 ◽  
Vol 27 (3) ◽  
pp. 359 ◽  
Author(s):  
RT Buckney ◽  
PA Tyler
Keyword(s):  
Surface Waters ◽  
Alkaline Earth ◽  
Ionic Composition ◽  
Salt Lakes ◽  
Salinity Range ◽  
Inland Waters ◽  
Chemical Parameters ◽  
Salt Pans ◽  
Saline Waters ◽  
Major Chemical

Analyses are presented of major chemical features of pans and lagoons in the sub-humid regions of Tasmania. The waters sampled are classed as fresh or saline, using a criterion which is a function of relative ionic composition. Saline waters are regarded as having ionic composition limited by the solubility of alkaline earth carbonates, and they have a composition akin to that of seawater. The fauna of salt pans is briefly mentioned. These analyses complete a survey of Tasmanian surface waters, and some relationships between ionic concentrations and other chemical parameters are reassessed for the entire salinity range (<10 ppm to > 200‰) of Tasmanian inland waters.

Aspect of the reproductive biology of the Gummy Shark, Mustelus antarcticus Gunther, from waters off the South coast of Western Australia

1990 ◽  
Vol 41 (6) ◽  
pp. 807 ◽  
Author(s):  
RCJ Lenanton ◽  
DI Heald ◽  
M Platell ◽  
M Cliff ◽  
J Shaw
Keyword(s):  
Reproductive Biology ◽  
Western Australia ◽  
Seasonal Changes ◽  
Sexual Maturity ◽  
Post Partum ◽  
Target Species ◽  
Eastern Australia ◽  
Mean Size ◽  
The Mean ◽  
Major Target

The gummy shark (Mustelus antarcticus) is a major target species in two substantial shark fisheries that operate in temperate Australian waters. Data on the reproductive biology of M. antarcticus in the waters off south-western Australia were obtained from samples collected by commercial vessels operating from Albany to Esperance, Western Australia. The samples contained a ratio of four females to one male. M. antarcticus is a viviparous, aplacental species. Males mature at a smaller size than females. Since the overwhelming majority of sharks sampled were mature, it was not possible to estimate precisely the mean size at which sexual maturity was attained. Examination of seasonal changes in the development of ova and testes, in uterine contents, and in embryo growth established that the period of parturition, mating and ovulation occurred over the 3 months between early November and early February. The gestation period was 11-12 months. Full-term embryos ranged in size from 30 to 36 cm total length and occurred in a sex ratio of one male to one female. The ovarian and gestational cycles proceed concurrently, with reproduction occurring annually. Only one of the 224 females analysed for uterine content was considered to be in a true post-partum condition. The number of embryos (N) per mother increased with the length of the mother (L) according to the regression N = exp(-4.13398 + 0.049171L). The reproductive biology of females collected off Albany and Esperance differed in some respects from that of females collected off south-eastern Australia.

A taxonomic reevaluation of North American Daphnia (Crustacea: Cladocera). I. The D. similis complex

1993 ◽  
Vol 71 (5) ◽  
pp. 908-925 ◽  
Author(s):  
Paul D. N. Hebert ◽  
Terrie L. Finston
Keyword(s):  
Species Recognition ◽  
Distinct Species ◽  
The Other ◽  
Allozyme Analysis ◽  
Distance Analysis ◽  
Daphnia Similis ◽  
Cyclic Parthenogenesis ◽  
Morphological Differences ◽  
Genetic Distance Analysis

Allozyme analysis of 28 populations of Daphnia similis s.l. from the western United States and Canada indicated the presence of three different species. One taxon, D. salina, is newly described and a second species, D. exilis, previously synonymized with D. similis, is also shown to be distinct. Species recognition is not solely reliant on allozyme analysis, as morphological differences among the species are conspicuous. Daphnia salina is a halophile, while the other two species occur in habitats of lower but variable salinity. All three taxa appear to reproduce by cyclic parthenogenesis, although levels of genetic diversity were so low in D. salina that determination of its breeding system was tentative. Genetic distance analysis suggested that D. salina diverged from the other two species some 27 million years ago, whereas D. exilis and D. similis separated 9 million years ago.

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