|A short note on the intensive culture of eel (Anguilla anguilla L.)|
Deelder, C.L. (1978). A short note on the intensive culture of eel (Anguilla anguilla L.). Aquaculture 13(3): 289-290
In: Aquaculture. Elsevier: Amsterdam; London; New York; Oxford; Tokyo. ISSN 0044-8486, more
Fish culture; Thermal aquaculture; Anguilla anguilla (Linnaeus, 1758) [WoRMS]; Brackish water; Fresh water
From a comparative study of enzymes in digestive organs of several fish species (reference untraceable), it was understood that the eel's stomach contains besides proteinase, a large amount of chitinase (even relatively more than is found in rainbow trout). With regard to this fact, the question may be put whether the eel does not need a certain amount of chitin in its food for good condition and growth. This question is all the more pertinent since it is known from culture trials that often the majority of cultured eel have poor growth or none at all, and their condition deteriorates steadily, leading to death from exhaustion. In August 1976 an orientating experiment was started with a small indoor recycling aquarium system, in which the water is filtered over active charcoal, and passed through a tank illuminated by fluorescent tubes and stocked with the floating liverwort Riccia fluitans. The water temperature varied between 16 degree and 19 degree C: no additional heating was used. This experiment was started with 64 eel, of about 20 cm length, which were in poor condition. Knowing the preference of eel for fresh food, it was decided to feed them on live organisms only. Larvae of the beetle Tenebrio molitor were chosen to make up the chitinous part of their diet, and larvae of the fly Calliphora erythrocephala were given as a supplement. Both food items are fairly inexpensive to rear. Within a few days, all eels were feeding and their condition gradually improved. No eels died. In April 1977 the 64 eels were measured and weighed, and subsequently consumed. The opinion of the tasting panel: 'delicious'. Main data were: average length: 35 cm (SD:4 . 61); mean K (= 100 W/L SUP-3 ): 0 . 186 (SD:0 . 03). Forty-five eels showed a K>0 . 17, mean: 0 . 201 (SD:0 . 02). Moreover, some had reached, and others nearly reached, the silvery stage.