Fifty years of devotion to spiders : a concise biography of Christo Deltshev , with a complete list of his publications and described taxa

Th is paper provides an overview of the life and scientifi c work of Dr. Christo Deltshev, the doyen of Bulgarian araneology. It also analyses his more important research contributions and provides a list of his scientifi c publications and the species he described.

It is both diffi cult and easy to write about the doyen of Bulgarian araneology Christo Deltshev.It is diffi cult because his work, although in one area -the study of spiders, is rather varied.And yet it is easy because we, the authors of this biography, know our colleague and friend Christo Deltshev and his development as a zoologist very well.We have witnessed how before our very eyes the enthusiastic lover of spiders, caves and mountains gradually turned into an erudite araneologist enjoying the respect of his colleagues from many countries.Th e seventieth anniversary of Christo Deltshev is reason enough to look back on his achievements in science and life and outline his Institute of Zoology and Museum), where he still works to this day.From 1972 to 1985 he was an Assistant Professor.His PhD thesis, which he defended in 1977, was entitled "Faunistic, taxonomic, ecological and zoogeographical investigations on the cave spiders of Bulgaria (Araneae)".Since 1985 he has been an Associate Professor.Th e director of the Institute of Zoology appreciated his organizational and management skills and in 1995 Christo Deltshev was elected head of the Department of Taxonomy, Faunistics and Zoogeography.He has occupied this position ever since.Two years later he was appointed Secretary of the Scientifi c Council of Zoology and Ecology with the High Attestation Commission.As an administrator he is still involved with the organization and procedures for thesis defense by zoologists and ecologists in Bulgaria.His work for the Council puts him in touch with many young people who share with him their passion for zoology.With his typical responsiveness and friendliness he was able to help many of them on diff erent occasions; indeed it is hard to fi nd anyone among the Bulgarian zoological community who doesn't know Christo Deltshev.
His valuable scientifi c results derive from his qualities and perseverance as a fi eld researcher.He has been connected with nature his whole life and is well acquainted with the Bulgarian mountains.We, the authors of this biography, had to overcome together with him storms, fog and hail and we know that his desire for explorations of caves and mountains is inextinguishable.In sunny and in stormy weather he never loses his good spirits.
Th e head of the Institute of Zoology, Professor Alexander Valkanov, took Christo, just after he started work, to his summer expeditions to explore the high-mountain lakes of Rila and Pirin.During one of these expeditions to the Seven Rila Lakes, together with German hydrobiologists, one evening at the camp fi re he found out that Christo was a fi re-dancer.Fire-dancing is an ancient folk custom from Strandzha Mountain in south-east Bulgaria during which the dancers -in a trance-like state -dance bare-foot over live coals.To the professor's question "Will you do it?"Christo took off his shoes, set the glowing embers ready, went around them and then several times walked over the still glowing coal."I have lived to see this miracle as well!", Professor Valkanov exclaimed, and was amazed to see there were no burn marks on Christo's feet.Christo's participation in Professor Valkanov's expeditions stirred his interest in the fauna of the high-mountain spiders of Bulgaria.
In the beginning of his scientifi c career he established cooperation with arachnologists from other countries (Carl Friedrich Roewer and Hermann Wiehle from Germany, Pierre Bonnet and Louis Fage from France, Josef Kratochvil and František Miller from the former Czechoslovakia, Herbert Levi from the USA).In 1972 he described his fi rst spider Protoleptoneta bulgarica, which turned out to be both a new genus and species.To make sure he was not mistaken he sought the opinion of Paolo Marcello Brignolli and František Miller, who were at the time among the best taxonomists of this group in Europe.Years later, already an established spider expert himself, Dr. Deltshev advised young zoologists during their fi rst steps in araneology and confi rmed the new species they had discovered.
Christo's love for caves started during his university years.Th e fi rst cave he visited was Kolkina Dupka at the village of Zimevitsa in the Stara Planina Mountain.When entering this precipice cave in 1960, he had to clamber over the corpses of several dead pigs.Th e more experienced cavers who were leading him saw that he did not shrink at the unpleasant sight and realized the boy would turn out to be a true speleologist.And so he did.His infatuation with caves did not diminish with time, even after an incident of almost tragic proportions took place.In August 1964, when he was climbing down the Bankovitsa abyss at Karlukovo village near Lukovit, several of the rungs of the self-made rope ladder broke and Christo fell 12 metres.His hip was broken in fi ve pieces and he had to spend four months in cast, with recovery taking another four months.From then on, throughout his life the injury tormented him whenever the weather got worse or when he strained himself, but it did not stop Christo from continuing his researches in high mountains and caves or from enjoying nature as a tourist with his family and friends.
Th us it was no wonder that it was in a cave that Christo held his wedding.It happened in 1968 in Temnata Dupka Cave in Iskar Gorge near Lakatnik.Christo had already graduated and started working as a researcher and thought it was time to start a family.And so Elena entered his life and she would become the pillar and support of his further progress.Th ey had three children, one after another, which was a rare case for a family of intellectuals in Bulgaria during the second half of the 20th century.So far Dr. Deltshev has visited and studied the fauna of several hundred caves in Bulgaria.He discovered some of them and for many he was among their fi rst explorers.He participated in the organization of many international, national and club caving expeditions.As well as Bulgaria, Christo also took part in international caving expeditions in Slovenia (1963), the Caucasus (1967), Austria (1968) and the Moravian karst in the Czech Republic (1980).His achievements in speleology were largely due to the infl uence which the inspirer of the speleological movement in Bulgaria, Petar Tranteev, had on him.Christo proposed to him his idea to make ascenders, which   were produced by Vesselin Gyaurov, and Christo tested them himself.His speleological organizational work concerns the Bulgarian Federation of Speleology -of w hich he was the vice-chairman from 1968 until 1993 -as well as the Academic Students' Speleological Club of which he was the chairman in the period 1978-1996.Since 1972 Christo Deltshev has taught a speleology course in the National Sports Academy and is the author of a textbook on speleology.
Christo is a friendly guy.He likes to entertain his colleagues and friends with stories of his expeditions and interesting things he had witnessed.For many years he used to dress like Santa Claus and give away presents to cavers in some mountain hut, and now he is doing this for the children and grandchildren of his colleagues.
In his more than 40 years of scientifi c research the araneological contributions of Christo Deltshev have been many in number.Th e main areas of his work and publications are taxonomy, faunistics, zoogeography and ecology of spiders in Bulgaria and the other Balkan countries.He has described as new the genera Protoleptoneta and Cryphoecina, as well as 34 species and 2 subspecies of spiders from 8 families.Th e largest number of taxa described by him belongs to the families Linyphiidae (17 species and 2 subspecies), Agelenidae (6 species), Leptonetidae (1 genus and 3 species) and Amaurobiidae (3 species).If we look at the genera, the largest number of newly described taxa belong to Centromerus (4 species and 1 subspecies), Malthonica (4 species), Lepthyphantes and Eurocoelotes (3 species each).Christo is a skilled illustrator and this gift largely helps his taxonomic work.Th e scale of his contributions can be judged also by the fact that all but one of the 38 taxa have been described by him alone.And the quality of his contribution can be estimated by the validity of all the described taxa; again with only one exception (Lepthyphantes gueorguievi has been synonymized).Th e newly described taxa all come from the Balkan Peninsula: Bulgaria (1 genus, 24 species and 2 subspecies), Greece (7 species), Serbia (2 species), Montenegro (1 genus and 1 species).Almost an equal number of the new taxa have been found in caves (16 species) and in mountains (17 species and subspecies), and another 3 species along the coast and in the lowlands.His permanent interest in taxonomy is evident from the even distribution of newly described taxa throughout time: 1970s (12 taxa), 1980s (10 taxa), 1990s (9 taxa) and the fi rst decade of the 21st century (9 species).
Christo Deltshev has conducted some other taxonomic modifi cations such as the establishment of 25 new synonyms and designation of lectotypes of 7 species.He revised the genus Tenuiphantes, the European species of Bolyphantes, the species of Centromerus in the caves of the Balkan Peninsula, and the genera Erigone, Tegenaria, Coelotes and Zodarion in Bulgaria.He also critically revised the spider species of the Balkan Peninsula described by Dr. P. Drensky (Deltshev 2003 [111]).Considerable too are his faunistic contributions to the distribution of spiders across the Balkan countries.Due to his research over many years the number of known species in Bulgaria increased by 237, in Serbia -by 73, in Macedonia (FYROM) -by 22 and in Greece by 11.He also discovered two families (one still unpublished) new for the fauna of Bulgaria.Another aspect of his contribution is the complex research and analysis of the araneofauna from the diff erent regions of Bulgaria.An excellent fi eld researcher, he conducted and published his studies on the spiders of the mountains Central Stara Planina, Rila, Pirin, the Eastern Rhodopes, Lyulin, Vitosha and Sashtinska Sredna Gora; of plain areas in Bulgaria such as the Black Sea Coast and Ludogorie; of some small but zoogeographically interesting territories such as Srebarna Lake, Shabla-Ezerets wetland, the Sofi a Region, Zemen and Kresna gorges and Sandanski-Petrich Kettle.
Th e climax of Christo Deltshev's work on the study of spiders in the northern part of the Balkan Peninsula are the critical checklist of Bulgarian spiders (Deltshev and Blagoev 2001 [104]) and the monograph "Th e Spiders of Serbia" (Deltshev et al. 2003 [113]).Th e checklist contains 910 species according to data based on 173 publications.It has been updated with an online list (Blagoev et al. 2002 [107]) containing up-to-date current information on 1007 species in 41 families based on the review of 226 items of literature.Th e monograph constitutes a critical catalogue of 618 species of 36 families based on all the literature fi ndings and new data from intensive faunistic research in Serbia.Th e localities of each species are plotted on a UTM map.
Zoogeography has always interested Christo Deltshev and because of this almost all of his taxonomic works are accompanied by a zoogeographic analysis.In his analysis of spiders of the Balkan Peninsula (Deltshev 1999 [87]) he concentrated on 1409 species from 47 families and selected the regions with the highest species diversity.In this research he established that 26.9 % of spiders (379 species) are endemic for the region and proved the important role of the Balkan Peninsula as a speciation center in Europe.Similar zoogeographic analyses have been published on the spiders of Bulgaria as well (Deltshev 2005 [124]), on endemic spiders of Bulgaria (Deltshev 1996 [67]) and the Balkan Peninsula (Deltshev 2000 [94]), and on troglobitic spiders of the Balkan Peninsula (Deltshev 1978 [20], 2008 [132]).
Some ecological problems also received Christo Deltshev's attention.He studied the population structure of spiders inhabiting cave entrances (Deltshev 1973 [7]) and researched the impact of pasture management on the number and biomass of spiders (Deltshev and Kajak 1974 [11]).He is interested in the factors which determine the assemblage structure of spiders (Popov et al. 2000 [102]).In the sphere of applied zoology he compared the biodiversity of spiders in genetically modifi ed and conventional potato fi elds (Kalushkov et al. 2008 [134]).
In the last 15 years Dr. Deltshev has carried out intensive studies on the issues regarding the protection of invertebrates in Bulgaria.He is one of the leading experts in drafting the National Strategy for Biodiversity Conservation of Invertebrates (Deltshev et al. 1998 [82]) and identifi ed the conservation signifi cance of spiders in the main protected territories in Bulgaria: the three national parks and some of the nature parks.
Th e overall number of publications by Dr. Deltshev as of June 2009 (including that in press) is 140.It includes the monograph "Spiders of Serbia" (Deltshev et al. 2003 [113]), a textbook on speleology and caving (Deltshev 1979 [23]) and books of popular science "Th e descendants of Arachna" (Deltshev 1988 [47]) and "Biodiversity of Pirin National Park" (Popov et al. 2005 [122]).One of the aspects of Christo Deltshev's international activities is his participation in the major arachnological and related associations.He became a member of the International Society of Arachnology (ISA), now seated in Berlin, almost from its beginnings 45 years ago, and he is currently the regional representative for Bulgaria for this most prestigious organization of arachnologists.Christo is also a member of the European Society of Arachnology (ESA), seated in Nancy (France), where he is now a member of the society's Council.In the European Invertebrate Survey (EIS), registered in the Netherlands, he is a member of the organization's Committee and he is also member of Arachnologische Gesellschaft (AraGes) seated in Bayreuth (Germany).
His international debut came at the 5th International Congress of Arachnology in Brno in 1971.Since then he participated in 23 international congresses, conferences and symposia; at eleven of which he was an invited speaker.Most of them were arachnological, such as eight international congresses of arachnology between 1971 (Brno) and 2004 (Gent), six European colloquia of arachnology between 1988 (Berlin) and 2008 (Bern).Other congresses were devoted to speleology (Olomouc, 1973;Budapest, 1989), invertebrate studies (Saarbrücken, 1995), mountain ecosystems (Abisco, 1997) and biodiversity of the Balkan fauna (Ohrid, 1998;Koper, 2001).nent European spider taxonomists.It is thanks to him that the Institute of Zoology possesses a perfectly arranged collection of spiders and database on their distribution across the Balkan countries.
In the year of Christo Deltshev's anniversary we wish him further success as a researcher, administrator and mentor to young researchers.New spider species are yet to be discovered and described by Christo, and more territories on the Balkan Peninsula await his study.

Figure 2 .
Figure 2. Christo and Elena's wedding in the Temnata Dupka Cave, with the offi cial announcement hung on the Lakatnik rock s close to the cave's entrance, November, 1968 (photo Konstantin Spassov).

Figure 3 .
Figure 3. Christo with his wife Elena, his daughter Victoria and sons Delyan and Ivan in front of the Svirchovitsa Cave near the village of Karlukovo, Bulgaria, in 1983 (photo Christo Deltshev).
Christo Deltshev's organizational skills were fully employed during the preparations for the 22nd European Colloquium of Arachnology, held in Blagoevgrad in August 2005.A total of 115 participants from 27 countries came to Bulgaria.Th e results of the symposium were published in a special issue of Acta zoologica bulgarica (Deltshev C, Stoev P (Eds) 2006.European Arachnology 2005.Proceedings of the 22nd European Colloquium of Arachnology, Blagoevgrad 2005.Acta zoologica bulgarica, Suppl. 1, 343 pp.).Th e participants brought home unforgettable memories of the collo quium, as well as the joys of the Melnik earth pyramids, and the Rhozhen and Rila monasteries, which they visited during a post-colloquium excursion.Not only his Bulgarian and foreign colleagues pay respect to Christo Deltshev.Different Bulgarian state and scientifi c institutions have presented him with awards.For his contribution to speleology Dr. Deltshev was awarded an Aleko medal (1972) and a medal for Special Merits (1984).He also received insignia of honour from the State Agency for Youth and Sports, the Bulgarian Tourist Union, the Bulgarian Federation of Speleology, the National Museum of Natural History, and the Institute of Zoology.Arachnologists and biospeleologists from diff erent countries have described species which they named after Christo Deltshev in acknowledgement of his work.Altogether, one genus and 13 species bear Christo's name.Nine of the species are spiders, there is one harvestman, one millipede and 2 beetles.Th e celebration of Christo Deltshev's anniversary at the National Museum of Natural History took place in the hall with a temporary exhibition called Spider Museum -an appropriate backdrop for the evaluation of his work.Th e results of his work reveal Dr. Deltshev to be an excellent araneologist, acknowledged as one of the most promi-

Figure 8 .
Figure 8. Christo at the 22nd European Colloquium of Arachnology, Blagoevgrad, showing the fi rst prize for best presentation given by young scientist (photo Dmitri Logunov).