caa a22 4500 397547269 CHVBK 20180308164741.0 cr unu---uuuuu 161202e19960501xx s 000 0 eng 10.1093/aesa/89.3.391 doi (NATIONALLICENCE)oxford-10.1093/aesa/89.3.391 Mori Hajime Department of Biology, Kyorin University School of Medicine, 6-20-2, Mitaka-shi, Shinkawa, Tokyo 181, Japan. Onset of Embryonic Heart Movement in the Waterstrider Qerris paludum insularis (Hemiptera: Gerridae) [Elektronische Daten] [Hajime Mori] The morphology of the developing embryonic heart in the waterstrider Gerris paludum insularis Motschulsky is reconstructed from serial histological preparations. The embryonic heart, the expanded posterior portion of the dorsal vessel, is derived exclusively from cardioblasts, as observed in other insect embryos. It seems that the basic structure of the embryonic heart in G. p. insularis is established at ≈60 h after katatrepsis at 20°C. However, the anteriormost part of the dorsal vessel is derived from mesodermal sacs that appear in the gnathal part of the embryo. Observations on individual G. p. insularis embryos after time-lapse photomicrography revealed that heartbeats begin as early as 72 h after katatrepsis at 20°C in close association with each swinging movement of the tip of the abdomen, which was observed at regular intervals of 8—10 min at that stage. Embryonic heartbeats at this stage occur only irregularly, whenever the swinging movement of the abdominal tip is about to cease, but within the next 24 h heartbeats become regular and continuous, whereas embryonic abdominal movements are no longer observed. Observation of embryonic heartbeat rates at each developmental stage in the single embryos were followed until 1 d before hatching; the rate increased almost 2-fold during that time. © 1996 Entomological Society of America Physiology, Biochemistry, and Toxicology nationallicence waterstrider nationallicence embryology nationallicence heart nationallicence heart rate nationallicence Annals of the Entomological Society of America Oxford University Press 89/3(1996-05-01), 391-397 0013-8746 89:3<391 1996 89 aesa https://doi.org/10.1093/aesa/89.3.391 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/aesa/89.3.391 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Mori Hajime Department of Biology, Kyorin University School of Medicine, 6-20-2, Mitaka-shi, Shinkawa, Tokyo 181, Japan NATIONALLICENCE 773 0- Annals of the Entomological Society of America Oxford University Press 89/3(1996-05-01), 391-397 0013-8746 89:3<391 1996 89 aesa Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford