WWW.WAS.ORG • WORLD AQUACULTURE • JUNE 2019 45 due to research and practical applications of aquaculture on agricultural land. The suggestion for a change in the law was already initiated by me around 1965. So it was, entrepreneurial men — and there were many of them — began the arduous and complicated task of creating a new water law for Spain and weaving connections in different places in the world to establish a new industry. We chose a kind of crayfish that needs the opposite sexes to reproduce, no known parthenogenesis or virgin birth, a species with an initial yield for the farmer and the fisherman until a production level is established that allows the establishment of processing centers, and a species with a high degree of resistance to warm water and drought. Finally in 1975 a paradigm shift took place in some rice fields on Isla Mayor that involved a land use change in the Marismas from grazing agricultural land, as practiced since the 1930s, to irrigated rice. The area was selected by Professor James Avault of LSU for the availability of water and because there was no species of autochthonous or alien crayfish such as the Astacus italicus or other species of commercial value such as the eel or glass eel that once traced the Guadalquivir River up to Alcalá de Gudaira. The book El Cangrejo confirmed the total lack of crayfish species in the Andalusian provinces. The crayfish de las Marismas is the largest crustacean species of temperate continental water. Its special adaptation is the wide gills to extract the little dissolved oxygen from the slow running waters, resistance to high water temperature, the female with a seminal receptacle, and an animal that digs into the bottom and builds a burrow with the classic chimney. Another advantage the American crayfish has over the European species is resistance to disease caused by a fungus that was inadvertently brought as ballast, in a wet sack of hemp, on a ship from the New World around 1850. The reference to the appearance of a new disease dates from 1860 in the Po River in the province of Lombardy in Italy. This disease is a tubular fungus that does not reproduce sexually but through a host. In the case of Aphanomyces astaci, the host is the cuticle of crayfish — irrespective of species — and in wet conditions. In 1898, Dr. Hofer of Munich described the disease as a bacterium and baptized it with the name Bacillus pestis astaci. The capture, quarantine, packaging, air transport, customs at the Madrid Barajas airport, sanitary inspection and the night trip to the Isla Mayor I describe elsewhere. Mr. Rafael Grau wrote in 1974 of the total failure of the stocking, but when I visited his rice paddy later, I showed by digging with my hands in the soil of the field that he was not correct. We set up a company and started crayfish production. The news of crayfish production and the market supply surprised the scientific world. It was then that the news came that the introduction of the crayfish de la Marismas was a plague and not a disease. This expression “crayfish plague” found scientific support and since then has been used in thousands of pages of newspapers, reports, edicts, laws: that the American crayfish is the culprit of the fungus. Truly the fungus does not survive outside the water, is asexual, in a tubular form, it only reproduces on the carapace of whatever crayfish species. Nor was the signal crayfish brought from Simontorp, Sweden responsible for the fungus, unless we question the papers issued (CONTINUED ON PAGE 46) LEFT: Spanish Procambarus fishermen adapted their years of frugal eel capture practices to find the most economical ways to set, check and transport items around the 70,000-ha rice growing region west of Sevilla. RIGHT: Originally used for the capture of local eels, handmade nets to capture Procambarus quickly became a profitable secondary industry for the townspeople of the village of Isla Mayor and surrounding area. With a minimum of investment, local men, young and old, were able to participate in the profitable, baitless capture of introduced Procambarus, interfacing well with other forms of erratic seasonal employment provided by forestry, agriculture and olive industries.
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