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1. Ventral aorta and afferent branchial, arteries. Ventral aorta is a single stout artery, running straight ahead, mid-ventrally below the, floor of pharynx. Reaching upto the hyoid arch,, it bifurcates into two short right and left innominate, arteries. Each innominate immediately divides into, first and second branchial arteries (af and af2)., Third, fourth and fifth branchial arteries also, arise from ventral aorta almost at regular intervals., Scanned with CamScanner

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From the upper end of each efferent branchial, from ventral aorta. The anterior most or the first, loop arises an epibranchial artery. The four, anterior side of fifth gill pouch. Adjacent loops, epibranchials thus formed run backwards and, inwards to join a large median dorsal aorta., of both sides arise by a common median aperture, While others arise independently, the fifth branchials, afferent branchial runs along the posterior border, of hyoid arch supplying branches to gill lamellae, of its demibranch. One of each of the remaining, four branchials enters one of the four interbranchial, septa to supply branches to its holobranchs, i.e., gill lamellae of both sides. The afferent vessels, break up into capillaries in the gill lamellae for, aeration of blood., 2. Efferent branchial and epibranchial, arteries. Aerated blood from capillaries of gills, is collected by a series of nine efferent branchial, arteries (ef to efg). Those running along the, anterior (pretrematic) and posterior (posttrematic), sides of a gill pouch join together forming a, complete loop encircling the gill pouch. Thus, the, first eight efferent vessels form four complete, loops around the first four gill pouches. The single, ninth efferent vessel (efo) runs alone along the, are, short, longitudinal, interconnected, connectives., by, ventral, 3., Scanned with CamScanner