摘要:

Calanus tonsusBrady is an abundant, deep water species in the strait of Georgia. Development is characterized by a distinct metamorphosis and the six nauplius and six copepodid stages are described.The life cycle extends over one year and breeding occurs in the spring at the surface. The nauplii and early copepodid stages are soon replaced by stage V which dominates the plankton from May to December.C.tonsusexists as an adult for approximately two months—January and February. Maturity is accompanied by marked degeneration of the mouth parts in both sexes, death following shortly.The retrograde development appears associated with a change in habits. Stage V stores up reserve food, and the mature females with the disappearance of feeding devices depend upon this accumulated food during the reproductive period.Euchaeta japonicaMarukawa occurs in limited numbers in the deep water of the strait of Georgia. It undergoes a similar metamorphosis toC.tonsusand the twelve stages are described.There is no definite spawning period but reproduction occurs throughout the year in deep water where development proceeds. Several broods may be produced by one female but the males are believed to die shortly after copulation.The nauplii differ from those ofC.tonsusdue to larger size, slight increase in length from stage I to stage VI and retarded development of the appendages.The conspicuous feature of the copepodid development is the extreme degeneration of the male mouth parts.

ISSN:0706-652X    

DOI:10.1139/f34-001

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

The physical and biological conditions in an experimental pond with concrete walls containing 33 cubic metres of water, initially fertilized with approximately 450 kg. (1000 lb.) of cow manure, were studied intermittently during four years. There was a large production of plankton, but it was subject to marked and sudden fluctuations, and the number of species found was not large. The fertilization caused extreme variations in the light conditions, oxygen content and pH value of the water.

ISSN:0706-652X    

DOI:10.1139/f34-002

出版商:NRC Research Press    

年代:1934

数据来源: NRC

摘要:

Comparative values for the replacements of bay of Fundy waters have been determined for each year of the period 1924–1930 inclusive, by a consideration of the differences between the annual ranges of temperature at various levels in the bay of Fundy. These differences in annual ranges of temperature may be correlated to some extent with the average amount of drainage water from the St. John river system and the "adverse excess" of winds.

ISSN:0706-652X    

DOI:10.1139/f34-005

出版商:NRC Research Press    

年代:1934

数据来源: NRC