Binomial Nomenclature – Definition, Advantages and Rules of Binomial Nomenclature

The Biology Topics of ecology involve studying the relationships between living organisms and their environment.

Tools for Study of Taxonomy – An Overview and Types of Taxonomical Aids with Its Uses

In this system the plant and animal species provide distinct and proper scientific names, using two words first the generic name, and second the species name. Binomial nomenclature is the scientific method of giving names to all organisms so that they can be easily distinguished from one another. In 1753, Carolus Linnaeus proposed the Binomial System of Nomenclature for giving the scientific names of plants and animals. According to this system, each organism, whether plant or animal, bears two names – the first is the generic name and the second is the name of the species. For example, the scientific name of modern man is Homo sapiens, where Homo is the generic name and sapiens is the name of the species. The standard references recognized for binomial nomenclature are Species Plantarum (1753) and the 10th edition of Systema Naturae (1758). Early rules of nomenclature were set forth by Linnaeus in his Critica botanica (1737) and in Philosophica botanica (1751).

Rules of Nomenclature:

Anyone can study, describe, identify, and give a name to an organism provided certain universal rules are followed. These rules are framed and standardized by the International Code of Botanical Nomenclature (ICBN) and the International Code of Zoological Nomenclature (ICZN). The codes are established and improved upon at the International Botanical and Zoological Congress held from time to time. Names of bacteria, viruses, and cultivated plants are decided by the International Code of Bacteriological Nomenclature (ICBacN), the International Code of Viral Nomenclature (ICVN), and the International Code of Nomenclature for Cultivated Plants (ICNCP).

Guidelines for Naming of Organisms:

• A scientific name consists of two words – first genus and second species. They should not have less than three letters and more than twelve letters.
• The generic name is written first. Its first letter is always capitalized. The rest part is short.
• No two plants or animal genera should have the same name.
• The specific name is written after the generic name. It should be short but can be compound, e.g., Hibiscus rosa-sinensis.
• The species name generally begins with a small letter.
• The names are derived either from the Latin language or are Latinized.
• The name of the Taxonomist who first described the name of the species is added at the end, e.g., Mangifera indica Linn.
• Names given to plants or animals before the publication of Species Plantarum (1953) and the 10th edition of Systema Naturae (1958) respectively are not accepted.
• The scientific name is printed in italics. It is underlined in hand-written form.
• In case of new name and description, it should be published in a widely circulated scientific journal.
• The type specimen should be kept in a recognized herbarium.
• In case, an organism has been given more than one name, the earlier legitimate one is recognized to be valid (Law of Priority).
• When the name of a species is revised the name of the original worker is retained in brackets. The name of the new worker is appended after the brackets, e.g., Albizzia Lebbeck (Linn.) Benth.
• The naming of a family or subfamily may be on the basis of an important genus, e.g., Family Asteraceae from, the genus Aster.

Trinomial Nomenclature

Modern scientists found it essential to recognize even the sub-species within the species. Thus, three words are used for naming the organisms. For example, the common lion is Panthera Leo. But lions of this species from different countries show minor differences from the original form. Therefore, a third name is introduced for this. The scientific name of the Indian lion is designated as Panthera Leo persica.

Synonym:
When two or more names are used for the same taxon (species or genus), it is known as a synonym, e.g., Thea chinensis (= Camellia sinensis). The earlier name is recognized as valid and the other name is called synonym.

Tautonym:
When the same word is used to designate both genus and species, the name is called a tautonym, e.g., Mains malus.

Homonym:
When two taxa (species or genera) have the same name, it is termed a homonym. In such a case, the earlier name is legitimate and the later name is a later homonym, e.g., South African Impatiens capensis, Thunberg (1794) is a later homonym of Impatiens capensis, Meerburg (1775). They are different species with the same name. Thunberg, therefore, is rejected and new name is given for that species: Impatiens duthiae.

Toponym:
A specimen plant or animal taken from an area regarded as the typical habitat is termed a toponym, e.g., in Mangifera indica the mango tree originated from India.

Suffix of Group from genus to division: ICBN deduced the use of particular suffixes for naming the groups of classification from genus to division. These are as follows:

Unit of Classification	Suffix	Examples
Genus	-a, us, um, on, es	Rosa, Taxus, Triticum, etc.
Subfamily	-oideae	Rosoideae, Caesalpinioideae etc.
Family	-ceae	Rosaceae, Poaceae, Malvaceae etc.
Order	-ales	Rosales, Malvales etc.
Class	-opsida	Magnoliopsida, Lycopsida, etc.
Subdivision	-phytina	Pterophytina
Division	-phyta	Bryophyta, Pteridophyta etc.

Advantages of Binomial Nomenclature:

• The names are of universal application for all the countries and languages.
• Each and every organism is provided with a definite scientific name irrespective of its importance.
• The names are precise and easier to recollect. A wrong name can be easily corrected.
• A newly discovered organism can be easily provided with a new scientific name.
• A new scientific name is thought of on the basis of its characteristics or individuality or place.
• The names indicate the relationship of a species with others present in the same genus.
• The names of the families and subfamilies is generally based on the name of type genus.
• Holotype: A particular specimen or illustration designated by the author to represent the type of a species. It is now essential to designate a holotype when publishing a new species.
• Isotype: It is believed to be a duplicate of the holotype, collected from the same place, same time, and by the same person, e.g., From several branches of a tree one becomes a holotype and the other is treated as an isotype.
• Neotype: It is a specimen selected to serve as a nomenclatural type of taxon when all the original material is missing.
• Paratype: It is a specimen cited with the original description other than the holotype or isotype.

Binomial Name of Some Common Plants:

1. Paddy	Oryza sativa
2. Wheat	Triticum aestivum
3. Maize	Zea mays
4. Palmyra Palm	Borassus flabellifer
5. Jute	Corchorus olitorius, C. capsularis
6. Coconut	Cocos nucifera
7. Mango	Mangifera indica
8. Peepal	Ficus religiosa
9. Banyan	Ficus benghalensis
10. Rubber	Ficus elastic
11. Banana	Musa paradisiaca
12. China-rose	Hibiscus rosa-sinensis
13. Changeble-rose	Hibiscus mutabilis
14. Lotus	Nelumbo nucifera
15. Pea	Pisum sativum
16. Butterfly Pea	Clitoria ternatea
17. Tea	Camellia sinensis
18. Lemon	Citrus medica
19. Swamp tree (sesban)	Sesbania grandiflora
20. Malabar Nut (Basak)	Adhatoda vasica
21. Brinjal	Sotanum melongena
22. Sensitive Plant	Mimosa pudica
23. Mustard	Brassica campestris
24. Sunflower	Helianthus annuus
25. Sal	Shorea robusta
26. Papaya	Carica papaya

Binomial Name of Some Common Animals:

1. Amoeba	Amoeba proteus
2. Entamoeba	Entamoeba histolytica
3. Monocystis	Monocystis bengaiensis
4. Paramoecium	Paramoecium caudatum
5. Euglena	Euglena viridis
6. Sycon	Sycon gelatinosum
7. Liver worm	Fasciola hepatica
8. Tape worm	Taenia solium
9. Round worm	Ascaris lumbricoides
10. Earthworm	Pheretima posthuma
11. Leech	Hirudinaria granulosa
12. Cockroach	Periplaneta Americana
13. Prawn	Macrobrachium rosenbergii
14. Achatina	Achatina fulica
15. Pila	Pila giobosa
16. Unio	Unio marginalis
17. Amphioxus	Branchiostoma lanceolatum
18. Bhetki	Lates calcarifer
19. Rohu	Labeo rohita
20. Channa	Channa punctatus
21. Magur	Clarius batrachus
22. Shingi	Heteropneustes fossilis
23. Shark	Scoliodon sorrakowah
24. Toad	Duttaphrynus melanostictus
25. Rana	Rana tigrina
26. Lizard	Calotes versicolor
27. Household Lizard	Hemidactylus fluviviridis
28. Naja	Naja naja
29. Pigeon	Columba livia
30. Guineapig	Cavia porcellus
31. Tiger	Panthera tigris
32. Lion	Panthera leo
33. Cheetah	Acinonyx jubatus
34. Man	Homo sapiens sapiens

Tools for Study of Taxonomy

In the identification or verification of a species, any documents either live specimens or preserved specimens
which help in the study of biology, specially the taxonomy, i.e., are called taxonomic tools or aids.

Herbarium

A herbarium is a depository of plant specimens in dry conditions, pressed and preserved on sheets. The sheets are arranged in accordance with any accepted system of classification. The herbarium is useful for people engaged in taxonomic studies.

Preparation of Herbarium Sheets:

1. Equipment:
Digger (khurpi) and pruning knife, sickle with a long handle, vasculum, polythene bags, magazines or newspapers, blotting papers, plant press, field notebook, herbarium sheets, glue, labels, small transparent polythene bags.

2. Plant Collection:
Plant collection should be done in such a way that it provides full information for its proper identification. The plants collected should have all the necessary parts such as leaves, inflorescence, flowers, fruits, and roots. The herbaceous plants are collected with both underground and aerial parts. The large-sized woody plants are represented by flowering and leafy twigs of proper length. The plants should be collected from different habitats in different seasons and at different stages of growth and reproduction. The collection of diseased, infected, or distorted plants should be avoided. At least 5-6 specimens per species should be collected and numbered accordingly. The following information should be recorded in the field notebook:

• Habit and Habitat
• Locality and Altitude
• Season
• Colour of Flowers
• Date of Collection

3. Pressing and Drying:
Immediately after collection, plants are pressed in between the sheets of blotting paper. The leaves, flowers, roots, etc. should be well spread while pressing. After normal pressing, the complete specimens within blotting papers are pressed in a field press. Drying of the specimens takes place by the absorption of water by blotting papers. The blotting sheets are to be changed frequently to avoid decay and blackening of the material. Initially paper is changed every 24 hrs. and after that 3-4 changes of longer duration are sufficient. The plants may also be dried with the help of artificial heat.

4. Protection from Insects and Pests:
The specimens are sprayed with fungicides like 0.1% solution of mercuric chloride in alcohol or rectified spirit, and pesticides like DDT, naphthalene, and carbon disulfide are used to check the growth of the fungus. This is called the poisoning of plants.

5. Mounting and Labelling:
After drying, the plant material is mounted on herbarium sheets of appropriate size (29 × 42 cm). The specimens are stitched or held by cellophane tape on by gum on the sheets. Only one specimen should be mounted on one herbarium sheet. Care should be taken so that the specimen is well spread and is preferably in the center of the herbarium sheet. Labeling of the specimen is done by entering the field information on the right-hand side lower corner of the herbarium sheet. It bears the name of the genus, species, family, date of collection, habitat, locality, name of the collector, and other information regarding the specimen. A design of the label is given below.

6. Storing of the Herbarium Sheets:
The herbarium sheets are arranged according to a system of classification and stored preferably in metallic cupboards. The storage place is disinfected to control insects and other pests. The area is also kept dry to check fungal growth. Small paper envelopes, called fragment packets, having seeds or extra flowers are attached to the paper sheet. An index register is maintained to locate the desired specimen in alphabetic order.

Importance of Herbarium:

• It provides information about the local flora as well as the flora of distant areas.
• It offers the facility for the identification of plants.
• It offers job and research facilities to the juniors, it also gives information on endangered species.
• It provides information about the ecology of different places.
• It helps to fulfill the public requirements by giving scientific information in respect of plants by organizing exhibitions, training courses, etc.
• The herbarium is used for maintaining type specimens of newly described taxa.
• The herbarium assists in the loan and exchange of plants for different purposes including research.

Important Herbaria and the Number of Specimens:

Name	Number of Specimens
1. Royal Botanic Gardens, Kew (London) (Largest herbarium)	6.5 million
2. Museum of Natural History (Paris)	over 6 million
3. Conservatoire at Jardin Botaniques de Geneve (Geneva)	over 5 million
4. V. L. Komarov Botanical Institute of Azerbaijan	4 million
5. New York Botanical Garden (New York)	4 million
6. Central National Herbarium (Indian Botanic Gardens) Shibpur, Kolkata, India.	2.5 million
7. Madras Herbarium, Coimbatore (MH), India.	1,50,000
8. Herbarium of National Botanical Research Institute, Lucknow, India.	80,000

Botanical Gardens

A Botanical Garden can be defined as a place to grow and maintain plants of different countries, according to their habitat and importance for the academic and economic benefit of mankind. Nowadays botanical gardens have green houses, rock gardens, palm houses, botanical ponds, laboratories, libraries, museums, and herbariums. The botanical gardens are mainly maintained by government and semi-government agencies and private organizations. In a botanical garden exclusively growing trees and shrubs is called arboretum. The first botanical garden was developed by Theophrastus. Hanging gardens of Babylon were masterpieces of ancient times. The first modern-day botanical garden Orto, Botanical Garden of Padua (Italy) was established in 1545.

Major Botanical Gardens:
There are more than 525 important botanical gardens in the world. Some major botanical gardens of the world are:

• Padua Botanic Garden, Italy (1545)
• Pisa Botanic Garden, Italy (1543)
• Leiden Botanic Garden, Netherlands (1594)
• 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 is an area of 300 acres but grows a very large number of plants.
• Indian Botanical Garden Shibpur, Kolkata. It is the largest botanical Garden in Asia spread over an area of 273 acres.
• Lloyd Botanical Garden, Darjeeling. Occupying an area of only 40 acres, the garden has a large number of terrestrial and epiphytic orchids, conifers, cycads, ferns, etc.
• National Botanical Garden, Lucknow (Sikander Bagh). It has an area of 70 acres. It grows a large number of diverse plants, palms, ferns, medicinal plants, Cacti, and ornamental plants. It has laboratories in different fields of botanical research.

Importance of Botanical Gardens:

• A large number of botanical gardens have well-maintained herbaria and libraries to facilitate research.
• Botanical gardens play a key role in the conservation of endangered plant species and genetic diversity.
• Since a wide range of plants are grown in botanical gardens, these provide ready material for biosystematic studies.
• Botanical gardens play an important role in the ex-situ conservation of plant species.
• Botanical gardens help improve the environment, purify the air, and serve as a habitat for a large number of animals.
• A large number of people visit the botanical gardens to enjoy the beauty of various ornamentals and other types of plants.
• Botanical gardens function as acclimatization centers for exotic plants of economic importance.

Zoological Parks

A zoo is a place where wild animals are kept in cages. The concept of a zoo has changed over the period of years. Instead of zoos, zoological parks are established. A zoological park is a park garden or other area in which various living animals are kept for exhibition and study. In zoological parks high standard of care is observed and the animals live under more natural conditions. Zoological parks are also meant for the breeding of rare fauna. They provide better recreation to the visitors.

Aims of Zoological Parks:
The zoological parks have the following aims as regards the wildlife.

• To develop interest in wild animals in the public.
• Zoos are involved in the conservation of many endangered species of wildlife.
• To conserve wildlife, special attention is being given to the protection of natural habitats and ecosystems and the captive breeding of wild animals.
• The Captive Breeding Specialist Group (CBSG), of the Survival Service Commission (SSC) of the International Union of Conservation of Nature and Natural Resources (IUCN) is closely associated with this Programme.

Care to Zoo Animals:

• Proper food and scientific humane treatment tend to increase the life span of zoo animals.
  The health of animals depends on four factors; enough food, fresh air, sunlight, and enough space for their movements.
• Adequate arrangements for the treatment, medication, regular check-ups, and pathological investigations are absolutely necessary to be made for the health and care of the animals.
• Animals should be regularly vaccinated.
• Successful growth of a zoological park can be estimated from the lower rate of mortality of animals, good breeding, and good health of animals.

Central Zoo Authority:
A Central Zoo Authority has been set up in our country to look after the management of zoological parks. It coordinates and supervises the activities of the zoos and the exchange of animals on a scientific basis.

Important Zoological Parks of India:

• National Zoological Park, Mathura Road, New Delhi.
• Mahendra Choudhury Zoological Park, Chhatbir, Punjab.
• Kanpur Zoological Park, Kanpur, Uttar Pradesh.
• Zoological Garden, Bikaner, Rajasthan.
• Gandhi Zoological Park, Gwalior, M.P.
• Indira Gandhi Zoological Park, Vishakhapatnam, Andhra Pradesh.
• Nandan Kanan Zoological Park, Bhubaneshwar, Orissa.
• Kamala Nehru Zoological Garden, Kankaria, Ahmedabad, Gujarat.
• Nehru Zoological Park, Hyderabad, Andhra Pradesh.
• Prince of Wales Zoological Gardens, Lucknow, Uttar Pradesh.
• Zoological Garden, Alipore, Kolkata.
• Padmaja Naidu Himalayan Zoological Park, Darjeeling, West Bengal.

Importance of Zoological Parks:

• Zoological parks are recreation centers for the public, especially children for visiting wild animals. There are children’s parks and restaurants where visitors can relax and have their meals or refreshments.
• For the amusement of the visitors, zoological parks offer animal rides such as camel rides, pony rides, and elephant rides.
• In large zoological parks, there are centers for research on nutritional requirements and breeding habits of animals. This is aimed at improving the lot of zoo animals.
• Zoological gardens play an important role in the ex-situ conservation of endangered animals.
• Zoological gardens are useful centers for studying live animal types by students.
• Because of captive breeding, Californian Candor (Gymnogyps californicans) and black-footed ferrets (Mustela nigripes) have been saved from extinction.

Museums

A 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.

Kinds of Museums:

• Art Museums: Art museums preserve and exhibit paintings, sculptures, and other works of art.
• History Museums: History museums illustrate the life and events of the past. Museums commemorating Mahatma Gandhi are in New Delhi, Bombay, and Ahmedabad.
• Applied Science Museums: These are also called science and technology museums. They demonstrate scientific principles and show their application in tools, machinery, and industrial processes.
• Natural Science Museums: They exhibit displays of animals, fossils, plants, rocks, and other objects and organisms found in nature. Plant specimens that can not be kept in herbaria e.g., algae, fungi, mosses, ferns, parts of Gymnosperms, fruits, underground storage organs, and other materials of interest are preserved in museums. The preservative solution consists of alcohol and formalin. Animal specimens like worms, insects, fishes, reptiles, etc., can also be kept in preservation solution in jars. Insects can be dried out and mounted in boxes. Larger animals are preserved in stuffed and skeleton forms.
• General Museums: They exhibit materials from several fields of study.

Important Museums of Natural Science:

• Natural History Museum, London.
• United States National Museum, Washington.
• Field Museum of Natural History, Chicago.
• National Museum of Anthropology, Mexico City.
• National Museum of Natural History, Paris.
• Indian Museum, Kolkata.
• Prince of Wales Museum, Mumbai.
• National Museum of Natural History, Delhi.
• Maharaja Sawai Man Singh (II) Museum, Jaipur.
• Anthropological Museum, Andaman and Nicobar Islands.

Importance of Museums:

• The role of museums is similar to those of herbaria.
• Standard museums have collections of plants and animals from various areas.
• Museums provide information not only about the local fauna and flora but also about other areas.
• They are used to deposit type specimens whenever new taxa are described.
• They are important centers for taxonomic studies like important numbers of various taxa, their important characteristics, study, and identification of various organisms.