A knowledge of the breeding and swarming habits and periods of marine, estuarine, and fresh water fishes must form the basis of intelligent action in regard to fish preservation and culture, and it is from this point of view that the following notes are offered.
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The lula ( Ophiocephalus striatus ) is the most important fresh water food fish of Ceylon, both as regards quality and quantity. It is also known by its Hindustani name «murral,» according to Mr. H. S. Thomas's latest spelling of the word, and by its Tamil name «viral». The Hindustani name is the one most currently employed outside Ceylon.
It is what Dr. Day calls a compound breather, being more essentially an air-breathing fish. The Ophiocephali « never obtain oxygen for any length of time from the air in solution in the surrounding water, but inspire it direct from the atmosphere, no matter how cool and charged with air the water may be »; and they « expire in a longer or shorter interval if unable to reach the atmospheric air. ». They are thus independent of the state of the water in which they are living, and « in carrying live specimens from the plains to the Xilgiri hills, this was most successfully accomplished in water largely mixed with mud ». 1
The adult lula feeds upon smaller fishes and frogs. In Ceylon it is known to be particularly partial to a near relative, the «pandaral kanaya» ( Ophiocephalus gachua ), whose recognition marks are the barred yellow and black pectoral fins and the tubular nostrils; it also likes «issu» (fresh water prawns) and «dandiya» (the Ceylon minnow, Rasbora daniconius ).
Mr. H. S. Thomas (Rod in India, 3rd edit., 1897, p. 234) says that « murral are the easiest of all Indian fish to introduce » ; they will « thrive in ponds and at various altitudes, so you can easily stock a pond if you desire, but they will speedily depopulate it of other sorts of fish.* The natives frequently put them into their wells, from which they can take them fresh as they want them. » This last practice does not seem to be common in Ceylon, but is occasionally met with, as in the resthouse well at Alut-oya in the Tamankaduwa district, North-Central Province. They are kept here, however, merely for show, being fed artificially once or twice a week with small fish.
Dr. Theodore Gill notes that the Ophiocephalids are in prime condition when perfectly fresh and throbbing. It would appear that they cannot be salted or dried successfully, and therefore that, however plentiful they may be, they cannot compete with the customary dried fish in curry.
The habit of brood-nursing or parental care of the eggs and young has been often described, as, for example, by Day , Thomas , and others, and more recently, from a comparative standpoint, by Gill. 2 In Mysore it was observed by Colonel Puckle ( quoted by Day ) that O. striatus that breeds twice a year , in June and December, the males constructing their nests amongst the vegetation at the edges of the tanks. In South Canara it is said to breed in December and January.
Although I have not yet had an opportunity of witnessing the nidification and brood-nursing of the lula, I have on two occasions secured samples of the fry. Part of a swarm was taken from the Galelawala, Barawe, near Hanwella, in the late afternoon on February 19, 1908. The total length (from snout to tip of caudal fin) varied from 32 to 37 mm. 3 The ground colour, especially at the sides of the body, was pellucid red, and the upper half of the eyes was bright red. The general shape was that of a tadpole, and there is reason to think that this is a fundamental form.
They were poured into a bath, where they were kept over night, restored to the chatty next day, and brought to Colombo (18 miles) by bullock coach arriving at 1 P.M. All except one or two were alive on arrival; many dead kuni small fresh water shrimp-like crustacea belonging to the genus Caridina , were in the chatty with them, which they were not eating. These kuni thrive equally well in running water, as low-country rivers and mountain streams, where they retreat under stones, &c., and in still water, as tanks and ponds, where they flourish among the vegetation near the edge. In some places they occur in such quantity as to make it worth while to dry them for use in curry. Their presence in water is a good sign, and they constitute an important source of fish food. Those which had been put into the chatty with the lula fry were perhaps too large. I was unable to keep a running supply of live kuni and did not succeed in finding out definitely the best food for the young fishes, but I kept some of them alive in an aquarium for more than 5 months, during which time I put in various nutrient substances, water plants, chironomus larvae (i.e., lake-fly larvae), roast gram, rice, chopped hard-boiled egg-yolk, &c., the principal pabulum being gram and yolk.
These substances promoted a luxuriant multiplication of microorganisms, more especially ciliate infusoria of the genera Stentor , Paramoecium , Blepharisma , (with hook-shaped rostrum), and Spirostomum , 4 . The water became absolutely milky with Spirostomum , , a protozoan animalcule, which is easily visible to the unaided eye, and is in fact the longest of the Ciliata. Gram which had been placed over night in the aquarium sometimes appeared like large flakes of snow in the morning, owing to the enormous aggregation of Spirostonia about the grains. I cannot say whether the young lula fed upon the protozoa, but those which survived were vigorous to the end. They were actually seen to nibble at the particles of yolk, but the truth is that to this day I do not know precisely what is the best vehicle of nutrition for lula fry when kept in close confinement under artificial conditions not even approximating to nature. The experiment, however, is useful in so far as it demonstrates their great viability.
The water supplied to the tank was well-water, and it was kept at a depth of 17 1/2 to 3 inches. At the outset a great many died owing to the too abrupt change. After the initial mortality more deaths occurred from time to time for which I was unable to account, except on the supposition that they were starving. On March 25, however, more than a month since the beginning of the experiment, I noticed one floundering helplessly amongst the floating weeds on the surface. It presented a meagre, starved appearance, but on opening it a prominent white fat-like mass was found in the body cavity partially concealing the viscera. This turned out to consist of two soft writhing Cestode worms (possibly Schistocephalus larvae). Exploring farther forwards in the body cavity, I found another worm of the same kind encysted; this also writhed inside its envelope. Other fry, which had died previously and had been preserved, were then examined and found to be similarly infected.
The body of the parasitic worm is shortly segmented, and the elongate head or scolex has a groove along each side and a terminal exserted sucker or rostellum. The integument contains numerous scattered oval calcareous copuseles. Larval cestodes which are found in young fishes usually achieve maturity in the intestine of fish-eating birds.
On April 19 a vigorous young lula was caught and measured. It had distinctly grown both in bulk and in length. The eyes reflected a delicate red flush from the lens; iris pale golden; a slight reddish tinge was still apparent along the sides of the caudal region; the definite markings had commenced to appear as about nine short black vertical demi-stripes on either side of the dorsal fin. It was very strong, active, and erect, not easily put on one side. The total length was 41.5 mm.; body length (excluding the tail fin) 34.5 mm. At this time the aquarium contained, besides the protozoa named above, some Rotifers and some Naiid worms.
Two dead lula removed from the aquarium on May 21 and 22 measured 43 and 40 mm. respectively. Another in full vigour, with the definitive body-markings well indicated, was taken from the aquarium on June 1; it measured no more than 39 mm. in total length; body length (excluding tail fin) 32 mm.; diameter across the branchial region 6.5 mm., across the projecting eyes 7 mm. At first I missed the red flush of the eyes which is so characteristic of young lula, particularly after they have attained a length of 4 or 5 inches, but upon placing the specimen in dilute alcohol the red colour developed. On July 8 seven of the healthy young fishes were caught, measured, and returned to the tank; their total lengths (including the tail fin) were 42.5, 44, 44.5, 45, 46, 47, and 48 mm.
Another sample of lula fry of the same age, or rather younger than those taken in February, was brought from Hanwella on May 22. They measured 30 to 31 mm. in length, and showed the same subtranslucent reddish or golden red colour throughout when seen from above. The sides of the body were of a pure roseate hue, the uppermost dorsal region being darkened in varying degree according to circumstances by the presence of scattered chromatophores capable of expansion and contraction, producing a more or less smoky appearance.
The occurrence of this second brood indicates an extended period of spawning during the first few months of the year, both before and after the rains. The first brood was taken towards the end of a period of drought, the second after heavy floods.
The predaceous habits of the adult lula, which seem to debar it from association with other fishes in stock ponds, do not apply in the same degree to the fry, nor to the adolescent stages up to a minimum length of 6 inches, and it would be possible, sooner or later, to establish reserves for rearing the young in places where the supply shows signs of diminution.
The laboratory experiment described above shows that the transition from a late postlarval stage (without any trace of the definitive body-markings) to an early adolescent stage takes place slowly, and that during this transition period they are exposed not only to the rapacity of avowed enemies, but also to the more insidious attacks of internal parasites.
Madaya or mada-karaya ( Ophiocephalus ) is a near relative of the lula, from which it differs in colour, scale-rows, fin-rays, and in habits. A young lula compared with a madaya of approximately the same length (5-6 inches) had 46 dorsal fin-rays, as against 31 in the latter; the lateral line dipped down two rows of scales below the twelfth dorsal ray in the lula, whereas it dipp?d to the next row only in madaya; anal fin of lula with 28 rays, of madaya 22; about 57 scales along the lateral line in lula, about 40 in madaya; ventral fins of lula below the pectorals, in madaya nearly reaching the vent.
The madaya is a mud-burrowing fish, extensively eaten, and also used as live bait for «moda» ( Lates calcariler ) and other large river fish, which are caught with a special bamboo rod supported over crossed sticks from the bank after sundown, for example, in the Kalu-ganga at Tebuwana.
On April 15, 1908, during rainy weather with intervals of sunshine, I observed a couple of mada-karaya in a clear shallow «wala» in the paddy fields at Bellana on the Matugama-Badureliya road in Pasdun Korale East. They were guarding a small brood of very young fry, a sample of which I secured with the assistance of Mr. John Dassenaike of Bellana, who accompanied me. One of the elders, rather smaller than the other (estimated about 6 inches long) and more brightly spotted, was probably the male. They were frightened away at our approach, but returned to the brood, which was advancing slowly in unison.
The young fry were all of one age, and measured only 6 millimetres in total length. They present (after preservation) three longitudinal white bands, namely, one median dorsal band with two spindle-shaped enlargements in front (see figure) and a pair of broad lateral bands commencing from the eyes.
They were moving about freely exposed in very shallow water under bright sunlight, in contrast with the usual habits of the adults, which are intensely cryptozoic. My sample consisted of upwards of 130 individuals, perhaps about one-tenth of the entire brood.
Some much older madaya fry were brought from Hanwella on May 22 in company with the second lot of lula mentioned above, and some very young kavaiya ( Anabas scandens , the climbing perch). They evidently did not belong to one brood, since they varied in length from 21 to 39 mm. One of about 32 mm., which may be selected for description, showed only a faint indication of a median dorsal golden line in front of the dorsal fin; this, however, is more distinct at a younger stage (21-26 mm.), where both the lateral and dorsal bands have a brilliant greenish golden tinge. A bright golden band commences from the snout, passes through the upper part of the eye and above the pectoral fin to the tail fin. The rest of the back is dark, the ground colour being resolved into about five close-set dark stripes on each side between the dorsal fin and the lateral golden band, and three or four similar stripes below the latter. The ventral surface in front of the anal fin is whitish, as it is also in lula fry. At the age represented by a length of 36-39 mm. the dorsal band has gone and the lateral bands have faded, merging into the ground colour and losing the golden sheen. The general arrangement of pigment in longitudinal stripes shows up very clearly after preservation. The madaya fry seemed to be rather less hardy than the lula fry.
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1 Day, F. Report on the Freshwater Fish and Fisheries of India and Burma . Calcutta, 1873, p. 25. Back
2 Gill, Th. Parental care among Fresh Water Fishes. Ann. Rep. (1905), Smithsonian Inst., Washington, 1906, p. 492. Back
3 About 1,25 to 1,5 inch. Back
4 On April 11 a pair of Stentor was seen in conjugation. On April 19 Paramoecium was noted as conjugating, Blepharisma dividing. Back
This article was published under the above title in: Spolia Zeylanica . V, pt. 19, 1908, pp 144-152.
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