Ershova, E.A. & K.N. Kosobokova. (2012). Morphology of genital system and reproductive biology of the arctic calanoid copepod Metridia longa. ОСОБЕННОСТИ МОРФОЛОГИИ ГЕНИТАЛЬНОЙ СИСТЕМЫ И БИОЛОГИИ РАЗМНОЖЕНИЯ АРКТИЧЕСКОЙ КАЛЯНОИДНОЙ КОПЕПОДЫ METRIDIA LONGA. Zoologicheskii Zhurnal. 91(2):138-147. (Russian).
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Ershova, E.A. & K.N. Kosobokova
2012
Morphology of genital system and reproductive biology of the arctic calanoid copepod Metridia longa. ОСОБЕННОСТИ МОРФОЛОГИИ ГЕНИТАЛЬНОЙ СИСТЕМЫ И БИОЛОГИИ РАЗМНОЖЕНИЯ АРКТИЧЕСКОЙ КАЛЯНОИДНОЙ КОПЕПОДЫ METRIDIA LONGA
Zoologicheskii Zhurnal
91(2):138-147. (Russian)
Publication
Available for editors
This study examines the morphology and internal structure of the male and female reproductive system of Metridia longa Lubbock, a common Arctic copepod, and discusses their biological implications. M. longa males exhibit dimorphic asymmetry, and the population contains two morphotypes of males that are mirror images of each other. The relative positions of asymmetrical structures in males are concordant among each other. These structures include the geniculate antennula, the 5th thoracic appendages, and the position of the gonad and genital opening. The genital segment of the female contains two widely placed copulatory pores that lead to two not interconnected spermathecs. The latter are connected to two gonopores, through which eggs are released. The majority of females in the population during all seasons had only one inseminated sper? mathec, either the right or the left. Bilaterally inseminated females were also present, but they composed only a minor percent of the population. Comparison of the ratio of right? and left?sided morphs of males and the ratio of left? and right?inseminated females implies that the morphotype of the male determines to which copulatory pore spermatophore will be most likely attached. Bilaterally inseminated females most likely were inseminated by 2 males of different morphotypes. Since each spermathec is connected to only one ovary, it is assumed that half of the eggs produced by unilaterally inseminated female remain unfertilized. The morphol? ogy of the genital structures, as well as literature data on egg production, implies that almost half of the eggs produced by females of M. longa are unviable and wasted.
