Regional Partnership Mediterranean
Within the “regional”partnership for the study of the Mediterranean area, and in accordance with the resolutions of the first workshop held in Gent (February 2002), the objectives of the research team in La Sapienza were the following:
1-Updating of cyst bank and data base settling according to INCO CA standards
2-Updating of information on Artemia salina resources in Italy
3-Screening of the Italian populations to asess eventual introductions of A.franciscana
4- Morphological studies by using Scanning Electron Microscopy (SEM) in search of characters enabling species separation.
1-Cyst bank updating
As to this point, there was an intensive exchange activity among Mediterranean partners (mainly Greece and Spain) of information and cyst samples. Samples existing in the collection of La Sapienza were labelled and settled according INCO standards, and the re-organized database was forwarded to the coordinator in ARC to eventually complement existing database.
2-Updating of Artemia distribution
Information on Artemia distribution in Italy was also revised and updated according to recent data (Mura, 1991,2001,2002).
A total of 17 findspots were listed: 12 for Artemia salina, 5 for A.parthenogenetica
The results of this part of the research were presented in Beijing regional workshop and are part of the following publications:
1999. Mura, G. Current status of the Anostraca of Italy. Hydrobiologia, 405:57-65.
2001. Mura, G. Updating Anostraca (Crustacea, Branchiopoda) distribution in Italy. J. Limnology, 60 (1):45-49.
2002. Moscatello, S., G. Belmonte & G. Mura. The coexistence of two Anostraca species in a salt water pond of southeastern Italy. Hydrobiologia, 486:201-206.
As to Artemia distribution in Europe, through cooperation and building a web of personal connections with Arabian Emirates and Belarus data were collected, (Mura & Hamza; Mura et al., articles in preparation) filling the existing gaps in those parts of Eurasia. Moreover, information has been collected also as to France, where limited information was available until present days. (material under study), in order to clarify confused data avialble (see Thiéry & Robert 1992).
3- Search for allochtonous species
All of the preserved samples of Italian bisexual populations (150-200 individuals per \sample) were screened for the presence of eventually introduced A.franciscana by using a morphological criterion (presence/absence of penis spine-like projections) recently introduced. According to this criterion no allochtonous species was detected in our samples (collections 1990-2000), and A.franciscana used in larviculture plants apparently did not yet colonize Italian saline waterbodies, even those “at risk” having larviculture plants located nearby.
Intensive sampling is being planned for the coming year, in order to update the situation (Sardinia and Sicily, in particular).
4-Morphological studies
Morphological traits such as frontal knob and basal penis pattern were used to perform intra and inter bisexual species comparisons.
Intraspecific comparisons
The available populations from the Mediterranean were analysed as to frontal knob morphology and ornamentation to eventually detect differences at population level. Due to different sources of the samples analysed (different salinities), previous studies were performed aiming at assessing influence of environmental salinity on the ornamentation of the considered characters. The results revealed that salinity does not affect the pattern of ornamentation either of frontal knobs or basal penis, in agreement with previous unpublished observations.
Comparison of frontal knobs ornamentation did not reveal significant differences among the western Mediterranean populations we examined, or compared to the eastern previoulsy examined by Triantaplyllides et al.,1997, except for a more dense ornamentation (spines and mechanoreceptors) in the Italian ones , than in the others.
As to penis morphology, though characterized by a certain variation, even at individual level, in the presence of the tiny spines sometimes occurring on the inner basal part of penis, the western mediterranean populations did not exhibit significant differences among each other and compared to the eastern ones considered in previous studies
It is concluded, in agreement with previous authors (Triantaphyllides et al., 1997), that all of the Mediterranean populations examined thus far belong to the species A.salina. Although a large gap still exists as to North African countries, we hope to fill it by means of intensive cooperation and exchanges with Colleagues from those countries.(Hamza for Egypt, for instance), in spite of the many difficulties encountered during previous attempts to contact people involved in Artemia business or research.
Interspecific comparison
By means of frontal knobs and penis morphology we also screened representatives of all the known non Mediterranean bisexulas ( a total of 5populations examined ) in order to find a discriminant character to tell species apart. The results (Mura & Brecciaroli, submitted) revealed that either frontal knob or basal part of penis pattern are a useful tool to tell non Mediterranean bisexuals apart. The criterion of presence/absence of spinelike projection only enables separation of mediterranean bisexuals from non-Mediterranean, so that it is concluded that other characters have to be sought. It is planned for future to analyse eversible penis morphology, that seems a good discriminant among A.franciscana and A.persimilis species (Torrentera & Belk, 2002). In the meantime an analysis of the morphology of the hybrids of different species (cross bred by Francisco Amat) weas also started in order to obtain information on their morphology in relation to the parental one, and to provide material for molecular and genetic analysis (Akis Abatzopoulos) to complement Amat’s morphometrical studies. For the coming year it is planned to widen the number of samples examined, which should also be provided by the Latino-American and the Chineese Colleagues, in agreemnet with the decisions taken during the Beijing regional workshop.
Preliminary analysis of the morphology of rare males from parthenogenetic populations revealed interesting features. For this reason a comparative work (Spain,Greece, Italy) is in progress to collect as large as possible numbers of “rare”males in order to study their morphology and to exchange material for molecular analyses. The results obtained will form the object of collaborative articles within the aims of the INCO project.
Thematic partnership : diapause
Artemia parthenogenetica from Taranto, recently discovered, was selected as a model to study the influence of variables suche as food, salinity and temperature, in determining the adoption of the reproductive mode. Studies are in progress, but preliminary rsuklts seem to indicate that temperature more than salinity affects the shift fron ovoviviparity to oviparity in this particular population.
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