A new Palaemonid shrimp distribution was found for the first time in the record in Japan in a pond in Matsushima town, Hamamatsu city, Shizuoka Prefecture, Japan. It was identified, as a result of a morphological examination, to be
Palaemonetes sinensis.
P. sinensis can be distinguished from indigenous Palaemonid shrimp by absence of the palp.
The habitat is isolated from the sea and larva of
P. sinensis has an ability to grow under freshwater. It is suggestive that the species has been transported either intentionally or unintentionally, but not by natural causes.
In order to acquire basic knowledge about the life history, a female reproductive cycle was investigated from October, 2005 to September, 2007. Oogenesis of
P. sinensis was classified in to six stages for this study: chromatin nucleolus, perinucleolus, yolk granule, primary yolk, secondary yolk, and tertiary yolk stage. Based on these classifications and histological features of ovaries, ovarian maturity was classified into four phases: multiplication, vitellogenic, maturation, and ovulation phases. The maturation phase and ovigerous female appeared between May and September. Moreover, it was suggested that multiple spawning at one reproductive season was confirmed from the relationship between the development of ovigerous egg and ovarian maturity.
View full abstract