THE FAUNA

6.0. FAUNA

6.1. Introduction

Biodiversity is an index of the incredible health of habitat.

Major portion of biodiversity was occupied by the flora and

fauna of an ecosystem. As a nutrient filter and synthesizer

of organic matter, mangroves create a living buffer between

land and sea. The rich and diversified life of this

ecosystem is due to high energy production capacity of

mangroves especially towards estuarine and marine

fertility (Heald and Odum 1970; Macnae 1974). In this

ecosystem the diversified habitats like the tree, soil and

water are occcupied by different groups of organisms

exposed to different sets of environmental conditions. The

animals inhabiting the intertidal region exhibit constant

interaction with variable salinity, muddy substratum and

periodic tidal flush and are unique to this habitat. The

fauna, as a whole , have greater mobility to choose their

habitat, unlike the plant community. Hence the number of

species representing the fauna is very rnuch greater than

the number of plant species occurring in rrlangrove area.

Mangrove environment seives as the potential -area for

brackish water aquaculture of prawns, crabes and fishes

as it happens to be Nature's own aquaculture, system

which is more stable and less susceptible to diseases and

epidemics. Visually the density of the fingerlings or

schooling of juvenile population in the mangrove waters is

comparatively more than open waters. Though the faunal

diversity of mangrove ecosystem of India, seems to be

varied and rich, it is f a r from being comprehensive, due to

inadequacy of coverage and lack of comparable data bases.

I4owevcr, the inputs during last ten years or. so promises

comprehensive information in years to come.

6.2. Review of Literatuxe

Mangrove environment pIays a vital role in the biology of

its faunal component. But this unique ecosystem had not

so far drawn the attention it deserved as far us its faunal

comporlent is concerned until recently. In the last 30

years, distribution of animal species, has been inventoried

from some parts of the mangrove ecosystem along the west

coast, east coast and bay islands of Andaman and Nicobar.

McClelland (1869) was the pioneer in exploring the

malacofauna of brackish water systems of Iower Bengal. I t

was followed by the works of Annandale (1907- 1925) on

Hydrozoa, Polyzoa, Entoprocta, etc. Kemp (1 9 19- 1923) on

crustaceans and Hora (1929-1955) on fishes who have

contributed much to our' knowledge of these estuarine

animals occurring in mangroves of Sundarbans. Studies on

fauna with special reference to estuarine biology of the

Sundal-ban mangroves have recently been given a boost by

Choud hury and his co-workers ( 1978-onwards).

A wealth of information was gathered from such

sources which is of immense value for further faunistic

studies of the mangrove habitat. I t was beyond the scope

of this study to include and or review all such

publications, however, important and recent articles are

referred here in. Nandi and Misra (1987) have recently

compiled a bibliography of the Indian part of Sundarban

with special reference to fauna, in which literature

pertaining to zoological researches, faunal studies and

fishery have been dealt with.

The crustacean fauna of mangroves are vast and varied

and includes prawns, shrimps, crabs, lobsters, hermit

crabs, cirripedes, isopods, mysids etc. After Alcock's work

on the Indian Decapod crustacea , some valuable

contri1.1utions an other crustaceans were made on the

taxonomy of Amphipoda by Annandale (1907); Much work

has been done on prawns and their fisheries from Hooghly

estuarine system by Rao ( 1969).

Almost a1 the works are on the population of prawns

in the backwaters or estuaries. The following are the work

done in some of the estuaries and backwaters, where

mangroves arc located. Henderson and M athai (19 lo),

studied some species of Palasrnorz from South India. A

preliminary study on the prawns from Travancore was

done by Nataraj (1947). Observations on the prawn

fisheries of the Killai backwaters were made by Gemma

Evangchne et-al, (1972). Dwivedi (1982) studied the

prospects of prawn culture. The prawn fisheries of

Godavari estuarine sys tern was studied by Ganapati

( 1969). Jayachandran (1984) made a detailed study on the

biology of the Palaemonid prawns of the south west coast

of India. Jayachandran and Joseph (1985) described a

ncw species of Macrobrarzchium from the south-west coast

o f India. The palaemonid prawns resources of the

cstuuriev of JCerala was studied in detail by ,l;iyachandran

( 1 987). The ecobiology, taxoilomy and dis tri b utiun

proximate, composition of the palaemonid pniwns of south

west coast of India was also studied by Jayachandran and

Joseph ( 1989). Rajendran (1999) reported seasonal

occurrence of juvenile prawn and environmental factors in

a Rhizophora mangal of south east coast. Hoq et a1 (2001)

studied the abundance and seasonal distribution of

Penaeus monodon post larvae in the Sundaarbans

mangrove. Jisha (2002) reported the fauna of a mangrove

ecosystem in a tropical estuary. Fisheries structure and

management implications in Sundarban mangroves were

studied by Hoq et al (2003).

Chakravarthy and Choudhary ( 1986) have reported

four species of fiddler crab, belonging to genus Uca from

Sundarban mangroves. Crab and Crab fisheries of

Sudarbans was reported by Nandi et al (1994). Nandi and

Das (1999 ) studied the distributioh of fiddler crabs in

Sundarban and found that sediment with mclre sand

particle is the deciding factor for their distributio~l. Nandi

and Das(1999) discussed the vertical distribution of

macrobenthos and noted that middle zone was occupied by

Brachyuran crab, Fiddler crab etc, the upper zone is

occupied by sesarma (Brachyura) and Uca sp ( Brachyura

). Insect fauna had not - received any attention until

recently.

Recent and worthwhile works on malacological fauna

of Sundarban mangroves are those of Subba Rao et-a1

(1983) and Nandi e t a1 (1999). Kasinathan and

Shanmugham ( 19861, while reporting of the molluscan

fauna of Pitchavaram have reviewed the mangrove

molluscs of Mahanade estuary and also of Godavari

estuary, Krishna estuary and Machilipatnam swamp, all

along the coast of Andhra Pradesh and have presented an

inventory of 15 genera and 3 1 species of gastropods as

well as 7 genera and 9 species of pelecypods. Wood boring

fauna of mangroves of India has been reported (Santha

Kumaran 1986) to comprises of 22 species under 12

genera of mollusc. Ross et a1 (1997) studied the

distribution and abundance of barnacles in a mangrove

forest. Faunal zonation and assemblages in the pacific

colwnbian mangrove were reported by Cantera et a1

(1999). Jisha 2002 reported the molluscan fauna of a

mangrove ecosystem in a tropical estuary.

Vertebrate species in the mangrove fauna of India are

varied and rich. All the classes and a species under

Hemichordates are documented. Extensive studies have

been made on fish and fisheries on the Hooghly-Matlah

estuarine system. Many fishes of the river Ganges

described by Hamilton-Buchanan (1 822) are known from

estuaries of Sundarban mangrove environment.

Annandde (1907,1922) and Hora

(1933,1934,a,b, 1935,1940,1943a) and more recently

several authors Viz Banerjea ( 1965a, b) , Gopalakrishnan

(1968), Jhingran (1968), Datta et-al, (1971) and Jayaram

(1999) have contributed to the study of fish fauna of

Hoaghly Matlah rivers. Gopalakrishnan (19731, Naskar

and Ctlakraborthy (1984) have reported on the fish and

fishery resources of the Sundarban delta. Christensen

(1983) while studying the benefits of rnanbq-oves give a

picture of the indirect impact of mangroves on the cash

value of commercial fish catches. Krishnamurthy and

Prince (1981) studied the early history of fishes from

Pichavaram mangrove ecosystem. Prince Jayaseelan

(198 1) also studied the icthyofauna of the mangroves of

Pichavaram. Manuel of fish eggs and larvae from Asian

mangrove waters were prepared by Jeyaseelan et. al,

(1998). Rao et al(1999) have listed 52 species under 42

genera for fmfishes in India. Fisheries structure and

management implication in Sundarban mangroves were

studied by Hoq et a1 (2003).

In Kerala observations on the fish and fisheries of the

Vembanad estuary was done by Shetty (1965). Kurien

(1980) studied the fauna of the mangrove swamps of the

Cochir~ estuary. Apart from this there are no other studies

on the fish fauna of the mangroves in Kerala. Nair et al

(1983) made a preliminary survey of the fishery resources

of the Ashtaniudi estuarine system. Kurup and Samual

(1983) studied the systematics and distribution of fishes of

the family Leiognathidae (pisces) of the Vembanad estuary.

They again in 1985 made an elaborate study of fish and

fishery resources of the ~emb-mad estuary. Kurup e t a1

(1990) studied the impact of Thanneermukkom barrier on

the fishery resources of t l ie Vembanad estuary. Attempts

were made to study the fish fauna of the the Kumarakom

and Asramom mangroves by Mohandas (1993).

Salirn Ali (1984) has done an elaborate study of the

birds of Kerala. He has cited the early works of birds in

Kerala such as the publications of Ferguson (1870) and

Hume (1876 and 1878). Salim Ali (1935) has published a

paper on the Ornithology of Travancore and Cochin and

later 1953 he has published a book on the birds of

Travarlcore and Cochin. Neelakantan ( 1958) has

published a book in the regional language, m;xlayalam with

the caption "Keralathile pakshikal". 1'3illon (196 1)

published a book on the birds of India and Pakistan

enlisting 2100 species and subspecies from this

subcontinent. Chang (1 984) reported the presence of

Brahminy Kite in Malaysian mangroves. Sreekumar et a1

(1987) has made a preliminmy ecological study on the

birds of the Kadalundi estuary. Deepakumar and

Narayanakurup (1991) has made a study on the migrant

shore birds in the estuarine habitat of Kadalundi and

Bharatapuzha estuaries. Jayson and Mathew (1 993 ) has

studied the birds of the Silent Valley National Park and

the adjoining forests of the Western Ghats of Kerala. En

1994 Mohandas made a comparative account of birds of

Asrarnom and Kumarakom mangroves. Jayson (2001)

studied the structure, composition and conservation of

birds in Mangalavanam mangroves, Cochin.

C:omprehensive account of Mammaliar1 fauna from

Sundarban was available. Mukherjee (1965,197'1,1981),

and Chaudhury and Chakraborty (1981) have reported on

the wild life of Sundarban and M a n d a l and Mukherjee

( 1965) have studied the Rhesus macaque of Sundarban. A

comprehensive general account of Sundarban has recently

been completed by Mandal and Ghosh. Sanyal (1992) has

enumerated ten genera twelve species uf mammals,

including tiger, civet cats, otter, dalphi11, porpoise,

batmonkey, deer and wild boa. A review of otters in

Malaysian and Singapore mangroves were reported by

Sivasothi et a1 (1994).

When compared with available data (Clough 1993) from

the mangroves of Indonesia, Thailand, Ecuador, the faunal

diversity of India with 5 13 species, so far listed, is not only

higher and richer than in Indonesia(l36 sp) in Thailand

(2 19 sp) Colombia (395 sp) and Ecuador (207 sp) but more

pertinently it reflects on the quantum and quality of

rt:levant studies and surveys in India (Banarjee, 199 1).

6.3. Matexials and Methods

Arthropods from the mangrove areas were collected and

procured from local fisherman for the present study.

Relevant literature was consulted to study the prawns

(Handerson and Mathai, 1910) and crabs. Fishes were

collected by using cast nets and hand nets from the

vicinity of the three stations in mangrove areas. Some

fishes were procured from the fisherman. Identification of

fish fauna in t h e study area was carried out by following

Munro (1967) Fisher and White head (1972) Day (1978)

and F A 0 species identification sheets for fishery purposes

( 1984) ,Jayaram (1999). The birds were identified by

using the methodolow of Salim Ali.

6.4 .Observation and Results

In Ayiramthengu the mangrove fauna is

characterized by its low species diversity but having larger

populations. Most of the earlier taxonomic descriptions

were made using preserved or dead specimens, which

provide no possibility of studying the natural colour

pattern of the faunal members. As the present study

provides live photographs of the fauna, the life colour can

easily be understood (Plate X - XVI). In the mang-rove area

the following species of Prawns were observed. (Fig on Plate

XII)

1. Penaeus indicus (W.milne Edwards 1837)

2. Metrrpenaeus dobsoni (Miers 1878)

3. Metapenaeus &finis (H.milne Edwards 1837)

The following species of crabs were observed. (Fig on Plate

XI)

1. Portunus pelagicus (Linnaeus )

2. Gelasimus dussumieri (X,milne Edwards

5. Sesama quadrata (Fabricius)

6. Metopograpsus messor (Forsskal)

7. Portunus sanguino tentus

8. Ucauca

The following species of molluscans were observed in the

mangrove area. (Fig on Plate XII)

4. Balanus sp.

In Ayiramthengu mangrove area where salinity of

water ranged between 0.34%0 and 6.28 21 species of

fishes were collected during present study. The following

are the species. Detailed systematics including order,

family, genus and species of all collected fishes are

presented in the Table no. 2 1. (Fig on Plate XI11 - XVI)

Ambassis gymnocephatus ( Lacepede )

Ambassis commarssonii (Cuvle r)

Carangoides praesius (Bennett)

Caranx ignobi lis (Forsskay

Chanos chanos (Forsskaf)

Etroptus suratensis ( Bloch)

EtropIus macu Zatus (Bloch)

Euryglossa orientalis ( Bloch & Schneider

C3srres filamentomis (Cuvier)

Gerres oyena ( Forsskal )

Liaa parsia ( Hamilton - Buchanan )

Valamugil ssheli ( ForsskaZ

Gazza mbnuta ( Bloch J

Leiognathus splendens ( Cuvier

Glossogobius giuris ( ~ a m i lton - Buchanan)

Mystus sp.

Oligo lepis acutipennh (Valenciennes)

1 Crmcean Fauna ' PLATE Portunus pelagicus (Linnaeus) Scylla serrata (Forsskal)

1 .I Sesarma quadrata (Fabricius) Gelasimus dussumieriQ (Hmilnie Edwards)

enaeus indicus (H.milne Edwards, 1837) 1

Villorita cyprinoides

Metapenaeus dobsoni(Miers, 1878) Metapenaeus &nis(H.milne Edwards, 1837)

1 Cerithihum fluviatilis Meretrix casta

I I

1 Mollu& Fauna I

Therapon jarbua(Forsska.1)

Liza tada (Forsskal)

Scatop hagus argus (linnaeus)

PLATE XI1 Gerres filamentosus(Cuvier)

Carangoides praeustus (Bennett)

PLATE XIV 1 Mystus SP. Etroplus rnaculatus(B1och) Etroplus suratensis (Bloch)

Euryglossa orientalis(B1och & Schneider) Caranx ipobilis (Forsskal)

1 Leiognathus splendens (Cuvier) 1

Ambassis gymnocephPlus (Lacepede)

1

1 Ambassis commersoni(Cuvier)

~azza'ryinuta (Bloch) ,.

I""" I

Gerres oyena (Forsskal) Liza parsia (Hamilton-Buchanan)

4

Glossogobius giuris(Hami1ton-Buchanan)

Egretta garzettn, garzetta

ELATE 'XVI 'i P Valamugil seheli(Forsskal)

Anhinga rufa melanogaster pennant

..an Fauna I

18) Scatophagus argus ( Linnueus

20) Oreochromis mossambica peters)

2 1) Lka tuda (Forsskal]

The following birds were observed in the Ayiramthengu

mangrove area. (Fig on Plate XVI)

1) Hal ius tur indus indus

2 Anhinga ru fa melanogaster pennant

1 . Haliastur indus indus [Boddaert)

Brahminy Kite

Local Name: Krishna - parundu

Size: That of the pariah kite -

Field Characters: A handsome rusty red or deep chestnut

hawk with white head, neck and breast. Abdomen brown.

Immature birds easily confused with the buzzard. Under

aspects of open wings grejrish with a reddish tinge; in

immature birds patchy as in the buzzard. Sexes alike.

Singly in the neighbourhood of water- si.rearrls, tanks

inundated paddy fields etc.

Status and Habitat: Resident, common. Low country and

occasionalIy to about 3000 feet. Its favourite haunts are

about the backwater villages and around other dammed

reservoirs.

Distribution outside Kerala: The entire Indian Union,

both Pakistan and Ceylon.

General Habits: Generally a scavanger, picking up bits of

floating garbage from the surface of water. The backwater

harbours', such as Alleppey and Quilon provide it with

comfortable living. Further inland it is met more

commonly during the monsoon when rain filled puddles

and flooded rice-fields supply an abundance of frogs and

land crabs. Small fish and snakes are also eaten. The call

is a harsh, wheezy squeal.

2.Anhinga rufa mdanopaster pennant

Indian darter-Snake bird

Local Name: Neer- kakka

Size: About that of a Kite.

Field Chaxacters: A black cormorant like water bird with

a long and slender S-shaped narrow head and pointed

dagger bill. Back heavily streaked with silver grey. Head

and neck velvety brown chin and throat whitish. Tail long,

SI iff and wedge shaped. Sexes alike.

Status and Habitat: Resident, fairly cornmon but not

abundant. Affects open placid streams, village tanks and

dammed reservoirs. On the last the exposed tops of the

submerged dead trees provide favourite look out and wing-

drying posts.

Distribution outside Kerala: Ceylon, all India, Burma,

Malaysia, Indochinese countries etc.

General Habits: Very like the cormorant's except that it is

more individualistic and does not hunt in co operative

bands. I t dives and chases fish under water, swimming

with speed, wings held half open and head and neck

swaying back and forth like a JaveLin-thrower preparing to

throw, A special, contrivance in the vertebrae of the neck

enables the bird to shoot its bill at the quaery as if

released by a powerful spring.

3.Egretta Garzetta Garzetta (Linnnaeus)

Little Egret

Local name: Chinnamunti

Size: About that of a domestic hen with larger legs and - neck.

Field characters: A lanky snow white marsh bird-a

smaller edition of the large Egret. In the breeding season it

develops a long drooping crest of two narrow plumes, in

addition to filamentous ornamental feathers on both breast

and back. Bill black at all seasons. Feet parti-colored

yellow and black. Sexes alikk Flocks on marsh land.

Status and Habitat: Resident frequents the backwaters,

inundated and water logged cultivation, streams etc.

Distribution outside Kerala: Ceylon, all India, Burma,

Malaysia, China e tc .

General Habits: More gregarious than the other birds but

some times also met as a solitary bird.

The only mammalian representative observed in

Ayiramthengu mangrove area was Otter (Lutra

perspicillata) .

6.6. Discussion

The muddy or sandy sediments of the rnangal was the

home to a variety of epibenthic, infaunal, and nleiofaunal

invertebrates. The composition and importance of these

communities vary enormously from habitat to habitat

depending on the sediment characteristics of the individual

mangal. Mangrove habitats and prawn/ shrimp populations

are tightly linked in many regions. Fauna of Ayiramthengu

mangrove ecosystem were categorized broadly in two

groups, ie (a) the aquatic component, like crabs, prawns,

snails, bivalves and mammals (b) terrestrial components

like birds. Similar types of classification of Malayasian

mangrove fauna was reported by Berry, 1972.

Juveniles and adults of three prawn species (Penaeus

indicus, Metapenaeus do bsoni, Metapenaeus a fj5nis) were

common in the Ayiramthengu mangroves. ( Fig. on Plate

XII) Robertson and Blaber (1992) proposed three

explanations for this resource fullness- First, organic

detritus e!xported directly from the mangroves provides food

rind habitat for juvenile penaeids in off shcrrr: areas (Daniel

and Robertson, 1990). Second, the waters in thc: ~~urnerous

channels and smal creeks of the the mangrove receive high

level of the terrestrial run off, reach in nutrients. Third, the

mangrove waterways directly serve as nursery grounds for

juvenile penaeids that move off shore and enter the

commercial fishery as they mature. Distribution of the

juveniles within the mangrove are strongly influenced by

salinity. Mohan et al., (1995) reported that the density of

juveniles will be highest at intermediate salinity.

There are a number of benefits for juvenile shrimp

and prawns living in mangrove habitats. The habitats are

complex and provides a variety of niches within which

species can exist. Like the mangroves of Muthupet,

Ayiramthengu mangroves showed that Metapenaeus

dobsoni show clear preference for detritus - rich muddy

substrata in which they feed. Primavera and Lebata (1995)

found that Metapenaeus were particularly active

burrowers. Chang (1984) has reported the dependence of

several penaeid prawn in the mangrove waterways of

Malaysia. M a c N a e (1968) has also strongly supported that

without the mangrove ecosystem several species of

shrimps and prawns may not exist and Mac Nae (1968)

strongly concluded that "no mangrove no prawn".

Crabs are characteristic members of the invertebrate

mangrove fauna and have received much attention. Some

indication of the diverse array of mangrove - associated

crabs can be found in annotated checklists from India

(Sethuramalingam and Ajmd Khan, 1991), Malaysia and

Singapore (Tan and Ng, 1994) and Brazil (Vergara - Filho et

al., 1997).

Within t he complex mangrove environrnen t , crabs fill

a variety of niches. For some species, the relationship with

mangroves is obligatory; they depend directly on the

mangroves for survival (Vergara Filho e t al., 1997). Others

simply have ranges the overlap the mangal. The present

study should that the mud crab Scylla serrata inhabits

algal bcds in the mangrove area. Chandrasekaran and

Natarajan ( 1994) made similar observations in Pichavaram

mangroves.

Crabs living in the mangal must adjust to significant

temperature and salinity fluctuations. Some, like the

grapsid Metopograpsus messor, retreat to burrows where

temperatures are less variable and consistently lower than

the sediment or air tempetatures. When it is out of the

burrow, Metopograpsus messor users evaporative cooling to

keep its body temperature lower than the surrounding air

(Eshky et aI., 1995). Among mangrove fauna, the

crustaceans specially the crabs, have shown greatest

specialisations in relation to feeding, respiration and

vision. These crustaceans belong to a few highly specialised

families viz. Grapsidae (sub family : Sesarminae),

Ocypodidae, Portunidae and X a n thidae. The mangorve

habitat crustacean fauna are the major detritus feeder and

play vital role in recycling of nutrients and mixing the

organic detritus to the mangrove substratum and enrich

the mangrove base soil and tidal water.

The molluscan fauna in Ayiramthengu included four

types of molluscs. (Fig on Plate XII) During monsoon

season when the salinity was low as 0.34 %o black clam

( Villorites cyprinoides) were abundant. I t has significant

economic importance, meat was consumed as food, used

as shrimp feed, shells were used for making quick lime.

The intertidal regions of the mangrove area occupy

abundantly the po tamids ( Cerithidiurn flu uiatilis)

throughout all the seasons. I t required moderately saline

water for survival and reproduction. Its shells were used in

bulk amount for making quick lime and also it was used

for making decorative items. During pre-monsoon season

bivalve (Meretriu casta) were abundant. When compared

with other molluscan fauna yellow clam require higher

salinity. Economically important shell fish. BaEanus sp.

found attached to intertidal stones and tree trunks of

mangrove trees.

Mangroves have a rich and diverse assemblage of

fish, some with commercial value. Other fish species are

important links in the mangrove food we'b. Still others are

only temporary residents that spend most of their life

history elsewhere. Whatever their role, all are important to

the character of the mangal. Fish in mangrove habitats are

important predators, consuming amphipotls, isopods,

shrimp, nematodes, insects, gastropods, other fish and

algae (eg. Erondu, 1990; ~ r e w e r and Warburton, 1992;

Williamson et a1 1994). In Ayiramthengu it was common to

find large numbers of larvae and juvenile fish in net

samples from mangrove area. Robertson and Blaber (1992)

present three explanations for the high density of juvenile

fish in mangrove waters. First, mangrove estuaries supply

an enormous food appropriate for juvenile fish (Chong et al

1990). Second, reduced visibility in the turbid mangrove

waters may reduce predation by large fish. Third, the

s truct urul complexity of the mangroves provides excellent

she1 ter and protection for the juveniles.

In Ayiramthengu mangroves the salinity varied from

6.28%0 to 0.34%0. Maximum salinity recorded during pre-

monsoon season was 6.28%0 and minimum salinity

recorded during monsoon season was 0.34%0 in study

sites. Present study showed similarities with the salinity

pattern of Hooghly-Matlah estuary which show peak during

pre-mor~sson period (Saha et al, 1971). Ekmar~ (1935) has

stated that the mangrove fauna was charactcrised by its

low species diversity but having larger population. The

above statement was apt to Ayiram,thengu mangroves.

Detailed systematic including order, family, genus and

species of all collected fishes are presented in the table

No.21. The fish fauna in Ayiramthengu mangrove

ecosystem belonged to 4 orders such as Perciformes,

Pleuronec tiformes, Gonorhync hiforme s and siluriformes.

Order Perciformes actually represents 9 families containing

39 generas, but in present study this order was

represented by 9 families which posess 14 gencra and 18

species. Order Pleuronectiforms actually represent one

family and two generas, but in present study this order

was represented by single family Soleidae which posess

only one genera EurygEossa. Order Gonorhy r~chiforrnes

represents family chanidae and posess one genus C hanos.

Order Siluriformes represented by family Bagridae actually

poscss 4 generae, but present study showed the presence

of single genus Mystus. In Kerala 7 species of Mystus were

reported. But the Mystus collected from this area do not

belongs to the 7 reported species.

rable No: 2 1 8Y8TElldATICS OF THE FISH FAUNA AYIRAMTIIEHOU -GROVE AREA.

ORDER

PERCIFORMES

I

FAMILY

Ambassidae

Mugilidae

(Glass fishes)

Carangidae King fishes

Leiognathidae (pony fishes)

Gemdae

Scatophagidae

Gobiidae

Cichlidae

CtElPUS

Ambassis

Oreochromis

V a l a m w Liza

SPECmS

commersoni

Carangoides

Leiognathus Caranx G a z a

G e n e s

Scatophagus

Glossogobius Oligolepis

Etmplus sumtensis mossambica

seheli parsia tada

praeustus

splendens ignobilis minuta

oyena

argus

giuris acuti pennis

m&tus

SPECIES

jarbua

orientalis

chanos

GRHU8

Therapon

~ @ o ~

Chanos

Mystus sp

ORDER

P L E U R O ~ R M E S

GONORHYNCHIFORMES

S L W R M E S

FAMILY

Tetra pontidae = Theraponidae w r perches)

Soleidae

Chanidae (mi& fish)

Bagridae

Tht: fish fauna of Ayiramthengu can be classifietl into

residents and migrants. The resident spt:cies is the one

which is represented by some or all the size goups during

all the months of the year. The migratory fishes enter and

remain in the estuary for short durations only. The

migratory species according to their salinity tolerence are

grouped in TabIe No. 22. Migratory fishes in Ayiramthengu

are two types marine and freshwater forms. Marine forms

include 13 species which are abundant during premo nsoon

and post monsoon seasons when the salinity was

comparably high than monsoon period. Three freshwater

species were abundant during monsoon season when the

siilini ties reaches similar to fresh water.

Resident fishes were purely estuarine. Estuarine

fishes constituted the majority of fishes living in the

mangrove area. These fishes were mostly with marine

affmities, were adapted to tolerate wide range of silinity

fluctuations. This group of fishes constitute the major

stock of permanent estuarine fishery resources and were

present through out the year. During monsoon they were

not abundant. Permanent estuarine fishcry resouce

includes mainly Etroplus surantensis. Etroplus surantensis

breeds twice a year during May-June and November-

February in Ayiramthengue. When eggs become mature,

the male and female fishes swim in pairs search of suitable

sites in mangrove area. The eggs are attached to

subrnergcd objects and are guarded by both parents. This

can be observed throughout Ayiramthengu mangrove area.

The hatching of eggs - which look like yellowish oblong

patches containing 2000 eggs in each patchs, take place in

about five days. The tiny fry which emerge out are guarded

by the parents. The best catches are obtained i n December

just before the breeding peak.

In the fish fauna majority used as food iishes. Some

of the commercially important shell fishes and fin fishes

are represented in table number 23. Liza parsia forms an

important fishery in the Kayamkulam lake where the

mangrove area located from July to February (Jayaram,

Mangroves provide important habitat for land birds,

shorebirds and waterfowl, and they are home to a number

of threatended species. The birds in the mangal may be

premanent residents that forage and nest in the nnangroves

and the mangrove waters or they can be te~nporisry visitors.

In the present study only three types of birds were

observed. All the three were resident and common but not

abundant. All the observed birds were fish eating birds.

Chang (1984) showed the presence of Brahminy Kite in

Malriysian mangroves. The above observation show

similarity with Ayiramthengu mangroves.

In the course of present study only rrlamnlalian reprcsentaiivt:

observed was Otter (Lutru perspicillata). Presence of Lutra

perspicillata in different mangrove regions of India was reported by

Gopal and Krishnarnurthy, (1 993). Ayirarnthengu mangroves are

undisturbed, luxuriant and rich in fish fauna. So otter prefer this

area as a comfortable breeding area.

-.

Table No: 22

List of fish fauna in Ayiramthengu

+ Marine-Fish *:. Fresh Water Fish P Estuarine Fish

Resident

P Scatophagus argus

k Etroplus maculatus

P Etroplus suratensis

Juveniles of EtropJus maculatus

P Oreochromis mossambica

P Oligolepis acutipennis

Juveniles of Scatophagus argus

Juveniles of Oreochrornis

mossambica

Juveniles of Oligolepis

acutipennis

Season

I'rc-monsoon

(3 -7 - 6.28Y~)

Monsoon

(0.3 4 - 1.2%0)

Post Monsoon

(1.2 - 3.7%0)

Migratory

4 Ambassis commersoni

4 Ambassis gymnocephalus

4 Gerres filamentosus

+ Gerres oyena

+ Liza parsia

+ Chanos chanos

*:+ Therapon j arbua

*:* Glossogobius giuris

*3 My stus sp

+ Euryglossa orientalis

+ Valarnugil seheZi

+ Liza tada

+ Gazza minuta

4 Carangoides praeustus

4 Caranx ignobilis

Juveniles of Gazza

Juveniles of Chanos

Juveniles of Caranx

Juveniles of Gerres

+ Leiognathus splendens

Table No: 23-a+ She1 fish and Fin fish species of Economic

importance from the ~ ~ i r a m t h e n ~ u mangrove area

Commercially Important Fin Fish Species

3. 1 Leiognathus splendens (Cuvier)

Sl. No.

1.

2.

4. 1 Valamugil seheli (Forsskal)

Fin- Fish Species

Ambassis cornmersoni (Cuvier)

Ambassis gyrnnocep halus (Lacepede)

5. 1 Gerres filarnentosus (Cuvier)

6. 1 Gerres oyena (Forsskal)

7. 1 Liza parsia (Hamilton - Buchanan)

8.

9.

Liza tada (Forsskal)

Chanos chanos (Forsskal)

10.

11.

12.

13.

Carangoides praestus (Bennett)

Caranx ignobiIis (Forsskal)

Gazza rninuta (Bloch)

EtropIus maculatus (Bloch)

14.

15,

16.

I 19. 1 Mystussp

Etroplus suratensis (Bloch)

Oreochromis mossambica (Peters)

Oligolepis acutipennis (Valenciennes)

17.

18.

Scatophagus argus (Linnaeus)

Glossogobius giuris (Hamilton - Bucharian)

20. Therapon jarbua (Forsskal)

Table No: 23.b.

Commercially important Shell-Fish species

I Prawns I Crabs I 1 . Penaeus indicus

(H. Milne Edwards, 1837)

1 . Scylla serrata

(Forsskal)

2. Metapenaeus dobsoni

(Miers, 1878)

3. Metapenaeus afinis

(H. Milne Edwards, 183 7)

Moiluscans

1 . Villorita cyprinoides

2. Meretrix casta

3- Cerithidium fluviatilis

2. Portunus pelagicus

(Linnaeus)

3. Portunus sang~inolentus

4. S e s m a quadrata

(Fabricius)

5. Meta pograpsus messor

(Forsskiil )

6. Gelasimus dussumieri

(H. Milne Edwards, 1837)