Sunday, August 12, 2007

Sex&fish: a Cod story

watercolor by marguerita

Staring down into several hundred sexually aroused cod.The fish were there because of calculated effort :
"Compare the families, find the best ones, and that's kind of the never-ending story."
Today, dozens of mainstream fish are being domesticated and will soon appear at supermarket counters everywhere. Yellow tail, halibut, red snapper and even Volkswagen-size blue fin tuna are all coming under some kind of human-controlled production. And whereas animals like sheep and cattle were adapted to fit the farm over thousands of years, many of the ocean species under development today could be tamed in as little as a decade.
Until recently I didn't pay much attention to this phenomenon.Will we prosecute the same war upon diversity at sea as we have on land?
All of these questions troubled me.

Cod by any criterion one
of the most important fish in the history of mankind,continues to be one of the foremost marine food resources: as fresh or frozen fish,in the form of bacalao (dried and salted cod) and stockfish (dried cod) and for its roe:baccalaureu in Latin
cabillaud in French, kabeljau,dorsch in German, kabeljauw Dutch,bacalhau Portuguese, treska,pertui Russian,turska Finnish, torsk Swedish, torsk,skrei Norwegian,torsk Danish,porskur Icelandic,dorz,watlusz Polish,tara Japanese.
Exploitation of available fishing grounds was heavy in medieval times,largely because of the demand for salted and dried cod for Lent,but it was nothing compared to the present scouring
of the sea with sophisticated equipment.The coloration of cod varies.
As cod has become scarcer and more expensive,its culinary merits have been more widely recognized.Its flesh,which separates into large flakes,is excellent,specially if really fresh.
Seafood ,A connoisseur's Guide and Cookbook
by Alan Davidson
Bacalhau -
a Portuguese import has been popular in Brazil for four centuries.
Popular dishes containing bacalhau include fried codfish balls (croquetas de bacalhau),tomato and pepper based stews,souffles,puddings,egg dishes.

The spawning activity of cod, Gadus morhua L.
Kjesbu, OS
Journal of Fish Biology. Vol. 34, no. 2, pp. 195-206. 1989.

Aspects of the reproduction of reared cod, Gadus morhua L., with special emphasis on the females,
were studied under laboratory conditions. The fecundity and condition factor were 2 multiplied by 5 and 1 multiplied by 5 times, respectively, that of wild cod. A total of 18 spawning females were kept in separate tanks/chambers, each with one or two males. Seven of the 18 females were classified as stressed, based upon behaviour, irregular spawning intervals and low fertilization rates of the eggs. The reared cod were found to spawn 17-19 batches. The number of eggs liberated in each batch normally followed a smooth, dome-shaped curve with time. The fertilization rate was normally 100%. Egg size decreased from first to last batch and the egg dry weight decreased by about 20-30%.

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