Fishes of the Western North Atlantic 6 5 



of Lepisosteus.^ I.episostei is chosen here because of the connotation carried by this 

 name. 



Relationships. It is customary in general works on living fishes to place the Lepi- 

 sostei next to the amiids, with which they agree : in the abbreviate-heterocercal nature 

 of their caudal fin skeleton (made evident externally by the dorsoposterior slope of the 

 rear boundary of the fleshy caudal peduncle); in their flattened, overlapping pelvic 

 bones; in their chambered swim bladder that serves as an accessory respiratory organ; 

 and in the presence of a rudimentary spiral valve in their intestine. However, they dif- 

 fer widely from the amiids in many respects. The body scales, for example, which are 

 thick and interlocking but not overlapping in the lepisosteids, are thin and widely over- 

 lapping in the amiids, but the fulcral scales that arm the margins of the fins in the 

 former are rudimentary in the latter. The long snout, the segmented "maxillary" bones, 

 a lower jaw articulating anterior to the eye, and the three rod-like branchiostegals of 

 the lepisosteids are replaced in the amiids by a short snout, unsegmented maxillaries, 

 a lower jaw articulating posterior to the eyes, and by 10—12 broad plate-like branchio- 

 stegals ; and the free margin of the branchiostegal membrane, which crosses the isthmus 

 in a continuous arc of long radius in the lepisosteids, is deeply incised there in Amia, 

 one side overlapping the other. In lepisosteids the preopercular bone does not extend 

 as far forward as that in the amiids, the cheek region is covered by irregular plates 

 in lepisosteids but not in amiids, there is no bony gular plate in the chin region be- 

 tween the branches of the lower jaw as in Amia, and the dorsal is much shorter in 

 lepisosteids than in amiids. The following internal differences deserve mention: the 

 vertebral centra, which are concave posteriorly but convex anteriorly in the lepisosteids, 

 are concave anteriorly as well as posteriorly in Amia\ the vertebral column in the tail 

 region is diplospondylous; and the arterial cone of the heart, which has eight trans- 

 verse rows of valves in the lepisosteids, has only two rows in the amiids. 



Among fossil groups, lepisosteids are usually associated with the Semionotidae, 

 some of which are known from as far back as the Jurassic. 



Spawning and Development. Spawning takes place entirely in fresh water during a 

 rather brief period beginning about mid-May and lasting until mid-June, in the latitude 

 of New York (j [1879]: 6^, 67). When Garfish move into shallows to spawn, each 

 female is accompanied by one to four males and there is a great amount of thrashing 

 during the breeding activities. Fertilization is external. The large numbers of individ- 

 uals that concentrate in the shoal areas suitable for spawning disperse rather suddenly 

 to other areas afterwards. 



The eggs are adhesive and adhere to the substratum. No parental care is given to 

 the eggs or young. On the ventral surface at the end of the snout the larvae have peculiar 

 adhesive suckers that are used for attachment to objects on or above the bottom. The 

 larvae are relatively inactive until the yolk mass is absorbed, but then they become very 

 active predators. 



A characteristic caudal filament that develops at the termination of the upturned 



5. Many authors have preferred the spelling Lepidosleus. 



S 



