PRISCILLA CACES-BORJA and S.B. RASALAN
Philippine Fisheries Commission
The culturing of sugpo (Penaeus monodon Fabricius) in the Philippines has been carried out for a very long time in association with the culturing of bañgos (Chanos chanos). They were grown simultaneously in the same fishponds, with sugpo as a secondary product; it was never raised alone. With the exploitation of the sugpo fry fishery, the more lucrative business of pure sugpo culture has developed.
The sugpo fry are caught commercially along the shores of Manila Bay from the early part of May until the end of October or early November, but in other places the fry enter fishponds with the incoming high tide. Different methods of catching fry, the selection of a site for cultivation, the construction and preparation of a pond, and the raising and harvesting of sugpo are described.
In spite of problems encountered in the culturing of sugpo, a comparison of the production of a pure bañgos culture, a mixed bañgos and sugpo culture, and a pure sugpo culture, shows that the latter gives the highest net income.
RAPPORT SUR L'ELEVAGE DE Penaeus monodon FABRICIUS (“sugpo”) AUX PHILIPPINES
Aux Philippines, l'élevage de la crevette Penaeus monodon Fabricius (“sugpo”) s'est très longtemps pratiqué en association avec celui des poissons Chanos chanos (“bañgos”). Ces deux animaux étaient élevés simultanément dans les mêmes étangs. Les crevettes représentaient une production secondaire et n'avaient jamais été élevées seules. Avec le développement des captures du frai de “sugpo”, l'élevage plus lucratif des seules crevettes a pris de l'expansion.
Le frai des crevettes est pêché commercialement le long des côtes de la baie de Manille depuis le début de mai jusqu'à la fin d'octobre ou au début de novembre; ailleurs, il est apporté dans les étangs de pisciculture par la marée haute. Les auteurs donnent des indications sur différentes méthodes de récolte du frai, sur le choix des lieux d'élevage, sur la construction et la préparation des étangs, ainsi que sur l'élevage et la pêche des crevettes.
Malgré les problèmes que pose l'élevage des crevettes, une comparaison entre l'élevage pur des bañgos, l'élevage mixte bañgos-crevettes et l'élevage pur de crevettes montre que celui-ci assure les revenus les plus élevés.
EL CULTIVO DE SUGPO, Penaeus monodon FABRICIUS, EN LAS FILIPINAS
El cultivo del sugpo (Penaeus monodon Fabricius) en las Filipinas se viene realizando desde hace mucho tiempo junto con el cultivo de sabalote o bango (Chanos chanos). Ambos se criaron simultáneamente en los mismos estanques piscícolas, con el sugpo como producto secundario; no se ha efectuado nunca la cría de éste aisladamente. Con la explotación de la pesquería de crías de sugpo se ha desarrollado el negocio más lucrativo del cultivo puro de sugpo.
Las crías de sugpo se capturan comercialmente a lo largo de las costas de la bahía de Manila desde principios de mayo hasta finales de octubre o primeros de noviembre, pero en otros lugares aquéllas entran en los estanques piscícolas con la marea alta. Se describen diferentes métodos de captura de las crías, la selección de los lugares apropiados para el cultivo, la construcción y preparación de los estanques y la cría y recogida de sugpo.
A pesar de los problemas con que se ha tropezado para el cultivo de sugpo, una comparación de la producción del cultivo único de bango, del cultivo mixto de éste y sugpo, y del cultivo único de este último, indican que el sugpo proporciona los mayores ingresos netos.
The culturing of sugpo (Penaeus monodon Fabricius) in the Philippines is as old as the culturing of bañgos (Chanos chanos Forskal), but sugpo was grown as a secondary product and was never raised alone. In many places in the Philippines, as in Mindanao and parts of southern Luzon where ponds are established near the probable breeding places of prawns, the fry just enter the fishponds and are continuously harvested.
Since sugpo fry are readily recognizable from other fry, their collection and commercial exploitation was developed and led to the sugpo fry fishery. This is now a distinct and lucrative fishery in many places in the Philippines, especially in the coastal towns of Cavite and Batangas, where they are caught from May to October.
Villadolid and Villaluz (MS) described the cultivation of sugpo with bañgos and separately.
2.1 Appearance and size
The sugpo fry generally appear along the shores of Manila Bay in the early part of May and continue until the end of October, sometimes extending to the early part of November. They are easily distinguishable by the dark brown pigment running through their transparent bodies, thus making them appear like small pieces of broken stick or debris. They usually measure from 10.0 to 15.2 mm. Delmendo and Rabanal (1956) gave the length of fry as 15.3 mm, but the latest sugpo fry surveys in Ternate, Cavite, (Caces-Borja, MS) have revealed some as small as 8 mm, much smaller than previously reported.
2.2 Fishing grounds
The fry are caught in almost all places in the Philippines where bañgos fry are found. In the northern parts of Luzon, sugpo fry appear rather later than the bañgos fry. The practice in the region is to gather the sugpo fry only when there is a demand for it.
Sugpo fry can also be found in tidal rivers, creeks, lagoons, and other shallow places with brackish water where they are brought in by the incoming high tide. They have been found attached to masses of drifting seaweeds. They also cling to various aquatic plants, such as the water hyacinth and lily, and semiaquatic plants of the family Gramineae which grow in swampy places below the tideline. They are found particularly after storms, which usually occur in the months of June, July and August. The sugpo fry migrate to the shore and into brackish waters for feeding and shelter. They remain in these places for not less than 6 mo, after which they return to the sea to spawn.
The Maragondon River contains fry of various sizes, and some early adults of up to 80 mm are caught further up the river, showing that the fry metamorphose in the river (Caces-Borja, MS). This is the largest river emptying into Manila Bay and apparently attracts and accumulates fry in their fresh water migration after having been hatched in the deeper, more saline waters just outside the Bay. Fig. 1 shows the Maragondon River, with its mouth in Manila Bay divided by Balut Island. The peak of the fry season occurs during the months of September and October with the northeast monsoon.
All along the western coast of Luzon, sugpo fry are found during the bañgos fry season.
The most important sugpo fry grounds surveyed by the Agricultural Department of the Development Bank of the Philippines are listed below:
Dagatdagatan Lagoon, Malabon, Rizal Province
Dongalo River, San Dionisio, Parañaque, Rizal Province
Binuangan River between Tanza, Navotas, Rizal and Obando, Bulacan
Mabolo River and Nalamok in Bacoor Bay and in Salinas, Tanza, Cavite Province
Binangbang River and other tributaries along the shores of Balayan Bay and along the shores of Sta. Clara, Batangas, Batangas Province
Tributaries along the shores of Pagbilao Bay and Tayabas Bay, Quezon Province
Tributaries along the shores of Pitogo and Macalelon, Quezon Province
Cabilihan River extending from Guinayangan, Tagkawayan and Calauag, Quezon Province.
Fig. 1 Map of a portion of Manila Bay showing the Maragondon River where there is an abundance of sugpo fry.
2.3 Collection and marketing
Sugpo fry are caught in several ways. The use of fish lures, locally called “bonbon”, is an easy method. The “bon-bon” is made of bundles of twigs or grasses tied to a long line of rattan, wire, or string at intervals of about 1 to 2 m. The common species used for this purpose is a salt-water grass, Paspalum vaginatum. Several lines of these lures are set up in the water by tying the opposite ends to wooden poles near the bank of the river at intervals of 10 to 20 m. The fry collectors then visit their lures and place their dip net beneath each bundle of grass. They raise and shake each bundle to catch the clinging sugpo fry into the net. Some experienced collectors are able to gather as many as 10 fry from one bundle at a time. During the peak of the season, one could gather as many as 1,000 fry in 1 h. Collections are also done at night with the use of flashlights. This is the usual method employed in the provinces of Batangas, Cavite and Rizal (Fig. 2).
Another method is by dip net. The collector gathers the fry by dipping a triangular net into the water, while sitting in his wooden ‘banca’ or dugout. From the net the fry are transferred to an earthenware jar by scooping them up with a white porcelain bowl. The jar is provided with a few shredded banana leaves for the sugpo fry to cling to. Fry are collected at least twice a day, regardless of the tide or weather (Fig. 3).
Some collectors sort their fry during collection to remove unwanted species and store the sugpo fry in lots of 100 to 250 in earthenware pots. The fry are later distributed to fishpond owners. The old practice was to transport fry in the same pots in which they were stored, but now the use of plastic bags is very popular because of their handiness and light weight (Caces-Borja, MS). These bags are half-filled with sea water and closed with elastic bands at the mouth. Then they are packed into ‘buri’ bags for easier handling. When they have to be transported for longer distances, the bags are aerated by the use of a bicycle pump.
The fry are sold at P13 to P35 per thousand depending on their abundance.1 During the height of the fry season in Ternate, Cavite, the price is as low as P13 per thousand. In Batangas, the sugpo fry dealers maintain their price of P25 per thousand throughout the whole season. In Dasol, Agno and Bolinao, Pangasinan Province, sugpo fry sells from P20 to P30 per thousand, with the peak price in August and September. This is the only place in northern Luzon where the catching of sugpo fry is commercialized. In La Union, there is no pure sugpo fry business; they are caught along with the bañgos fry during the months of February to July, and sell for only P10 per thousand.
1 3.86 Philippine pesos (P) = 1 U.S. dollar (January 1967)
Fig. 2 The ‘bon-bon’ method of catching sugpo fry.
Fig. 3 The dip-net method of catching sugpo fry.
3.1 Selecting the site
Surveys made in 1965 on behalf of the Development Bank of the Philippines in cooperation with private fishpond operators have studied current fishpond practices in the cultivation of sugpo. The report notes the following important factors to be considered in the selection of a fishpond site:
Source of water
The availability of water supply is very important. There should be an available supply of fresh, brackish and salt water, depending upon the stage of growth of the shrimp. Fresh water has been found more favorable during the early stages of development, while brackish to saline waters are conducive to faster growth in the later stages.
Type of soil
Areas with sandy clay to clay loam are preferable for construction and for good growth of algal food, while sandy clay suits the creeping and burrowing habit of the sugpo.
The area should be within the reach of ordinary tides to be easily filled to a depth of at least 3 ft. Ponds with elevated bottom should be excavated so that they could be filled during the dry season when tides are low.
3.2 Constructing the pond
Delmendo and Rabanal (1956) described a model layout for a 10 ha Penaeus pond project as shown in Fig. 4. The whole area is enclosed by a main dike with a concrete main water control gate (mg), of double-opening type, placed at a point easily accessible to the main portion. This should open into a head pond (hp), which should be the deepest portion of the system.
The whole area may be partitioned into the head pond (hp), two nursery ponds (np), together occupying 1 ha, and two rearing ponds (rp) of 4.5 ha each. The rearing ponds open to the head pond by two secondary gates (sg).
The entire fishpond system should be so levelled that the bottom gradually slopes from the periphery to the head pond and to the main water control gate. A system of special depressions or canals is constructed in each nursery and rearing pond, running from the periphery towards the head pond, through the secondary gates, as indicated in Fig. 4. These canals facilitate harvesting.
3.3 Preparing the ponds
Villadolid and Villaluz (MS) described the preparation of a sugpo fry nursery pond, usually the smallest compartment in a brackish-water fishpond system. Each pond is built with wooden gates, 1.5 to 2 ft (0.5 to 0.7 m) wide, provided with wooden slabs for water control, and with fine-meshed bamboo screens covered with abaca cloth (sinamay) to prevent the entrance and exit of sugpo fry as well as predatory species. Current practices make use of nylon screens instead of sinamay for durability. After cleaning and levelling the bottom, the nursery ponds are dried for a period of 4 to 6 wk, depending on weather conditions. Then, tidal water is let into the pond to a height of from 3 to 10 cm to induce the growth of ‘lab-lab’ (microbenthos) which will serve as the food of the young fry. New tidal water is let in to maintain the original height of the water. In about a month the nursery pond is ready for stocking.
Fig. 4 Model layout for a 10 ha Penaeus pond project.
Delmendo and Rabanal (1956) stated that there was no standard method of raising sugpo in ponds. Shrimp cultivation is generally considered as a supplementary source of income and seldom are special ponds set apart for this purpose. However, the best results have been observed to stem from previously prepared nursery ponds for sugpo. The preparation of these nurseries for sugpo follows the same procedure as in Chanos culture, that is by cleaning, levelling, draining and drying the bottom. Then ‘lab-lab’ is grown on the pond bottom, and the pond is ready for stocking.
Current fishpond practices give great importance to the preparation of the ponds. According to technical information from the Development Bank of the Philippines, which gives loans for sugpo culture, things to be done are:
The fishpond should be cleared of unnecessary vegetation to assure maximum sunshine to enhance better growth of both the bluegreen algae (included in ‘lab-lab’) and the filamentous green algae (‘lumut’). Short branches and twigs of swamp trees should be installed on the pond bottom to provide shelter or refuge from enemies as well as a place for attachment.
Gates and dikes
The area should be provided with a strong concrete main gate, so that tidal water may frequently be allowed to flow in and out of the ponds to provide aeration, especially in the evenings. The area should be surrounded by a sturdy main dike capable of withstanding water pressure while maintaining 3 ft (0.9 m) of water within the ponds. Provisions for proper installation of bamboo screens (‘baklad pahasang’) should be made with nylon or sinamay nettings whenever necessary to prevent the possible escape of stock and the entrance of predatory species.
Levelling, liming and fertilizing the pond soil
The entire fishpond bottom should be levelled in such a way that it slopes gradually from the periphery toward the water control gate. The liming of the pond bottom at the rate of at least 10 bags of agricultural lime per ha is needed to obtain good results in sugpo culture. The lime serves to absorb excess carbon dioxide in the water, as well as to supply the necessary calcium needed by the shrimps, especially during their molting periods. Fertilization with inorganic commercial fertilizers may be practised but not with organic manures.
Eradication of predators
It is necessary to clear the ponds thoroughly of predatory species before stocking, because sugpo are prey to carnivorous fishes and other predators due to their clinging and sluggish habits. Methods have been described by Villadolid and Villaluz (MS) and Delmendo and Rabanal (1956).
3.4 Raising the sugpo
Two ways of culturing sugpo are employed: (i) the usual way of a mixed culture with bañgos, and (ii) the more recent way of pure culture, i.e. only sugpo fry are stocked in the ponds.
In a mixed culture, the sugpo fry are planteu in a pond that has already a stock of bañgos fry. This is to prevent predation on the bañgos fry. Stocking is done during the cooler part of the day in order to minimize the effect of a sudden change in temperature.
Pure culture is being practised by a few fishpond owners operating large areas of fishponds. In stocking the fry, care is taken to distribute them as evenly as possible over the pond. Sugpo fry, when newly stocked in a pond, do not wander about immediately in search of food. They remain where they are liberated and become easy prey to any predaceous species that might come upon them.
The stocking rate in the nursery pond is 300,000 to 500,000 fry to 1 ha in pure culture. In the rearing pond, the rate of stocking depends upon the availability of food. The fry are kept in the nurseries for a period of 1 to 1½ mo, after which they are transferred to the rearing ponds. A pond with good growth of ‘lab-lab’ and provided with supplementary feed of animal protein can be stocked with 2 sugpo per m2, or 20,000 per ha. However, the ordinary practice of fishpond owners is to stock the rearing ponds with 1 sugpo per m2, or 10,000 per ha.
The food of the sugpo consists of ‘lab-lab’, a biological association of minute plants and animals growing on the mud floor of fishponds. Rabanal (1952) made a comprehensive analysis of the components of ‘lab-lab’, identifying many types of fungi, bacteria, diatoms, algae and small animals.
In addition to the ‘lab-lab’, supplementary feeds are given. These consist of dead fish, dead animals and small crabs, which are ground into meal and piled in a corner of the pond. This serves partly as food and the unconsumed portion serves as fertilizer. Another method of supplementary feeding is to dip miscellaneous small fishes in boiling sea water, to soften the flesh, and place along the sides of the dike where the sugpo start feeding late in the afternoon or evening.
Rice bran is also used as a supplementary food for the sugpo fry. Filamentous algae are not allowed to grow in the nursery ponds, to prevent entanglement of the fry among the filaments. Instead, small bundles of dried twigs are placed to provide something for the fry to cling to during their early weeks of life. Sampling is also made easy by simply raising the twigs and collecting the attached fry. Villadolid and Villa luz (MS) stated that after the sugpo have attained a length of about 54 mm they lose their clinging instinct.
After a period of 1 to 2 mo, during which the sugpo fry have grown to a size that can be transplanted to the bigger rearing ponds, shrimp traps are set to catch the sugpo. These traps are made of bamboo screens of ‘baklad’ set in the pond bottom. There is a leader or guide screen, a forechamber, and a catching chamber or cod end. The shrimps seem to have no schooling habits and do not all enter the traps. Those left are picked out of the mud, after draining the pond slowly to allow the shrimps to go to the deeper areas. The young sugpo are now transferred to the bigger rearing ponds. In cases where the nurseries are adjacent to the rearing ponds, a portion of the dike that separates the ponds is opened and the sugpo are driven through the opening by disturbing the pond and scaring them. The rearing ponds are provided with ‘lumot’ or filamentous green algae which serve as the food for the bañgos and the sugpo.
Studies being undertaken by the Philippine Fisheries Commission on the food of the sugpo have shown a better growth and higher survival rate among sugpo fed with fish flesh in different forms, i.e. raw, blanched or powdered. Although the data gathered in these feeding experiments have not been thoroughly analyzed, a cursory inspection of the results showed a greater size increase in those with animal protein in their diet than those fed only with the natural food in the fishpond.
The sugpo under cultivation attain marketable size in a period ranging from 5 mo to 1 yr.
A study on the rate of growth of sugpo in ponds was undertaken at the Dagatdagatan Salt-Water Fishery Experimental Station, Malabon-Navotas, Rizal, covering the periods from September 1943 to April 1944 and September 1950 to August 1952 (Delmendo and Rabanal, 1956). It showed that the sugpo which had been raised in ponds for 1 yr measured on the average 229.8 mm in total length and 32.0 mm in body depth and weighed 95.1 g. The largest specimens of this age may, however, be as long as 250 mm and weigh about 120 g, while others may be as small as 180 mm long with a weight of 50 g. A kg of 1 yr old sugpo may contain 8 to 20 individuals. Table I shows the average rate of growth of Penaeus monodon under cultivation.
Average rate of growth of Penaeus monodon under cultivation
|Duration of Culture||Total length (mm)||Body depth (mm)||Weight (g)|
Harvesting the marketable sugpo from the rearing ponds is a difficult job because of their burrowing habit and non-gregarious instinct. Some loss is suffered in this operation because of their habits, although different methods of capture are employed to minimize this loss.
Delmendo and Rabanal (1956) described three different types of bamboo screen traps, namely the ‘bakikong’, the ‘paabang’ and the ‘aguila’.
The ‘bakikong’ has a leader consisting of 1 or 2 bamboo screens staked and oriented perpendicularly or diagonally from the pond dike which leads the shrimp to a forechamber from which the shrimps are led into the cod end or catching chamber. A light is installed in the catching chamber at night to attract more catch. This type is especially effective during dark nights, particularly if there is water movement caused by renewal or draining.
The ‘paabang’ consists of the catching chamber, which is centrally located, and 2 wings to screen the water passage. This is set to intercept the shrimp at some narrow gap in the fishpond system. This type is especially designed for dark nights and when strong currents of water can be made to flow through the passage where they are set.
The ‘aguila’ is a modification of the ‘bakikong’ consisting of a leader, comparatively longer than that of the ‘bakikong’ and 2 chambers strategically located at both sides at the end of the leader. This is set in the deepest portion of the pond and the catch is more or less continuous regardless of the time of day or night or whether or not the flow is regulated.
Besides the bamboo screen traps, net traps are also used. A bag net of coarse cotton twine, mounted on a wooden frame, fitting into special grooves in the gate, has come into general use in the cropping of shrimps in ponds. This net is called the ‘lumpot’. It is a sort of bag net tapering to an open end which is closed by tying with a piece of string. It is usually set at the main control gate, the water being previously raised to the maximum height at high tide. Thereafter, at sundown the water is allowed to go out with great force. The shrimps are carried by the current the end of the bag where they are collected from time to time by a man stationed on a dugout canoe.
4.1 Lack of fry
The most important problem facing the sugpo industry is the apparent lack of fry for stocking. The known sources of sugpo fry are good only for certain months of the year and are not enough to meet the demands of fishpond operators. This is the main reason why many operators will not venture into the pure culture of sugpo.
A preliminary survey of the sugpo fry resources in the country shows a seasonal abundance of fry in certain areas. However, the fishery is not always exploited for several reasons:
There is no market; these places are often out of reach of operators and are not generally known
The people in the community lack the technical skill for gathering or collecting fry
The people in the community are engaged in other occupations like rice-farming
Sugpo fry cannot be recognized from other kinds of shrimp
4.2 Low rate of survival
A second problem is the low rate of survival of the sugpo. On average, the rate of survival, based on the amount of marketable sugpo recovered from fishponds, is 20 percent. This could be due to the food, presence of predators, natural mortality or the non-recovery of some due to their burrowing habits. Some fishpond operators, however, have recovered as much as 60 percent from rearing ponds stocked at 10,000 fry per ha. These operators have given supplementary feeds to their stock.
4.3 Difficulty of cropping
A third problem is the difficulty of cropping. During cultivation, the sugpo are cropped twice, i.e. at the time of transfer from nursery to rearing ponds and at harvest time for the market. The methods employed are not yet good enough to effect a total catch because of the burrowing and non-gregarious habits of the sugpo. These have still to be improved.
Observations made by technical men of the Development Bank of the Philippines, Agricultural Department, on actual practices in the cultivation of sugpo, show that 1 ha of nursery pond with sufficient food supply can accommodate as much as 500,000 sugpo fry. In the rearing pond, the rate of stocking should be 1 sugpo for every m2 or at least 10,000 sugpo per ha in the case of pure culture of sugpo, and 1 sugpo for every 2 m2 in the case of a mixed culture of bangos and sugpo.
Assuming 50 percent survival from the time of cultivation in the rearing pond to the time they are harvested, 1 ha of fishpond (in the case of pure culture of sugpo) can yield about 5,000 marketable sugpo, equivalent to 250 kg (20 to 1 kg) valued at P1,250 based on the wholesale price of P5.00 per kg.
In a mixed culture of bañgos and sugpo, 1 ha of pond will yield about 1,000 marketable sugpo (based on 20 percent survival) equivalent to 100 kg valued at P500.00 (based on P5.00 per kg).
Comparative production from 1 ha fishpond using the three types of cultivation (i) bañgos alone, (ii) bañgos + sugpo, (iii) sugpo alone Average cost per kg of bañgos is P1.80 whereas 1 kg of sugpo costs P5.00
|Types of culture||Intensity of stock||Cost of stock|
Table II shows the comparative production yield from 1 ha of fishpond with respect to the three types of cultivation, namely: (i) pure culture of bañgos, (ii) mixed culture of sugpo and bañgos, and (iii) pure culture of sugpo.
With the cost of 1 sugpo ranging from P0.02 (fry stage) to P0.05 (juvenile stage), marketable-sized sugpo cost from P3.50 to P6.50 per kg, depending on their quality and size. The market value is highest during the Holy Week and Christmas seasons, when 1 kg costs from P7.50 to P9.00. A pure culture of sugpo would certainly give a bigger annual income than either a mixed culture of bañgos and sugpo or a pure culture of bañgos alone.
Caces-Borja, P., (d.u.) Preliminary observations on the sugpo fry resources of Manila Bay and its approaches. (MS)
Delmendo, M.N. and H.R. Rabanal, 1956 Cultivation of ‘sugpo’ (jumbo tiger shrimp), Penaeus monodon Fabricius in the Philippines. Proc.Indo-Pacif.Fish.Coun., 6(2–3):424–31
Mane, A.M., D.K. Villaluz and H.R. Rabanal, 1952 Cultivation of fish in brackish and estuarine waters in the Philippines. In Philippine Fisheries Handbook, prepared by the Technical Staff of the Bureau of Fisheries, Manila,pp. 132-41
Rabanal, H.R., 1952 Methods and problems of collecting eggs and fry for transplantation. Proc.Indo-Pacif.Fish.Coun., 3(2–3):196–201
Villadolid, D.V. and D.K. Villaluz, 1950 The cultivation of sugpo, Penaeus monodon Fabricius in the Philippines (Paper presented before the end meeting of IPFC at Cronulla, MS)
Villaluz, D.K., 1965 General information on shrimp (sugpo) cultivation in the Philippines. 12 p. (mimeo)