Chilopoda Scoiopendromorpha: India
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Chilopoda Scoiopendromorpha
Introduction
The myriapods are worm-like (Myrias =thread;-pedes =feet), multi-segmented, multi-legged, ttacheate (i.e., air-breathing through trachea), land arthropods. On the basis of the segmentation of their body and possession of number of pairs of legs per segment the myriapods are divided into four classes: 1. Chilopoda, 2. Diplopoda, 3. Pauropoda and 4. Symphyla. No.1 is called Opisthogoneate, and Nos. 2-4 as Progoneate.
Although Class Symphyla shows a close resemblance with the insects, the chilopods are the animals from which the present-day insects are believed to have descended. The chilopods are the group of animals which bear one pair of legs per segment. The diplopods, however, have two pairs of legs per segment, which is presumed to be formed by the fusion of two segments.
Both chilopods and diplopods live mainly, hiding in the day time in damp, dark places, ~nder stones, cow dung, flower-pots, bark of trees; in gardens, cultivated and semi-cultivated lands or in the wild.
Economic Importance
The scolopendrid centipedes are animals of economic importance despite the fact that they are poisonous and their bite is painful. They are predators of many species of pests of crops (Khanna, 1977 a). It is evident from the literature that they have been found eating oil the millipedes, grubs of some harmful beetles, larvae of butterflies and moths, termites, etc. Even small birds and lizards are often seen to have been eaten by centipedes. At the same time on account of their retiring habits, the centipedes tend to escape I by using poisoJl as a mechanism of defence. There are numerous scattered accounts of the ill-effects of their bite (McCann, 1931; Jangi 1984; Khanna and Tripathi, 1984). The centipede-bite may cause OOOaema, Lymphangites with inflammation of skin and subcutaneous tissues and ulceration, and in most cases, a localised nacrosis may also take place.
Historical Resume
While no major contribution seems to have been made on the orders Lithobiomorpha, Geophilomorpha and Scutigeromprpha of class Chilopoda, in India, comparatively good accounts on the taxonomy, biology, ecology, myology, locomotion, etc., are available on the centipedes belonging to order Scolopendromorpha.
From the time of Linnaeus (1758) till date not much work on the taxonorny of the Indian Scolopendrid centipedes seems to have been carried oul From the survey of the available literature it is noticed that Haase (1886/87), Pocock (1890, 1891, 1892) Kraepelin (1903), Gravely (1910, 1912a, and 1912b), Silvestri (1919, 1924), Chat;nberlin (1913, 1920, 1944, 1959), Attems (1930), Verhoff (1937), Jangi (1955a, 1955b, 1956, 1957, 1959 and 1966), Vazirani and Khanna (1976, 1977), Khanna (1977a, 1977b), Ahmed (1980), Khanna and Tripathi (1984a, 1984b, 1985a, 1985b, 1986, 1987 and in press), have made their contributions to the study of this group of centipedes.
A considerable amount of work, has, however, been undertaken by contemporary workers outside India. Noteworthy among them are the works of Bucherl (1946, 1974), Crabill (1955, 1960), Demange (1963, 1967), Dobroruka (1968, 1969, 1973), Lawrence (1953, 1955, 1966, 1968), Lewis (1966, 1967, 1968a, 1968b, 1973, 1978, 1982 and 1986), Wurmli (1972, 1975), Chelazzi (1977a, 1977b), Koch (1983a, 1983b, 1983c, 1984, 1985a and 1985b), Koch and Bergman (1984) and Koch and Colless (1986).
Workers like Shukla (1965, 1968, 1971 and 1973) have conducted certain researches on the internal morphology and food and feeding habits of the most common centipede Scolopendra morsitans Linn. Khanna (1977) has studied the food and feeding habits of Scolopendra valida Lucas. He (1984, 1987) has also undertaken the ecological studies on some selected species of centipedes in and around Dehra Dun. Shukla (1974, 1975) has studied the amino-acid contents in different body systems in Scolopendra morsitans; Kanwar and Nagpal (1981) on the poison in the centipede Otostigmus ceylonicus; Jangi and Dass (1984b) on the centipede venoms; and Khanna and Tripathi (1984) on the hannful and beneficial effects of the scolopendrid centipedes.
Studies from Different Environs
The information available on centipedes from different ecosystems, as at present, cannot be claimed to be complete and comprehensive. The reports of the studies undertaken by previous authors like Chamberlin, Haase, Gravely, Pocock, Attems, etc., were based on stray collections. No efforts had been made to collect them from different ecosystems. Some concerted efforts have been made by Khanna 1917 (Desen ecosystem); Ahmed 1980 (Andaman and Nicobar Islands); Jangi and Dass 1984 (Deccan Plateau); Khanna and Kumar 1984, Khanna and Tripathi 1984, Khanna 1987 (Western Himalayan ecosystem); Khanna and Tripathi 1985 (Terai of Uttar Pradesh) and Khanna and Tripatbi (under publication) (Conservation areas), in this direction.
Estimation of Taxa
Out of the 17 genera of the Scolopendrid centipedes known world-over, 8 genera are found in India.
Khanna (1987, thesis) undertook the study on the centipedes of the family Scolopendridae, which in India, is 1O)0wn to be represented by two subfamilies (Otostigminae and Scolopendrinae) and three tribes (Scolopendrini, Asanadini and Otostigmini). These include altogether seven genera viz., Scolopendra, Cornwcephalus, Asanada, Otostigmus, Rhysida, Ethmostigmus and Digitipes; the rust three belonging to subfamily Scolopendrinae and the four to last subfamily Otostigminae. These genera contain, in all, 73 species (including 21 subspecies). Out of these, only five genera viz., Scoiopendra, Cormocephalus, Asanada, Otostigmus and Rhysida are represented in the Western Himalaya, Uttar Pradesh, by 20 species.
A detailed account of taxonomy and distribution of Indian species has been provided by Khanna (1987, thesis) besides providing a checklist. While reviewing the status of the family Scolopendridae in India, he has come to the conclusion that out of the total known Indian species (including subspecies), 71 are Oriental (comprising 59 as fully endemic, 10 Indo-Malayan and two Indo-Malayan extending to Australia); 4 Palaearctic; 7 Ethiopian; one circumtropical and two cosmopolitan in distribution.
Classified Treatment
Class Chilopoda consists of four Orders : 1. Geophilomorpha, 2. Scolopendromorpha. 3. Lithobiomorpha, and 4. Scutigeromorpha. First two orders belong to Epimorpha (body segments complete at the time of hatching), and last two orders belong to Anamorpha (body segments completed after hatching).
The centipede Craterostigmus tasmanianus Pocock occurring in Tasmania and Newzea1and, occupies a position intermediate between Lithobiomorpha and Scolopendromorpha (langi, 1966). It has 15 pairs of legs, 15 sterna and 7 pairs of spiracles, as in Lithobiomorpha.
