Jovan Hadži
Encyclopedia
Jovan Hadži was a Slovenia
n zoologist.
Hadži began his career in Zagreb
. In 1920, he moved to Ljubljana where he became the head of zoological institute at the then established University of Ljubljana
. Between 1951 and 1972, Hadži was the head of the Biological institute at Slovenian Academy of Sciences and Arts
(SASA). In 1938, he became a full member of SASA.
Hadži was perhaps most widely known for his unique theories of animal evolution. He devised a system of classification in which he divided the animal kingdom into six phyla
: Protozoa
, Parazoa
, "Ameria" (animals with no segments), "Oligomeria" (animals with few segments), "Polymeria" (animals with many segments) and Chordata. His choice of characters important for classification was generally discredited by his contemporaries, and the system was never accepted by zoologists. However, due to its simplicity, the system was widely used in science education in former Yugoslavia. His other major theory was that of the origin of metazoa - he developed an existing hypothesis stating that the first multicellular animals resembling today's flatworms
evolved from multinucleate
ciliate
s in which cell nuclei
became separated by cellular membranes. Again, the theory emphasized similarities of structure while disregarding other important characters, so it was never generally accepted.
Hadži's faunistical work focused on the invertebrate
fauna of caves and mountains where he described more than a hundred new species and genera
. He was also an active cave explorer and acted as a president of the Slovenian society for cave exploration (Društvo za raziskovanje jam Slovenije) between 1927 and 1945.
For his contributions to zoology, Hadži received Prešeren Award
in 1956. In 1969, he received the honorary doctorate by the University of Ljubljana. Several invertebrate species were named after him by other zoologists, such as Astagobius hadzii, Cyclopina hadzii, Isohypsibius hadzii, and Niphargus hadzii
.
Slovenia
Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...
n zoologist.
Hadži began his career in Zagreb
Zagreb
Zagreb is the capital and the largest city of the Republic of Croatia. It is in the northwest of the country, along the Sava river, at the southern slopes of the Medvednica mountain. Zagreb lies at an elevation of approximately above sea level. According to the last official census, Zagreb's city...
. In 1920, he moved to Ljubljana where he became the head of zoological institute at the then established University of Ljubljana
University of Ljubljana
The University of Ljubljana is the oldest and largest university in Slovenia. With 64,000 enrolled graduate and postgraduate students, it is among the largest universities in Europe.-Beginnings:...
. Between 1951 and 1972, Hadži was the head of the Biological institute at Slovenian Academy of Sciences and Arts
Slovenian Academy of Sciences and Arts
The Slovenian Academy of Sciences and Arts is the national academy of Slovenia, which encompasses science and the arts and brings together the top Slovene researchers and artists as members of the academy....
(SASA). In 1938, he became a full member of SASA.
Hadži was perhaps most widely known for his unique theories of animal evolution. He devised a system of classification in which he divided the animal kingdom into six phyla
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
: Protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
, Parazoa
Parazoa
The Parazoa are an ancestral subkingdom of animals, literally translated as "beside the animals".-Description:Parazoans differ from their choanoflagellate ancestors in that they are not microscopic and have differentiated cells. However, they are an outgroup of the animal phylogenetic tree being...
, "Ameria" (animals with no segments), "Oligomeria" (animals with few segments), "Polymeria" (animals with many segments) and Chordata. His choice of characters important for classification was generally discredited by his contemporaries, and the system was never accepted by zoologists. However, due to its simplicity, the system was widely used in science education in former Yugoslavia. His other major theory was that of the origin of metazoa - he developed an existing hypothesis stating that the first multicellular animals resembling today's flatworms
Turbellaria
The Turbellaria are one of the traditional sub-divisions of the phylum Platyhelminthes , and include all the sub-groups that are not exclusively parasitic. There are about 4,500 species, which range from to in length...
evolved from multinucleate
Multinucleate
Multinucleate cells have more than one nucleus per cell, which is the result of nuclear division not being followed by cytokinesis. As a consequence, multiple nuclei share one common cytoplasm. This can be the consequence of a disturbed cell cycle control Multinucleate (also multinucleated,...
ciliate
Ciliate
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to flagella but typically shorter and present in much larger numbers with a different undulating pattern than flagella...
s in which cell nuclei
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
became separated by cellular membranes. Again, the theory emphasized similarities of structure while disregarding other important characters, so it was never generally accepted.
Hadži's faunistical work focused on the invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
fauna of caves and mountains where he described more than a hundred new species and genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
. He was also an active cave explorer and acted as a president of the Slovenian society for cave exploration (Društvo za raziskovanje jam Slovenije) between 1927 and 1945.
For his contributions to zoology, Hadži received Prešeren Award
Prešeren Award
Prešeren Award is the highest decoration in the field of artistic and in the past also scientific creation in Slovenia awarded each year to one or two eminent Slovene artists...
in 1956. In 1969, he received the honorary doctorate by the University of Ljubljana. Several invertebrate species were named after him by other zoologists, such as Astagobius hadzii, Cyclopina hadzii, Isohypsibius hadzii, and Niphargus hadzii
Niphargus hadzii
Niphargus hadzii is a species of crustacean in family Niphargidae. It is endemic to Slovenia, and is named after Slovene zoologist Jovan Hadži.-Source:* Sket, B. 1996. . Downloaded on 10 August 2007.-External links:*...
.