14 
Charles K. Biernbaum 
(Dexter 1953). Eulimnadia ventricosa occurs in the Atlantic drainage 
from Maryland to Georgia (Fitzpatrick 1983), but has not been 
previously reported from South Carolina. 
Of the 25 cladoceran species collected, only three were widely 
distributed and, when present, usually abundant: Simocephalus serru- 
latus, Eurycercus ( Bullatifrons ) vernalis, and Ilyocryptus spinifer. Of 
these, S. serrulatus was the most commonly encountered species. 
Simocephalus serrulatus had two pulses of increased numbers: May 
through June and December, with June’s population increase being 
especially pronounced. Population fluctuations of E. vernalis were 
similar, with pulses occurring in June and from December through 
January. 
Four cladoceran species ( Simocephalus exspinosus, Ceriodaphnia 
reticulata , Scapholeberis kingi , Macrothrix rosea ) were widely dis- 
tributed in the refuge, but usually present in small numbers. There were 
occasions, however, when each of these species was abundant. 
Simocephalus exspinosus , for example, reached very high densities in 
the borrow pit and adjacent pools referred to above from July through 
January and in a swamp and flooded forest floor in January. It was 
widely distributed at other locations and at other times, but in low 
numbers. Ceriodaphnia reticulata , otherwise found in low numbers, 
became very abundant in a ditch and impoundment in June 1983. 
Scapholeberis kingi reached enormous numbers in a borrow pit in June 
1983. There were fairly high numbers of Macrothrix rosea in a few 
samples. Like the species mentioned above, Chydorus cf. C. sphaericus 
and Diaphanosoma brachyurum were widely distributed, but never 
collected in abundance. This is in contrast to the findings of Mallin 
(1984), who found D. brachyurum to be one of only two major 
cladoceran species (the other being Bosmina longirostris) in an acidic 
South Carolina impoundment. 
Three cladoceran species were very restricted in their distribution, 
but usually abundant when present. In August 1982 Daphnia laevis 
reached enormous numbers in a swamp adjoining Dingle Pond, a 
habitat that was dry in August 1983. That species was found nowhere 
else in the refuge. Elsewhere, Daphnia laevis has often been found in 
temporary ponds (Brooks 1959). Sida crystallina was restricted to Lake 
Marion and a few impoundments, being very abundant in the lake 
during June 1983. Monospilus sp., although restricted to the lake, was 
found there in large numbers. 
Frey ( 1982a, b,c) urged caution when identifying cladoceran species 
because several species, previously believed to be cosmopolitan, have 
been found to be species complexes, e.g. Black’s (1980) report on 
Bosmina longirostris and that by Frey (1980) on Chydorus sphaericus. 
