SPAWNING HABITS OF THE MUSSEL MYTILUS CALIFORNIANUS CONRAD,WITH NOTES ON THE POSSIBLE RELATION TO MUSSEL POISON:MUSSEL POISON.I

U.CA Pub.Zool.vol.41,no.5, 1936-01-01. Paperback. Good. University of California Publications in Zoology, Vol. 41, No.5, pp. 35-44, plate 3, 1 figure in text. University of California Press [Published date: 1936]. Booklet, 12 pages. In good condition. Grey paper covers have light bumping to edges and Light overall scuffing, aging, fading and soiling. Binding tight (staple bound). Pages lightly aged but otherwise unmarked. NOT Ex-Library. [Excerpt from intro] ERELY INVESTIGATION of mussel poison indicated that its nature was pssibly much like that of Fugu poison, found in the gonads and digestive diverticula of toad fishes. According to Meyer, Sommer, and Schoenholz (1928), there was some suspicion that mussel poison might also be the basic product of the sex metabolism of the mussel. They suggested that this assumption did not explain the sudden appearance of the highly potent toxin at regular intervals.In the years which followed, however, changes in the appearance of the digestive diverticula were observed, which led to the belief that a thorough study of the spawning habits of Mytilus californianus in relation to the poison was of importance.Stating that a definite spawning period was unknown, Rankin (1918) reported that dealers in shellfish had suggested that the mussels were spawning as early as April or May, but pointed out that the mussels in the region around San Diego were not in a spawning condition until late July. Working at Scripps Institution of Oceanography, La Jolla, California, Coe (1932) showed that attachment of Mytilus califomianus to experimental blocks takes place as late as October, and that free-swimming larvae are very numerous in the warmer summer months. This would indicate that the mussels spawn fromJune to September.