TAXONOMICAL AIDS (TOOLS FOR STUDY OF TAXONOMY)
Techniques, procedures and stored information that are useful in identification and classification of organisms are called taxonomic aids. They are required because taxonomic study of plants, animals and other organisms are basic to almost all branches of biological studies for their proper identification and finding their relationships with others. Identification of organisms requires both field studies and intensive laboratory studies.
A prime source of taxonomic studies is the collection and preservation of actual specimens of plants and animals. The information about habitat, habits and other observable traits is also recorded alongwith the specimen.
Herbarium, Botanical Gardens, Museum, Zoological Parks (Zoos) and key are important tools used in identification of plants and animals.
I. HERBARIUM
Herbarium is a place where dried and pressed plant specimens, mounted on sheets are kept systematically according to a widely accepted system of classification. Herbarium is a repository or store house for future use. Every institute teaching botany, school college or university, has a small or large herbarium. Very large herbaria are maintained by botanical gardens and institutes connected with plant systematics.
Every student of botany is required to collect plant specimens and prepare herbarium sheets.
Equipment. Digger and pruning knife, sickle with long handle, vasculum, polythene bags, magazines or newspapers, blotting papers, plant press, field notebook, herbarium sheets, glue, labels, small transparent polythene bags.
Method of Specimen Collection and Mounting. An area is selected for botanical net is preferable to visit the same site in different seasons. For herbaceous species the entire plant with intact parts is collected. For others, shoots having flowers, leaves and fruits are selected and cut with the help of pruning knife. Sickle with long handle is used if the desired twigs are present at a height. Diggers are used to obtain underground parts like root system, tuber, bulb, corm, rhizome, etc. The collected material can be placed in polythene bags or vasculum.
Vasculum is a special box with a length of 45-60 cm, depth of 25 cm and width of 20 cm. It keeps the material airtight and prevents wilting till the same is placed inside drying sheets. The collected specimens are spread over magazine or newspaper sheets. Care is taken to spread the leaves properly and to separate the petals so as to expose the essential organs. If the specimen is longer than the sheet, the same can be gently bent in n or w form. Some of the flowers are kept open so as to facilitate examination of floral parts.
Some of the leaves are bent to expose dorsal (under) surface. Magazine and newspaper sheets are now put inside the press. Plant press consists of two boards with straps for tightening. Details of collection should be jotted down in the field notebook. For this every collected material is given a number. The details include plant size, branching, root system and specialised underground organ, flower colour, topography and date of collection. Preservative liquid used for storing fleshy organs is FAA (10 ml. formalin, 5 ml. glacial acetic acid, 50 ml. of 95% ethyl alcohol and 35 ml. of water).
After 24 hours, the sheets are changed. Blotting papers can be used. They help in quick drying. Two or three changes are required at an interval of 3-5 days for complete drying of the specimens. Some workers prefer to maintain the specimens in drying sheets for 1-2 months. Meanwhile herbarium sheets are selected. They are available in different colours. The general size is 30 x 45 cm. It is slightly shorter in American herbaria (29 x 41 cm). Good quality glue is applied to the back of dried specimen and the same is placed over the herbarium sheet.
Students prefer to use cellotape but the same should be avoided as its retaining power is little. Labels (7 x 12 cm) are fixed over the lower right hand corner of the sheets. Information about the family, genus, species, author, plant characteristics, area, date and collector’s name is given over each label. The sheets are now covered with polythene or tissue paper in order to avoid tearing of delicate parts. Heavy parts like fruits or seeds are kept in a paper or polythene packet and attached to the sheet. (Diversity in the Living World Books Notes Study Material)
Herbarium sheets are arranged according to a system of classification, e.g., Bentham and Hooker in India. The specimens belonging to the same genus are often packed together and placed in steel cabinets. The specimens are treated with 0.1% mercuric chloride for preventing fungal attack DDT, naphthalene and carbon disulphide are also used as pesticides. Repelling chemicals (e.g., Moth or naphthalene balls) are placed alongwith herbarium sheets for protection against insects. (Diversity in the Living World Books Notes Study Material)
Uses of Herbarium. (i) It provides information about the local flora as well as flora of distant areas. (ii) Herbaria are used for correct and authentic identification of unknown plants. (iii) It provides information about the ecology of different places. (iv) The information is useful in locating wild varieties and relatives of economically important plants. The same is helpful in breeding programmes for evolving newer and better varieties. (v) It depicts the morphological variations found in species. (vi) Information is obtained as to the season of flowering of various plants. (vii) It serves as a quick referal system for taxonomic studies. (Diversity in the Living World Books Notes Study Material)
Identification of Species
Manuals, floras, monographs, catalogues and keys are used in identification of species.
Manual. It is handy book containing instructions as to occurrence, collection and identification of species found in a particular area.
Flora. It is a book containing information as to the habitat, climate, seasonal changes, distribution, description and index of plants found in a specific area. (Diversity in the Living World Books Notes Study Material)
Monograph. It is treatise having all information about a particular taxon like family or genus.
Catalogue. It is list or register that enumerates methodically all the species found in a particular place, often with brief description aiding identification. (Diversity in the Living World Books Notes Study Material)
Key. It is booklet containing list of characters and their alternates which are helpful in identification of various taxa- class, order, family, genus and species. (Diversity in the Living World Books Notes Study Material)
II. BOTANICAL GARDENS
Botanical gardens are sufficiently large sized tracts where plants of different types and areas are grown for scientific and educational purposes. The first real botanical garden was developed by Theophrastus (370-285 B.C.). Of course, gardens were part of Indian, Chinese and Roman cultures. “Hanging Gardens” of Babylon were considered to be wonders of ancient times. Modern day botanical gardens contain besides out-door plants, green houses, library, research laboratory and herbarium with documented collection of various taxa.
There is an International Association of Botanical Gardens (established in 1962) which coordinates research and exchange of plant materials. The important functions of botanical gardens are: (i) Growing important plants of local flora. (ii) Keeping record of local flora. (iii) Providing living plant material for systematic work. (iv) Supplying seeds and material for different aspects of botanical research. (v) Growing and maintaining rare and endangered plants. (Diversity in the Living World Books Notes Study Material)
Establishment of modern botanical gardens began in 16th century- Pisa, Italy (1543), Padua Gardens, Italy (1545), Jardin de Jussieu, France (1593) and Leiden, Netherland (1594). Some major botanical gardens of the world are:
- Main Botanical Garden, Moscow. Largest garden, spread over an area of 900 acres.
- Bundes Garden, Vienna. It is spread over an area of 400 acres.
- Royal Botanical Garden, Kew (London). It has an area of 300 acres but grows very large number of plants.
- Kebun Raya (Botanical Garden) Bogor, Java. Spread over an area of 200 acres the garden has a section with virgin rain forest.
- Arnold Arboretum, Boston (U.S.A.). It supports a very large number of bonsai trees and green houses.
- Indian Botanical Garden Sibpur, Kolkata. It is the largest botanical garden of Asia spread over an area of 273 acres which is famous for its Great Banyan tree, Palm house. Succulent plants, Indian grasses, Water lilies, etc.
- Lloyd Botanical Garden, Darjeeling. Occupying an area of only 40 acres, the garden has a large number of terrestrial and epiphytic orchids, a large number of conifers. cycads, ferns and alpine plants. (Diversity in the Living World Books Notes Study Material)
- National Botanical Garden, Lucknow (Sikander Bagh). The garden has an area of 70 acres. It grows a large number of diverse plants, palms, ferns, medicinal plants, cacti and ornamentals. The garden has laboratories of different fields of botanical research.
Two famous botanical gardens of South are Botanical Garden, Ootacumand and Lalbag Gardens, Bangalore.
III. MUSEUM
What is Museum? The word museum comes from the Greek word mouseion. In ancient Greece the mousein was the temple of the Muses, the goddesses of arts and sciences. Museum is an institution where artistic and educational materials are exhibited to the public. The materials available for observation and study are called a collection. A collection may include scientific specimens, works of art and exhibits and information on history or technology. (Diversity in the Living World Books Notes Study Material)
There are five main kinds of museums namely art museums, history museums, applied science museums, natural science museums and general museums. (Diversity in the Living World Books Notes Study Material)
Functions of Museums. Museums perform the following functions:
- Acquisition of Materials. Every new object that a museum adds to its collection is called an acquisition. Museums acquire objects in several ways, of which field collection is one of the most useful. The scientists and technicians go outside to gather specimens and data on a particular subject which are within the scope of the museum.(Diversity in The Living World Books Notes)
- Recording of materials. Each acquisition is listed carefully by specialist staff. As soon as objects are received, the data, the source, the method of acquisition and other available informations are entered in the record register.
- Preservation of Materials. The primary purpose of museums is to preserve selected objects. Curators (persons incharge of museums) know that no specimens will last forever. What museums undertake to do is to prolong the life time of the objects. Preservation in a museum consists of two steps. (i) specimens must be put into a condition that checks deterioration. (ii) the specimens must be protected.
- Research. One important use of museum is to extract as much knowledge as possible from the specimens. Many museums publish scholarly journals, series of papers and books to make available the results of research on their collection.
- Exhibition of Materials. Various members of the museum staff prepare the acquisitions for exhibition. The specimens selected for exhibition are put on view in numerous ways. The choice of approach and technique depends largely on the purpose of exhibit.
- Education. A number of universities conduct some courses in certain subjects at In order to take advantage of the collection. Thus museums help in spreading education. (Diversity in the Living World Books Notes Study Material)
Following Museums are Important from Natural Science Point of View
- Natural History Museum, London,
- United States National Museum, Washington.
- La Plata Museum, La Plata, Arg.
- Field Museum of Natural History, Chicago.
- Zoology Museum, Amsterdam, Neth.
6. Sugarlands Museum, Great Smoky Mountains National Park in eastern Tennessee.
- Rock Creek Nature Center, Washington.
- National Museum of Anthropology, Mexico City.
- Mus éé de l’Homme, Paris.
- Anthropological Museum, Andaman and Nicobar islands.
- Forest Museum, Andaman and Nicobar Islands.
- National Museum of Natural History, Delhi.
- Prince of Wales Museum, Mumbai.
- Maharaja Sawai Man Singh (II) Museum, Jaipur.
- Indian Museum, Kolkata.
IV. ZOOLOGICAL PARKS (ZOOS)
A zoo is a place where various living animals are kept within enclosures, displayed to the public and may be used for study. Animals may also be bred. Infact concept of zoo has changed. Instead of Zoos, Zoological Parks or Zoological gardens are established where high standard of care is observed and the animals live under more natural conditions. The animals provide better recreation to the visitors.
The Role of Zoological Parks in Wildlife Conservation. The regular zoo movement in India, began in the year 1855 when the first zoo was set up in Chennai. In the zoological parks animals enjoy protection, fine sun-shine, fresh air and above all ample open space to play about. They have now become repositories of threatened wildlife and a store house of the knowledge on animal behaviour, their breeding habits, etc. Zoological park is the place where they are assured of food, medical care and treatment and where they also feel safe from their natural enemies.
The establishment of zoological parks helps in providing knowledge about different native and exotic wild mammals, birds, reptiles, fish and flora to the Public in general and school children in particular. Zoological parks are very useful in spreading knowledge on the wildlife wealth of the country.
Zoological parks all over the world have been involved in the rescue of many species eatened with extinction. Our country has made good progress in the rehabilitation of some angered species. The Crocodile Rehabilitation Project being run by the FAO to rehabilitate crocodiles. Similarly the Himalayan Musk Deer is being bred at Kufri. Attempts have also been made for preserving other species like Blackbuk, Sambar and Spotted Deer.
Similar projects for pheasants and partridges are under way. Conservation efforts have been made world by breeding birds and mammals in parks and releasing them in free state as in case of the Great Indian Bustard, Houbara Bustard, Hawaiian Goose, European Bison, etc. The zoological parks, therefore, are playing an important role in wildlife conservation.(Diversity in the Living World Books Notes Study Material)
Zoos of India. The abbreviation “zoo” was first used for the London Zoological Gar. dens, which opened for scientific study in 1828 and to the public in 1847. The number of major animal collections open to the public around the world now exceeds 1,000, around 80 percent of them in cities.
The Central Zoo Authority of India (CZA) manages all Zoos in India.
- Alipore Zoological Gardens, Kolkata
- Allen Forest Zoo, Kanpur
- Arignar Anna Zoological Park (Vandalur Zoo), Chennai
- Birsa Munda Jaivik Udyan, Ranchi
- Guwahati Zoo, Assam, India
- Indira Gandhi Zoological Park, Visakhapatnam, Andhra Pradesh
- Jawaharlal Nehru Biological park, Bokaro Steel City
- Jaipur Zoo, Jaipur
- Jijamata Udyaan, Mumbai, Maharashtra
- Lucknow Zoo, Lucknow
- Madras Crocodile Bank Trust
- Mahendra Chaudhury Zoological Park, Chhatbir, Punjab
- Marble Palace Zoo, Kolkata
- Mysore Zoo, Karnataka
- Nandankanan Zoo, Orissa, India
- National Zoological Park, Delhi
- Nehru Zoological Park, Hyderabad, Andhra Pradesh
- Pt. G.B. Pant High Altitude Zoo, Nainital, Uttarakhand, India
- Padmaja Naidu Himalayan Zoological Park, Darjeeling
- Parassinikkadavu Snake Park
- Sakkarbaug Zoological Garden, Junagadh, Gujarat
- Sanjay Gandhi Jaivik Udyan, Patna
- Sepahijala Zoo, Tripura
- Sree Venkateswara Zoo, Tirupati, Andhra Pradesh
- Rajiv Gandhi Zoological Park, Pune, Maharashtra
- Trissur Zoo, Thrissur, Kerala
- Tilyar Zoo, Rohtak
- Thiruvananthapuram Zoo, Trivandrum, India
V. KEY FOR IDENTIFICATION
Key or taxonomic key is an artificial analytic device having a list of statements with dichotomic table of alternate characteristics which is used for identifying organisms. Usually a couplet or two contrasting characters are used. The one present in the organism is chosen while the other is rejected. Each statement of the key is called lead. Separate taxonomic keys are used for each taxonomic category like family, genus and species. Two types of keys are commonly used indented (or yolked) and bracketed.(Diversity in the Living World Books Notes Study Material)
Indicated Key (Yolked Key). The key contains a sequence of choices between two or more characteristics. By careful selection of character at each subdivision the exact name of the organism can be arrived at. (Diversity in the Living World Books Notes Study Material)
Bracketed Key. The key uses contrasting characters like the indented one but they are not seprated by intervening subdividing characters. Instead, each character is given a number in brackets.(Diversity in the Living World Books Notes Study Material)
Diversity in the Living World Books Notes Study Material
Diversity in the Living World Books Notes Study Material