Chapter 5

FISH CONSERVATION STUDIES

I. Evaluation of changes in fish assemblages through comparison with

past records

Monitoring the occurrence of species and their populations has been a basis for

* assessing the effects of environmental impacts (Spellerberg 1996). Fish fauna of an area

may change for reasons such as habitat alteration, pollution and over fishing. To have an

insight into the various threats that contribute to the decline of a species or an assemblage

of species, there has to be a basic data of the distribution and abundance of the species of

an area. Such information could be the basis of evaluation of past, present or future

changes in the species composition and abundance of the fish fauna.

Inspite of a number of publications on the freshwater fishes of Kerala, there have

been no attempts to compile this information since Hora & Law (1941). In this chapter,

an attempt is made to review some of the earlier work carried out prior to the present

study. An attempt is also made to compare the present findings with some of the earlier

records so as to evaluate changes that have occurred in the fish assemblages.

Discussion

Prior to the present study, about 149 species of freshwater fishes belonging to 24

families and eight orders had been recorded from Kerala, of which 73 species were

reported after the study of Hora & Law (1941) (Table 5.1). Out of these 73 species, 24

were newly described species, of which 5 species are reported from northern Kerala .

A total of 100 species were recorded by earlier workers from the rivers of

Northern Kerala (Table 5.1). In the present study a total of 96 species of fishes were

recorded from northern Kerala (Table 2.5), 14 species recorded by earlier workers were

not recorded in the present study (missing species) (Table 5.2). Two of the 'missing

species' are 'single records', i.e., not recorded by any other worker after their first record,

either from the same or any other place. They are Pangio hashai and Glyptothorax

clevissinghi.

Two of these 'missing species' are commercially important and are exploitatively

fished for food (H.periyclrensis and Channa micropeltus). Use of various destructive

methods of fishing such as explosives or poison in the rivers may be the reason for their

disappearance. Dynamiting also destroys or alters the habitats of the fishes. It was

observed that these commercially important species were mostly found in the lowland

areas. Another threat faced by this group of fish was habitat loss by sand mining, which

disturbed and destroyed the breeding grounds. This was observed in all the major rivers.

Twelve of the 'missing species' were hill stream fishes. These species were affected

mainly due to alteration in their habitats. All these species were smaller in size and were

not commercially important. Pollution and deforestation were the other threats. Many of

the highland areas in Kerala are occupied by rubber, coffee, tea and cardamom plantation,

and pesticides and herbicides runoff from these plantation affecting the fish fauna.

In the present study 10 species that are not recorded by earlier workers are

reported. Of these 2 species are new additions to the fish fauna of Kerala, viz., Tor tor

and Esomus thermoicos, 3 species viz., Puntitis parrah, P. sophore, Barilius bendelisis

are widely distributed along the lowland waters. Dayella malabaricu was not listed by

earlier workers, but this species is included in the list due to its record from moderately

high altitudes. With the inclusion of these species to the earlier list the total number of

typical freshwater fishes recorded from Kerala is coming to 110.

New species from northern Kerala

Compared to the southern Kerala the number of new species recorded from

northern Kerala was less. Indra & Rema Devi (1981) and Rema Devi & Indra (1984)

described two new species from Silent Valley (Kunthi river), Homaloptera pillai and

Garra menoni respectively.

Shaji & Easa (1995) described another new species, H. Me~ioni, from

Indekkuthodu, a tribuatty of Bhavani river at Simvani in the Western Ghats.

Easa & Shaji (1995) recorded a new species, Pangio bashai, from the Chalickal

tributary of Chaliyar river in Nilambur. Manimekalan & Das (1998) described a new

species, qbptothorax davissinghi, from Karimpuzha of Chaliyar river basin.

Other additions from northern Kerala

Rema Devi & Indra (1986) studied the fish fauna of Silent valley National Park

and added Glyptothorux annandalei to the list of fish fauna of Kerala. Easa & Basha

(1995) added 26 species to the basic list. Of these 3 species were introduced and 2

species were migratory, excluding these 5 species, the following 21 species are included

to the basic list. They are Puntius clrola, Osteocheilus brevidorsalis. 0. Nashii, Labeo

potail, L.ariza, Esomus danricus. Brachydanio rerio, Garra mcClellandi, Clarias

dussumieri, Mystus punctatus, M.armatus. Balitora mysorensis, Poecilia reticulata,

Nemacheilus nilghiriensis, N.petrubanerescui, Nsemiarmatus, N.sinuatus, Chanda

ranga, Crossocheilus periyarensis, Schismatorhyncus deraniyagali and Homaloptera

menoni.

Rema Devi et al. (1996) extended the distribution of Pangio goaenszs (Tilak) to

Kerala, and collected this species from Chaliyar river. Lal Mohan & Rema Devi (1998)

listed Chela fasciata as new addition to the fish fauna of northern Kerala. Aorichthys aor

and Heteropneustes microps are the new additions made by Amnachalam et al. (1998)

from Chaliyar riber, and they also extended the distribution of Hypselobarbus

periyarensis to northern Kerala. Shaji et al. (1995) recorded P.denisonii for the first time

from northern Kerala from Aralam Wildlife Sanctuary. Gopi (1997) extended the

distribution of Silurus wynadensis to northern Kerala, reported this species from

Chandragiri river, Kasargod.

Introduced or exotic species

Gopinath (1942) gave an account of the introduction and acclimatization of exotic

fish in the state, commencing in 1906, with the introduction of trout by the Munnar Game

Association in the Vnnan Devan Hills, lying at the north-eastem extremity of southern

Kerala. Brown trouts were introduced from Scotland between 1906-1916, while eggs of

the Rainbow Trout were obtained from the Government hatchery in Ootacamund (Ootty)

in 1918. In 1940, definite proof of the breeding of trout in the Eravikulam stream in

Hamilton's plateau was obtained (Gopinath 1942). A trout hatchery has been functioning

at Rajamalai since 1941. In 1943, Dr. Freeman transplanted Rainbow Trout fingerlingsin

the Konalar streams, near Valparai, Tamil Nadu from the Munnar High Range Zone,

Kerala (Jhingran & Sehgal 1978). In 1938, Gambusia affinis was successfully introduced

and reared in the rearing ponds near Neyyattinkara - for the purpose of malaria control

(Gopinath 1942).

Of the 30 reservoirs in Kerala, fishing, as an organised activity is being carried

out in 13 reservoirs by the Department of Fisheries, Government of Kerala. There was no

mention of the presence of any introduced species in the list of freshwater fishes of

Travancore by Hora and Law (1941). After Hora & Law (1941), some workers recorded

introduced species from the different parts of Kerala. Catla catla and Chanos chanos

were first introduced into the Periyar lake in 1946 and 1947 respectively. Catla catla was

brought from the Godavari river, while Chanos chanos from Krusadai island, Gulf of

Mannar (Chacko 1948). Subsequent studies by Zacharias et a[. (1996) and Arun et a1

(lC'96) were not able to record the two above mentioned introduced species from the

Periyar lake, but hey recorded two other exotic species Cyprinus carpio communis and

Oreochromis mossambica. Easa & Basha (1995) reported four introduced species from

the Kerala part of Nilgiri Biosphere Reserve. A recent study by Thomas & Azis (1999)

reported five introduced species from Peppara Reservoir, constructed over Kararnana

river, Thiruvananthapuram District.

The present study recorded nine introduced species, of which 3 were not of Indian

origin. Cyprinus carpio communis, Catla cutla and Labeo rohita were abundant in many

reservoirs, and were also recorded in the lowland areas during the monsoon, after the

shutters of dams were opened. Oreochromis mossambica was widely distributed and

were noticed even in the hill streams, but were not recorded from the very steep streams

with high current velocity. Poecilia (Lebistes) reticulata, an aquarium fish, was also

recorded from the Periyar river. Rainbow trout (Salmo gairdnerii) was recorded from the

high altitude areas of Eravikulam National Park, Chinnar WLS and Konalar streams,

Grass Hills, Valparai. These results shows that the population of local species is showing

an alarming decrease in their number. Absence of natural enemies of the introduced

species may be the major cause for their increased survival. -

106

Table 5.1: Compiled list of freshwater fishes recorded from Northern Kerala

1 Family - Notopteridae 1 1 Notoptems notoptems (Pallas)

First record

3 1 A. bicolor bicolor McClelland + I Hora &Law (1941)

Northern Kerala

S. No.

2

Species

Order: Osteoglossiformes

~ u c h . ) I

6 H. kurali Menon & Rema Devi + Menon & Rema Devi

Order: Anguilliformes Family - Anguillidae Anguilla bengalensis

4

H & L = Species listed by Hora & Law (1941); * =Additions to Hora & Law's list ; +=Range extensions to southern or Northern Kerala

+

order: Cypriniformes Family - Cyprinidae Sub-family: Cyprininae Hypselobarbus curmuca (Ham.-

Chacko (1948)

+ Hora & Law (1941) 1

I

S. No. 62

63 64

65 66 67 68 69 70

71

72

-

+ G. hughi Silas G. gotyla stenorhynchus (Jerdon) G. jerdoni (Day) G. surendranathanii Shaji et al. Crossocheilus ~eriyarensis Menon

Family - Balitoridae I Sub-family: Balitorinae

Species

Horadandia atukorali britlani Rerna Devi & Menon Sub-family: Garrinae Garra mcClellandi (Jerdon) G. menoni Rema Devi & Indra

. . & Jacob C. latius Iatius (Ham.- Buch.) Sub-family: Schizothoracinae Lepidopygopsis typus Raj

74 75

76 77 78 79

80 81 82

1 83 I N. evezardi Dav I + IHora&Law(1941) 1

Hora & Law (1941) - Silas (1954) Zacharias el al. (1996) Hora &Law (1941) Shaji et a[. (1996)

i

36 N. monilis Hora - 87 Easa & Basha (1995) 88 N. petrubanerescui (Menon) t Easa & Basha (1 995) 89 N. semiarmatus Day * Easa & Basha (1995)

Northern Kerala

* a

I

t

H. monfana Herre H. pilIai Indra & Rema Devi

Bhavania australis (Jerdon) Balitora mysorensis Hora Travancoria jonesi Hora T. elongata Pethiyagoda & Kottelat

Sub-family: Nemacheilinae Nemacheilus botia (Ham.- Buch.) N. denisoni denisoni Day N. denisoni pambarensis Rema

1 Devi & Indra

I 1 90 1 N. striatus Day

First record

Rema Devi & Menon (1992)

Easa & Basha (1995) Rema Devi & Indra

Menon & Jacob 1 (1996) Easa & Basha (1995)

Raj (1941b)

( (1984)

+ *

+ *

1

Herre (1945) Indra & Rema Devi

Hora & Law (1941) Easa & Basha (1995) Hora & Law (1941) Pethiyagoda & Kottelat (1994)

Hora & Law (1941) +

Rema Devi & Indra

1 S. 1 Species 1 First record No. 119 120

12 1

122 123

I I 1 1 Order: Svngnathiformes I

-

GIyptothorax anamalaiensis Silas G. annandalei Hora

124

125

" - 1 Family - Syngnathidae

G. devissinghi Manimekalan & Das

G. housei Herre G. madraspatanus (Day) Order: Cyprinodontiformes

Kerala + *

Family - Belonidae Xenentodon cancila (Ham.- Buch.) Family - Aplochcilidae Aplocheilus lineatus (Val.)

Silas (1 95 1) Rema Devi & Indra

*

+

127 - 128 129 130

(1986) Manimekalan & Das (1998) Herre ( 1942) Hora & Law (1941)

+

+

Sub-family Sicydiaphinae

Hora & Law (1941)

Hora &Law (1941)

Order: Perciformes Family - Ambassidae Parambassis dayi (Bleeker)

Parambassis thomassi (Day) Ambassis nalua (Ham.- Buch.) Pseudambassis ranga (Ham.-

139

.

+ *

Hora & Law (194 1

Family - Anabantidae Anabas testudineus (Bloch) Family - Belontidae

Hora &Law (1941)

Hora & Law (1941) Hora &Law (1941) Easa & Basha (1995)

- + p

H & L - Species listed by Hora and Law (1941); (*) - Additions to the Hora and Law's

list after 1941; (+) - Range extensions to southern or northern Kerala

----- 149 ~ & ~ d o n travancoricus Hora & + 1941)

Table 5.2. Species recorded by earlier workers, but not recorded during this

study (Missing species), from northern Kerala

Nair 1 Total 100

11. Ecologically sensitive areas for long tern1 monitoring and

conservation

Due to pollution, loss of habitat, disturbance and changes in land use are the main

reasons for the decline in the populations but their cause and effect cannot easily be

demonstrated without data from monitoring and surveillance studies. For without long-

term studies it is difficult to distinguish between natural changes and those changes

caused directly or indirectly by pollution and other impacts (Spellerberg 1993).

The selection of ecologically sensitive or index areas is equally important for a long-

term monitoring programme. These areas must be the areas with outstanding natural

value for hydrological, geological and biological resoursces that should be carefully

managed (Mc Neely ef al. 1990). The first stage in the selection of ecologically sensitive

areas for long-term monitoring is the development of criteria which will satisfy the

coservational needs of the natural populations and habitats existing in that areas. In the

present study the following criteria were adopted for long term studies.

a) The selected site should have maximum diversity in fish fauna, especially threatened

species.

b) The site should have an essential habitat for the survival of one or more globally or

nationally threatened species.

C) The site must have land-scapes of outstanding value or unique habitat types preferred

by a group of fishes.

d) The site must be relatively free from disturbances that destroys the natural habitats of

fishes like pollution, deforestation, large scale illegal fi shing, sand mining.

The followir_" sites of different river systems in Kerala were selected for long term

monitoring and conservation,

1. Bharathapuzha river (Fig. 5.1)

Site: Kunthi river, subtributary of Bharathapuzha river

Location: Silent Valley National Park.

District: Palakkad

The Silent Valley National Park is entirely drained by the river Kunthi and its

tributaries. The river has unpolluted water with undisturbed riparian vegetation having

high canopy value (20.95%) except at Patharakadavu (10%) and Sirendri (10%). The

river passes through evergreen vegetation throughout its course. Bedrock, gavel,

boulders and pebbles are the most dominant substrate in most of the study sites (Easa &

Basha 1995).

A total of 12 species were reported from this area (Easa & Basha 1995 and Rema

Devi & Indra 1986). The important species recorded were; Homaloptera montana

(Nationally Important and Endangered species); Glyptothorax annandalei (Endangered

species), only known from Silent Valley and Muvattupuzha river in Kerala; Garra

menoni (Globally Important, Endemic and Endangered species), only known from

Kerala; and Homaloptera pillai (Globally Important, Endemic and Endangered species),

entirely restricted in its distribution to the Silent Valley. In the present study 18 species

were collected. Of these the following 12 species are considered as the new additions to

the fish fauna of Silent Valley; and they are as follows, Mystus armatus, M.oculatus,

Glyptothorax anamaliensis, G.madraspatanus, Nemacheilus evezardi, Bhavania

australis, Garra mcClellandi, R.daniconius, Barilius bakeri, Hypselobarbus joshuai,

Zkhudree and Osteochilus brevidorsalis. While the following three species viz, Channa

gachua, Anguilla bengalensis and Glyptothorax annandalei recorded by earlier workers

were not recorded in the present study.

The main reason for selecting this area for long-term monitoring and conservation is

the presence of rwo globally important and endemic species. Even though the stream

flows through a national park, the river should be declared as fish sanctuary to stress the

importance for the need to conserve its rare fish fauna.

Fig.

2. Bharathapuzha river (Fig.5.2)

Site: Punchola, tributary of Nellipuzha

Location: 40 kms away from Palakkad

District: Palakkad

'A total of 18 species were recorded from Punchola tributary, which include,

Bhavania australis, Barilius bendelisis, Tor khudree (all are Vulnerable) and

Glyptothorax madraspatanum (Endangered). This is a typical habitat for hill stream

fishes. Major substrates are gravel, sand, pebbles and cobbles. Land use pattern is human

settlements with agricultural lands. The fish fauna of Punchola stream is under threat due

to the use of pesticides and fungicides in agricultural lands, exploitative fishing by the

locals, and the reduced bank vegetation due to large scale clearing of the riparian habitat.

Presently this area is not protected.

3. Bhavani river (Fig. 5.3)

Site: Main river and connected streams

Location: Part of Nilgiri Biosphere Reserve

District: Palakkad

This area includes the main river and connected streams of the Nilgiri Biosphere

Reserve (NBR). Present and past studies have shown the richness of the fish fauna of this

area. Easa & Basha ( 1 995) conducted a survey in the Kerala part of NBR, in which they

reported 24 species from this tract. In the present study 19 species were collected. The

important species collected from this area include Garra rnenoni (Globally Important,

Endemic and Endangered species), only known from Kerala; Homaloptera menoni

(Globally Important and Endemic species, distributed only in the Pattiyar tributary of this

regi~n in the world); Balitora mysorensis (Critically Endangered species, only known

from two rivers in Kerala); Nemacheilus monilis (Critically Endangered species of

Kerala, known only from two rivers); Nemacheilus semiarmatus (Endangered species)

and also Osteochilichthys nashii, Garra gotyla stenorhynrus and Bhavania australis (all

are Vulnerable species). The areas out of the reserve forest are highly disturbed.

Pig.5.3. Nellipuzha tributary of Bharathapuzha river

4

I 1- r"' I

I'OT1'ASSEILI - rn I K M

1 -.

76" 35' Fig. 5.2. Bhavani river, Nilgiri Biosphere Reserve

4. Vytiri river (Fig. 5.4)

River: Kabini

Location: Nilgiri Biosphere Reserve

Disnict: Wayanad

Diversity of fish fauna is very high, 19 species were recorded from this area.

Major species recorded are O.nashii, Tkhudree and B.australis. A unique habitat for

1a1-ge hill stream fishes belonging to the family Cyprinidae, as this area is with heavy

water column and also with deep rocky pools with very low temperature.

The four areas mentioned above need special attention to protect not only the fish

fauna but also other aquatic organisms and their habitats from human activities. These

sites should be declared as 'fish sanctuaries'. The following are some of the

recommendations for long-term monitoring studies in these areas:-

1. The population density, distribution, habitat preference and biology of the threatened

species should be studied on a long term basis.

2. Water quality and other hydrological parameters like surface runoff, stream flows and

silt load should be regularly monitored.

3. The impact of exotic species on the native fish stock should be assessed.

4. The impact of dams on the natural spawning migration of fishes should be assessed.

5. The impact of human settlement and change in land use pattern and habitat alterations

on the fish fauna should be assessed.

Fig. 5.4. Vytiri river, tributary of Kabini river