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-- C u l t u r e s ( b i o l o g y ) --
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| Q 1. | ||
| Is it possible to increase the yield of animals in the sea by applying chemical fertilizers as it is done on farms? |
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| Q 2. | ||
| Is there any research currently in progress that would indicate that commercial "farming" of either the northern lobster, blue crab, stone crab or king crab could be feasible? I realize the time factor for growth could not bean economic factor and that the raiser would have to wait until the "herd" was in all stages, from spat to full-grown. |
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| Q 3. | ||
| Would tarpon fingerlings imported into our larger lakes and rivers feed on the Tilapia which we have released as prey for larger food fish? Only a slight degree of salinity is present in our lakes, but I understand that tarpon will adapt themselves to fresh, salt or semi-fresh water. Our local native people require these fish as a food source of protein. |
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| Q 4. | ||
| It appears to me that the east coast fisheries are missing the boat on a fabulous food item! Has any attempt ever been made to transfer the Pacific Ocean abalone to the Atlantic Ocean? |
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| Q 5. | ||
| The Tilapia has been introduced into many less-developed areas as a cheap source of protein-rich human food, and evidently cultivation has been successful. I would like information on the feasibility of Tilapia cultivation in the United States. |
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| Q 6. | ||
| There are several semi-enclosed saltwater bays and ponds in my area in which I would like to attempt commercial fish farming. Do you think this is feasible? |
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| Q 7. | ||
| How is artificial fertilization of eggs accomplished with fishes? |
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| Q 8. | ||
| What is the status of the bluefin tuna ranching project discussed in the May-June 1977 issue of Sea Frontiers? Also, has anyone succeeded in rearing the bluefin from egg? |
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| Q 9. | ||
| Has aquaculture been considered in restoring the depleted New England stocks of Atlantic salmon? |
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| Q 10. | ||
| I have read about the success that Soviet scientists have had in rearing hybrid and natural species of sturgeon in the Caspian Sea. Is sturgeon culture being carried out in the United States? |
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| Q 11. | ||
| I want to try to raise larval marine fishes in my aquarium. Where can I obtain information on how to grow rotifers to feed newly hatched fishes? |
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| Q 12. | ||
| Is it true that Coca Cola Company in involved in marine shrimp culture? Also, what other United States firms are undertaking this type of venture? |
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| Q 13. | ||
| I have heard that blue-green algae might increase the yield of fish from Philippine milkfish ponds. Do these algae really have potential in mariculture? |
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| Q 14. | ||
| Since dolphins can be reared in captivity, would it be profitable to farm them in order to supply the needs of oceanariums for these mammals, instead of taking them from the wild? |
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| Q 15. | ||
| Are there sponge farms in operation at this time? |
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| Q 16. | ||
| Are groupers, snappers, or jacks being commercially cultured as food fishes in the United States? |
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| Q 17. | ||
| Can the common Florida spiny lobster be farmed commercially? |
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| Q 18. | ||
| During my visit to Miami, Florida in December 1988, I purchased a packet of fresh fish labeled "Saint Peter's fillet." The butcher said the fish was imported from Costa Rica, where it was the product of aquaculture. A neighbor claimed that the fish was imported from the Sea of Galilee. When cooked, the fish tasted like snook. Can you tell me what fish is marketed under this appellation? |
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| Q&A 1. | Is it possible to increase the yield of animals in these a by applying chemical fertilizers as it is done on farms? New Orleans, Louisiana |
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| In different parts of the world this technique has been used both experimentally and on a commercial scale in an attempt to increase the fish yield in the sea. Under natural conditions, the sea can only support a limited population of marine animals. The food chain in the sea is very complex, small animals feeding on small plants, larger animals feeding on the small animals and in turn being fed upon by the fish. Theoretically if the abundance of any link in the chain could be increased, the fish would also increase in quantity. In most marine situations, it does not appear to be feasible to introduce a sufficient number of living organisms to have a significant effect on the food chain. The method which has been used is that of applying chemicals or organic waste to the water to increase the abundance of the lowest living link in the food chain, the tiny plants. If this were done in the open sea an enormous wastage would occur since the ocean currents would disperse the fertilizer and perhaps also the organisms feeding on it. Thus it seems that this experiment could only be successful if conducted in an enclosed area of water. Some water exchange may be necessary to maintain the oxygen supply. An experiment of this type was carried out in an inlet on the west coast of Scotland. This technique has also been used in pond culture work in Japan and elsewhere. While an increase in the yield of fish flesh can be obtained using such methods, the gain is not usually in proportion to the amount of fertilizer applied. Some of the fertilizer may be wasted if it sinks to the bottom and became unavailable to living organisms. Some of the fertilizer will be taken up by organisms which do not enter into the food chain of the fish whose yield the experiment is intended to increase. Such organisms may prey upon the organisms in the food chain or on the fish themselves. Hence it is possible, under special circumstances to increase the yield of marine animals, but "sea farming" will pay only rarely, if at all. |
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| Q&A 2. | Is there any research currently in progress that would indicate that commercial "farming" of either the northern lobster, blue crab, stone crab or king crab could be feasible? I realize the time factor for growth could not be an economic factor and that the raiser would have to wait until the "herd" was in all stages, from spat to full-grown. New York City, New York |
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| You may be reasonably sure that it is not feasible to farm lobsters or crabs. Time is not the only deterrent; rather, it is the complicated life history of these crustaceans and the very heavy mortality of the young stages. In the case of some of the species it has not even been possible to raise the animals from the egg to adulthood under laboratory conditions, let alone commercially. |
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| Q&A 3. | Would tarpon fingerlings imported into our larger lakes and rivers feed on the Tilapia which we have released as prey for larger food fish? Only a slight degree of salinity is present in our lakes, but I understand that tarpon will adapt themselves to fresh, salt or semi-freshwater. Our local native people require these fish as a food source of protein. British Solomon Islands Protectorate |
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| The importation of tarpon into your lakes and rivers as a predator on Tilapia probably would not solve your food problem. Tarpon is generally considered to be a very poor-tasting fish and is eaten by few people. If you would like to conduct experiments on the suitability of a fish of this nature it would be wiser to consider the ox-eye herring, Megalops cyprinoides. This closely related species would doubtlessly by easier and less expensive for you to obtain, for it is distributed throughout the southwest Pacific and Indian oceans. |
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| Q&A 4. | It appears to me that the east coast fisheries are missing the boat on a fabulous food item! Has any attempt ever been made to transfer the Pacific Ocean abalone to the Atlantic Ocean? Philadelphia, Pennsylvania |
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| The west coast abalones are cold-water animals living in ecological conditions which are not found on the east coast of the United States, except in very small areas in the New England States. The large edible abalones are not abundant animals and stringent laws are necessary on the Pacific coast to maintain them at even a low level. It would probably take years, even if conditions were proven suitable, for abalones to establish themselves in any quantity in New England. It is a general rule that it is not advisable to introduce foreign species into an area without a careful ecological study since, in unforeseeable ways, this may so upset the natural balances in marine life in the area, that very serious consequences may result. |
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| Q&A 5. | The Tilapia has been introduced into many less-developed areas as a cheap source of protein-rich human food, and evidently cultivation has been successful. I would like information on the feasibility of Tilapia cultivation in the United States. Playa del Rey, California |
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| It would, of course, be possible to raise Tilapia in the United States, but the desirability or financial practicality of this is questionable. There are many native fishes (mostly various species of sunfish)which are better suited to our situation. In Hawaii, experiments have been conducted in the raising of Tilapia for live bait for tuna fishing, but this is a different matter. |
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| Q&A 6. | There are several semi-enclosed saltwater bays and ponds in my area in which I would like to attempt commercial fish farming. Do you think this is feasible? Nassau, Bahamas |
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| Although fish farming of some freshwater species, such as trout, is commercially successful, it is doubtful whether a comparable venture could be set up in the Bahamas to farm marine fishes. Few commercially valuable marine species feed directly on phytoplankton, so that several steps between the primary producer and the final product level are required. By-passing these many steps means feeding the product species dry animal-protein pellets, which are expensive. Coupled with the costs of labor, capital, research, and maintenance, it would be difficult for any such venture to be profitable. |
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| Q&A 7. | How is artificial fertilization of eggs accomplished with fishes? Augusta, Georgia |
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| In those fish species in which artificial fertilization has been successful, the process sometimes requires injections of various compounds, chiefly mammalian hormones and salmon pituitary extract, into the fish to induce ripening of sperm and eggs. The amount and kinds of materials injected depends on the size and species of fish used. When the eggs are ready to be fertilized, they are stripped from the female fish by pressure applied to the abdomen and are then placed in a small bowl. Sperm is similarly stripped from the males and the two are mixed together to effect fertilization. If done correctly, a large percentage of the eggs are usually fertilized. These are aerated and incubated until they hatch. |
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| Q&A 8. | What is the status of the bluefin tuna ranching project discussed in the May-June 1977 issue of Sea Frontiers? Also, has anyone succeeded in rearing the bluefin from egg? Kokomo, Indiana |
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| Fewer bluefin tuna (Thunnus thynnus) were ranched in the pens of Janel Fisheries Ltd. (Nova Scotia) in the 1979 season than in previous years. The project relies on the fact that Atlantic bluefins move inshore in early summer to feed on forage fishes. There they are captured by northeast fishermen, who sell them to Janel Fisheries for fattening in holding pens and subsequent sale to the Japanese market. By fall 1979, however, only 58 T. thynnus had been taken for impoundment, possibly due to lowered stocks of this species or a reduced availability of forage fishes in the area. Researchers at Kinki University Fishery Experimental Laboratory, Wakayama, Japan have succeeded in hatching T. thynnus from ripe eggs obtained from bluefins captured and reared in holding pens. The eggs were hatched in tanks with water temperatures of 71.6 degrees to 75.2 degrees Fahrenheit, and the larvae grew 4 millimeters in the first four days. The Japanese are now attempting to develop methods to rear this species to post larval stages. |
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| Q&A 9. | Has aquaculture been considered in restoring the depleted New England stocks of Atlantic salmon? Lewiston, Maine |
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| Yes. Young Atlantic salmon are being flown from New England to the National Oceanic and Atmospheric Administration's (NOAA)aquaculture experiment station at Manchester, Washington. There, they are raised in saltwater pens in Puget Sound where moderate year-round seawater temperatures of 42 degrees to 60 degrees Fahrenheit induce rapid growth. When mature, the fish are spawned, and their eggs are shipped to Fish and Wildlife Service (FWS) hatcheries in New England. There, the fish are hatched, reared, and released into streams entering the Atlantic. During the next 10 years, NOAA and FWS anticipate shipping up to 5 million such eggs annually to the Northeast from Washington State and, hopefully, self-sustaining salmon runs will be reestablished in New England. |
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| Q&A 10. | I have read about the success that Soviet scientists have had in rearing hybrid and natural species of sturgeon in the Caspian Sea. Is sturgeon culture being carried out in the United States? Carson City, Nevada |
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| A hatchery for white sturgeon (Acipenser tranmontanus)and green sturgeon (A. medirostris) has been established at the University of California's laboratory at Davis. Mature male and female specimens are caught in the wild and carefully transported to the hatchery. There, sperm and egg development is stimulated by injections of pituitary hormones extracted from sturgeon and other fishes. A few days later, the eggs are removed from the female through a small incision in the abdomen and mixed with sperm milked from the male. The incision in the female is stitched, and the fish can be released or reconditioned for reuse. After fertilization , the eggs are washer by hand to remove their sticky coating and are incubated. After about six days, the larvae hatch and are placed in large rearing tanks. When their yolk reserves are depleted, they accept live brine shrimp. At a length of 2 to 3 inches, the fingerlings are released in the wild in an attempt to reestablish sturgeon populations in areas where they have declined to low levels. Culture of sturgeon has also been initiated at the Orangeburg National Fish Hatchery in South Carolina - in this case with the Atlantic sturgeon (A. oxyrhynchus). The toothless, prehistoric-looking sturgeon is highly valued for its flesh and eggs. In addition, its swim bladder is the source of isinglass, a pure translucent gelatin used in making glue and as a clarifying agent for white wines. Further information about this most interesting fish is given in "The Diminishing Sturgeon," Sea Frontiers, vol. 7, no. 2, May 1961 and "Elegy in the Caspian Sea, " Sea Frontiers, vol. 12, no. 6,November-December 1966. |
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| Q&A 11. | I want to try to raise larval marine fishes in my aquarium. Where can I obtain information on how to grow rotifers to feed newly hatched fishes? Bangor, Maine |
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| Although among the smallest multi-celled animals, rotifers have played a major role in the successful rearing of larval marine fishes. They fill the gap in sources of food between the time the fish larvae start to eat and when they are large enough to eat brine shrimp nauplii. Marine rotifers are available at aquarium stores under the name Ocean Plankton. Instructions for their culture have appeared in "The Mighty Rotifer, "Freshwater and Marine Aquarium, August 1978 and "Grow Some Rotifers, "Marine Aquarist, vol. 8, no. 4, 1977. Rotifer culture is the subject of a cooperative project currently being carried out by Dr. Terry Snell of the University of Tampa, Florida and Dr. Esther Lubzens of the Institute of Oceanographic Research in Haifa, Israel. |
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| Q&A 12. | Is it true that Coca Cola Company in involved in marine shrimp culture? Also, what other United Stated firms are undertaking this type of venture? Del Rio, Texas |
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| The Coca Cola Company and F.H. Prince Company are planning to build a joint $10 million, 100-acre commercial shrimp farm on the north shore of Oahu, Hawaii. The new facility will be the same type as the prototype the two companies operated at Puerto Penasco, Mexico, with expertise provided by scientists of the University of Arizona and University of Sonora. The prototype farm has proved most successful for rearing the marine shrimp Penaeus stylirostris. The facility consists of several structures including the hatchery for the egg stage, the nursery for developing post larvae, and a number of 200-foot-long tanks called raceways, or troughs, in which the post larval shrimp grow to maturity. The raceways are located inside are-pressurized plastic "greenhouses" (aquacells) and are thereby protected from windblown sand and bird predators. The Puerto Penasco facility is currently operated by the University of Sonora. Among other United States firms involved in mariculture and research on various species of Penaeus are Marifarms at Panama City, Florida; Ralston Purina, with production facilities in Panama and research activities at Crystal River, Florida; Aquabiotics, Inc. at Park Forest South, Illinois; Commercial Shrimp Culture International, Port Isabel, Texas; Intensive Culture Systems, Summerland Key, Florida; Solar Aquafarms, Encinatats, California. The basic research of many organizations has stimulated these commercial ventures. This includes current research at the National Marine Fisheries Center (Galveston, Texas), Texas A&M University, and the Oceanic Institute (Hawaii), as well as the earlier work of the Japanese and of the University of Miami (see "Shrimp Farming," Sea Frontiers, vol.20, no. 2, March-April 1974). |
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| Q&A 13. | I have heard that blue-green algae might increase the yield of fish from Philippine milkfish ponds. Do these algae really have potential in mariculture? Stockton, California |
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| Blue-green algae, which are considered by some not to be true algae but instead more closely related to bacteria, are considered promising candidates for the future mariculture operations. According to Dr. Adira Mitsui of the University of Miami Rosentiel School of Marine and Atmospheric Science, this is due to their fast growth rate, their lack of a cell wall which makes them easy to digest, and their nutritional qualities-some of them are 60 percent protein and contain almost all essential amino acids. Furthermore, some species of blue-green algae have the ability to utilize or fix atmospheric nitrogen, eliminating the need for costly nitrogenous fertilizers. This nitrogen-fixing capability allows the need for costly nitrogenous fertilizers. This nitrogen-fixing capability allows them to outcompete other types of algae that might contaminate their culture. Researchers in Mitsui's laboratory have isolated hundreds of different types of blue-green algae and are testing their nutritional value by feeding them to various animals. Results indicate that the best type of blue-green algae to feed to an animal depends greatly on the particular species of animal. Certain types brought about faster growth in rotifers than traditional algal feeds, while other types caused brine shrimp to grow faster. (Rotifers and brine shrimp are two important animals used in the larval grow-out of many fish and shrimp.) In feeding experiments of the blue-green algae with a fish, small specimens of a saltwater Tilapia hybrid tripled in size in just seven days. Tests revealed that the majority of blue-green algae in Mitsui's collection were not toxic to test animals. The University of Miami researchers currently are determining the best means of feeding the blue-green algae that are most suited for mariculture. Work is also under way to develop simple but efficient means of growing them to make their culture commercially feasible. |
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| Q&A 14. | Since dolphins can be reared in captivity, would it be profitable to farm them in order to supply the needs of oceanariums for these mammals, instead of taking them from the wild? New York City, New York |
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| Although the current market value for a minimum-legal-length dolphin (about 6 1/2 feet) is about $10,000, this hardly makes up for the expenses incurred in rearing it. First, there are the obvious costs associated with providing these large pelagic animals with adequate food, space, and clean saltwater. Then, there is the cost of a separate tank for the two-year isolation of mother and calf, from the time she is recognized to be pregnant until the calf is ready to be handled. In addition, if the facility is to rely on producing its own brood stock, costs will include maintaining females for about six years until they mature. The cost of the captive-raised dolphins must be competitive with that of wild-caught specimens, for which most oceanariums possess collecting permits. Farmed dolphins, like all other marine mammals, are subject to the Marine Mammal Protection Act, which strictly regulates any activities involving these animals. The cost of obtaining the necessary permits to keep dolphins as proscribed by this act would be substantial. At present, only two groups - the U.S. Navy and Sea World in Orlando, Florida - raise dolphins on a large-scale basis. Other oceanariums also raise dolphins born at their establishments when the opportunity presents itself, but the reasons for such undertakings are general related to conservation and public image, not to making a profit on the calf. |
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| Q&A 15. | Are there sponge farms in operation at this time? Chevy Chase, Maryland |
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| To the best of our knowledge, there currently are no large-scale commercial sponge-culture operations, although demand for natural sponges continues to be greater than the supply. Natural sponges are more absorbent and heat resistant than synthetic sponges and, in a variety of specialized applications, such as use in hospitals and for insulation in rockets, cannot be replaced by synthetics. In spite of this, sponge culture has been an uncertain business. In the Bahamas, the Florida Keys, and the South Pacific, sponge farming has been tried with mixed success. While the technical difficulties were overcome, the operations suffered major losses from disease, poaching, and vandalism. The major problems facing such an enterprise are obtaining exclusive control of suitable habitats for sponge cultivation and substantial start-up costs. In the most common method, wired sponge cuttings are attached to concrete disks via a perforation and placed in a suitable shallow environment with clean, flowing seawater. In the three to four years before the first harvest, a commercial farm would have to invest in the labor necessary to place hundreds of thousands of these disks on the sea bottom. In addition, the farm might require seven to ten years to make a profit. Over such a long period of time, the chance of sponge disease and the high labor costs involved make sponge culture in the United States a risky business. In less-developed countries with lower labor costs, the proven techniques of sponge culture, combined with the high demand for natural sponges, might make farming of these animals practical. |
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| Q&A 16. | Are groupers, snappers, or jacks being commercially cultured as food fishes in the United States? New York City, New York |
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| To the best of our knowledge, groupers (family Serranidae), snappers (family Lutjanidae), and jacks (family Carangidae)currently are not being used in U.S. commercial mariculture operations. Some species of these groups are being tested for their mariculture potential, particularly in other countries. There are several problems that currently limit the use of many fish species in mariculture . For some species, the entire life cycle is not known or cannot be completed under laboratory conditions. This is a major drawback that the Japanese have encountered in raising yellowtail (Seriola quinqueradiata): fish larvae are difficult to raise from the eggs and usually must be caught in the wild and transported to the mariculture facility for captive grow-out. Other problems encountered when rearing some fish species include the high cost of food, high quality of water required for rearing, and low rearing densities sometimes required. Any or all of these could make a given species of fish prohibitively expensive to rear in captivity. Farm-raised groupers, snappers, and jacks would be more expensive than those caught in the wild. |
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| Q&A 17. | Can the common Florida spiny lobster be farmed commercially? Boca Raton, Florida |
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| The spiny lobster (Panulirus argus) is a poor choice for a commercial farming operation, in part because of its long and complex larval development. We do not know of any published reports that P. argus has been artificially reared through all larval stages. It is estimated that from 6 to12 months are required for P. argus to pass through a series of delicate larval stages, requiring at least 12 molts. During these stages, the animal requires carefully monitored conditions and almost constant attention. Even if this species could be reared through all its larval stages, the juveniles would still have to be fed in captivity for several years before they could be sold. It is likely that the extended care and feeding of the lobsters would not be economical. While, at this time, intensive farming of P. argus seems impractical, artificial lobster shelters have been constructed in a number of Caribbean countries. The shelters are supposed to increase he number of lobsters an area can support be increasing the habitat available to the animals. It is not known if the shelters actually increase the lobster population, or only concentrate the existing number of animals. The shelters are a possible first step toward extensive ranching of spiny lobsters using wild juveniles; see BioScience, 37(5):309-312, May 1987 and Proceedings of the First International Conference on Warm-Water Aquaculture-Crustacea, pages 238-245 (1983). |
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| Q&A 18. | During my visit to Miami, Florida in December 1988, I purchased a packet of fresh fish labeled "Saint Peter's fillet." The butcher said the fish was imported from Costa Rica, where it was the product of aquaculture. A neighbor claimed that the fish was imported from the Sea of Galilee. When cooked, the fish tasted like snook. Can you tell me what fish is marketed under this appellation? Middletown, Rhode Island |
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| The fillets you purchased were probably from the blue tilapia (Tilapia aurea), a species raised on aquaculture farms in Central America. Tilapia spp., which are cichlid mouthbreeders, are reared in both fresh and brackish water in many parts of the world. Among these is a hybrid tilapia developed in Florida and marketed under the name "cherry snapper." As reported in Underwater Farming (Pineapple Press, Sarasota, FL,1988), its mild-flavored fillets are popular in restaurants. Fast-breeding, highly productive tilapia have been selected as a major food source for the Biosphere II project in Arizona. In September 1990, eight scientists plan to enter the 200,000 cubic meter (260,000 cubic-yard) Biosphere II, a closed ecological system that is expected to provide the necessary water, oxygen, and food for two years of habitation. Details about the project are given in "Biosphere II: a world apart," New Scientist, 18 March 1989, pages 34-35. |
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Rosenstiel School of Marine & Atmospheric Science Library
University of Miami, FL USA 4600 Rickenbacker Causeway, Miami, Florida 33149 Phone: 305 421 4060 Fax: 305 421 9306 E-mail: libcirc@rsmas.miami.edu |
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