Bivalve Diversity IJF

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Indian J. Fish., 45(2) : 177-181, Apr.-Jan., 1998

Note

A survey of bivalve molluscs in Gulf of Mannar,India

P. SHAUL HAMEED AND S. S. N. SOMASUNDARAM

P. G. Department of Zoology, Jamal Mohamed College,

Tiruchirapalli — 620 020, India

ABSTRACT

Out of 55 species of bivalve molluscs collected from Gulf of Mannar, 49 speciesbelonging to two subclasses, four orders and eighteen families were identified

and classified. Mandapam and adjacent islands maintain a rich bivalvediversity than the other areas. A depleting trend on bivalve species diversityin the Gulf of Mannar was evident from the present study when comparedwith earlier records and the significance of the study is discussed.

The Gulf of Man nar mai ntai ns a rich

biological diversity of both marine flora

and fauna. The twenty one tiny islands

in the Gulf of Mannar near Mandapam

have a rich and varied marine fauna in

the lagoon and in and around the coral

reefs. The Gulf of Mannar has been

declared as a Marine National Park by

the Tamil Nadu State Government in1972. The Govt, of India has proposed

to establish a Marine Biosphere Reserve

Authority (Anon, 1984). A detailed in

vestigation on the fauna has become

imperative in this most productive area.

This has become more important in the

case of molluscs which ar e indiscrimi

nately exploited. Earlier works on mol

luscs of the Gulf of Mannar include

Thurs ton (1895); Iyengar and

Parthasarathy (1927); Thomas (1972);

Satyamurti (1952); Nayar 91955);

Alaga rswami (1966); Appuku tta n (1972);

Nair and Rao (1974) and Nair and

Dhramaraj (1980). Investigation on the

biodiversity of bivalve molluscs will

help in finding out the level of exploita

tion and depletion of the resource whe n

compared with the earlier data.

The Gulf of Mannar is a marine

province situated between India and Sri

Lanka along the longitute from 78° 08'

E to 79° 30' E and latitute from 8° 35'Nto 9° 20' N. This geographical area runs

from Pamban Is land inc lud ing

Rameswaram to Cape Comorin along

India's southeast coast. The rich biologi

cal diversity of the Gulf of Mannar is

largely due to th e prese nce of diversified

habitats such as seaweed beds, coral

reefs, mangrove s, rocks and sand y and

muddy shores. The entire stretch of

Gulf of Mannar (including islands) from

Mandapam to Cape Comorin was con

sidered for the bivalve survey and this

study was undertaken for a period of two years from January '94 to December

'95 (Fig. 1).



P. Shaul Hameed & S. S. N. Somasundaram. 178

Fig. 1. Map ui' Gull ol' Mannar.

Bivalve survey

Since most bivalves of the Gulf of

Mannar are eulittoral, they were hand

picked directly from their habitats at

th e time of low tid e. Biva lves occupying

relatively deeper waters were collectedfrom boats operating power dredging.

Identification of specimens was carried

out with the help of the reference

specimens at the museum of Central

Marine Fisheries Research Institute

(CMFRI) at Mand apam and with the

reference the books including Bulletin

of Madras Government museum, New

Series -Natura l His to ry Se lec t ion ,

(Satyamurti, 1952). The identified spe

cies and their systematics were verified

with the Zoological Survey of India,

Calcutta.

Out of 55 species of bivalves col

lected, 49 species belonging to two

subclasses, four orders and 18 families

were identified. Six species are yet to be

identified. A broad systematics of the

identified species is as follows.

Subclass : Pteriomorpha

Order : Arcoida

Family : Arcidae

Species :

1. Scapharca inaequivalvis

(Bruguiere)

2. iS. qubernaculum (Reeve)

3. Trisidos tortuosa (Linnaeus)

4. Area complanata Chemnitz

Order : Mytiloida

Family : Mytilidae

Species :

1. Perna viridis (Linnaeus)

2. P. indica Kuriakose and Nair

3. Modiolus metcalfei (Hanley)

Family : Pinnidae

Species :

1. Pinna atropurpurea Sowerby2. P. bicolor Gmelin

3. Atrina vexillum (Born)

Order : Pterioda

Family : Pterioidae

Species :

1. Pteria chinensis (Leach)

2. Pinctada vulgaris (Schumacher)

Family : Malleidae

Species :

1. Malleus malleus (Linnaeus)

Family : Pectinidae

Species :

1. Volachlamys tranquebarica (Gmelin)

2. Chlamys crassicostata (Swerby)

3. Spondylus imperialis Chenu

4. Decadopecten plica (Linnaeus)Family : Anomiidae

Species :

1. Placenta placenta (Linnaeus)

Family: Ostreidae



Bivalues of Gulf of Mannar 179

Species:

1. Crassostrea cuttackensis (Neuton

& Smith)

2. Saccostrea cucullata (Born)

3. Lopha folium (Gmelin)

Subclass: Heterodonta

Order: Veneroida

Family: Lucinidae

Species:

1. Anodontia edentula (Linnaeus)

Family : Carditidae

Species :

1. Cardites antiquata (Linnaeus)

2. Cardita varieguata (Bruguiere)

Family : Cardiiae

Species :

1. Trachycardium flavum (Linnaeus)

2. Cardium coronatum (Spengler)

Family : Tridacnidae

Species :

1. Tridacna maxima (Roding)

Family : Mactridae

Species :

1. Mactra turqida (Nobrellects)

2. M. mera DeshayesFamily : Solenidae

Species :

1. Solen lamarckii (Deshayes)

2. Cultellus maximus (Gmelin)

Family : Tellinidae

Speceies :

1. Tellina ansulata Linnaeus2. Macoma ala (Hanley)3. M. bruguiera (Hanley)

Family : Donacidae

Species :

1. Donax cuneatus Linnaeus2. D. cortum Linnaeus

3. D. faba Schroeter

Family : Semelidae

Species :

1. Semele crenulata (Sowbery)

Family : Veneridae

Species :

1. Gafrarium tumidum (Roding)

2. G. dispar (Dillwyn)3. G. divaricatum(Gmelin)4. Meretrix casta (Gmelin)5. Callista erycina (Linnaeus)6. Paphia textrix (Schroeter)7. P. malabarica (Schroeter)8. Dosinia discus (Reeve)9. Sunetta scripta (Linnaeus)

10. Circe scripta (Linnaeus)11. Disina modesta (Sowbery)

Of the four orders, Venero ida was

predominant over the other orders and

it included nearly 56 % (28 out of 49

species) of total number of the species

recorded in the present investigation.

The distribution of bivalves in the

different regions of the Gulf of Mannar

is given in Table 1. A scrutiny of the

tabulated species shows tha t Manda pam

and the adjacent areas maintain a

richer bivalve diversity than the other

sampling stations. The species of

Scapharca, Pinna, Placenta, and Dosinia

were abundant whereas green mussel

Perna viridis and brown mussel P.

indica were conspicuously absent.

These mussels were plenty in the

southern parts of the Gulf of Mannar

(Tuticorin, Kundankulam and Cape

Comorin). Rocky shore of these regions

provide a suitable substratum for P.

viridis an d P. indica. The species of

Donax were found in almost all the



P. Shaul Hameed & S. S. N. Somasundaram

TABLE 1. Distribution of bivalve species in different regions of Gulf of Mannar

S. no. Species Manda- Tuti- Kund- Cape

pam corin anku- Como-

(Pamban-Kilakarai) lam rin

1. S. inaequivalvis

2. S. qubernaculum

3. T. tortuosa

4. A. complanata

5. P. viridis

6. P. indica

7. M. metcalfei

8. P. atropurpurea

9. P. bicolor

10. A. vexillum

11. P. chinensis

12. P. vulgaris

13. M. malleus

14. V. tranquebarica

15. C. crassicostata

16. S. im.peria.lis

17. D. plica

18. P. placenta

19. C. cuttackensis

20. S. cucullata

21. L. folium.

22. A. edentula

23. C. antiquata

24. C. variegata

25. T. flavum

26. C. coronatum

27. T. maxima

28. M. turqida

29. M. mera

30. S. lamarckii

31. C maximus

32. T. ansulata

33. M. a/a

34. M. bruguiera

35. D. cuneatus

36. D. scortum

37. Z). /a.6a

38. S. crenulata

39. G. tunmidum

40. M. casta

41. C erycina

42. P. tertra;

43. P. malabarica

44. D. discus

45. S. scripta

46. C scripta

47. Z). modesta

48. G. dispar

49. G. divaricatum

+ : Recorded;

+

+

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+

_ :

--+

+

+

-+

--—-+

-+

+

-+

+

+

+

--+

-----+

----+

+

+

+

---+

--+

+

-

-++

--+

—-+

+

--—-+

-+

+

-+

+

+

+

--+

-----+

----+

+

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-+

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-

---

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------+

+

-

---

Not recorded

180

sandy beaches of the Gulf of Mannar.

Among the three species, Donax faba is

predominant in number over D. cuneatus

an d D. scortum. The relative abundance

of D. faba and D. cuneatus was found

to be approximately in 3:1 ratio. The

veneriod clams such as Gfrarium

tumidum were restricted in distribution

but were found in large number in a

specific area between Chinnappalam,

Kundugal Point and in Krusadai Island.

The bivalves belonging to the genera

Malleus, Pteria, Pinctada, Pinna and

Spondylus occupied the eulittoral zone

which is always sub-tidal. Some of th em

are byssus bearing forms such as ear

shell (Pinna) and pearl oyster (Pinctada).

A dense population of Pinna was found

in several patche s in t he Gulf of Man nar .They are closely associated with sea

weed beds in and around the different

islands such as Krus adai , Man nal i and

Pumuruchan. Four species belonging to

the family Arcidae were recorded in the

present study. Scapharca spv Trisidos

and Area occupy a specific habitat of

muddy bottom with lot of decomposing

organic matter. The family Semelidae

was represented by a single species

namely Semele crenulata which is a

burrowing form in sandy shores.

The study on bivalve species in the

Gulf of Mannar indicates a depleting

trend in abundance when compared

with the earlier reports. About 152 spe

cies were reported from this area by

Satyamurti (1952) while the present

study could record only 55 species. Inte

nse fishing activities for shrimps indis

criminately scoops out the bivalve speci

es which are subsequently thrown out

on the shore. This is especially true for

the reef dwelling bivalves and the ir de

pletion is attributed largely to the ille

gal mining of coral reefs. Consequently

the bivalve mollusc population is vanishi-

http://im.peria.lis/

http://im.peria.lis/



Bivalves of Gulf of Mannar 181

ng faster than getting replenished. It is

imperative to create an awareness

among the fishermen community about

th e import ance of species diversity and

they may be instructed to put the

commercially 'unimportant' organisms

like bivalve molluscs back to water soonafter the fishing operation.

Acknowledgment

The authors thank Prof. N. Abdul

Samadh, Principal and Dr. M. Subra-

man iam , Head, Dep art men t of Zoology,

Jamal Mohamed College, Tiruchirapalli

for institutional support. The authors

are also grateful to the Ministry of

Env ir onm ent and Forest, Govt, of India,

New Delhi for funding the research

project.

References

Alagarswami, K. 1966. Studies on someaspects of biology of the wedge clam

Donax faba Gmelin from Mandapamcoast in Gulf of Mannar. J. mar. biol.

Ass. India, 8 : 56-75.

Anon. 1984. Man and bisopheres —Establishment of biosphere reserve in India. Gulf of Mannar Marine Biosphere Reserve, Project Document No.5, 105 pp.

Appukuttan, K. K. 1972. Coral-boringbivalves of Gulf of Mannar and Palk

Bay. Proc. Symp. Corals and Coral Reefs, Marine Biological Associationof India, Mandapam, p. 379-398.

Iyengar, M. and O. Parthasarathy 1927.Krusadai Island flora. Bull. MadrasGovt. Mus. N.S., 1 : 185-188.

Nayar, K.N. 1955. Studies on the growth of Wedge clam Donax cuneatusLinnaeus. Indian J. Fish., 2: 325-348.

Nair, R.V. and K.S. Rao 1974. The Commercial molluscs of india. Bull. Cent.

Mar. Fish. Inst, No. 25, 168 pp.

Nair, N.B. and K. Dharmaraj 1980. Woodboring molluscs of the Palk Bay andthe Gulf of Mannar. Mahasagar, 13 :249-260.

Satyamurti, S. T. 1952. The Mollusca of

Krusadai Island, Gulf of Mannar. Bull. Madras Govt. Mus. (Nat. Hist.),

1 (2) (Part 7), 201 pp.

Thomas, P. A. 1972. Boring sponges of thereefs of Gulf of Mannar. Proc. Symp.Corals and Coral Reefs, Marine Biological Association of India,Mandapam, p. 333-362.

Thurston, E. 1895. Rameswaram Island andthe fauna of Gulf of Mannar. Bull.

Madras Govt. Mus., 2 : 108-112.

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Bivalve Diversity IJF