66 Memoir Sears Foundation for Mari?ie Research 



vertebral column is generally kept in constant rapid motion, as are the fringed, fleshy 

 pectoral fins. The caudal filament atrophies at different times in the various species. 

 Fin rays develop much sooner in the pelvic than in the pectoral fins; hence the pelvics 

 are actually well-defined fins while the pectorals are still delicately fringed, fleshy stumps.* 



The lateral-line sensory system appears early in life, before any scales are formed. 

 The lateral-line scales develop in a posterior-to-anterior direction, as do the other body 

 scales. Usually by the time the anterior lateral-line scales are developed, lateral scales 

 have formed on the caudal peduncle; on the lateral areas, scales develop ahead of those 

 on the mid-dorsal and midventral regions. Moreover, those of the mid-dorsal area de- 

 velop ahead of the ones on the midventral section, so the breast Is the last to become 

 scaled. The most posterior fringe of scales that Is superimposed on the bases of the 

 caudal rays does not appear until after the scales on the whole anterior part of the lateral 

 line and on the body up to the region of the pelvic fins have developed. This terminal 

 fringe of scales usually contributes one to three scales to the lateral-line count. Fulcral 

 scales appear after the fins are otherwise well developed. The caudal fin Is somewhat 

 of an exception In that one to three rays form In the superior region following the caudal 

 filament. The last of these upper rays may not be fully developed until the early juvenile 

 stage Is reached. 



Differential growth of structures is pronounced in the Garfishes; although it be- 

 comes less marked with age, it does not terminate with maturity. The diameter of the 

 orbit continually changes in proportion to other parts of the body — particularly to 

 snout length, Interorbital distance, and postorbltal distance. Primarily because workers 

 have failed to consider such changes properly, the systematlcs of these fishes has been 

 in a chaotic condition for many years.' Males not only mature at a smaller size but 

 grow to a smaller size than females, and sexual dimorphism exists In some structures, 

 e. g. length of snout In the Spotted Gars. 



Habits and Food. The Garfishes are sluggish creatures most of the time. During 

 the summer they frequent the surface waters and appear more or less motionless for 

 minutes at a time. In streams below barriers, such as dams or falls, frequently large 

 numbers of Longnose Gar can be seen near the surface on bright sunny days. In this 

 quiet state, the caudal fin is usually undulated slowly while they are at rest or moving 

 slowly forward or backward. But they are capable of swimming rapidly for short dis- 

 tances by rapid undulations of the body. When disturbed, they immediately "sound." 

 In the winter they are found in the deeper waters; the shrimp trawlers frequently 

 catch Alligator and Longnose Gars In their trawl nets from the deep holes of estuaries 

 and bayous in the salt marshes of Louisiana. 



During the summer months the periodic surfacing of Garfishes Is a common sight, 

 and there Is some debate about their successfulness in gulping air during these surface 



6. A young specimen of L. osseus without scales and with the peculiar fleshy pectoral fins induced Rafinesque to 

 describe the form as a new genus, Sarchirus {^6: 418). 



7. L. Agassiz {4: 360) recognized the remarkable changes that take place in the ontogeny of Garfishes, and 

 possibly this was the reason he never followed through with the description of 22 supposed new species, most 

 of which were discovered during a journey in the eastern United States (L. Agassiz, j: 136). 



