INTRODUCTION. 



Peioe to commencing an account of the fishes existing in India and Burma, it will be necessary to 

 define the Geographical limits of the countries or seas the Ichthyology of which I propose to describe. They may 

 be briefly summed up as the regions of Sind, India, Ceylon, Assam and British Burma extending eastwards 

 to Mergui in the Tenasserim Provinces, and including the Mcobar and Andaman Islands in the Indian 

 Ocean. The boundaries are the Beloochistan and Sulieman ranges of mountains on the West and North- 

 West, the Himalayas and Upper Burma on the North and North-East, and the Indian Ocean to the South. 

 Within the foregoing area we find, as might be anticipated, vast difierences of climate as well as of locality. 



The rivers vary in their conditions owing to the season of the year, the rainfall, and other 

 circumstances, both natural and artificial. " Some rivers, as those which descend from the Himalayas, possess 

 Alpine sowrces, and in the hot months of the year are chiefly fed by the melting of ice and snow, while in the 

 monsoon season they are filled by the rains. Thus in the commencement of March, floods begin in the 

 Indus, when inundations are more due to melting snows than to the fall of rain ; on the contrary, in 

 the upper regions of the Ganges and Jumna, the rainfall is very considerable, occasioning floods, which subside 

 as rapidly as they rise. During the cold season these rivers being unreplenished by rains or melted snows, 

 are at their lowest. 



In rivers destitute of Alpine sowces, as the Nerbudda, Kistna, Godavery, and those arising on the 

 Western ghauts or lower hill ranges, snow rarely falls and never remains for any length of time. Along 

 with these must be classed as being of the same character, the aflluents of the larger snow-fed rivers, and it is 

 in such where the temperature of the water is higher, that most of the hill fishes (excepting some loaches 

 and perhaps the Sehieothoradnce) breed. If we take as an example the rivers on the Malabar coast, which as 

 a rule have their origin in the Western ghauts, we perceive that they receive the full force of the South- West 

 monsoon, which commencing in June, continues about three months. It is only at this period of sudden rises 

 and falls of the river, that breeding fish can ascend to the hill ranges for the purpose of depositing their ova 

 in suitable localities. As the monsoon ceases, the waters subside, and the breeding fish descend to the plains, 

 leaving the young to be reared in the pools remaining in the hill streams. 



The rivers of the plains may be divided into those which have always a fair supply of water, as the 

 Indus, Ganges, Brahmaputra and Irrawaddi : and others which are comparatively dry during part of the year. 

 In some of these latter this deficiency of water is increased by what remains being abstracted for irrigation 



purposes. ..... 



During the rainy months of the year rivers are usually at their highest, submerging the contiguous 

 country, and filling the numerous tanks : here many fish retire to breed and are entrapped by every device 

 the ingenuity of man can conceive. 



Weirs or bunds, as I have observed, afiect fisheries by preventing the ascent of breeding fish to their 

 spawning grounds. Irrespective of this, any descending a river and arriving at a weir, find an obstruction to 

 their further progress down stream, but a large quantity of water being deflected from its natural course 

 down an irrigation canal, they as a consequence descend by this the only open route. Once down a canal and 

 over a single fall, there is no possibility of their return, and as these canals are being constantly dried in order 

 that the engineers may examine their structure, they become vast traps for the destruction of the finny 

 tribes, as successive waves of living fish pass down them only to die. 



We find the same process going on elsewhere, although to a less extent. Thus in Malabar as the dry 

 season commences, water is required to irrigate the second rice crop ; but the rivers are very low, so the formers 

 collect stones, lay them across the stream, filling in the interstices with shingle and stopping up the crevices 

 with bushes and mud. In this way the water which is stocked with fry is diverted into rice fields : the young 

 fish pass in to these levelled and partitioned localities, and if the water does not return to the river, but is 

 expended in the fields, they cannot escape destruction. Even if it does return to the river, fine traps 

 •which do not permit the smallest fry to escape are fixed in every constricted place. 



If we examine into what are the fish which inhabit these pieces of fresh water as well as the tanks, 

 lakes, and marshes of India and Burma, we find most diversified forms. Some are exclusively confined to 

 the fresh waters, while others enter rivers from the sea for breeding or to catch their prey. 



The subject of the migrations of fish during the rains is of importance, being mostly effected for the 



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