ichthulin

from The Century Dictionary.

• noun A constituent of the eggs of certain fishes, especially cyprinoids, containing from 52.5 to 53.3 per cent, carbon, from 8 to 8.3 hydrogen, 15.2 nitrogen, 1 sulphur, and 0.6 phosphorus.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Physiol. Chem.) A substance from the yolk of salmon's eggs.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun organic chemistry A substance from the yolk of salmon roe.