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)