Cardiovascular and Ventilatory Changes During Ecdysis in the Blue Crab Callinectes Sapidus Rathbun

Publisher Website
Google Scholar
Abstract
The increase in body volume due to the uptake of water during molting is associated with more than a 5-fold elevation of hemolymph hydrostatic pressure. Hydrostatic pressures begin to increase prior to exuviation (stage D4), rise to a maximum in stage E, and then quickly begin to decline (stage A1). This decrease, which precedes the termination of water uptake, may be due to the elevated rate of urine formation permitted by the large excess of hydrostatic over colloid osmotic pressure. By stage A2, hydrostatic pressures have returned to intermolt (stage C) levels. Slow pressure pulses initiated late in stage D4 provide the mechanism of separating the old from the new carapace. The heart continues to beat at a variable but clearly lower rate, compared with stage C, throughout the cycle. Although ventilatory flow decreases significantly during stage A1 and at least early stage A2, it does not cease, and the period of hypoventilation is relatively brief.