InNeognathophausia ingensthe anterior border of the heart lies in the anterior part of the cephlothorax and is assigned to the first thoracic segment. The heart extends though the whole thorac. Its posterior end lies in the eight thoracic segment. Cardiac arteries occur segmentally throughout the whole thorax as well. One artery in the eighth pair represents the descending artery which branches above the ventral nerve chord. The heart, by a posterior aorta, is elongated into the pleon and is equipped with lateral arteries.
InNeognathophausia ingens, the heart is, by the posterior aorta, elongated into the pleon and is equipped with lateral arteries. The anterior border of the heart lies in the anterior part of the cephalothorax assigned to the first thoracic segment. The hear extends through the whole thorax. The posterior end lies in the eight thoracic segment. Cardiac arteries occur segmentally throughout the whole thorax as well. One artery of the eighth pair of the cardiac arteries represents the descending artery branching above the ventral nerve chord. (Wirkner, 2009) A descending artery is an artery that emanates from the heart and connects to the ventral vessel. InN. ingenstwo arteries connect the dorsal and ventral vessels, but in some studies show that only one branch of the arteries makes the connection. (Wirkner, 2009)
