Freshwater Fish Zoogeography 
45 
a number of downstream records of F. escambiae, however, one of 
which (UF-FSU 3042) is in close proximity to the scarp. In the Apala- 
chicola River drainage, only F. escambiae is found in downstream 
areas, but it also ranges up into the Flint River system as far north as 
Albany, Georgia, where it is abruptly replaced by F. lineolatus . 3 Exten- 
sion of the range of F. escambiae into this area, well above the limits of 
the Cody Scarp, may be attributable to the combination of natural ero- 
sional and depositional processes often seen in the lower sections of 
large rivers, which cause the lowland type of habitat to be extended well 
upstream. 
Elsewhere the influence of the Cody Scarp becomes less obvious. 
Apparently only F. lineolatus occurs in the series of endorheic lakes 
located, near Tallahassee, mostly below the scarp in an area midway 
between the Ochlockonee and St. Marks drainages. In the Aucilla 
drainage a dichotomous distribution pattern seems to emerge. There F. 
escambiae is limited to the more westerly Wacissa system, situated 
entirely below the scarp, with F. lineolatus the only species in the 
Aucilla system proper (where collections exist from both upstream and 
downstream areas). 4 Those drainages situated to the east (Econfina, 
Fenholloway, Steinhatchee), between the Aucilla and Suwannee, lie 
entirely in the lowlands. They apparently are inhabited exclusively by F. 
lineolatus , even though the presence of F. escambiae in the lower 
Suwannee River would logically lead one to expect that species to 
exhibit a continuous distribution along the northeastern Gulf coast of 
Florida. Considering the coastal distribution pattern of F. escambiae , 
together with the presence of (and thus probably in competition with) F. 
lineolatus upstream, it seems unlikely that F. escambiae would have had 
the opportunity to enter the Suwannee via headwater stream capture, as 
is believed to have been the case with a number of other species (see 
subsequent discussion). Possibly those small drainages lying between the 
Aucilla and Suwannee were endorheic at certain critical times during 
the past, which thus would have made them unavailable to colonization 
by F. escambiae. 
Despite certain inconsistencies, it seems clear that the overall dis- 
tributions of Fundulus escambiae and F. lineolatus , as well as those of 
3 A single individual of Fundulus lineolatus (UF-FSU 4521), which is presumed to be a 
bait-fish release, has been collected in the Apalachicola River proper below Jim Wood- 
ruff (= Lake Seminole) dam. 
4 A series of eight specimens from the headwaters of the Wacissa River (UF-FSU 939) 
contains seven Fundulus escambiae and one F. lineolatus (all adults). This is thought to 
have resulted from mixing of collections; but if not, it represents the only record of F. 
lineolatus from the Wacissa system and one of only three cases of known sympatry 
between the two species. 
