An outbreak of food poisoning in Canada during autumn 1987 was traced to cultured blue mussels (Mytilus edulis) from the Cardigan Bay region of eastern Prince Edward Island (P.E.I.). The toxin, identified as domoic acid, had not previously been found in any shellfish and this outbreak represents the first known occurrence of human poisoning by this neurotoxin. A plankton bloom at the time of the outbreak consisted almost entirely of the pennate diatom, Nitzschia pungens f. multiseries, and a positive correlation was found between the number of N. pungens cells and the concentration of domoic acid in the plankton. Nitzschia pungens f. multiseries isolated from Cardigan Bay produced domoic acid in culture at levels (1 to 20 pg∙cell−1) comparable with values estimated for N. pungens in the plankton samples. Isolates of several Cardigan Bay phytoplankton, including the closely related species Nitzschia seriata, failed to produce domoic acid. Other Nitzschia spp. and two Amphora coffeaeformis isolates also failed to produce domoic acid. We conclude that N. pungens was the major source of the domoic acid in toxic mussels in eastern P.E.I. The recurrence, in November 1988, of a monospecific bloom of N. pungens and the presence of domoic acid in plankton and mussels reinforced this conclusion.

. 67,481 (1989).The causative agent of toxicity in cultured mussels from a localized area of eastern Prince Edward Island has been identified as domoic acid, a neuroexcitatory amino acid. The toxin was isolated by a number of different bioassay-directed separation techniques including high-performance liquid chromatography, high-voltage paper electrophoresis, and ion-exchange chromatography, and characterized by a number of spectroscopic techniques including ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance. The isolation and purification methods are described in detail and some new analytical data for domoic acid are reported. On a identifie l'agent qui est la cause de la toxicit6 des moules d7Clevage provenant d'une zone localisCe de la portion est de l'ile du prince Edouard; il s'agit de l'acide domoi'que, un acide amink neuro-excitant. On a is016 la toxine en faisant appel L un certain nombre de techniques de skparation basCes sur des essais biologiques parmi lesquelles on peut citer la chromatographie liquide B haute performance, 1'Clectrophorkse sur papier B voltage ClevC ainsi que la chromatographie d'Cchange ionique; on l'a caractCrisCe par un certain nombre de techniques spectroscopiques dont I'ultraviolette, l'infrarouge, la spectromCtrie de masse et la rtsonance magnCtique nuclkaire. On dCcrit en detail les mCthodes d'isolement et de purification et on prksente des donnCes analytiques nouvelles concernant I'acide domoi'que.Mots cle's : toxine des coquillages, acide domoi'que, neurotoxine, analyse baste sur des essais biologiques.[Traduit par la revue]

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MonnIsox, c. M., eNo P. H. oopNsp. 1978. Distribution and morphology of the rodlet cell in fish. J. Fish. Res. Board Can. 35: 101-116.A short review of the work done on the rodlet cell is presented. The morphology and distribution of rodlet cells in several species of fish, primarily marine, is described and compared with that reported by other authors, mainly in freshwater fish. The morphology in freshwater and marine fish is similar, but variations are present in different tissues ln the same fish. The rodlet cell was found in a wide range of tissues in most of the fish studied. It usually occurs in epithelia, with the apex facing the lumen. The possible function of the rodlet cell is discussed. MonmsoN, c. M., nNn P. H. oopNsr. 1978. Distribution and morphology of the rodlet cell in fish. J. Fish. Res. Board Can. 35: 101-116.Les auteurs passent bridvement en revue les travaux eftectu6s sur les bitonnets. Ils d6crivent la morphologie et la distribution des bAtonnets chez plusieurs espdces de poissons, surtout de mer. Ils les comparent avec les observations d'autres auteurs, en grande partie sur des poissons d'eau douce. La morphologie est semblable chez les poissons d'eau douce et les poissons de mer, mais il existe des variations dans diff6rents tissus d'un m6me poisson. On trouve des bdtonnets dans une gamme 6tendue de tissus chez la plupart des poissons 6tudi6s. La cellule se rencontre ordinairement dans l'6pith61ium, l'apex donnanr sur la lumidre. On analyse la fonction possible de la cellule en bitonnet.

The morphology of the digestive tract of the cod (Gadus morhua) was studied from dissections and histological sections.The stomach of the cod is between the siphonal and caecal types described by Grasse; and has well-developed glands compared to other teleosts. Glands are also present in the numerous pyloric caeca and intestine, and it appears that the constant replacement of the epithelial cells occurs from these. "Pear-shaped" cells which could be enzyme-producing are present in both the epithelium and glands of the ileum and pyloric caeca.The pancreas of the cod is diffuse. Islets of Langerhans were found in the pancreatic tissue along the bile duct as well as at the apex of the gall bladder as described by McCormick and between the pyloric caeca as described by Rennie. lReceived for publication November 30, 1965. t607 J. Frsn. RBs. Bo. CeNloa,23(10), 1966. Printed in Canada, J. Fish. Res. Bd. Can. Downloaded from www.nrcresearchpress.com by San Francisco (UCSF) on 12/03/14For personal use only. JoURNALFISHERTES RESEARCH BoARD oF CANADA, voL, 23, No. 10, 1966 the material was dehydrated, cleared in benzene, embedded in Paraplast (Canlab, Montreal), and sectioned at 7rr. Stains used included Harris' haematoxylin and eosin, Mallory's trichrome, and Heidenhain's Azan methods.The presence of mucus was demonstrated by the alcian blue method for acid carbohydrate, and the technique of Humason and Lushbaugh (1960) was used for reticulin, collagen, and elastin. The aniline blue staining in the latter technique was found to be unsatisfactory, so after staining in orcein the slides were first rinsed in 70/6 alcohol then distilled water, and finally stained for 5 min in 0.5/6 aniline blue in distilled water with 5/6 phosphotungstic acid. The slides were rinsed in distilled water, left in L/6 acetic acid in water 5 min, transferred to 95/6 alcohol, dehydrated, cleared, and mounted. Most of the stains used have been described by Humason (1962) : Exceptions are those used for the pancreas, which were Gomori's chromium haematoxylin phloxine technique (Greep, 1954), Gomori's azan technique (Cowdry, 1943), the alcian blue method for acid mucopolysaccharides, and the periodic acid-Schiff reaction (PAS) described bv Pearse (1960).