Dates of spawning of Antarctic euphausiids

The paper considers the determination of time of breeding of five species of Antarctic Euphausiids. The original and literature data on age composition of larvae gave the possibility to calculate the dates of the beginning, termination and periods of high and the most intension of spawning. In the waters of different origin and on different latitudes euphausiids begin to spawn in a usual succession (Makarov, 1979): Euphausia triacantha - E. frigida - Thysanoessa macrura - E. crystallorophias - E. superba. The spawning of each species begins later in waters of high-latitude origin. The same connection exists for the period of the most intensive spawning. The termination of spawning in the waters of high-latitude origin is earlier then in the waters of an other type. The correlation with a geographical position of a region (latitude) is obvios for the beginning and maximum of the spawning while for the termination it is obscure. All the species of Antarctic Euphausiids exept E. superba are spring-spawning while the last is summer-spawning.