heart

(Order Cladocera):

In circulatory system, typically short, muscular pumping organ located anterior to brood chamber in trunk. Blood enters heart through single pair of ostia and is pumped anteriorly into a sinus, although certain predatory water fleas have been described as bearing anterior bulbous arterious and short anterior aorta. (elongate, oval, subovate) [Stachowitsch, 1992].

(Order Notostraca):

In circulatory system, elongate, muscular pumping organ extending through 11 thoracic segments above digestive tract. Blood enters heart through 11 pair of ostia and is pumped anteriorly [Stachowitsch, 1992].

(Order Diplostraca):

In circulatory system, muscular pumping organ extending from head (from maxillule-bearing somite) into third trunk somite. Blood enters heart posteriorly and through typically four pairs of ostia [Stachowitsch, 1992].

(Order Anostraca):

In circulatory system, elongate, muscular pumping organ extending through entire body above digestive tract. Blood from pericardial sinus enters heart through ostia and is pumped anteriorly [Stachowitsch, 1992].

(Class Cephalocarida):

In circulatory system, muscular pumping organ extending through thorax; bears pair of ostia in each somite [Stachowitsch, 1992].

(Order Cumacea):

Muscular pumping organ of circulatory system. Relatively short, located dorsally in more anterior pereon segments (pereonites). Bears one pair of ostia and gives rise to anterior and posterior aortas as well as series of lateral arteries [Stachowitsch, 1992].

(Order Tanaidacea):

Elongate, muscular pumping organ of circulatory system. Located within pericardial sinus above digestive tract; typically extends through entire pereon. Bears two pairs of ostia (in pereonites 2 and 3) and gives rise to single anterior lorta, pair of posterior aortas, and up to several pairs of lateral arteries [Stachowitsch, 1992].

(Order Decapoda):

In circulatory system, relatively short, muscular pumping organ located dorsally in posterior region of cephalothorax. Receives blood from pericardium through three pairs of ostia and pumps ii anteriorly, posteriorly, and ventrally via numerous blood vessels (aortas, arteries) [Stachowitsch, 1992].

(Order Amphipoda):

Elongate, muscular pumping organ of circulatory system; located within pericardial sinus above digestive tract and extending through most of pereon (first to sixth segments). Bears three pairs of ostia and gives rise to anterior and posterior aortas as well as series of lateral arteries [Stachowitsch, 1992].

(Order Isopoda):

Muscular pumping organ of circulatory system; relatively short, located above hindgut in abdomen (pleon). Bears one to two pairs of ostia and gives rise to anterior aorta and series of lateral arteries [Stachowitsch, 1992].

(Order Mysida):

In circulatory system, muscular pumping organ above digestive tract in thorax. Bears two or three pairs of ostia and gives rise to series of aortas and arteries [Stachowitsch, 1992].

(Order Stomatopoda):

Main longitudinal vessel of circulatory system. Located middorsally above digestive tract and gonads and extending through most of thorax and abdomen. Bears 13 pairs of ostia and gives rise to series of paired, segmentally arranged lateral arteries to anterior and posterior aortas [Stachowitsch, 1992].

(Order Leptostraca):

In circulatory system, elongate, tubular pumping organ extending above digestive tract and gonads from posterior region of head to fourth pleomere. Bears 11 ostia and gives rise to numerous arteries as well as anterior and posterior aortas [Stachowitsch, 1992].

(Subclass Branchiura):

In circulatory system, muscular pumping organ located dorsally in last thoracic somite (fourth thoracomere). Receives blood through pair of ostia at posterior end and pumps it anteriorly via aorta, ventrally and posteriorly through additional openings [Stachowitsch, 1992].

(Subclass Cirripedia):

Rostral sinus [Stachowitsch, 1992].

(Subclass Copepoda):

In circulatory system of certain copepods, relatively short, muscular pumping organ located dorsally in anterior region of thorax. Recieves blood from pericardium through three ostia and pumps it anteriorly via aorta [Stachowitsch, 1992].

(Class Ostracoda):

In circulatory system of certain ostracods, relatively short, muscular pumping organ located anterodorsally behind eye. Receives blood from pericardium through pair of posterodorsal ostia and pumps it through anteroventral aortic valve and aorta as well as through posteroventral hepatic valves [Stachowitsch, 1992].

(Class Remipedia):

Main longitudinal vessel of circulatory system; located middorsally above digestive tract. Muscular portion restricted to head (cephalon) region [Stachowitsch, 1992].

(Superorder Syncarida):

Muscular pumping organ of circulatory system. In anaspidacean, elongate, extending dorsal to digestive tract from first thoracic to fourth abdominal somite. Bears pair of ostia at level of third thoracic somite (thoracomere) and gives rise to aortas and arteries. In bathynellacaens, relatively short, located in fourth thoracomere [Stachowitsch, 1992].

(Order Thermosbaenacea):

Muscular pumping organ of circulatory system. Short, located dorsally in first thoracic segment (thoracomere). Bears pair of ostia and gives rise to anterior and posterior aortas [Stachowitsch, 1992].

(Order Euphausiacea):

In circulatory system, relatively short, dorsoventrally flattened pumping organ; located within pericardial sinus in posterodorsal region of cephalo-thorax. Bears two pairs of ostia and gives rise to numerous anterior, posterior, and lateral blood vessels (aortas, arteries) [Stachowitsch, 1992].