George V. Triantaphyllidis

International study on Artemia XLIX. Salinity effects on survival, maturity, growth, biometrics, reproductive and lifespan characteristics of a bisexual and a parthenogenetic population of Artemia

Two Artemia populations, a bisexual from San Francisco Bay (California, USA) and a parthenogenetic from Tanggu area (Tianjin province, Peoples Republic of China) are assayed for their tolerance and fitness in various salinity levels. This study was carried out under laboratory conditions where salinity effects upon special characteristics of the two Artemia populations, such as survival, growth rate, maturation, morphology, fecundity and life duration, were recorded. This evaluation revealed that the two populations examined exhibits significant differences in their response against elevated salinity levels. Furthermore, specific biometric parameters can be a useful tool for the discrimination and/or determination of their distribution in a mixed population, which, in fact, is the case in Tanggu salt works. Artemia franciscana seems to be a more effective colonizer at higher salinities. The data presented in this study may generate useful suggestions for proper management of the solar saltworks at Tanggu although further experimentation is needed.

International study on Artemia. LIII. Morphological study of Artemia with emphasis to Old World strains. I. Bisexual populations.

A detailed morphological and allometrical study was performed withadult males and females of eleven bisexual populations of brineshrimp Artemia. Multivariate procedures, discriminant andcluster analysis, allowed to separate and group together populationswhich exhibit great genetic similarities. The eleven populationsstudied form four distinct groups: the A. franciscana group,the A. tunisiana group, the A. urmiana group and abroader group which includes Eastern Old World populations. Scanningelectron microscopy revealed differences in the male genital organsof an A. tunisiana population by lacking a medial protuberancein the base of the penes while the pattern of the ectodermal ridgesof the brood pouch of A. urmiana markedly differed from theother populations studied.

International study on Artemia. LII. Incubation of Artemia cyst samples at high temperature reveals mixed nature with Artemia franciscana cysts

Abstract We present evidence that incubation of brine shrimp Artemia encysted embryos (cysts) at high temperatures (36–37 °C) suppresses hatching of cysts from a parthenogenetic population, while at the same time allowing cysts of the New World bisexual species ( A. franciscana ) to hatch. This approach is used to verify the presence of contaminating foreign material from the New World in natural cyst populations of Old World A. parthenogenetica, A. sinica, A. urmiana and A. tunisiana . We demonstrate that high temperature incubation can be routinely applied to cysts from natural Artemia populations occurring adjacent to fish and shrimp hatcheries, to determine the extent and source of contamination.

International study on Artemia. LIV. Morphological study of Artemia with emphasis to Old World strains. II. Parthenogenetic populations.

Eleven morphometric and one meristic character in 15 parthenogeneticArtemia populations have been studied by using discriminant andcluster analysis as well as scanning electron microscopy.Discriminant analysis revealed five main groups of morphologicalpatterns: (i) the coastal Chinese populations together with apopulation from Kazakhstan, (ii) the inland Chinese salt lakepopulations, (iii) the Greek populations, (iv) one African populationfrom Namibia and (v) a Chinese population from Xuyu (Jiangsuprovince). Cluster analysis was not always in agreement withdiscriminant analysis and these results are discussed.

International study on Artemia. LVI. Characterization of two Artemia populations from Namibia and Madagascar: cytogenetics, biometry, hatching characteristics and fatty acid profiles

Two parthenogenetic Artemia populations from southern Africa, one from Swakopmund saltworks (Namibia) and another from Ankiembe saltworks (Madagascar) have been studied. The population from Namibia is mainly diploid (2n=42) with few tetraploid individuals (4n=84), while the one from Madagascar was found to be triploid (3n=63). No chromocenters have been observed in either of the two populations. The Namibian population has smaller cysts and nauplii compared to those of the Madagascar population. Discriminant analysis revealed significant differences in the biometry of the adults from the two populations. The two populations exhibited very good hatching characteristics. The study of fatty acid methyl esters revealed that the Namibian population belongs to the ‘fresh water’ type of Artemia showing low levels of eicosapentaenoic acid, whereas the population from Madagascar displayed exceptionally high levels of eicosapentaenoic acid, belonging to the ‘marine water’ type.

International study onArtemia. LI. New survey ofArtemia resources in the People's Republic of China

We have surveyed 7 inland salt lakes and 14 coastal saltworks in the Peoples Republic of China (P. R. China) which are natural habitats for the brine shrimpArtemia. We report here on the location of the lakes, the mode of reproduction of theArtemia and the opportunities for achieving self sufficiency in cyst production for use in the local aquaculture industry. Because of frequent misunderstandings regarding the identification of a specific habitat, a new identification system for each population is proposed, using a numerical code which identifies the province, the habitat and the date of collection. Information of newArtemia populations is included as well as data on their reproduction mode.

International study onArtemia. L. Review of the literature onArtemia from salt lakes in the People's Republic of China

This literature survey covers data on the distribution, genetics and biology ofArtemia from the Peoples Republic of China (P. R. China) and the use of the brine shrimp in aquaculture and salt production. The vastness of the territory, the unfamiliar geography and the diversity of the habitats, have often lead to ambiguities and contradictions, leaving a gap in our knowledge about the Chinese populations ofArtemia. However, information aboutArtemia from P. R. China has recently become available and this is an attempt to summarize it.