The reproductlve cycle of glant scallops Placopecten magellan~cus was examlned over a 13 yr perlod from 1978 to 1990 at several sltes wlthln Passamaquoddy Bay New Brunswick Gonosomatlc Index (GSI) and gonad weight were obtalned from scallops sampled approximately monthly From 1985 to 1990 samples were collected every 2 wk durlng the gonad r l p e n~n g and about weekly durlng the spawning perlod Scallops In Passamaquoddy Bay had one main spawnlng perlod between July and September wlth peak spawning occurnng durlng August Spawnlng was not a cont~nuous and complete process but was ~ntermlttent, wlth 2 to 3 spawnlng events There was concordance between these spawnlng events and the lunar/tldal cycle s u g g e s t~n g a tldally related spabvnlng cue Spawnlng was h~g h l y synchronous wlthln local populatlons between sexes, and wlthln the bay Onset duratlon and penodlclty of spawnlng were also slmllar between years The long-term GSI pattern and maxlmum level In the reproduct~ve cycle of glant scallops from Passamaquoddy Bay were annually consistent Thelefore ~t appears that In Passamaquoddy Bay changes In potential reproductlve output (Independent of s u e and numbers) may not be as Important In the determlnatlon of recruitment for scallops as factors operating at other llfe-hlstory stages

Levels of Gonyaulax excavata toxin in sea scallop (Placopecten magellanicus) tissues were monitored in eastern Canada on a monthly basis between 1977 and 1981. All tissues but the adductor muscle were found to be highly toxic in Bay of Fundy scallops, with negligible toxicity observed in scallops from Georges Bank, the outer Scotian Shelf, and Northumberland Strait scallops. Level of Bay of Fundy toxicity was much higher than previously observed (maximum digestive gland toxicity: 150 000 μg/100 g in March 1978), and recent average monthly toxicity for Bay of Fundy scallop roe ranged from 184 to 286 μg/100 g. Considerable fluctuation in toxicity can occur between adjacent months, and peak toxicities in sea scallops occur during fail and winter months. Scallop roe fisheries should be permitted to be established for scallops fished from the northern part of Georges Bank and Northumberland Strait. However, a closed zone for scallop roe should be established in the Bay of Fundy and adjacent Scotian Shelf.Key words: scallop, PSP, Gonyaulax, Placopecten, mollusk

A method is presented which enables infaunal juvenile bivalves to be separated from associated sediment with a combination of elutriation and flotation techniques. Simple elutriation is used to remove less dense organic detritus and a relatively new, nontoxic compound (sodium polytungstate) is used to create a heavy liquid that sorts the bivalves from sediment by relative density. The technique was applicable to 12 species of molluscs of various sizes and was 98–100% effective in separating juvenile Mya arenaria, ranging from 0.5 to 24 mm in shell length, from surrounding sediment.

Three different isolates of Pseudomonas and two of Mycobacterium capable of the utilization of camphor as sole carbon source were isolated from soil. Evidence was obtained indicating that the strains of Pseudomonas and one of the strains of Mycobacterium metabolize camphor via pathways already described for Ps. putida. The other strain of Mycobacterium appeared to use a different pathway involving the 6-exo-hydroxylation of camphor. The disappearance of camphor and the time course of accumulation of intermediates in its degradation is described for one strain of Pseudomonas. IntroductionThe pathway of camphor degradation shown in Scheme 1 (Conrad 1965b) has been established for Pseudomonas putida strain ppG 1 and Pseudomonas strain C5 (Bradshaw et al. 1959;Conrad et al. 1961Conrad et al. , 1965a Hedegaard and Gunsalus 1965) and Ps. testosteroni (Jacobsen et al. 1964). A second different pathway, involving the 6-exo-hydroxylation of camphor followed by conversion of the hydroxyl group to a keto group and ring cleavage, has been described for an orange-pigmented diphtheroid strain Tl (Kay et al. 1962;Chapman et al. 1963Chapman et al. , 1966Kuo 1965).The studies described in this report were aimed at examining the types of bacteria capable of using camphor as a carbon source that could be isolated from soil, and the way in which these isolates degraded camphor.

Summary A comparison of the efficiency of strontium chloride M broth and mannitol, selenite, cystine broth in the recovery of Salmonella sp. was made. The former was found to be inferior and was ineffective in suppressing the growth of Proteus sp.