A comparison of the vibratory muscle, tail epaxial muscle, and body epaxial muscle respiratory activities in Sistrurus miliarius, Coluber constrictor, and Natrix fasciata

The rattlesnake can be distinguished from other types of snakes by its rattling apparatus. Klauber (1956) describes the rattle as an apparatus consisting of varying numbers of three lobed keratin segments. The segments arc arranged in a string by the loose interlocking of the segment lobes. The rattle is attached to tho. snake by the style, the modified terminal vertebra of the rattlesnake. The style is distally branched, forming a rigid core for the proximal rattle segments. A sound, unique to the rattlesnake, is produced when the segments arc vibrated at great frequencies by the snake\u27s posterior tail musculature (Klauber, 1956). Forbes (1967) used isolated tissue QO2\u27s, succinct dehydrogenase activity, and cytochrome oxidase activity to compare the tail respiratory activities of a number of snakes. The vibratory muscle respiration of C. horridus was compared to two non-rattling snakes: Agkistrodon contortrix (the copperhead snake) a non-rattling tail vibrator belonging to the rattlesnake family, Crotalidae; and Thamnonhis sirtalis (the garter snake), a non-vibrating member of the family Colubridae. Forbes (1967) found that the rattlesnake vibratory muscle was very specialized in respiratory activity when compared to its own body epaxial muscle. This specialization was also present, but not as great in A. contortrix. Thamnophis sirtalis showed no tail muscle respiratory specialization. The present investigation seeks to expand Forbes\u27 study by determining if muscle respiratory specialization exists in another rattlesnake, and to determine if a tail vibrator of another family, Colubridae, possesses any degree of tail muscle specialization. Sistrurus miliarius (the pigmy rattlesnake) was chosen to be compared with a tail vibrator, Coluber constrictor (the black racer), and with a non-tail vibrator, Natrix fasciata·(the southern banded water snake), both members of the family Colubridae. Rate of oxygen consumption and the activities of two respiratory enzymes (succinic dehydrogenase and cytochrome oxidase) of isolated muscle were used as indices of respiratory activity