"Nocturnal release of parthenogenetic neonates of the marine cladocerans, Pseudevadne tergestina and Evadne nordmanni (Branchiopoda: Onychopoda), in the Inland Sea of Japan with observations by infrared-light video microscopy."
2002
"Onbe, T. "
"The marine cladoceran Pseudevadne tergestina Claus (Branchiopoda: Onychopoda:Podonidae) was once again confirmed to release its neonates during the hours of total darkness almost exclusively between 10 p.m. and 4 a.m. based on specimens collected in July 1973 and 1985 in the central part of the Inland Sea of Japan. The behavior of nocturnal release of neonates of this species, together with another podonid Evadne nordmanni Loven, collected respectively in September 1992 and May 1993, was successfully observed and recorded in the laboratory for the first time by means of infrared-light video microscopy. Molting of a mother animal in both species begins at the basal part of the carapace, either posterior to the neck or posterior to the postabdomen, which opens the carapace wide and enables neonates quickly to be freed from the mother into the water. Further molting of the mother is delayed until all the neonates are released. Subsequent molting is centered in the cephalothoracic regions, ending with shedding of the casts of thoracic appendages,and the newly molted individual immediately swims away. Some mother animals were recorded to have died after completing the release of their neonates successfully but without executing their final molt."
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