Abstract

Australia has two species of Artemia: A. franciscana introduced to salt works and apparently not spreading, and parthenogenetic Artemia presently spreading widely through southwestern Australia. In addition, and unique to Australia, there are 18 described species of Parartemia in hypersaline lakes. All Parartemia use a lock and key mechanism in amplexus and hence have distinctive antennal-head features in males and thoracic modifications in females. Various factors, including climatic fluctuations and isolation, contribute to a far higher diversity in the southwest of the continent. There are few congeneric occurrences of Parartemia possibly due to their consuming largely uniform allochthonous organic matter rather than multisized planktonic algae. In P. zietziana there are 2–3 cohorts a year each persisting 3–9 months. Up to 80% of assimilation is used in respiration and at times energy balance is negative, which accounts for its continuous mortality, inconsistent growth rates and unpredictable recruitment. Many species are as osmotically competent as Artemia, but are at a disadvantage in hypersaline waters >250 g L-1 as they lack the haemoglobin of Artemia. Parartemia acidiphila and P. contracta live in markedly acid waters to pH 3.5, where dissolved carbonate and bicarbonate are unavailable, and hence they must have evolved an additional proton pump to produce ATP from endogenous CO2. Occurrences of some species have been severely curtailed by lake salinisation (which includes acidification and changes in hydroperiod), so that their continued existence is in doubt. A few species of the otherwise freshwater Branchinella occur in mainly hyposaline waters.

Highlights

  • Halophilic anostracans occur in two monogeneric families in the Artemiina, a major subdivision of the Anostraca

  • Australia has a plethora of anostracan species living in inland saline waters, more than any other continent, and besides these, there are many Branchinella, mainly in hyposaline waters [3]

  • The salt tolerant fairy shrimp, Branchinella buchananensis is considered endangered in New South Wales and under the Fisheries Management Act of 1994 it has been declared a vulnerable fish (!) species

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Summary

Introduction

Halophilic anostracans occur in two monogeneric families in the Artemiina, a major subdivision of the Anostraca. Halophilic Branchinella While generally not being called brine shrimps, a few species of the freshwater genus Branchinella live in saline waters Most notable among these is Branchinella simplex in salinas in the middle Goldfields of WA and B. buchananensis in some saline lakes in northwest NSW and inland Qld (Figure 1). The salt tolerant fairy shrimp, Branchinella buchananensis is considered endangered in New South Wales and under the Fisheries Management Act of 1994 it has been declared a vulnerable fish (!) species It occurs in a few [47] known localities in the state and one of these contains an economic deposit of gypsum, which in the 1990s was proposed to be mined. The present owners of the lake are much more sympathetic to its ecology

Conclusions
16. Geddes MC
19. Daday E
22. Geddes MC
25. Timms BV
29. Geddes MC
33. Conte FP
37. Marchant R
39. Timms BV
41. Hammer UT
Findings
47. Timms BV
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