Figures: Lebertia sp. nov.
1. lateral view; 2. mouth part area; 3. "acetabula"

Larvae di Chironomidi (Orthocladiinae e Diamesinae) Chironomid larvae of Orthocladiinae and Diamesinae

Capsula cefalica larvale di Diplocladius cultriger (sorgente Antermon Bassa) Larval head capsule of Diplocladius cultriger (spring Antermon Bassa)

Chironomids are the most abundant components of the spring macrobenthic fauna. These opportunistic insects inhabit a great variety of aquatic habitats, from lentic to lotic ones, thanks to their ability to tolerate wide chemico-physical gradients. Therefore they can colonize almost every kind of ecological niches in freshwater ecosystems. Some taxa developed special physiological, morphological and behavioural adaptations to survive extreme conditions, like freezing and droughts.
Thanks to their ubiquity and species richness (about 15000 species recorded all over the world and more than 400 in Italy), Chironomids are considered good bioindicators for habitat assessment. At present, about 70 species are recorded from Alpine springs, mainly belonging to Orthocladiinae and Diamesinae subfamily. Many are rheophilic and cold stenothermal organisms, adapted to live in mountain streams and reocrene springs. Some species are rare and stenoecius, such as Diplocladius cultriger Kieffer 1908, an orthoclad found in the spring Antermont Bassa during the CRENODAT survey: this is the first record of this taxon in the Italian Alps.

By now the botanical working group, coordinated by Marcello Tomaselli from the Parma University, performed a lot of vegetation relevés (about 85 in 2005 and 50 in 2006). More than 120 species of bryophytes and about 90 of vascular plants have been till now identified. Among bryophytes the most widespread are several species belonging to the genera Palustriella, Plagiomnium, Rhizomnium and Philonotis. The list of most common species includes also Brachythecium rivulare, Bryum pseudotriquetrum, Cratoneuron filicinum and Scapania undulata. A specimen very close to Palustriella falcata was collected in the springs Rislà and Antermont: the collected samples have a pluristratose lamina like to that of Palustriella pluristratosa, a species recorded and described for the first time in Switzerland. Presently, Prof J.P. Frahm (University of Bonn) is performing a molecular analysis on this interesting specimen. Among vascular plants Cardamine amara, Saxifraga stellaris, S. rotundifolia, and Crepis palustris are the most commons species. Also different species of the genus Epilobium are very frequent.

Besides this mainstream of the work we’re performing two field experiments: the first one deals with the growth rate of Palustriella commutata artificially exposed to three different treatments: submersion, sub-emersion and emersion. The second one aims at investigating the relationships between the water content of several species and their pigments investigated by means of spectrophotometer.

Springs are an interesting ecotone to be studied and represent a hard challenge for zoologists. Among the several taxa which can be found living in a spring (dipteran, copepods, molluscs, mites, diatoms etc...) nematodes (Fig.1) play an important ecological role. Their diversity is high. At the moment more than 70 species of nematodes had been found in springs sampled within the Crenodat project. Nematodes we found are distributed all along the entire trophic web since they can be bacteriovorous (Tobrilidae, Plectidae) (Fig. 2 –3), herbivorous (Dorylamidae) (Fig. 4) and predators (Monochidae). They can be used to assess environmental condition through the application of indexes such as the Maturity Index based on their reproductive strategy.

Springs has never been deeply studied and it is easy to find new species adapted to this habitat. During the identification of nematodes sampled in the Crenodat project we found a new species of Eumonhytera.
In a couple of spring two nematodes belonging to species Tobrilus zakopanensis (Stefanski, 1924) and Eumonhystera tatrica (Daday, 1896): at the moment these two species were known only from a mountain region on the border of Poland and Slovakia (Tatry). The presence in these spring suggests the hypothesis of a biogeographical relict left behind since last glaciation.

pic 1: Habitus of Plectus parietinus.



Epitobrilus allophysis (Stephansky, 1924), bacterial feeder. The arrows indicate the mouth cavity and a tooth beneath it.

Pic2: The connession between pharynx and the intestine.

pic3: The arrow indicates the odontostyle.

pic 4

Three aquatic Oligochaete families are found in spring environments: Tubificidae, Lumbriculidae and Haplotaxidae. Some Lumbricidae can also be found, e.g. Eiseniella tetraedra, and Enchytraeidae, which include terrestrial and aquatic species and have been found to be very common in underground aquatic (Giani et al., 2001) and ecotonal environments, such as springs (Sambugar et al., 2005).
In this last study, the fauna examination of several European springs highlighted the important role, also in these environments, of Oligochaetes, one of the most abundant and diversified groups of invertebrates, following the Diptera Chironomidae. Over 70 species have been identified; the coenoses appear to be made up by a great nucleus of ubiquitous species and by rare crenobitic and stygobitic species. Enchytraeidae and Tubificidae are the most abundant and species-rich families.
The importance of springs as ecotones between underground and surface environments is underlined by the compositions of communities made up by genera, e.g. Pristina, which are very frequent in underground waters, other genera, e.g. Rhyacodrilus, Buchholzia and Trichodrilus, which are often present in cave stygofauna, and yet other genera, e.g. Cognettia, which are common in soils and superficial water courses. Two environmental variables that mostly affect the Oligochaetes coenosis composition are the substrate and the geology of the spring area.

OLIGOCHAETES OF SPRINGS IN TRENTINO
Enchytraeidae are the most diversified family in the springs of Trentino, followed by Tubificidae, Lumbriculidae and Haplotaxidae.
About one third of Enchytraeidae is represented by Cernosvitoviella, the sole genus with only aquatic species. Cognettia cognettii, C. cfr. glandulosa and Fridericia discifera, which were found in some springs, are indicated for the first time for Italian spring environments. Cognettia sphagnetorum and Mesenchytraeus armatus, both holarctic and amphibious species, had already been signaled for spring environments: the former for a spring in France and for a spring in Italy, the latter for several Italian springs (Sambugar et al., 2005). Enchytraeus, Fridericia, Henlea, Marionina and Cernosvitoviella are found genera and were already known for surface and underground waters.
The Tubificidae Nais alpina, N. communis, N. variabilis, N. simplex and Tubifex tubifex are cosmopolitan and ubiquitous, having already been found in spring environments. The presence of T. tubifex in helocrene springs underlines its choice of environments with a high content of organic detritus.
The tubificid Pristina bilobata, the lumbriculid Stylodrilus heringianus and the haplotaxid Haplotaxis gordioides are stygophyles and corroborate the ecotonal characteristics of spring environments since these are points of contact between underground and surface habitats. H. gordioides is signaled for ther first time for Italian spring environments.
The studies on Italian springs carried out to date confirm, even as regards oligochaete populations, the peculiarity and complexity of such environments, points of high biodiversity that must be protected and preserved.

REFERENCES CITED
Giani N., Sambugar B., Rodrìguez P., Martìnez-Ansemil E., 2001. Oligochaetes in southern European groundwater: new records and an overview. Hydrobiologia, 463: 65-74.

Sambugar B., Martìnez-Ansemil E., Giani N., 2005. Oligochaetes from springs in southern Europe. Bollettino del Museo Civico di Storia Naturale di Verona, 29, Botanica Zoologia: 93-106.

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Ostracodi (Crustacea, Ostracoda)

Altogether, 100 samples collected on different substrata from 64 alpine springs were analysed. In 9 samples no ostracods were found, in 6 samples only immature stages were present, while other 6 samples contained only empty valves. Both soft parts (dissected in glycerine and stored in sealed slides) and valves (stored dry in micropaleontological slides and used for scanning microphotographs) were checked for species identification, using Meisch (2000)...

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CRENODAT – Freshwater lichens
Juri Nascimbene - University of Trieste, Biology Department, via Giorgieri 10 – 34100 Trieste

Lichens mostly colonise terrestrial habitats. However, a few species are restricted to submerged or partially inundated habitats. Freshwater lichens are widespread thorough Europe as typical elements of vegetation of springs, rivers, and lakes. Freshwater lichens belong to a few genera the most representative being Verrucaria. Species distribution is affected by several ecological parameters such as inundation, substrate and water pH, substrate stability, light, silting, and eutrophycation. Since they are sensitive to habitat modifications and threatened by water pollution, they could be used in freshwater biomonitoring. For their conservation a generalized habitat protection is a prudent approach that can compensate for poor taxonomic knowledge, especially in protected areas. Particular care should be devoted to springs, due to their structural vulnerability. Springs are considered the optimal habitat for several species of Verrucaria.
Forty-three freshwater lichens are known from the Italian Alps. The species belong to 20 genera, the most species-rich being Verrucaria (19% of the total), Aspicilia (10%), Dermatocarpon (10%) and Staurothele (10%). Crustose lichens with sexual reproduction comprise 80% of the total. The photobiont is mostly a coccoid green alga (72%), while cyanobacteria and trentepohlioid algae are less frequent (21% and 7%, respectively). The altitudinal distribution of freshwater lichen richness has a maximum in the subalpine belt near the treeline (93% of the total), followed by the montane belt (77%), the alpine belt (63%) and the submediterranean belt (9% only). The subalpine belt also hosts the highest share of those species restricted to the Alps in Italy (91%), followed by the alpine belt (78%) and the montane belt (60%). Most species (80%) colonise acid or subacid rocks and have an ecological optimum in well-lit habitats.
Among aquatic Verrucaria species found during CRENODAT project, Verrucaria funckii can be considered the most representative, since it is rather frequent in several springs on perennially inundated siliceous substrates, in different altitudinal belts. The material collected was submitted both to morphological and molecular analysis for a correct identification. Verrucaria funkii belongs to a rather critic group including V. hydrela and V. elaeomelaena, both found in the spring of Trentino, mostly on siliceous and calcareous rocks respectively. This group is characterized by a gelatinous green, olive-green, brownish thallus in which the algae are often typically arranged in columns. Spores length normally ranges between 20-25µ.


 

Verrucaria sp. with a greenish gelatinous thallus in Val Borzago (Adamello Natural Park)

 

Verrucaria sp., thin section of the thallus and a of a fruiting body containing the spores. The gelatinous thallus covers the fruiting body. Algae are arranged in columns.

   

Verrucaria margacea grows mainly on siliceous rocks in perennialy/periodically inundated habitats. It normally has a dark coloured thallus and it is characterized by large spores (at least 25µ in length)

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