Cockroaches are insects of the order Blattodea, sometimes called Blattaria, of which about 30 species out of 4,600[1] total are associated with human habitats. About four species are well known as pests.
Among the best-known pest species are the American cockroach, Periplaneta americana, which is about 30 mm (1.2 in) long; the German cockroach, Blattella germanica, about 15 mm (0.59 in) long; the Asian cockroach, Blattella asahinai, also about 15 mm (0.59 in) in length; and the Oriental cockroach, Blatta orientalis, about 25 mm (0.98 in). Tropical cockroaches are often much bigger, and, contrary to popular opinion, extinct cockroach relatives and 'roachoids' such as the Carboniferous Archimylacris and the Permian Apthoroblattina were not as large as the biggest modern species.
Among the best-known pest species are the American cockroach, Periplaneta americana, which is about 30 mm (1.2 in) long; the German cockroach, Blattella germanica, about 15 mm (0.59 in) long; the Asian cockroach, Blattella asahinai, also about 15 mm (0.59 in) in length; and the Oriental cockroach, Blatta orientalis, about 25 mm (0.98 in). Tropical cockroaches are often much bigger, and, contrary to popular opinion, extinct cockroach relatives and 'roachoids' such as the Carboniferous Archimylacris and the Permian Apthoroblattina were not as large as the biggest modern species.
The Cardiovascular System of CockroachesThe heart of the cockroach is elongated, thick, muscular, tubular and 13-chambered. It lies in the pericardial sinus of the haemocoel. Each chamber of the heart receives oxygenated blood from the dorsal sinus through one pair of slit like openings called ostia. The heart contracts in a postero anterior direction and the blood also flows posteroanteriorly. The alary muscles are responsible for the circulation of blood. The first chamber leads into an aorta, which opens in the head sinuses which are connected to the pericardial sinus through perineural and perivisceral sinuses.
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The video above shows the cardiovascular system of a cockroach that was dissected.
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