Chapter 1

INTRODUCTION

Western Ghats - an overview

The State of Kerala is blessed with forty-four rivers (41 rivers flowing towards

west and 3 flowing towards east) originating fiom the Western Ghats, cut across the state,

with their innumerable tributaries. Apart from rivers, bac kwatcrs, wetlands, a long coastal

belt also contributes to the richness of water resources of the state. Most of the rivers are

small, and being entirely monsoon-fed turn into rivulets in summer especially in the

upper reaches.

The Western Ghats occupy the western Peninsular India, between the latitudes

8' 20" N Latitudes and 73" 77" East Longitudes (Fig. 1. I). The Western Ghats cover a

practically unbroken relief dominating the west coast of the Indian peninsula for almost

1600 krn fi-om the river Tapti in the north to the tip of Peninsular India.

Zoogeographically, the Western Ghats can be divided into three parts: a northern

division, comprising the Deccan Trap area fiom the Tapti river down to 16' N latitude

about the level of Goa; a central division, extending from 16" N latitude southwards and

including the Kudagu and Wayanad region of south Kamataka and Nilgiris; and a

southern division, comprising the Anairnalai, Palni and Cardamom hills of Kerala

(B hirnachar 1945).

The western ghats are the main watershed in peninsular India from which all the

principal rivers namely, Godavary, Krishna and Cauvery originate and flow east emtying

into Bay of Bengal. A very large number of short perennial , torrential west flowing

rivers also originate fiom it. The avetage height of the ghats is less than 1500 m above

sea level. But in the southern reaches it rises up to 2002 m and to exceptionally higher

peaks of 2500 m and above. Along its entire length this hill range has only one total

discontinuity, the Palghat gap in Kerala, where for more than 30 krn there is a gap which

has a floor height of less than 100 m above sea level (Nayar, 199 1).

Kerala's Western Ghats cover approximately an area of 20,000 sq. Km, out of

which administratively forest areas cover about 8000 sq. krn. Intact climax forest

ecosystems and representative areas of forest types, sub types, edaphic stages, etc. even

in partially man-modified forms extend over approximately 2000 sq.km. in nine

geographically different locations (Nayar, 199 1).

Major hill ranges of Kerala part of Western Ghats

Natural topographic features such as mountain ridges and valleys divide Western

Ghat region into nine hill ranges (Nayar, 199 1).

A. The Agasthyamalai range: is the southern most reaches of Western Ghats. It extends

from the Mahendragiri near Kanyakumari in the extreme south to the Ariankavu Pass

near Shenkottai. The north eastern comer of this range has a significant area of forests on

the eastern slope, forming the catchment area of the Thamrapami river. There are short

hill ranges or isolated hillocks scattered along the valleys of Kallada and Achenkoil rivers

in their upper reaches.

B. The pandalam hills: this region of rugged stretch of mountains is situated south of

Peermade-Kumily-Kumbalam axix extending south up to the Achenkoil valley. The

northeastern parts of this hill ranges are drained by the Periyar river and the northwestern

parts by the Pamba river.

C. The Cardamom hills: is an extensive plateau north of Pandalam hills extending north

for almost 80 km up to the edge of the High Ranges, at an average elevation of 900 m

above sea level. The entire eastern edge is drained by Periyar. The Western slopes are

drained by Manimala, Meenachil 'and Muvattupuzha rivers.

D. The High Ranges: Most wide and highest reach of the Western Ghats in Kerala. High

Range part is divided in to three sub regions- the central High Range proper (Kannan

devan hills), the eastern Anjanad and the western Pooyankutty-Edamala valleys. The

Kannan Devan hills are drained by Muthirapuzha. The Anjanad valley is drained by the

tribuatries of the esat flowing Amaravathy river.

E. The Nelliampathies and the Anamalais: The Nelliampathy hills form the southern

and the south-westem margin of the Palghat gap and they extend south, enclosing

Parambikulam basin. The western edges of the Nelliampathies are drained by Puzhakkal

and Karuvannur rivers. The Parambikulam basin drains towards south and west through

the Chalakudy river. The upper reaches of the east-west Chalakudy valley are formed by

Sholayar tributary of the Chalakudy river and the lower reaches by the main Chalakudy

river.

P. The Paghat hills: The northern tip of the Paghat gap is the Palghat hills. The southern

and wetsem faces of the Palghat hills are drained by the tributaries of the Bharathapuzha

and Siruvani and the Attappadi plateau by the east flowing Bhavani and its tributaries.

G. The Nilgiris: The most extensive eastern spurhill of the Western Ghats, the Nilgiris, is

a high steep plateau, rising from the edge of the Mysore plateau in the north and

extending south up to Bhavani with its eastern end approaching the Biligirangans, a part

of the Eastern Ghats, north of Moyar. The Silent Valley and Attapadi forests are on the

south-west comer and extensive forest draining into Chaliyar cover most of the western

slopes. The Nilgiri mountains are mostly in Tamil Nadu and only the south-western and

western slopes are in Kerala.

H. Wayanad: is an east sloping medium elevation plateau. Kabini and Moyar rivers

drain the Wynad-Gudalur tract into Tamil Nadu. Most of the forests of Wayanad are

destroyed by its conversion in to plantations, clearance for settlements etc. The isolated

high ridges along the south-westem comer of Wayanad are the Camel's hump

Mountains.

I. Brahmagiris: The north -eastern comer of Wayanad rises up to into a hill range called

the Brahrnagiris. It descends extremely steeply to the plains of Kerala towards west, and

is drained by a number of small rivers. Only a part of the Brahmagiri western slope is

drained by the Aralampuzha falls in Kerala. This range of hills continues north to the

Netravathy water shed and is the northern limit of the southern Western Ghats.

Biodiversity of Western Ghats

The Western Ghats are region of high diversity and high endemicity of fish fauna,

perhaps because of the latitudinal and altitudinal gradient phenomenon and it is one of the

18 biodiversity hot spots which harbour 30% of total life forms known from India. It

includes most of the remaining tropical rain forests of Peninsular India and is a home to

several endangered and endemic species of flora and fauna. The rate of endemisrn is

reflected in the case of lower vertebrates like the reptiles, amphibians and fishes. The

highest concentration of endemic amphibians are found in this region. Out of 216

amphibians, 93 (5%) species are known only from this area (Inger and Dutta, 1986).

Among the 487 reptiles reported from India, 190 species are found in the Western Ghats

and out of this 5% are endemic (Kumar et al., 1998). Out of 23 0 species of freshwater

fishes 1 14 are known only from this tract.

Scope and importance of the study

Fish communities in hill streams are highly adapted to the torrential nature of

their habitats; the highly specialized adaptations in turn confine them to these streams

(e.g. Glyptothorax sp., Homaloptera sp., Balitora sp., Pseudoeheneis sp. etc.). The degree

of specialization also make them highly sensitive to any changes in their habitats. These

changes are largely caused by anthropogenic activities in the catchment area, which have \

reached such levels that some of the more specialized species arc facing extinction.

Different aspects of this fragile ecosystem have been studied to some extent. Few

systems worldwide have been modified by man more than freshwater aquatic systems.

Among the aquatic systems, hill streams are in a more precarious condition as regards

their ecological status, because of their metastable eco-geography. The conditions

downstream are determined by what happens upstream in the catchment area. As

extensive areas of drainage of river basins are altered, the condition in the stream and

associated systems change, and so does the nature of the aquatic habitat and associated

aquatic communities. Many anthropogenic activities such as vegetation removal,

agriculture in the catchment area, construction of dams, construction of new roads

through the forests, canalization and pollution have an adverse impact on the diversity,

abundance and community characteristics of the aquatic flora in an ecosystem.

Available historical information provides a basis for comparing current conditions of

habitat and communities with those of the past and helps to document activities leading to

change. Basic information on the existing habitat and aquatic communities is necessary to

develop management plans for their conservation. Comparison of altered habitats with those

that have remained largely unaltered provides a framework for evaluating the current status

of the communities.

The present data available on fishes does not give any information on the endangered

species and their status, except for the Mahaseers (Tor sp.) (Kulkami & Ogale 1978; Ogale

& Kulkarni 1987). Moreover, in the rUCN Red Data List of threatened animals, only two

endangered fish species namely Horaglanis krishnai (Clari idae) and Schist urn sijuensis

(Balitoridae) are incuded from India (IUCN 1990). The National Bureau of Fish Genetic

Resources has instituted a programme to catalogue fish species, but it currently does not

include any information either on the status of communities or their habitats. Considering all

these factors, this study was undapken.

REVIEW OF LITERATURE

One of the incarnations of "Lord Vishnu" is in the form of fish to rescue 'Vedas'

from 'Asuras'. Thus fishes have been a part of Indian culture and have appeared in

mythology. In several temples of Kerala, there are ponds to protect fishes and there is a

religious fete like "Meenuttu" (feast for fish). The word Matsya itself denotes that an

object delights and is a synonym to the nutritive value of the flesh of the fish (Hora, '

1948a). The Malayalam term for the fish ('Meen') owes its origin to the Sanskrit word

' Mina' meaning scattering or splashing water. The ancient Hindus knew greatly about the

external features and habits of a variety of freshwater fishes of the Indo-gangetic plain

and fishes appeared in Ramayana (Hora, 1934; 1935d; 1948a, b; 1950a;, 1951a,b,c;

1952a; 1953a,b).

The Great Aristotle (BC. 384-322) can be considered as the pioneer in

Ichthyological studies as he attempted to distinguish between the aquatic mammals and

fishes. His knowledge on the habit, habitat, propagation, migration and utility of fishes

was proved to be correct.

In 'Mansallosa', King Somesvara (1 127AD) classified fishes as scaled, scale less,

ascending rivers, marine and freshwater inhabitants (Jayaram, 200 1 a). As Day (1 865a)

comments, no branches of natural history has received less attention than ichthyology.

The traditional uses of fishes were briefly narrated by Day (1 865 a).

Belone gathered knowleqge of about 110 fishes during the middle of sixteenth

century during his investigations in the Mediterranean sea. The book "De aqua tilibus

libri duo" was an important progress in Ichthyology. Randelt's (1 507- 1557) work "Libri

de piscibus marinus" reveals his thorough knowledge on the anatomy of fishes . Ray and

Willughby (1635-72) contributed much to the taxonomy of fishes. The book entitled

"Historia piscium" describes the fishes collected during their journeys in Great Britain

(Day, 1875-78).

Linnaeus, Peter Artedi (1705-1734) is considered as the father of Ichthyology

and he contributed knowledge on external morphology and anatomy of fishes, includes

the description of fourty five genera and seventy-two species; also presented a list of

preceding workers. The final work consist of the synonymy and systematic works of the

present day (Gunther, 1994 reprint). Linnaeus (1 75 8, 1 766-G8), father of taxonomy

contributed much to the taxonomy of fishes also. Bloch's (1785-1795, 1797) work was

unique with great number of illustrations. Lacepede's (1798-1803), "Histoire des

poissons" and Cuvier and Valenciennes's (1 828- 1 849) "His to ire Naturelle des poissons"

are indispensable for any fisheries related studies. Nelson (1976, 1984, 1994) presents a

modem introductory systematic treatment, diversity, and zoogeography of all major fish

groups in the world.

It was Hora (1948a & b; 1952), who made the pioneering attempts to unearth the

scientific knowledge obscured in the classics .of India (1948a & b; 195 1; 1952; 1953

a&b).

Studies on fishes of Western Ghats rivers and their tributaries were mostly

conducted during the 19' and the first half of the 2oth century. In general the studies

emphasized the taxonomical and zoogeographical aspects of the fish fauna (Jerdon 1849;

Day 1865, 1875; Hora 1921, 1922, 1936, 1937, 1942, 1943; Pillay 1929; John 1936; Hora

& Law 194 1; Hora & Misra 1942; Hora & Nair 194 1 ; Raj 194 1; Menon 195 1 1987; Silas

1951a, 1951b, 1952, 1953, 1954; Jayararn 1955; Rema Devi & Indra 1986; Menon &

Rema Devi 1992; Rema Devi 1992).

Major Ichthyological studies on Indian fish fauna

Fishes attracted the people since Vedic times and they classified fish based on

shape and structure as seen from Kautilya's Arthashasthra, King Someswara's

Manasallosa etc. Till the advent of the English, we were unaware of the scientific value

and uses of fishes. As Day (1 875-1 878) comments, the first Indian who wrote on the

Indian fishes was Bloch whose work entitled Auslandische Fishe was published in 1785.

This was continued by Schneider in 1801 and his work included many Indian marine

forms. Lacepedes (1 798- 1803) Histoire des Poissons contains many Indian forms. In

Russel's (1803) Fishes of Vizagapatanarn, 200 forms are delineated and described.

Cantor's work was published as 'Notes on the Indian fishes' in the Journal of the Royal

Asiatic Society during 1839- 1850. McClelland (1 839) published a memoir on Indian

Cyprinidae in Asiatic Researches. Before this, Sykes made a report on the Fishes of the .

Dukhun but it remained unnoticed for a long time, subsequently published in 184 1 in the

Transactions of Zoological Society of London. Bleeker's (1853) Ichthyologische fauna

van Bengalen included all the fishes known from India (Day, 1875-78).

Blyth, a curator of the museum of Royal Asiatic Society of Bengal gave several

interesting articles on the Indian fishes in their proceedings on the Fishes of India during

(1858-60). Gunther (1859-1870) of British museum made a compilation of the fishes in

the museum and published as catalogue of the fishes in the museum and published as

catalogue of the fishes in the collection of the fishes of the British museum. This deals

with 6,843 well-established species and 1,682 doubtful species.

The more scientific systematic study on the Indian freshwater fish fauna started

with Hamilton-Buchanan's (1822) account of the fishes found in the river Ganges.

Beavan (1877) published a book on the freshwater fishes of India in which he gives a

clue on the distribution pattern of some Malayan species found in peninsular India.

Information on the fish fauna of Malabar region was made by Hamilton (1 877) during his

journey through south India. All these pioneer researchers laid a solid foundation for

Indian systematic Ichthyology. Nevertheless, a comprehensive and authoritative account

on the fishes of Indian region was published only during 1875-78 and 1889 by Francis

Day.

Day included 1,418 species of fishes found in the temtories of present Republic

of India, Pakistan, Bangladesh, Myanmar and Sri Lanka. Besides the text, a separate

volume of illustrations with 195 plates was also issued. Even today, the publications by

Day remain as an important reference manual for the Ichthyology of Indian region. After

Day, during the intervening hundred years, there was nothing substantially published to

fill the lacuna. We had to wait till Sunder La1 Hora (1920-55) for further information.

The publications of Hora are indispensable for any student of Indian Ichthyology. Hora

published over 440 papers, and established three families, 28 genera, and ' 139 species

(Jayaram, 1976). Hora made mainly the revisionary studies in the thirties. He published

his studies in various heading such as "Notes on the fishes in Indian Museum". The .

survey and documentation carried out during 1920- 1955 by Hora brought out information

on the freshwater fishes of various river systems of India. Most of the works are

concentrated in the northeastern States of India. Very few attempts were made in south

India.

Misra published a series of checklists and aids for the identification of the fauna

of India and adjacent countries (Misra 1947, 1952, 1953, 1962, 1969, 1976a,b). These

studies were continued by the publication of Tilak (1987), Menon (1987, 1992 b) and

Talwar (1995). Datta Munshi and Srivastava (1988) published the fauna of India volume

dealing mainly with the taxonomy of fishes of India and adjacent countries. Jayaram

(198 1, 1991, 1999) and Talwar and Jhingram (1 99 1) supplemented information on the

inland fish fauna of India. Recently many foreign workers are also engaged in freshwater

fish fauna studies of Indian region (Mirza, Banarescu, Nalbant, Kottelat, Rainboth,

Howes, Pethiyagoda) (Shaji, 1998).

Hora's (1 949d; 1950b; 1953~) "Satpura hypothesis" generated interest on the

freshwater fishes in the rivers of the Western Ghats. Hora (1926; 1937a; 1941a and

1942 a) added several species from the Western Ghats and made surveys in several parts

of India. Bhimachar (1945) made zoogeographical studies of the Western Ghats based on

the distribution of hill stream fishes. Besides these, Molesworth and Bryant (1921), Hora

(1936), Hora and Misra (1 942), Silas (1 95 I), Rajan (1 959, Jayaram ( 1 98 1,19321,

Johnsingh and Vikrarn (1 986), Yazdani and Singh (1 990,199 1 ), Ilango (1 990), Indra

(1 99 1, 1992), Remadevi (1992), Remadevi and Ilango (1993), Menon et al. (1 993), Singh

( 1 994), Remadevi, and Menon (1 994), Arunachalam et al. ( 1 997), Manimekalan and

Singh (1997) and Arunachalam et al. (1998) also made some studies in peninsular India.

Recently Daniels (2002) made information on the endemic fishes of the Western Ghats

and the Satpura hypothesis. .

Studies on the fresh water fish fauna of Kerala

Fish fauna studies of Kerala starts with Jerdon's (1 848) and Hamilton's (1 877)

journey through south India. A systematic account of the fishes is available from Day's

(1865) "Fishes of Malabar" - this book is considered as germ for the publication of

"Fishes of India". After Day's monumental work, the next fish fauna study in Kerala was

by Pillay (1929), in which he listed 369 species from Travancore region. John (1936)

published information on fish and fisheries of Travancore. Based on the above stud-ies

Hora and Law (1941) published a comprehensive list of 76 species of typical freshwater

fishes of Travancore.

Chacko (1948) listed indigenous fishes from the Periyar lake. Later, Silas (1950,

195 1, 1952, 1954) documented fishes of the Travancore region. Freshwater fishes in the

headwaters of Bhavani river was studied by Rajan (1955). Remadevi and Indra (1986)

reported fish fauna of Silent Valley. In 1994 Pethiyagoda and Kottelat described three

new species from the Chalakudy river in central Kerala. Easa and Bhasha (1995)

conducted a survey on the habitat and distribution of stream fishes in the Kerala part of

the Nilgiri Biosphere Reserve and recorded 92 species. The distribution of freshwater

fishes in Wayanad was studied by Shaji and Easa (1995). Shaji et a1 (1 995) documented

the fish fauna of Aralam wildlife sanctuary in Kannur district of Kerala. The fish fauna

of Pambar river, Chinnar wildlife sanctuary was studied by Easa and Shaji (1996). Fishes

from the Periyar Tiger Reserve was documented by Arun et a1 (1 996) and Zacharias et a1

(1996). Biju, et al. (1998) documented the freshwater fishes of Parambikulam Wildlife

sanctuary. Recently, Thomas et a1 (2002) studied the fish fauna of streams south of

Palghat gap in Kerala and reported 117 species. They also reported the distribution of

endemic and endangered species.

Habitat Studies

Regression-based models for assessing fish habitat were recommended by

McClendon and Rabeni (1987) and Scarneechia and Bergersen (1987), mainly to identify

Scarneechia and Bergerson (1 987) used Regression based approaches for

modeling fish-habitat relations to relate salmonid productivity to habitat variables such as

substrate diversity, width to depth ratios, and area of zero velocity water in rocky a

mountain streams. Wesche et al. (1987) used this approach to establish relations between

the abundance of brown trout Salmo trutta abundance and the amount of cover in stream

channels. Lanka et al. (1987) found that geomorphic stream variables were significantly

related to Salmonid standing stocks.

Shirvell and Dungey (1985) used microhabitat models to establish the habitat

requirements of adult brown trout. Moyle and Baltz (1985) developed micrihabitat

models for an assemblage of fresh water fish in a California stream. Leonard and Orth

(1988) used microhabitat information from habitat guild representatives to identify

stream flow requirements for protecting an entire fish community.

The basic. aspects of stream ecology relevant to ecological monitoring were

mentioned by various authors (Reid and Wood, 1976; Cummins, 1979; Holden, 1979;

Stalnaker, 1979; Winterboum and Townsend, 1991; Berg, 1993; J NABA, 1997; and

Smith, 1997). Armantrout (1995) discussed the technique of aquatic habitat inventories

using remote sensing. The need of Global Positioning System and Geographic

Information System in aquatic habitat studies were documented by Jeffrey and Edds

(1997), Issak and Hubert (1997) and Richards and Host (1994). Florshein and Coats

(1996) predicted ' Dynamic Equilibrium' as a model for restoration in rivers and

wetlands. A restoration design using the concept of dynamic equilib~ium accommodates

dynamic natural processes and accounts for the evolution of dynamic natural systems.

The methods for the assessment of fish habitat in various inland water bodies,

especially in streams were explained by a number of workers (Vi tousek, 1 977; Cowardin,

1982; Oswood and Barber, 1982; Cuplin, 1986; Karr et al, 1996; La Mounty, 1986;

Molloy and Strble, 1988; Poff and Ward, !989; Armantrout, 1990 a and b; Kreshner et al.

1992; Seiler and Linder, 1995; and Dunne, !998) . Armantrout (1994) systematically

documented the condition of world's aquatic habitats.

Important studies on fishes in relation to their habitat conditions include those by

Sheldon (1 968), Lotrich (1 973), Anderson et a1 (1 98 I), Karr (1 98 I), Angermeir and Karr *

(1983, 1984), Watson and Balon (1984), Rahel (19841, Huish et al. (1986), Galzin and

Legendre (1987), Layher and Maughan (1988), Taylor (1988), Bain et a[. (1988) Winston

(1995), Scott and Hall (1987), and Braaten and Berry (1 997).

Some of the studies conducted in India in relation with physico-chemical

properties of water include those by Bhunya and Mohanty (1 990) in Ansupa lake, Orissa;

Ahrnad and Singh (1 990) in Kawar lake , Bihar; Seshavatharam (1 990) in Kolleru lake in

Andhra Pradesh; Seshavatharam et al. (1990) in lake Kondakaria, Visakapatanam.

Abbasi et al. (1997) studied the physico- chemical parameters of water in Pookot- a rare

high altitude lake in Wayanad distict, Kerala. Abbasi (1997) also conducted detailed

studies on the water quality of Punnurpuzha river in Kerala.

The important ecological studies in relation with the aquatic habitats conducted in

Kerala were the following: Harikrishnan and Aziz, 1 9 89; Sahib and Aziz, 1989;

Chandrashekara,1992; Nair et aZ.1992; Abraham and ~alakrishnan, 1993; Burton and

Sivaramakrishnan, 1993; Padmalal and Seralathan, 1994; Kumar and Chattopadhyay,

1995; Abbasi et al, 1997; Greller et al. 1997; and Suraj et ~2.1997.

Studies on the Freshwater fishes of Northern Kerala

The areas lying north of the Palghat Gap gained the attention of researchers only

in the 1980~~ except for the study by Rajan (1 955). The recent studies from this region are

by Indra & Rema Devi (1981), Rema Devi & Indra (1986), Shaji et al. (1995), Easa &

Basha (1995), Easa & Shaji (1995, 1996), Manimekalan & Das (1 998), and Reghunathan

(1998). All these studies were restricted to only six rivers: Kabini, Bhavani, Chandragiri,

Chaliyar, Valapattanam and Bharathapuzha. There has been no major work in the

remaining 19 rivers of northern Kerala. Moreover, these studies were limited to restricted

locations such as the Kerala part of the Nilgiri Biosphere Reserve and the Aralam

Wildlife Sanctuary. Detailed studies were not conducted in the remaining areas especially

on the distribution of freshwater fishes including hill stream fishes. Moreover, in spite of

a number of recent publications on freshwater fish fauna of Kerala, hard,ly any effort was

made to compare the present status and abundance of the fish fauna with those of the

past.

Hence the present study was taken up in the rivers of northern Kerala with the following

objectives:

To assess the current status and distribution of hillstream fishes of major

rivers of Northern Kerala.

TO study the habitat preference of selected hillstream fishes.

To evaluate the fish assemblages by comparing the past records and the

present conditions.

Dietary analysis of selected hill stream fishes.

Identify ecologically sensitive areas for long term monitoring and

conservation of fish fauna and their habitats.

STUDY AREA

Kerala: the land and its rivers

Kerala (8" 17' 30" to 12' 47' 40" N and 74' 5 1 ' 57" to 7 7 O 24' 47" E) is one of

the smallest states of India. The state is flanked by the Western Ghats as a natural wall on

the eastern side and the Arabian sea on the western side. Along its entire length, the

Western Ghats have only one major discontinuity, the Palghat Gap, in Kerala. Due to the

Palghat Gap, Kerala can be divided into two regions - southern Kerala (south of the

Palghat Gap) and northern Kerala (north of the Palghat Gap). Based on the topography,

the land resources of the state generally fall into well-defined natural divisions, each

running almost parallel in the north-south orientation. They are 1) Lowland (< 75 m

above MSL) 2) Midland (75 - 500 m above MSL), 3) Highland (500 - 750 m above

MSL) and 4) High Ranges (>750 m above MSL) (Ipe et al. 199 1).

Northern Kerala and its rivers: Kasargod, Kannur (Cannanore), Wayanad, Kozhikode

(Calicut), Malappuram and parts of Palakkad (Pal ghat) districts constitute northern

Kerala. The major hill ranges of this area are Palghat Hills, Nilgiris, Wayanad and

Brahmagiris. Twenty-four rivers flow through this region, seven of which originate from

Kamataka state. Besides this, Thootha and Malampuzha tributaries of the Bharathapuzha

river system also flow through this area. The major rivers of northern Kerala are

Chandragiri, Valapattanam, Chali yar and Bharathapuzha. Faunistical ly this area is very

important due to the presence of the Silent Valley National Park, Aralam Wildlife

Sanctuary and Wayanad Wildlife Sanctuary (fig. 1.1).

Study area: 19 out of 24 rivers and Thutha and Malampuzha tributaries of

Bharathapuzha were covered during the present study (Table 1.1). Collections were also

made from the protected areas namely, Silent Valley National Park, Aralam Wildlife

Sanctuary and Wayanad Wildlife Sanctuary. Visual count was the main method adopted

in Silent Valley National Park. Regular collections (once in three months) were made

from Bharathapuzha river.

Climate

Kerala falls under per-humid and humid climatic types except the southern most

pockets of the State and the eastern part of the Palghat region, which come under moist

sub-humid climatic type. The State as a whole experiences mega thermai climate (lype

et al. I 99 1).

Rainfall

The rainfall distribution in Kerala is bimodal. The State gets heavy rains during

both monsoons (South-west and North-east monsoons). The average annual rainfall of the

State is 2963mrn.The highest rainfall is recorded at Neriyamangalam (Ernakularn district)

and the lowest at Chinnar (Idukki district). The southern parts extending £?om Ponnani to

Thiruvananthapuram show two peaks in the months of June -July and October during

south-west and north-east monsoons respectively .The effective rainfall in the northern

region is about 40% and is 80% in the southern region .The mean annual number of rainy

days over the State is 126 with the minimum (45days) at Chinnar and maximum

(172days) at Neriyamangalam. Nearly 60% of the annual rainfall is received during the

south-west monsoon (Iype et al. 199 1).

Temperature

The mean annual temperature varies from 25.4 '~ to 3 lo C in the central parts of

Kerala. However, a major portion of the midland records temperature under 27 SOc. The

diurnal variations are not high (5-7'~) except in the highland zones where the difference

goes up to 15' C. March, April and May are the summer months during which the mean

annual temperature varies between 29' -31". Due to high rainfall during the south-

west monsoon, the temperature comes down during July-August and starts increasing

from October onwards (Iype et al. 199 1).

Table 1.1. Rivers and river basins of northern Kerala

S. No.

I

I

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

(*) - Rivers

Source: Water Resources of Kerala. PWD, Thiruvananthapuram, 1974.

Name of river

Mancheswararn

Uppala

Shiriya

Mogral

Chandragiri

C hittari

Neeleswaram

Length (lan)

16

50

67

34

105

25

46

Catchment area (krn3

Tamil Nadu '

- - -

- -

Kerala

90

76

290

132

570

145

190

Kariamgode

Kavayi * Peruvamba * Ramapuram * K U P P ~ ~

Valapattanam

Ancharakandi

Thalasseri * Mahe

Kuttiadi

Korapuzha * Kallayi

Chali yar

KadaIundi

Thiroor

Bharathapuzha - Bhavani

Kabini

not covered during

Total

90

250

587

132

1406

145

190

- -

-

-

-

-

-

-

-

388

- -

1786

- -

I

Kamataka

174

297

-

836

- -

561

143

300

52

539

2 867

412

132

394

583

624

96

2923

1122

117

6186

1920

562

64

3 1

5 1

19

82

110

48

28

54

74

40

22

169

130

48

209

37.5

56.6

the study period.

429

143

300

52

469

1321

4 12

132

394

583

624

96

2535

1122

117

4400

1920

562

132

-

-

-

70

546

-

-

- -

-

-

-

Rivcrs 1. Matnjawarnm 2. U l,pafa 3. Sl~itiya 4. Mogral 5. Cl~andragiri 6. Cllittari 7. Nccleswaram 8. Kiriyamgodc 9. JGt~ilyi* 10. Pcruvarnba* 11. R~mayuram* 12. Kuppam 13. Vrlapaftanam 14. Aochurakandi IS. Thalassery* 16. Mahi 17. Kuttiftdi 18. Korapwha* 19. KaXayi 2(1. Clr alipar 21. Kitdalundi 22. Thirnor 23. Kabini 21. Blravani 25. Iicrhcry 26. Puxhakl;a¶ 2:. K;lnlvt&nur 28. CJ~alalcudy 29. PeriyAr 30. hluvattupuzhit 3 1. Mccnach il 32. f inirnala 33. Pamba 34. Actrenkavil 35. Pikllikkrl 36. Etllada 37, 1flrikk:rra 38. Ayrnor 39. \';rm;lnapu lqam 40. M;rrnYnl 4 1. K;tr;rrnan;i 42. Ncyyvf 43. E~nrhnr 44. Bharathapushtl

METHODS

The study was carried out from 1998 to February 2002. Fish collections were

taken from 105 sites of the study area. Most of the samplings was done during the

pre-monsoon period, and some during the post-monsoon and monsoon period. Survey of

India toposheets (1:50,000) were used to pinpoint the approachable sites for sampling.

After reaching the sampling sites, careful observations were made from the bank

(bankside counts) and visual counts from a roughly 2 m2 area was carried out in clear

waters. As sampling was done mainly during the pre-monsoon period, the water was

rarely turbid. Thereafter, various sampling methods or fishing gears such as cast net and a

circular net (with very small mesh size and sinkers around the edge), were used. The

collected fish specimens were preserved in 10% formalin and kept in the field station for

identification and further studies. Each sampling method was used thrice at each

collection site. The sampling methods are discussed below.

Bankside counts: Fishes in pools and slow moving, shallow, fresllwatcr streams and

small rivers could be sampled by this method. This method was suitable in most of our

study locations, as most of the rivers of Kerala are very small, especially the hill streams.

In this sampling method, first the stretch of water to be surveyed is divided into small

overlapping sections. Once in position, the investigator waits in motionless for at least

five minutes before counting, so as to minimize the effects of disturbance. After the

count, the investigator moves away from the stream bank before proceeding to the next

observation site. Counts are best made on sunny days. The deilsities of the different fish

species can be derivod by dividing the total number of individuals of each species by the

area sampled.

Advantages: Cheap, fast and easy; very appropriate for shallow water bodies; for

counting fry, which seek mainly shallow slow moving watcr habitats; allows checking

parameters, such as fish size and many features of the enviroilment such as water depth,

current speed, substrate type, and vegetation; it also allows detailed behavioural

observations to be made; stress to fish is minimal.

Disadvantages: The arrival and presence of the observer will disturb the fishes and they

may take a long time to leave cover and resume their activities following disturbance, or

may not return at all.

Cast netting: Fishes in shallow water or on the surface, in still or slow flowing water can

be sampled by this method. Cast nets are circularly shaped, with weights around the .

perimeter. They usually have a central line, which is retained in the hand for hauling the

net after it has been cast. Large mesh sized cast nets are used for catching bigger fishes - they sink down faster than small mesh sized cast nets.

Advantages: Simple to use and easily repeatable.

Disadvantages: Little is known of their efficiency and selectivity; in deep water bodies it

cannot be operated due to the presence of woody debris and dense vegetation, moreover,

the fishes will escape before the net reaches the bottom of deep water bodies.

Other methods

The other methods used for fish collection were: Hand held scoop nets (which

were inserted below the water surface and brought up sharply) and sieving by cloth or

mosquito nets (applied in suitable places). In some small streams, temporary bunds were

constructed to catch the trapped fish.

Physical and Chemical parameters

The following chemical properties of water were measured adopting standard

analytical methods: 1. Temperature (Die1 digital thermometer), 2. pH (digital pH scan

meter), 3. DO (Merck oxygen kit), 4. Conductivity (digital conductivity meter).

The physical parameters considered for the study were: 1 . Flow rate 2. Transparency

(Visual'method), 3. Width and depth of the streams, 4. Canopy or coverage 5. Altitude

(Altimeter) and 6 . Substrate distribution (Substrates were divided into seven types based

on the size (detritus, mud, sand, gravel, cobble, boulder and bedrock (Murphy & Wills

1 996)).

Classification and Nomenclature

Fishes were identified mainly by following Talwar & Jhingran (1991) with

modifications from Menon (in press). A lot of inconsistency and confusion has been

noticed in the classification and nomenclature of fishes of some families, mainly

Cyprinidae and Nernacheilinae. This confusion is very clear in adopting the generic name

Puntius Hamilton and Barbus Cuvier. Hamilton-Buchanan placed some species under the

division Puntius and a few others under the division Cyprinus. Day (1878, 1889) used the

name Barbus in a wide sense, although in his key he utilized the Bleekerian names

without any indication of their status. Hora et al. (1939), Hora & Law (1941), Hora &

Nair (194 I), Hora (1942) treated Puntius as a subgenus of Barbus. Misra ( 1 962) used

Puntius for all species described in his work. Yazdani (19921, Menon & Rema Devi

(1995) have revived the Bleekerian names Barbodes and Hypselobarbus to accomodate

some species of Puntius and Gonoproktopterus (Jayaram 1999), while Talwar &

Jhingran (199 1) and Jayaram (1999) used Puntius, Gonoproklopterus and Neolissocheilus

for representing this genus. Here in this study adopted Puntius and Hypselobarbus has

been used for naming these genera. Talwar & Jhingran (1 99 1) included all the species of

the subfamily Nemacheilinae in one genus, viz., Nemacheilus, while Jayaram (1999)

treated it under many genera namely, Nemacheilus, Schisturn. Mesonemacheilus.

Oreonectes, Nernachilichthys etc. Moreover, Jayaram (1 999) divided the family

Cyprinidae into subfamilies, tribes and subtribes, in which he classified the family

Cyprinidae into five subfamilies: Leucisinae (= Hypothalmichthynae), Danioninae (=

Rasborinae), Cyprininae, Oreininae (= Schizothoracinae) and Ganinae. Danioninae has

been divided into two tribes, viz., Oxygasterini and Danionini; Cyprininae into four

tribes, viz., Cyprinini (C yprini and Tores - Subtribes), S ystomini (Osteobramae and

S ystomi - Subtribes), Semiplotini, and Labeonini (Labeones).