Interbranchial Septum Research Articles

The structure of the gills of the elasmobranch, Scyliorhinus canicula (1).

The anatomy of the blood supply to the gills of the dogfish, Scyliorhinus canicula, is described. The anatomical basis for a counter-current exchange system at the respiratory surfaces is reported. Within the interbranchial septum there is a capillary network joining all the afferent branchial arterioles of the gill. The structure of the walls of the corpus cavernosum is found to be of smooth muscle cells supported by a basal lamina and connective tissue and lined by endothelial cells containing phagocytic vesicles. Both the capillary network and corpus cavernosum are suggested to function in smoothing the pressure pulses of the blood flow. Pre- and post-lamellar vessels and pre- and post-lamellar sphincters are described. The sphincters are thought to control the number of secondary lamellae physiologically in the respiratory circuit, and by retaining blood within nonperfused lamellae to act in conjunction with pillar cells (contracting in antagonism to the hydrostatic skeleton of the blood) to maintain the rigidity of secondary lamellae in the water current. Whorls of cells of unknown function are found within the interbranchial septum. In the epithelium lining the water channel large cells having a complexly branching plasma membrane and a very large central vacuole occurs. The cytoplasm lining the lumen contains numerous vacuoles each surrounded by a double membrane.

Structure of Respiratory Organs of <i>Esomus dandricus</i> (Ham.)

In Esomus dandricus (Ham.), 4 pairs of gills are present with secondary lamellae having a thin lamellar epithelium. The space, which is present in between the proximal margin of gill filaments and branchial septum, forms the so-called water channels to distribute water along the length of the gill filaments. Number of mucous glands and taste buds are present on the gill- rakers and gill head region. The gill filaments of the two-hemi branches are long and alternately arranged to each other, unequal in length and are separated by a comparatively long interbranchial septum (covering about 42% of the total length of the filaments). Tertiary lamellae are absent. Keywords: Fish, Esomus dandricus, Respiratory organsdoi:10.3126/on.v1i1.305Our Nature (2003) 1: 49-52