Marine
Research and Management
Editors
V.N. Pillai and N.G. Menon
Central Marine Fisheries Research Institute
(Indian Council of Agricultural Research) Tatapuram P.O., Cochin-682 014
Kerala, India
2000
4 0 Flatfishes, goatfishes and whitefishes
p. B e n s a m , P. D e v a d o s s , Grace Mathew, K.M.S.A. H a m s a , V. Gandi, S. Lazarus, P.U. Zachariah, M. Feroz k h a n and P. J a y a s a n k a r
ABSTRACT
Although in order to exploit tiicse minor aemersai resources there are no specialised fishing efforts, their contribution to demersal Jinjish production is substantial, mostly exploited by bootom trawl-
ing in recent years. The annual flat fish production has been amounting upto 63,344 t in 1992, that of goatfishes upto 33,300 t in 1991 and of whitefish to 25,340 t in 1985. Of late, Kerala has accounted for 47% flatfish production, followed by Karnataka-Goa 23% and Maharashtra 14%. For goatfishes, Tamilncidu-Pondicherry is responsible for 41% followed by Kerald 30% and Andhra Pradesh
13%. Gujarat has been harvesting 49% of the Whitefish yield, followed by Karnataka-Goa 18 % and Maharashtra 13%. The
present paper brings together all the available data published and unpublished on the fishery and biology of various species contributing to the fisheries in different parts of the country. Based on these it is seen that the catch of the Malabar sole can be margin- ally increased in Calicut but not in Mangalore. In the case of the whitefish, there is an all-India decline in production in all the states due to indescriminate exploitation ofjuveniles by corXsiderably small cod end mesh size of bottom trawls. The present paper draws at- tention to the gaps still existing in our knowledge and the future research need on the fishery and biology of the important species, stock assessment estimates,relationships between the parental stocks and the progeny: the bottom hydrological conditions and the biological characteristics of the various populations in space and time, for realising the Maximum Sustainable Yield and for imple- mentina their management and conservation.
Introduction
T h e f l a t f i s h e s a r e b e n t h i c , c a r n i v o r o u s , b e l o n g to t h e O r d e r Pleuronectlformes have both the eyes on one side of the body a n d Include t h e
dir:^
Marine Fisheries Research and Management
flounders, h a l i b u t s , soles, plaice, d a b s and t u r b o t s . The Important families are : Psettodidae, having sinistral or dextral eyes a n d with a single genus Psettodes; Bothidae, having sinistral eyes with genera s u c h a s Bothus and Pseudorhombus: and pleuronectidae, having dextral eyes, with genera such as Samaris, Synaptura, Zebrias. Solea, Paraplagusia and Cynoglossus. Many species are greatly esteemed for their delicate and flavored meat, are cheap and within he easy reach of the low income public. In recent years, the a n n u a l total production vary from above 24, OOOt in 1982 to more t h a n 63,300 t in
1992,forming a b o u t 2.8% of the a n n u a l marine fish production.
Goatfishes or red mullets usually live in shallow waters with a sandy and / o r muddy bottom, are carnivorous and belong to the family Mullidae.
The i m p o r t a n t genera available in Indian region are : Mulloides. Parupeneus a n d Upeneus. Most of the species are well known table fishes. Some are used as live baits for t u n a fishing. The recent a n n u a l production from this re- source ranges from more t h a n 2 8 , 0 0 0 t a s in 1988 to more t h a n 3 3 , 3 0 0 t a s in 1991.
The whitefish or b u t t e r fish or milk trevally is Lactarius lactarius belonging to the family Lactaridae and occurring in shallow waters u p t o a b o u t
100m depth, in wide ranges of sea bottom. It is also carnivorous and much esteemed a s a food fish. The recent a n n u a l production h a s ranged from more t h a n 2 0 , 0 0 0 t as In 1983 to more t h a n 25,300t as in 1985.
In view of the importance of these r e s o u r c e s in the marine fisheries of India, investigations on their fishery, biological characteristics and / o r stock a s s e s s m e n t were u n d e r t a k e n in the Central Marine fisheries Research Insti- t u t e for some time.
Materials and m e t h o d s
Although a b o u t ninety species of flatfishes and twenty of goatfishes are reported from India, only a few c o n t r i b u t e to fisheries of appreciable m a g n i t u d e . The d a t a on the a n n u a l c a t c h s t a t i s t i c s of t h e s e r e s o u r c e s presented in the paper are collected, estimated and documented by the Central Marine Fisheries Research Insltitute from time to time. The materials and m e t h o d s of r e s e a r c h e s on the fisheries a n d biology of variovis species have been documented by C h i d a m b a r a m (1945) , S e s h a p p a (1964, 1973, 1975, 1976, 1978), J o n e s and Menon (1951) S e s h a p p a and Bhimachar (1951,1954,
Flatfishes, goatfishes and whitefishes 1995), George (1958), Pradhan (1959, 1960, 1965, 1969 a,b,c,), Thomas (1969), De groot (1974), Devadoss and Pillai (1974), J a m e s et al. (1974), Abraham and Nair (1976), Luther etal.[i982), S e s h a p p a and Chakrapani (1987) Mathew et al. (1992) and Khan and N a n d a k u m a r a n (1993). Reports on the early developmental stages of flatfishes are those of Gopinath (1946), J o h n (1951), Nair (1952 a,b), S e s h a p p a and Bhimachar (1955), J o n e s and P a n t u l u (1958), Kuthalingam (1957,1960), B a l a k r i s h n a n a n d Devi (1974) and R a m a n a t h a n and Natarajan (1979); of the goat fishes are those of Gopinath (1946) Uchida et al. (1958) a n d B e n s a m (1984); a n d of the whlteflsh is t h a t of Nair (1952).
The p a r a m e t e r s of growth stock a s s e s s m e n t , yield,biomass and related ones were estimated by Von Bertalanfy equation (Beverton and Holt, 1957) and based on the s t u d i e s of Thompson and Bell (1934), Pauly (1983) and Sparre (1987).
Biology
Specieis composition :- Only a few species of marine flatfishes contrib- ute to large c a t c h e s along the Indian coast; and infact only a single species, Cynoglossus macrostomus (Norman) forms a fishery of importance, mostly along Kerala a n d K a r n a l a k a coasts. A larger growning species C. dubius (Day) also contributes to a minor fishery along the above coasts; and small n u m b e r s of species s u c h a s C.lida (Sleeker), C. punticeps (Richardson), C. bilineatus (Lacepede) C. arel (Scheider), Paraplagusia a n d Pseudorhombus; are reported to a p p e a r in small quantities in Karnataka. Species of Solea, Synaptura and Pseudorhombus are occasionally t a k e n in small q u a n t i t i e s from i n s h o r e catches, especially S. ovata ((Richardson) P. arsius (Hamilton) a n d Psettodes erumei Schneider, the last sometimes called the "Indian halibut" occuring in small quantities along both the coasts and recorded from deeper a r e a s also.
Along the east coast P. erumei and C. arel, C. bilineatus, C.punticeps, Zebras quagga (Kaup), P.erumei a n d Pseudorhombus a n d Heteromyceterias a t m a n d a p a m ; P.earumei and P. arsius occur t h r o u g h o u t the year a t portonovo while the other species t h a t have occurred there seasonally are Caret. C. lida, fseudorhombus malayanus Bleeker and Laepos nigrescens Lloyed.
In India, t h e i m p o r t a n t species of goatfishes are : U. sulphureus (Cuvier), U.uitatus, (Forsskal), U. (ragula (Richardson), U. b e n s a s i (Temminck and Schlegal), U. sundaicus (Bleeker) U. molluccensis (Bleeker) and Parupeneus Indicus (Shaw).
Marine Fisheries Research and Management
There is only one species of whitefish Lactarius lactarius.
Food and feeding :- The Indian Psettodidae and Cynoglossidae have been classified into three feeding behavioural groups, viz., fish feeders, c r u s t a c e a n feeders a n d polychaetes-molluscs feeders. Among all flatfishes the Malabar sole C.macrostomus is found to be bottom feeder preferring mainly a diet of p o l y c h a e t e s , a m p h i p o d s a n d s m a l l bivalves; w i t h t h e p o l y c h a e t e worm Prionospio pinnata to be the d o m i n a n t item in the stomach d u r i n g some peri- ods. The food consumed is generally related to the n a t u r e a n d a m o u n t of b e n t h i c organisms available. A comparative s t u d y on the food in relation to n a t u r e of the organisms and their colonisation in the Malabar a r e a s h a s re- vealed three distinct food type a r e a s , a polychaete d o m i n a n t Quilandy-type, a bivalve d o m i n a n t Thalassery-type and a mixed type. Among these a r e a s , the fishery was observed to be the best in the first type a r e a which h a s predomi- nantly muddy bottom.
In the case of P. erumei. P r a d h a n (1969 a) a n d A b r a h a m a n d Nair (1976) from the west coast have reported t h a t this species feeds on fishes, molluscs and c r u s t a n c e a n s , and concluded t h a t it is a voracious carnivore, swallowing organisms a s a whole. P r a d h a n (1969 a) h a s pointed out t h a t the major c o m p o n a n t is teleosts and cephalopods while c r u s t a c e a n s and bivalves are subsidiary ones; and t h a t the juveniles did not show any specific differ- ence on the food and feeding h a b i t s in comparison with the a d u l t s . P.arsius is also a carnovore feeding on fishes, molluscs a n d c r u s t a c e a n s , both pelagic and demersal as reported by p r a d h a n (1959). Although these species are principally b e n t h i c , the occurrence of pelagic fishes s u c h as Thryssa a n d Stolephoras in the s t o m a c h c o n t e n t s indicates their occasional migration to the water column, an actvity noted in m a n y other flatfishes also.
The food of goatfishes consists manly of c r u s t a n c e a n s , molluscs and p o l y c h a e t e s ; t h e j u v e n i l e s feeding on s m a l l e r C r u s t a c e a s u c h a s Mysis, cumacea, zoea larvae, young ones of Acetes. larval molluscs, fish eggs and larvae ( K u t h a l i n g a m , 1 9 5 5 , 1956; R a b i n d r a n a t h , 1966; T h o m a s , 1969).
Kuthalingam (1955, 1956 ) h a s concluded t h a t the juveniles of P. indicas may be surface feeders and the a d u l t s perform vertical migrations for feeding while
U. cinnabarinus was found to feed on fast swimming c r u s t a e c e a n s such as Squilla, Acetes and Matuta; and t h a t it is a selective feeder. T h o m a s (1969) h a s noted t h a t U. tragula is also a selective feeder on p r a w n s and c r a b s .
From available literature a n d u n p u b l i s h e d d a t a collected, it is found
"620"
Flatflshea, goatflshes and whUeflshea t h a t the whitefish also is carnivorous feeding on teleostean fishes (mostly anchovies), s h r i m p s and other c r u s t a c e a n s (Chacko, 1944; D e v a n e s a n a n d Chacko 1944; C h i d a m b a r a m a n d Kurian 1952; J a m e s et al. 1974). According to J a m e s et al, (1974), the Juveniles feed more on c r u s t a c e a n s r a t h e r t h a n on the other items.
Age a n d growth :- C. macrostomus h a s been reported to grow to a b o u t 17 cm in total length; b u t b u l k of the commercial c a t c h e s in the s o u t h w e s t coast is m a d e u p of 10-13 cm g r o u p s a l t h o u g h the range is from 5.5 to 15.5 cm.
S e s h a p p a a n d B h i m a c h a r (1955) have reported t h a t females tend to grow at a faster rate t h a n m a l e s . The scales of t h i s species have growth rings formed d u r i n g the monsoon s e a s o n on t h e m which c a n be u s e d in t h e a s s e s s m e n t of age and growth. Usually the vast majority of the fish during September-October fishing s e a s o n m e a s u r i n g 10-12 cm are one year old a n d are p r o d u c t s from t h e previous s p a w n i n g s e a s o n . Besides, considerable q u a n t i t i e s of the two year old fish also have been found during certain years, m e a s u r i n g 14-15 cm with lesser growth i n c r e m e n t in the second year; b u t three year old specimens of 16-17cm are rare in the catches. According to Khan and N a n d a k u m a r a n (1993), the fish grows to a b o u t 6 cm when it is a b o u t 6 m o n t h s old, 10 cm a t 1 year, 12 cm at 1 1/2 years, 13 cm at 2 y e a r s a n d 14 cm at 2 1/2 y e a r s . However, s t u d i e s u n d e r t a k e n a t Mangalore during 1992-95 suggest t h a t the fish a t t a i n s a b o u t 15 a n d 18 cm respectively at the end of the 1st a n d 2nd y e a r s .
S e s h a p p a (1975) h a s observed the length range of C.dubius a t C a h c u t a s from 2.2to 41.2 cm In total length, the vast majority being in the range of 5 to 40 cm; and the fishery is mostly s u p p o r t e d by 17 to 24 cm size groups. A s t u d y of growth rings on scales h a s revealed t h a t the first ring, probably a s - sociated with the monsoon is formed when the fish is a b o u t 18 cm total length, p e r h a p s indicating one year old. The d a t a also indicate t h a t fishes of 25 cm total length are a b o u t 2 y e a r s old a n d of 2 9 - 3 0 cm are 4 y e a r s old.
The s t u d i e s of P r a d h a n (1969 c) at Mumbai have indicated t h a t P.
erumei r e a c h e s length of 22,42 and 55 cm at the end of the first t h r e e years of life a n d t h a t t h e p o p u l a t i o n s along b o t h the east a n d west coasts are homoge- n e o u s .
Based on length freauency studies Thomas (1969) has concluded that U.tragula a t t a i n s a length of 12 cm at t h e end of the first year a n d a b o u t 15-
Marine Flsherieg Research and Management
16 cm a t the end of second year. S t u d i e s u n d e r t a k e n on U.sulphureus at Madras indicate t h a t the fish a t t a i n s 12,16, and 18 cm at the end of the first three years of life.
According to Chacko (1944) and C h i d a m b a r a m and Kurian (1952), the size range of commercial c a t c h e s of the whlteflsh is 11 to 26 cm along the s o u t h e a s t coast. J a m e s et al. (1974) have reported from Mangalore t h a t the whlteflsh a t t a i n s a length of 15 cm at the end of the first year, 21 cm at the end of the second year and t h a t t h e life s p a n is only two y e a r s . The s t u d i e s at Mangalore during 1992-95 Indicate t h a t the fish r e a c h e s a b o u t 20 and 25 cm respectively a t the end of the first and second years of life.
L e n g t h - w e i g h t r e l a t i o n s h i p : - T h e l e n g t h w e i g h t r e l a t i o n s h i p of C.macrostomus at Calicut is w(g) = 0.0000 3 7 5 9 L 2 . 6 1 2 8 [mm] Khan and N a n d a k u m a r a n (1993). At Mangalore the relationship is: Log W= -5.9242 + 3.3416 * Log L; r = 0.68. Kutty a n d Qasim (1969) have observed t h a t there is no m a r k e d difference in the growth r a t e of male a n d female C. macrolepidotus a n d t h a t the length ( in cm) -weight (in gm) r e l a t i o n s h i p is Wt= 0.001107 L 3.4148.
The length- weight relationship of i m m a t u r e and m a t u r e U.tragula ar- rived at by T h o m a s (1969) is Log W = -4.8776 + 2.9638 log L for the former and Log W= -5.3756 + 3.2015 log L for the latter. In U. bensasi the relation- ship is Log W = -4.1347 + 2.6809 Log L.
At Mangalore the lenght-weigth relationship of the whlteflsh is Log W = - 4 . 9 0 6 5 5 + 3.005 * Log L ; r = 0.9
Size a n d age at first spawning :- C. macrostomus from Calicut a t t a i n s sexual m a t u r i t y at a length of 10-12 cm when it is less t h a n one year old and u s u a l l y t h e eggs are ready for release a t a b o u t 12 cm length when the fish is a b o u t one year old (Seshappa and Bhimachar, 1955). In Mangalore the size a t first m a t u r i t y a s observed during 1992-95 is 11 cm. C.dubius becomes sexually m a t u r e and Spawns at a length of a b o u t 28 cm and t h a t the mini- m u m size at first m a t u r i t y is 28.7cm (Seshappa. 1975). P r a d h a n (1965) re- ported t h a t P.erumei females at Mumbai m a t u r e first at 41 cm.
T h o m a s (1969) h a s recorded t h a t the size a t first m a t u r i t y in U.tragula along the s o u t h e a s t coast is a b o u t 12 cm when the fish is a b o u t one year old.
Flatfishes, goatflshes and whlteflghes In the case of the whitefish the male a t t a i n s sexual m a t u r i t y at 16 cm and the female at 18 cm along the s o u t h e a s t coast according to Devanesan and Chacko (1944); b u t at Mangolore J a m e s et al (1974) observed t h a t the size at first m a t u r i t y is 12-13 cm, when the fish is a b o u t one year old.
Spawning season:- Spawning of the Malabar sole at Calicut commences by a b o u t October and extends u p t o the p r e m o n s o o n m o n t h s of April-May (Seshappa and Bhimachar, 1955); while in Cochin it is in S e p t e m b e r a s well as in April-May (Mathew et ai. 1992). At Mangalore also the major spawning is observed to be from October t h r o u g h March, with the peak d u r i n g Novem- b e r - J a n u a r y . In the case of C.dubius at CaHcut, S e h s a p p a (1975) h a s ob- served t h a t the spawning season commences from a b o u t October / December more or less similar to t h a t of the Malabar sole. The spawning s e a s o n of P.erumei at Mumbai Is stated to be September- October by P r a d h a n (1965).
Among go&t fishes, JJ.tragula was observed to spawn a t M a n d a p a m from May to November (Thomas, 1969) while a t Madras U. sulphureus s e e m s to have an extended breeding from September through J u n e with two peaks during September-December a n d March-May.
In the case of the whitefish, the sawning s e a s o n off t h e s o u t h e a s t coast is d u r i n g November-February period when the fishery is a t its peak (Chacko, 1944: Devanesan and Chacko, 1944). J a m e s et al (1974) have opined t h a t off Mangalore it, s p a w n s almost t h r o u g h o u t the year with a possible peak during J a n u a r y - May. The multiplicity of ova diameter modes h a s indicated t h a t the fish s p a w n s in b a t c h e s over a prolonged period.
Sex ratio and fecundity :- In C. macrostomus S e s h a p p a a n d B h i m a c h a r (1955) have found t h a t the sexes become differentiated a t a b o u t 6-7 cm and t h a t sex ratio is variable from time to time, the average being 1 M : 1.4 F. At Mangalore it h a s varied from 1 M : 0.57 to 1.65 F during 1992-95 and the fecundity of the species h a s ranged from a b o u t 6,540 to 19,890 eggs for fishes of 13.6 and 15.7 cm TL respectively. The sex ratio of C.dubius a t Calicut showed 3.47 M: 3.047 F (Seshappa, 1975). P r a d h a n (1965) h a s found the sex ratio of P.erumei at Mumbai as IM : 3.8 F; t h a t there is sexual segregation in certain m o n t h s a n d t h a t the fecundity is 3 1 , 380 to 12,19.080.
Among goatfishes, Thomas (1969) h a s observed the sex-ratio of U.tragula at M a n d a p a m a s IM: 1.92F and its fecundity a s 19,000to 9 2 , 8 0 0 . In M a d r a s . U.sulphureus h a d a sex ratio of IM: 1.75 F.
Marine Fl8herie« Research and Management
The sex-ratio of the whitefish at Mangalore is 1 M : 0.2 to 1.1 I F (James e t a f . 1 9 7 4 ) a n d the s t u d i e s during 1992-1995 have indicated a similar trend.
The fecundity of the species estimated by J a m e s etal. (1974) is 9,000-79,000 eggs in fishes of 16.3 to 21.4 cm TL, weighing 60-124gm. During 1992-95, the e s t i m a t e s made are a b o u t 8,950 eggs in a fish of 14.3 cm and 3 1 , 3 4 0 eggs in a n o t h e r of 18 cm TL.
Fishery
Flatfishes :- The total flatfish landings along the Indian coast h a s been estimated to fluctuate from a b o u t 2 , 0 0 0 t as in 1951 to a b o u t 6 3 , 3 4 4 t as in 1992. The landings have recorded a distinct Increasing trend with the advent of bottom trawling a n d registered a regular production of more t h a n 10,000 t from 1968, crossing the 15,000 t mark In 1 9 8 1 , 24,00t in 1982 and attained more t h a n 4 0 , 0 0 t in 1984. However, there was a decline from the 1984 level In 1985 a l t h o u g h a recovering trend was observed until 1991. The year 1992 h a s witnessed a n all-time record of 63,344 t followed by a decline to 4 6 , 6 6 0 t In 1993 a n d still lesser to 4 4 , 2 0 0 t in 1994. The average production d u r i n g t h e five y e a r s period of 1990 - 94 is 4 4 . 2 7 0 t which Is a b o u t 7 % of t h e total demersal flnflsh production a n d 2 % of the total marine fish production of India. Of the total production, a b o u t 90% is from the west coast a n d 10%
from the east. Groupwise, the tongue soles c o n t r i b u t e to a b o u t 9 3 % followed by the Indian h a l i b u t [Psettodes] 6% and a variety of flounders 1%, consisting of Pseudorhombus, Samarias, Bothus, etc. The tongue soles are usually shallow water forms while the h a l i b u t Is available in deeper w a t e r s .
Among all t h e species of flatfishes available in India, it is only the Malabar sole C.macrostomus which forms a regular fishery from ancient times a l o n g t h e s o u t h - w e s t c o a s t In t h e s t a t e s of Kerala a n d K a r n a t k a ; a n d documented atleast from the beginning of this century. Rao (1967) h a s pointed out t h a t the region between Mulki In K a r n a t a k a a n d Kollam in Kerala is the i m p o r t a n t zone for the Malabar sole. According to S e s h a p p a (1973), in the pre-war years the a n n u a l production was a b o u t 9,400t there was an increasing production form 1944 onwards with record production in 1950-51, a m o u n t i n g to a b o u t 18,800t. Some regular features observed by him are: best landings d u r i n g September, considerable decline d u r i n g October, restricted fishery a t the central sector in the following m o n t h s and little catches in the premonnsoon m o n t h s . D u r i n g t h e p r e m e c h n i s e d era, t h e i m p o r t a n t g e a r s u s e d were:
c a s t n e t s , b o a t s e i n e s [Paithu vala) in Kerala a n d s h o r e - s e i n e s [rampani.
Flatfishes, goatfishes and whlteftshes kairampani) in K a r n a t a k a . Certain other gears namely Nethel vala. Pattamkolli vala a n d Chooda vala also were u s e d to harvest the sole. S e s h a p p a (1973) h a s reported high c a t c h e s in p r e m o n s o o n m o n t h s , dominated by juveniles.
With t h e i n t r o d u c t i o n of m e c h a n i s a t i o n from the sixties, t h e fishing p a t t e r n h a s changed, from c a p t u r i n g the s h o a l s at the surface a n d s u b s u r f a c e re- gions by indigenours gears to effective c a p t u r e by bottom trawlers. After com- m e n c e m e n t of m e c h a n i s a t i o n a n d bottom trawling, the b u l k of t h e Malabar sole c a u g h t is by t h i s gear with a m e s h size of 15 to 2 5 mm operated mostly from small trawlers of 14 m OAL in the depth zone of 10-50 m, a l t h o u g h non- m e c h a n i s e d country crafts are also employed in certain locations.
Among v a r i o u s s t a t e s , the West Bengal-Orlssa zone h a s recorded t h e least a n n u a l production of flatfishes ranging from 6 to 810 t with a b u n d a n c e during 1985-87. In Andhra Pradesh, t h e production was not quite impres- sive until the eighties (56-247t). In 1981 there was a s u d d e n s p u r t of 2,210 t a n n u a l yield, which w a s followed by higher production (850 to 1,630 t) when compared to t h e production until 1980. A similar t r e n d w a s observed in Tamilnadu-Pondicherry with the a n n u a l catches ranging from a b o u t 120 to 1,180 t between 1956 a n d 1979; b u t crossing the 2.240 t m a r k in 1980.
S u b s e q u e n t l y the production ranged from 1,630 to 3,840 t with the p e a k in 1991, showing a higher level. In Kerala, the flatfish production h a s shown a steady increase, from 7,610 t in 1956, crossing the 10,000 t m a r k in 1958, b u t declined s u b s e q u e n t l y . With fluctuations in between, the production h a s crossed the 12,000 t level in 1974, again to record a decline until 1980. There- after there w a s a steady increase, crossing t h e 20, 0 0 0 t m a r k in 1989 al- t h o u g h declining by a b o u t 2 8 % in the next year. In K a r n a t a k a , t h e a n n u a l c a t c h e s ranged from a b o u t 720 t in 1986 to 1,660 t in 1971 and crossed the 2,500 t level in 1974. S u b s e q u e n t l y the fishery h a s declined to a b o u t 680 t in
1984 b u t showed considerable improvement in s u b s e q u e n t y e a r s a n d reach- ing t h e all-time peak of 19,080 t in 1992. In M a h a r a s h t r a a n d Gujarat t h e flatfish production may be said to have stabilised only since the seventies, ranging from a b o u t l , 8 0 0 t to the peak of 6,910 t in 1993 in the former a n d a b o u t 2,460 to 6,790 t in the latter s t a t e . During the p a s t a b o u t ten years, Kerala h a s contributed to the b u l k average a n n u a l production of 4 7 % fol- lowed by K a r n a t a k a - G o a 2 3 % a n d M a h a r a s h t r a 14%.
According to Mathew et al. (1992), the m a x i m u m p r o d u c t i o n of flat- fishes in the west coast is from Kerala (40%) followed by K a r n a t a k a - Goa (35%), where the Malabar sole constitutes t h e b u l k of t h e yield. In the Malabar
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Marine Fisheriea Research and Management
coast of Kerala, bulk of the landings is immediately after the monsoon, within two or three m o n t h s ; and the fishery is characterised by wide fluctuations. In Cochin, Mathew et al, (1991) have noted a direct and positive correlation between the catch rate and the Intensity of rainfall a s well a s the peak u s u - ally occurlng in J u n e , after the onset of the monsoon. In K a r n a t a k a - Goa the b u l k of t h e p r o d u c t i o n i s d u r i n g t h e m o n s o o n a n d p o s t m o n s o o n . In Maharashtra and Gujarat the bulk of the production is during premonsoon and postmonsoon m o n t h s , usually higher production during the latter period in M a h a r a s h t r a a n d vice versa in Gujarat. Among various species, P.erumei c o n t r i b u t e s u p to 15% of the total faltfish production in both t h e s e s t a t e s (Mathew et al. 1992), However, an organised fishery for this fish is not reported from any part of the country (Prabhan, 1969c). The all-India a n n u a l halibut landings which have ramained at a b o u t 1,384 t in 1982-83 have recorded a g r a d u a l I n c r e a s e a s a r e s u l t of e x p a n s i o n of fishing to d e e p e r a r e a s s u b s e q u e n t l y upto 70-100 m depth in recent times a n d crossing t h e 2,870t production in 1990, At Mumbai, prior to introduction of bottm trawling the occurrance of P.erumei in commercial catches was rare and seasonal (Prabhan, 1969 c), c a u g h t mostly in the stationary type of bag n e t s , popularly called
"Dol", But since the inception of bull-trawling by new India Fisheries Ltd, there was considerable increase in the catches of this fish, mostly from Mumbai proper, Cambay,Veraval, P r o b u n d e r a n d Dwaraka.
Goatfishes :- Prior to the advent of commercial bottom trawling the in- digenous crafts and gears s u c h a s shore-seines, boat seines fish t r a p s , etc.
were responsible for the production of goat fishes, T h o m a s (1969) h a s stated t h a t the fishery had some magnitude in the s t a t e s of Andhra P r a d e s h and Tamllnadu in the east coast a n d Kerala, K a r n a t a k a and M a h a r a s h t r a in the west coast. According to him, U. sulphureus and U. vittatus were the two species available in the above s t a t e s except in Tamllnadu where P.indicus and U. tragula are the d o m i n a n t ones. The all India production of goatflsh ranged from 1,110 to 1,513 t d u r i n g 1950-55 period: and in 1956 there was a s u d d e n and t r a n s i e n t s p u r t in production to more t h a n 10.400t, which was followed by a rapid decline and fluctuation a r o u n d 3,027 t as in 1964 to 1,526 t in 1956; and an all time low of 1,344 t in 1967, although recovering subsequently.
After the s p u r t in 1956, the next peak recorded was so late a s in 1974 when a production of more t h a n 7,000 t was recorded which was again followed by a s u d d e n decline to a b o u t 2,640 t in 1975, The 10,000 t mark was crossed for the second time only In 1987 after a lapse of more t h a n 3 0 years and this
Flatfishes, goatfishes and whiteflshes w a s followed by a record production of 2 8 , 4 6 3 t in 1988. Again, there was a decline in the next year a n d further reduction in the s u b s e q u e n t two years. It may be seen from the above d a t a t h a t the all-India goatfish producion is m a r k e d by wide fluctuations a n d s u d d e n and t r a n s i e n t s p u r t of increase fol- lowed by decline.
Among various s t a t e s , the a n n u a l production was meagre in West Ben- gal-Orissa zone, usually ranging from 1 to 34 t u p t o 1979. The production h a s increased in the eighties, reaching the peak of a b o u t 420 t In 1985, fol- lowed by a gradual decline thereafter a l t h o u g h reaching a b o u t 370 t in 1993.
In Andhra Pradesh, the landings have varied from 170 to 1,220 t till the sev- enties after which there was a higher level of yield, reaching a b o u t 4,080 t in
1987, although declining later. A similar trend was observed in T a m l l n a d u - Pondlcherry a n d Kerala with a peak of 11, 380 t in 1988 and declining there- after in Tamilnadu-Pondicherry; with a n all time peak of 18,820 t in 1990. In Kerala production was m u c h lower, marked by wide fluctuations a n d there w a s n o further recovery a t all. In Gujarat the fishery h a s commenced only from early seventies, increased in q u a n t u m thereafter, reached an all time p e a k of 18,195 t in 1985; declined by 64% of the above in the next year Itself;
and led to a meagre of 1,3271 in 1993 (93% lesser t h a n in 1985). Among various s t a t e s during the p a s t a b o u t ten years, Gujarat is responsible for the bulk production of 49%, followed by Karnataka-Goa 18% a n d M a h a r a s h t r a
13%.
White fish :- In s o u t h - e a s t coast, the main fishery for the whitefish is from Novemeber to February (Chacko, 1944; Devenesan a n d Chacko. 1944;
C h i d a m b a r a m a n d Kurian, 1952), At Mangalore, J a m e s et al. (1974) have observed t h a t the fishery is s u p p o r t e d by 0 and 1 + year old fish a n d t h a t the fairly high fecundity seems to allow for necessary r e c r u i t m e n t . Kaikini (1975) h a s observed t h a t off M u m b a i - S a u r a s h t r a waters whitefish concentrated in the depth range of 2 0 - 4 5 m, the 3 0 - 3 5 m zone being the optimum one. The depth ranges were observed to change according to the season, the catch rate being the highest during April-June period. A gradual n o r t h - s o u t h migration of the species from Kutch commences in April and c u l m i n a t e s by the follow- ing J a n u a r y at Cambay.
Marine Flsherio Research and Management S t o c k a s s e s s m e n t
S e s h a p p a a n d C h a k r a p a n i (1987) have studied t h e extence of s t o c k s of the Malabar sole a n d opined t h a t although there is some variability in the merlstic c h a r a c t e r s among different centres, t h e samples from Cochin per- h a p s belong to a stock different from those of other centres. In Calicut, Khan a n d N a n d a k u m a r a n (1993) h a v e s t u d i e d t h e p o p u l a t i o n d y n a m i c s of C.macrostomus d u r i n g 1987-92. According to them t h e i n s t a n t a n e o u s rate of total mortality during the period was 2.5; the average a n n u a l landing was a b o u t 959; a n d the m a x i m u m s u s t a i n a b l e yield (MSY) Is a b o u t 1,694 t, which is m u c h higher t h a n t h e a n n u a l h a r v e s t . Based on t h e s e d a t a a n d the exploitation ratio, the total s t a n d i n g stock was estimated a s a b o u t 2,592 t there. They have also concluded t h a t the yield can be Increased by e n h a n c i n g the effort u p to a value of 0.96. However, since the increment in yield will not be r e m u n e r a t i v e beyond a value of 0.87, Increasing it beyond 0.87 will not c o m m e n s u r a t e with Increase in the effort. At Mangalore during 1992-95 the exploitation r a t e w a s estimated to be 0.727; t h e MSY a s a b o u t 2,513t; a n d it is estimated t h a t a n additional of 357 t can be harvested, although the ex- ploitation r a t e is above o p t i m u m .
In the case of whlteflsh a t Mangalore, t h e s t u d i e s have shown t h a t the exploitation rate during 1992-95 Is 0.694; t h a t the average a n n u a l catch of 2 5 7 t is almost equal to t h e MSY of 2 6 8 t, although the actual catch during 1994-95 h a s a m o u n t e d to 429 t.
S t u d i e s have not yet been u n d e r t a k e n on the stock a s s e s s m e n t of goatfishes.
Conservation and m a n a n g e m e n t o p t i o n s
There is no specialised fishery targeted for flatfishes, goatfishes and whlteflsh in any p a r t of the Indian coast, including for the Malabar sole. The b u l k of the catches for t h e s e r e s o u r c e s are bycatches in the fisheries targeted for other resources s u c h as s h r i m p s . According to Khan a n d N a n d a k u m a r a n (1993) the effect of fishing on the stock of Malabar sole available at Calicut is negligible and t h a t the p r e s e n t fishing effort there c a n be Increased two-fold from the p r e s e n t level of harvesting 959 t to 1,646 t which can be considered as the economic yield. They have concluded t h a t from the p r e s e n t effort of only 0.4, It can be increased to 0.87 for achieving s u c h a p u r p o s e . However,
Flatfishes, goatfishes and whlteflshes the s t u d i e s u n d e r t a k e n a t Managalore Indicate t h a t the p r e s e n t exploitation r a t e there for Malabar sole is a b o u t the optimum. Also, since a b o u t 8 3 % of the present a n n u a l yield there is from the region u p to a b o u t 30 m depth, which Is overexplolted for vaious resources and since a b a n on bottom trawling upto 5km from the coast is at p r e s e n t u n d e r the active consideration of K a r n a t a k a Government, further intenslficaion of exploitation in the above region shall be only counter-productive. Studies on yield -mesh curve a t Mangalore also Indicate t h a t any change from the present length at first capture of 11 cm will only r e d u c e the yield per recruit.
In the case of the white fish studied a t Mangalore during 1992-95, it is seen t h a t the p r e s e n t fishing effort Is 5.938 a n d t h a t any change from the p r e s e n t length at first c a p t u r e of 14 cm will only r e d u c e the yield per recruit.
As the average a n n u a l MSY at Mangalore is a b o u t 2 6 8 t, a s a g a i n s t t h e a n - n u a l average catch of 2 5 7 t a n d since the actual catch is 429 t d u r i n g 1994- 95, It Is seen t h a t the resource Is being overexplolted there; a n d t h a t this level h a s to be decreased.
The whiteflsh is one resource t h a t h a s been showing a g r a d u a l a n d c o n s i s t e n t decline on a n all-India b a s i s from a n all-time a n n u a l peak p r o d u c - tion of 2 5 , 3 3 7 t in 1985 from low levels In the sixties a n d seveties. The de- cline h a s been so alarming t h a t it h a s reached an all-time low of a mere 4,189 t in 1993, which is only a b o u t 16.5% of the production In 1985. The decline Is very m u c h marked in the s t a t e s of Andhra Pradesh, Tamilnadu-Pondlcherry, Kerala, K a r n a t a k a -Goa and M a h a r a s h t r a ; b u t not so m u c h in Gujarat, In the s o u t h - w e s t coast, in a single centre, Vizhinjam alone according to Luther et al. (1982), the a n n u a l production which w a s 62.4 t In 1970 h a s gone down to a meagre 0.1 t in 1979. From t h e s e facts, it can be easily stated t h a t in order to m a i n t a i n t h e MSY from t h i s valuable resource, it is very m u c h essen- tial to reduce the intensity of its exploitation by reducing the q u a n t u m of production increasing the cod-end m e s h size for rational c a p t u r e a n d con- serving the potential s p a w n e r s , in order to e n s u r e continuity of higher pro- duction In all the s t a t e s
E c o n o m i c s and marketing
Although for large-sized flatfishes s u c h as the h a l i b u t there is d e m a n d in the market, small sized species like the Malabar sole, fetch only Rs. 5 to 1 5 / k g in the local m a r k e t s , . Accordingly, a b o u t 90 % of the small sized soles
-cm^
Marine Fisheries Research and Management
are s u n d r i e d with other fishes s u c h as s a r d i n e s , sciaenids, silver bellies etc.
and sold,out during nonflshing s e a s o n s at a rate of Rs. 10 - 2 5 / kg.
Goatfishes are esteemed as good quality fishes for food and are mostly consumed in the fresh condition at a price of Rs. 15 - 4 0 / k g . When the catch exceeds the local d e m a n d s the fishes are svindrled along with other fishes.
Prior to sundrying on the beach, the fish is kept in salt solution for a day.
After this, the fish is packed in b a s k e t s s u c h as of palmyrah leaves a n d t r a n s - ported to interior m a r k e t s . Some species of goatfishes are used as live baits for t u n a fishing in the island of Minicoy, as reported by J o n e s a n d Kumaran (1959) and J o n e s (1964),
The whitfish h a s good d e m a n d in local m a r k e t s in fresh condition with a price tag of Rs. 3 5 - 50 / Kg. Almost the total catch is consumed in the fresh condition, although small proportions are s u n d r i e d and fetch prices of Rs. 8 0 - 1 0 0 / k g during nonfishing s e a s o n s .
Future research priorities and c o n c l u s i o n
In view of the fact t h a t there is no special targeted fishing of these re- sources in any part of the Indian coast a s at present, the future research priorities for these r e s o u r c e s c a n n o t be delinked from those of the oihers which are also c a u g h t by the same crafts and gears employed. Preliminary s t u d i e s of S e s h a p p a a n d C h a k r a p a n i (1987) have indicated t h a t there are two major stocks of Malabar sole, viz, the Cochin stock and the general stock. In order to impliment meaningful stock a s s e s s m e n t s t u d i e s of this resource in K e r a l a - k a r n a t a k a region, it is essential to confirm this aspect by more ex- h a u s t i v e s t u d i e s in space and time a n d also by involving modern biochemical methods of racial investigations. Also, if different stocks are present, the degree of their intermingling and the role if any of them on the variations in production will have been u n d e r t a k e n in one or two centres so far , s u c h s t u d i e s will have to be u n d e r t a k e n in the other centres also and a wholistic picture will have to be obtained. Similar s t u d i e s on the i m p o r t a n t flatfishes from off M a h a r a s h t r a and Gujarat also are an essential prerequisite t h a t will have to be u n d e r t a k e n .
Another area which needs u r g e n t attention is the evaluation of the rela- tionship between the parental stocks of various s p e c i e s / s t o c k s and their prog- eny. Although the fecundity e s t i m a t e s of a few species of the r e s o u r c e s have b e e n w o r k e d o u t no a t t e m p t s e e m s to h a v e b e e n m a d e to e s t i m a t e the
Flatfjghes, goatflsheg and whtteflsheg fecundities of the total populations year after year, to correlate the fecundities with the s t r e n g t h of the r e s u l t a n t p r o g e n y / y e a r classes a s well a s to develop statistical and predicatable models b a s e d on the findings.
Although r e s e a r c h work on the fisheries and biology a s well a s environ- mental p a r a m e t e r s of the fishing g r o u n d s in which t h e s e r e s o u r c e s are avail- able h a s been u n d e r t a k e n In certain localities, concerted effort on collecting d a t a from the benethic a r e a s where these r e s o u r c e s occur do n o t seem to have been u n d e r t a k e n so far. In order to elucidate the relationship existing between t h e environmental p a r a m e t e r s a n d the biological c h a r a c t e r i s t i c s of species in space a n d time which r e s u l t in the variations in p r o d u c t i o n from year to year, it is absolutely essential to implement collections of d a t a on the same, to analyse them, to interpret the r e s u l t s a s well a s to develop models for forecasting of prodcution in relation to environmental p a r a m e t e r s .
In order to finalise the MSY a s well a s to e n s u r e economic sutainability it is u r g e n t to study the optimum cod-end m e s h size for t h e s e r e s o u r c e s in space a n d time; a s well a s to enforce the r e s u l t s a n d r e c o m m e n d a t i o n s with- out any compromise.
R e f e r e n c e s
Balakrishanan, K.P. 1963. Fish eggs and larvae collected by the Research Vessel Conch, 2. Bull. dept. mar. biol.oceanogr., Univ, Kerala , 1: 81 - 96.
B a l a k r i s h a n a n K. P. and C.P.L. Devi 1974. Larvae of some flatfishes from a tropical estuary. In: J.H.S. Blaster (Ed.) The early life history offish. Springer Verlag Berlin, Heidelberg.
Bensam, P. 1965. On the eggs and early larval stages of the Malabar sole Cynoglossus semifasciatus Day. Indian J. Fish., 12 (1) : 9 0 - 9 8 .
Bensam, P. 1984. Observations on a few early developmental stages of some fishes of Porto Novo Coast, India. Ph.D. Thesis, Annamalal University.
Chacko, P.I. 1944. On t h e bionomics of t h e big-jawed j u m p e r , Lactarius lactarius (Cuv.
& Val.) Curr.ScL, 13 : 108.
C h i d a m b a r a m K. 1945. The spawning season of t h e Malabar sole (abstract). Proc.
3 2 n d Indian Sci. Congr. Pt. 3,Abstracts : 113.
C h i d a m b a r a m K. and O.K. Kurian 1952 . Certain observations on t h e bionomics and fishery of big-Jawed j u m p e r Lactarius lactarius Cuv. &Val. (abstract). Proc.
"63?
Marine PUherie» Research and Management
39th Indian Sci. Congr. Pt.3 Abstracts : 327-328.
De groot, S.J. 1974. Gaps in t h e s t u d i e s on behaviour of Indian Ocean flatfishes be- longing to the Psettodidae and Cynoglossidae. J. mar.biol. Ass. India, 15 (1) : 2 5 1 - 2 6 1 .
Devadoss, P. and P. K.M. Pillai 1974. Observations on t h e food of juveniles of Psettodes erumei (Bloch) Indian J. Fish.. 20 (2) : 664 - 667.
Devanesan, D. W. and P.I. Chacko 1944. Bionomics of t h e big-jawed j u m b e r Lactarius lactariiLS (Cuv. & Val.) (abstract). Proc. 31st Indian Sci. Congr. P t . 3 Ab- stracts : 86.
Devi. C.B. L. 1969. O c c u r r e n c e of t h e l a r v a e of Pseudorhombus elevatus Ogilby (Heterosomata-Plsces) along t h e southwest coast of India. Proc. Indian Acad. Set. 70 B : 178 - 185.
Devi C.B. L. 1981. Developmental c h a r a c t e r s of bothid flatfishes of t h e genus Psettona.
Rapp. P. -V. Reun. Cons. Int. explor. Mer 178 : 588 - 589.
George, P.C. 1958. Sole fisheries. In: Central Marine Fishseries Research Station, Mandapam Camp, Fisheries of the west coast of India.
Gopinath K. 1946. Notes on the larval and postlarval stages of fishes found along the Trivandrum Coast. Proc. nat. Inst. Sci. India. 12 (1) : 72-79.
J a m e s , P.S.B.R., S.L. S h a n b h o g u e and T.R.C G u p t a 1974. Biology and fishery of Lactarius lactarius (Schneider) off Mangalore. Indian J. mar. Set. 3 : 72- 79.
J o h n , M.A. 1951. Pelagic fish eggs and larvae of the Madras Coast. J. zoof. Soc. India.
3 (1) ; 38-66.
J o n e s . S. 1962. A preliminary survey of the common t u n a bait fishes of Minicoy and their distribution in Laccadive Archipelago. Mar. biol Ass. India. Proc.
Symposium on Scombroid fishes, pt. 2; 643-680.
J o n e s , S. a n d M. Kumaran 1959. The fishing i n d u s t r y of Minicoy Islands with special reference to t h e t u n a fishery. Indian J. Fish., 6 (1) : 30-57
J o n e s S. and P.M.G. Menon 1951. Notes on the bionomics and developmental stages of some Indian flatfishes. J. zooL Soc. India. 3(10) : 7 1 - 8 3 .
J o n e s , S. and V. R. Pantulu 1958. On some larval a n d juvenile fishes from t h e Bengal and Orissa Coast. Indian. J . Fish., 5 (1) : 118-143.
Kaikini, A.S. 1975. Regional and seasonal a b u n d a n c e of t h e Whitefish Lactarius lactarius
' 6 3 2 '
Flatfishes, goatflghes and whltefisheg (Schneider) in the trawling g r o u n d s off B o m b a y - S a u r a s h t r a Coast, 1957- 6 3 . Indian J. Fish.. 21 (1) : 89 -108.
Khan, M.F. a n d K. N a n d a k u m a r a n 1 9 9 3 . P o p u l a t i o n d y n a m i c s of M a l a b a r sole Cynoglossus macrostomus Norman along Calicut coast. Indian J. Jish.. 40 (4) : 225 - 230.
Kuthalingam, M.D.K. 1955. The food a n d feeding h a b i t s of juveniles and a d u l t s of four fishes of Madras. J. Madras Univ.. 2 5 B (3) : 2 3 5 - 2 5 3 .
Kuthalingam, M.D.K. 1956. The food and feeding h a b i t s of some Madras fishes. J. Ma- dras Univ.. 26 B (3) 4 6 5 - 4 7 8 .
Kuthalingam, M.D.K. 1957. Life history and feeding h a b i t s of Cynogl ossus linga (Ham.
Buch). J. zooL Soc. India. 9(2) : 2 0 8 - 2 1 5 .
Kuthalingam M.D.K. 1960. An account of t h e life history a n d feeding h a b i t s of a sole [Solea elongata Day). J. Madras Univ.. 30 B (2&3) : 87-96.
Kutty, M.K. 1967. Observations on t h e growth and mortality of t h e large-scaled tongue sole Cynoglossus macrolepidotus (Bleeker). Proc. nat. Inst Set India., 3 3 : 94 - 110.
Kutty, M.K. a n d S.Z. Qasim 1969. Theoretical yield s t u d i e s on t h e large-scaled tongue sole Cynoglossus macrolepidotus (Bleeker) from t h e Arabian Sea. Bull, natlnst. Sci. India., 38 : 864-875.
Luther, G. P.N.R. Nalr, G. Gopakumar a n d K.P. Nalr 1982. The p r e s e n t s t a t u s of small-scale traditional fishery at Vizhinjam. CMFRI, Mar. Fish. Infor. Serv.
T&ESer.. 38 : 1-16
Mathew, G., M.F.Khan and K. N a n d a k u m a r a n 1992. Present s t a t u s of exploitation of fish and shellfish r e s o u r c e s : Flatfishes and F l a t h e a d s . Bull. Cent. Mar.
fish. Res. Inst. 45 : 197-204.
Nair, R.V. 1952 a. Studies on some fish eggs and larvae of t h e Madras p l a n k t o n . Proc.
Indian Acad. Set. 3 5 B (5) : 181-208 .
Nair, R.V. 1952 b. Studies on some post larval fishes of t h e Madras p l a n k t o n . Proc.
Indian Acad. Set. 35 B (5) : 225-244.
Pauly, D. 1983. Some simple m e t h o d s for the a s s e s s m e n t of tropical fish stocks. FAO Fish.Tech. Paper. 2 3 .
P r a d h a n , M . J . 1 9 5 9 . A p r e l i m i n a r y n o t e on t h e food a n d f e e d i n g h a b i t s of Pseudorhombus elevatus Ogilby. J. Bombay nat. Hist. Soc, 56 (1) : 141- 144.
dm;::)
Marine Flaheries Research and Management
P r a d h a n , M.J. 1960. Studies on the biology and fishery of Psettodes erumei (Sch). Ph.
D. Thesis, University of Bombay.
Pradhan, MJ. 1965. Observations on the m a t u r i t y and spawning of Psettodes erumei (Such). Indian J. Fish.. 9(2) : 580 - 589,
P r a d h a n M.J. 1969 a. Fishery biology of Psettodes erumei (Schneider) an Indian Ocean flatfish, I. Bull, nat inst. Sci. India.. 38 : 885-894,
P r a d h a n , M.J. 1969b, Fishery and biology of Psettodes erumei (Schneider) a n Indian Ocean flatfish, II Bull, nat Inst. Sci. India., 38 : 8 9 4 - 9 0 5 .
P r a d h a n . M . J . 1969 c. Fishery and biology of Psettodes erumei (Schneider) an Indian Ocean flatfish. III. Bull, nat Inst. Set India.. 38 : 906 - 926.
R a b i n d r a n a t h , P. 1966. Biology and seasonal distribution of the pelagic food fishes of Travencore coast. Kerala University Publication.
R a m a n a t h a n , N, and R. Natarajan, 1979, Flatfish eggs, larvae and their development.
Aquaculture, 18 : 349 -366,
Rao, K,V.N, 1967. The flatfishes. In: CMFRI Recreation Club, M a n d a p a m Camp, Souvenir, 2 0 t h Anniversary of Central Marine Fisheries Research In- s t i t u t e (Government of India).
S e h s a p p a , G, 1964, Length frequency s t u d i e s on t h e Malabar sole Cynoglossus semifasciatus Day, Indian J. Fish., ii (i) : 5 3 3 - 5 4 6 ,
S e s h a p p a , G, 1 9 7 3 . The flatfish r e s o u r c e s of t h e west c o a s t of India In: ICAR, New Delhi, Proc. Symp. Living resour. seas around India.
S e s h a p p a , G. 1976. On t h e fishery and biology of t o n g u e sole Cynoglossus dubius Day at C a h c u t , Kerala. Indian J. Fish.. 21 (2) : 3 4 5 - 4 5 6 .
S e s h a p p a , G. 1978, Report on a collection of tongue soles [Cynoglossus spp) from Moplah Bay with a description of C, lida (Bleeker), Indian J. Fish., 2 3 :
1 6 0 - 1 7 3 .
S e s h a p p a , G a n d B,S. B h i m a c h a r 1 9 5 1 . Age d e t e r m i n a t i o n s t u d i e s in fishes by m e a n s of scales with special reference to t h e Malabar sole Cynoglossus semifasciatus Day, Curr. Set. 20 : 2 6 0 - 2 6 2 .
S e s h a p p a , G. a n d B. S. B h i m a c h a r 1954. S t u d i e s on t h e age a n d growth of t h e Malabar sole, Cynoglossus semifasciatus Day. Indian J. Fish., 1 : 145 - 162.
S e s h a p p a , G, and B. S. B h i m a c h a r 1955. S t u d i e s on t h e fishery and biology of the Malabar Sole Cynoglossiis semifasciatus Day. Indian J. Fish., 2 (1) : 180 - 2 3 0 .
Flatfisheg, goatfishes and w h l t e f l s h e s S e s h a p p a , G and B.K. C h a k r a p a n l 1987, A c o m p a r i s o n of meristic c h a r a c t e r s of t h e
Malabar sole Cynoglossus semijasciatus Day from different c e n t r e s of the west coast of India. J. mar. biol. Ass. India, 26 : 1 2 3 - 1 3 1 .
S p a r r e . P. 1987. Computer p r o g r a m m e s for fish stock a s s e s s m e n t : l e n g t h - b a s e d fish a s s e s s m e n t for Apple II c o m p u t e r s . FAO Fish. Tech. Paper. 1 0 1 , S u p p l . 2 0 .
T h o m a s , P.A. 1969. The goatfishes (Family Mullidae) of the Indian Seas. Memmoir 3.
Marine Biological Association of India, M a n d a p a m C a m p .
Thompson, W.F. and F.H.Bell 1934. Biological s t a t i s t i c s of t h e Pacific h a l i b u t fish- ery, 2. Effects of c h a n g e s in fishing i n t e n s i t y u p o n total yield and yield per u n i t of gear. Rep. Int. Fish. (Pacific halibut) Comm.. 8.
Uchida, K., S. Imai, S. Mito, S. Fujiota, Y. Shojima, T. S e n t a , M. T a h u k u a n d Y. Dotu 1958. Studies on the eggs, larvae andjuveniles oj Japanese fishes, Ser.
I. Kynshu University, J a p a n .
