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2009 SOUTHEASTERN NATURALIST 8(2):267–276
Enneacanthus chaetodon (Blackbanded Sunfish): An
Imperiled Element of Maryland’s Coastal Plain Ichthyofauna
Jay V. Kilian1,*, Scott A. Stranko1, Richard L. Raesly2, Andrew J. Becker1,
and Patrick Ciccotto1
Abstract - In 2002 and 2006, we conducted a survey of historical collection localities
for Enneacanthus chaetodon (Blackbanded Sunfish) in Maryland. Blackbanded
Sunfish were detected at only one of six historical localities. This locality consisted
of 17 quarry ponds, but the Blackbanded Sunfish was collected in only three of these.
These ponds were characterized by low pH (<4.9), dense submerged and overhanging
vegetation, and the absence or low abundance of non-native piscivores. The
acidic nature of these ponds may provide refuge from predation for Blackbanded
Sunfish by limiting numbers of non-native piscivores such as Micropterus salmoides
(Largemouth Bass) and Pomoxis nigromaculatus (Black Crappie). As a result of
the surveys described herein, the Blackbanded Sunfish state status in Maryland was
elevated from Threatened to Endangered.
Enneacanthus chaetodon Baird (Blackbanded Sunfish) is a small
centrarchid typically associated with heavily vegetated, tannin-stained
dystrophic ponds, swamps, and slow-moving habitats of streams and rivers
(Jenkins and Burkhead 1993, Lee et al. 1980). This species is sporadically
distributed on the Atlantic Coastal Plain from New Jersey to Florida and
on portions of the Gulf slope in Georgia (Lee et al. 1980). Throughout this
range, the Blackbanded Sunfish is absent from many areas, resulting in many
disjunct populations (Jenkins et al. 1975, Lee et al. 1980, Sweeney 1972).
Peculiar absences of this species throughout portions of its range are hypothesized
to be the result of saltwater inundation into freshwater habitats caused
by sea-level rise during the Pleistocene epoch (Sweeney 1972). Competition
with other centrarchids may also explain the absence of Blackbanded Sunfish in areas with otherwise suitable habitat (Jenkins et al. 1975). Although
considered secure in New Jersey and South Carolina, the Blackbanded
Sunfish is considered imperiled, vulnerable, or presumed extirpated in Pennsylvania,
Delaware, Virginia, North Carolina, Georgia, and Florida (Arndt
2004, NatureServe 2008). Recent efforts to collect Blackbanded Sunfish in
Florida were unsuccessful (Tate and Walsh 2005).
The historical range of Blackbanded Sunfish in Maryland includes the
Nanticoke, Wicomico, and Pocomoke river basins on the Delmarva Peninsula,
in which the majority of historical collection localities are ponds or
1Maryland Department of Natural Resources, Monitoring and Non-tidal Assessment,
580 Taylor Avenue, Annapolis, MD 21401. 2Frostburg State University, Department
of Biology, 101 Braddock Road, Frostburg, MD 21532-1099. *Corresponding author
268 Southeastern Naturalist Vol. 8, No. 2
impoundments in the Nanticoke and Wicomico river basins. The most recent
collection of Blackbanded Sunfish was in 1999 from an unnamed pond in
a quarry pond complex located along Marshyhope Creek in the Nanticoke
River basin. There is only one record for a lotic population of Blackbanded
Sunfish in Maryland. This collection was made from Old Mill Branch, a
tributary to the Pocomoke River on the Delmarva Peninsula (Speir et al.
1976). Lotic systems within the historical range of Blackbanded Sunfish
in Maryland were sampled extensively from 1994 to 2006. The Maryland
Department of Natural Resources’ Maryland Biological Stream Survey
(Kazyak et al. 2005) and others (McIninch 1994; Raesly 1995, 1996) have
sampled over 185 stream sites in the Nanticoke, Wicomico, and Pocomoke
river basins, including Old Mill Branch. Blackbanded Sunfish has not been
collected from a stream or river in Maryland since 1976.
Given the extensive effort that has been focused in lotic systems, and
the dearth of effort in lentic habitats in Maryland, we conducted a survey of
ponds and impoundments where Blackbanded Sunfish were historically collected.
The objectives of this study were to determine the current distribution
and status of Blackbanded Sunfish in Maryland and determine what factors
may be correlated with the distribution of the species.
In the summer of 2002 and 2006, we attempted to collect Blackbanded
Sunfish from six historical collection localities (Fig 1). These localities
Figure 1. Locations of historical collection localities for Blackbanded Sunfish
sampled in 2002 and 2006.
2009 J.V. Kilian, S.A. Stranko, R.L. Raesly, A.J. Becker, and P. Ciccotto 269
included Leonards Mill Pond, Williams Pond, Schumaker Pond, Tony Tank
Lake, Smithville Lake, and the complex of quarry ponds where Blackbanded
Sunfish was last collected in Maryland.
We sampled all five impoundments and 17 ponds within the quarry pond
complex using electrofishing. While electrofishing in dense vegetation, the
vegetation was searched extensively for small fishes, and dip nets were used
to sweep through and lift the plants to increase capture efficiency. A 14-foot
jonboat outfitted with a Smith-Root Model KVA electrofisher was used to
sample all non-wadeable habitats. The boat was positioned perpendicular to
the shoreline and electroshocking was conducted moving from deepwater
offshore to shallow inshore habitats. Backpack electrofishing (Smith-Root
Model 12; Haltech Model HT-2000) was used in wadeable margins of ponds
and impoundments. Sampling was conducted until all available habitats
had been sampled and no new species of fish were captured for at least
600 seconds. With the exception of Schumaker Pond, Tony Tank Lake, and
Smithville Lake, abundances of fish species were qualitatively assessed as
rare, common, or abundant.
In the summer of 2006, temperature (°C), pH, acid-neutralizing capacity
(ANC; μeq/L), dissolved oxygen (mg/L), specific conductance (mS/cm), and
dissolved organic carbon (DOC; mg/L), were recorded at 15 quarry ponds
and two impoundments (Williams Pond and Leonards Mill Pond) in addition
to fish sampling. With the exception of ANC and DOC, which were analyzed
at the University of Maryland Appalachian Laboratory, all water chemistry
parameters were measured using a Hydrolab Quanta. Principal component
analysis was used to visualize potential patterns in these variables as they
relate to the presence of Blackbanded Sunfish. Variables were tested for
normality with a Kolmogorov-Smirnov test in SAS Enterprise Guide (SAS
Institute 2006). Specific conductance was the only variable that failed the
test for normality, and was subsequently log10(x) transfromed. A correlation
matrix was used to run the principal component analysis in PC-ORD (Mc-
Cune and Medford 2006).
We collected 27 species of fishes, including all three species in the genus
Enneacanthus, using electrofishing (Table 1). Blackbanded Sunfish were
collected in very low abundances from only three ponds in the complex of
quarry ponds. These ponds were characterized by low pH and ANC (less
than 4.9 and 12.8, respectively; Table 2), an abundance of submerged logs
and limbs, dense aquatic vegetation, and few non-native piscivores (i.e.,
Micropterus salmoides (Lacepède) [Largemouth Bass] and Pomoxis nigromaculatus
(Lesueur in Cuvier and Valenciennes) [Black Crappie]). The pond
with the largest collection of Blackbanded Sunfish (7 individuals) was the
only habitat with an abundance of Ceratophyllum demersum L. (Coontail)
along the entire shoreline.
Principal component analysis illustrates the distinct chemical and biological
nature of the lentic habitats where Blackbanded Sunfish were collected.
270 Southeastern Naturalist Vol. 8, No. 2
Table 1. Numbers of Blackbanded Sunfish collected and qualitative abundance of other fish species collected in 2002 and 2006. R = rare: comprising smallest
proportion of total catch; C = common: well represented in the catch, but not rare or abundant; A = abundant: comprising largest proportion of total catch. X
indicates that the species was present, but abundance was not recorded. WP = Williams Pond, LMP = Leonards Mill Pond, SP = Schumaker Pond, TTL = Tony
Tank Lake, and SL = Smithville Lake.
Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 WP LMP SP TTL SL
Ameiurus natalis (Lesueur) (Yellow Bullhead) R R R R C C C R R R X X
Ameiurus nebulosus (Lesueur) (Brown Bullhead) R R X X
Anguilla rostrata (Lesueur) (American Eel) C C C C C C C R C A R R C R X X
Aphredoderus sayanus (Gilliams) (Pirate Perch) C R R C R R X X X
Cyprinus carpio (L.) (Common Carp) C
Dorosoma cepedianum (Leseuer) (Gizzard Shad) R C A C R R R
Enneacanthus chaetodon (Blackbanded Sunfish) 1 1 7
Enneacanthus gloriosus (Holbrook) R R A A A C A C C C R C C C X X
Enneacanthus obesus (Girard) (Banded Sunfish) X
Erimyzon oblongus (Mitchill) (Creek Chubsucker) R R R C C R R C A R R R X X X
Esox americanus (Gmelin) (Redfin Pickerel) X
Esox niger ((Leseuer) (Chain Pickerel) C R C R R C C C C C C R R R C X X X
Etheostoma fusiforme (Girard) (Swamp Darter) R R R R R R R X X
2009 J.V. Kilian, S.A. Stranko, R.L. Raesly, A.J. Becker, and P. Ciccotto 271
Table 1, continued.
Species 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 WP LMP SP TTL SL
Etheostoma olmstedi (Storer) (Tessellated Darter) R X X X
Gambusia holbrooki (Girard) (Eastern Mosquitofish) R R X
Lampetra aepyptera (Abbott) (Least Brook Lamprey) X X
Lepisosteus osseus (L.) (Longnose Gar) R C R
Lepomis hybrid R
Lepomis gibbosus (L.) (Pumpkinseed) R R R R R C X X X
Lepomis macrochirus (Rafinesque) (Bluegill) A A A A A C A A C A A R R C A A A X X X
Morone americana (Gmelin) (White Perch) R R
Micropterus salmoides (Largemouth Bass) A A A C R R A A C C R R C C A A X X X
Notemigonus crysoleucas (Mitchill) (Golden Shiner) R C C R C C C C R C R R R A X X X
Noturus gyrinus (Mitchill) (Tadpole Madtom) R R X X
Perca fl avescens (Mitchill) (Yellow Perch) R R C
Pomoxis annularis (Rafinesque) (White Crappie) C
Pomoxis nigromaculatus (Black Crappie) R R C R C A C R C C R A C X X
Umbra pygmaea (DeKay) (Eastern Mudminnow) R A R C R X X X
272 Southeastern Naturalist Vol. 8, No. 2
The eigenvalues of the first three principal component axes were all greater
than their respective broken-stick eigenvalues (Table 3), and the first two
principal components were plotted (Fig. 2). The first principal component
axis accounted for 48% of the total variance and represented ANC, pH, and
specific conductance gradients among historical sites. The second principal
component axis accounted for 29% of the total variance and represented a
dissolved organic carbon gradient (Table 3). Sites where Blackbanded Sunfish were collected and non-native centrarchids were not abundant had lower
pH and ANC values (Fig. 2). Although the small sample size inhibits a rigorous
statistical test of the data, we believe the principal component analysis
identifies a pattern in the distribution of Blackbanded Sunfish.
Although detection may be incomplete due to the application of a single
sampling method (electrofishing) in this study, our results demonstrate that
Blackbanded Sunfish are exceedingly rare in Maryland and the species’
range has declined dramatically. We did not detect Blackbanded Sunfish at
five of the six historical collection localities. Only six other extant populations
of this species were known in the entire Chesapeake Bay watershed at
the time this study was conducted. All six of these are from the Nanticoke
River drainage in Delaware (K. Kalasz and C. Martin, Delaware Division
of Fish and Wildlife, Smyrna, DE, pers. comm.). Historically, Blackbanded
Sunfish were likely widespread throughout the Nanticoke and Wicomico
rivers in Maryland and Delaware, where they inhabited both lotic and lentic
Table 2. Water chemistry of ponds and impoundments used in principal components analysis.T =
temperature (ºC), ANC = acid neutralizing capacity (μeq/L), DO = dissolved oxygen (mg/L),
SpCond = specific conductance (mS/cm), and DOC = dissolved organic carbon (mg/L).
Pond/impoundment T pH ANC DO SpCond DOC
Quarry Pond 1 21.1 5.96 70.3 3.5 0.026 6.1
Quarry Pond 2 20.3 6.38 168.2 2.2 0.039 2.5
Quarry Pond 3 18.9 6.29 308.6 3.4 0.085 5.8
Quarry Pond 4 21.6 6.30 146.9 5.0 0.051 5.5
Quarry Pond 5* 21.4 4.75 12.8 4.0 0.052 9.1
Quarry Pond 6* 20.6 4.87 -0.3 2.0 0.047 9.4
Quarry Pond 7 19.9 6.37 294.1 4.8 0.068 6.5
Quarry Pond 8 19.4 5.66 261.5 2.4 0.050 5.7
Quarry Pond 9 20.3 4.53 6.9 1.5 0.047 14.4
Quarry Pond 10 21.3 5.10 82.1 2.5 0.029 8.7
Quarry Pond 11 19.6 5.80 244.3 2.9 0.089 9.7
Quarry Pond 12* 24.3 4.66 -11.0 4.9 0.032 1.7
Quarry Pond 14 22.7 5.20 -10.0 3.4 0.038 2.6
Quarry Pond 16 22.5 5.07 64.1 5.7 0.025 5.6
Quarry Pond 17 22.7 5.56 64.6 4.3 0.027 7.0
Williams Pond 20.5 5.64 336.1 4.7 0.075 11.2
Leonards Mill Pond 21.1 6.08 370.7 4.8 0.093 10.2
*Blackbanded Sunfish detected.
2009 J.V. Kilian, S.A. Stranko, R.L. Raesly, A.J. Becker, and P. Ciccotto 273
systems. However, all known extant records are from isolated fragments of
Although somewhat cursory, the patterns observed in this study are
consistent with other studies describing Blackbanded Sunfish habitat. Blackbanded
Sunfish have occasionally been observed in bodies of water with pH
levels above 7.0 and can successfully reproduce in neutral or alkaline waters
(Graham 1978, Hoedeman 1974). However, they have most often been found
Figure 2. Principal
component analysis of
water chemistry variables
sites. Dark circles (●)
are sites where Blackbanded
collected and non-native
not abundant; filled
squares (■) are sites
Sunfish were not collected
abundant; and open
squares () are sites
Sunfish were not collected
piscivores were not
the axes are presented
in Table 1.
Table 3. Results of the principal component analysis for water chemistry variables. Eigenvectors
are reported for the first 3 axes for each variable, as well as eigenvalues and percent of
variance explained by the first 3 axes.
Variable Axis 1 Axis 2 Axis 3
pH 0.51 0.33 0.42
Acid neutralizing capacity (μeq/L) 0.62 -0.02 0.05
Dissolved oxygen (mg/L) 0.17 0.52 -0.83
Specific conductance (mS/cm) 0.56 -0.29 -0.11
Dissolved organic carbon (mg/L) 0.11 -0.74 -0.35
Eigenvalue 2.39 1.45 0.79
Broken-stick eigenvalue 2.28 1.28 0.78
% of variance 47.87 29.04 15.82
274 Southeastern Naturalist Vol. 8, No. 2
in highly acidic habitats. Conversely, Graham and Hastings (1984) suggested
that survival of Largemouth Bass and Black Crappie may be reduced
by low pH. Graham (1993) documented a decline in Largemouth Bass and
Black Crappie abundance as pH dropped below 6.0, and absence from waters
more acidic than 4.5. Although our sample size was small and detection may
be incomplete, Blackbanded Sunfish were found only in acidic ponds with
few or no non-native centrarchids suggesting that acidic conditions may
provide refuge from predation and/or competition.
Due to pervasive alterations to the physical, chemical, and biological
conditions of Delmarva streams and rivers, only a few suitable insular lentic
habitats may remain for Blackbanded Sunfish in Maryland. The reduction of
beaver and the removal of millponds have likely contributed to the decline
of suitable habitat within lotic systems. Acidic, dystrophic habitats favored
by this species have been further reduced by large-scale removal of forests,
stream channelization, eutrophication, and liming of land for agriculture.
Current conditions of the large majority of Delmarva freshwater habitats
may be more suited to non-native centrarchids than to the native Blackbanded
In addition, factors responsible for the insular nature of the current
Blackbanded Sunfish distribution have made meta-population interactions
all but impossible for this species. It has not been observed in any stream or
river in Maryland since 1976 (Speir et al. 1976), nor in Delaware since 1995
(K. Kalasz and C. Martin, pers. comm.). The isolation of Maryland’s extant
populations of Blackbanded Sunfish also makes the species vulnerable. With
a maximum lifespan of only four years (Schwartz 1961), one poor recruitment
year or even a minor disturbance of the few habitats where they occur
could result in extirpation from Maryland. Without the connection of populations
living in ponds via habitable river systems, conserving this species is
likely to be challenging.
Surveys for this species with additional gear types (e.g., seining and minnow
traps) are needed to provide a more comprehensive determination of
Blackbanded Sunfish presence in Maryland (MacKenzie et al. 2004). Estimating
detection probabilities for Blackbanded Sunfish for each gear type
would provide useful information to guide future surveys in Maryland as well
(Albanese et al. 2007). Including additional habitat and chemical parameters
in future surveys may also reveal other factors important in determining the
current Blackbanded Sunfish distribution in Maryland. These surveys will
also provide sufficient information for a more rigorous statistical examination
of factors associated with this species. Such information will be important in
managing this species. In the interim, however, the information provided by
the results of this study reveal an immediate need for conservation action. Protection
of the area surrounding the ponds where the species is currently known
to occur is imperative. To the extent possible, Largemouth Bass and other
non-native centrarchids should be relocated from these ponds, and stocking
of these species therein should be discontinued. Depending on the results of
2009 J.V. Kilian, S.A. Stranko, R.L. Raesly, A.J. Becker, and P. Ciccotto 275
follow-up surveys and the status of Delaware populations, possible re-introduction
of Blackbanded Sunfish may be explored in the future.
As a result of the surveys described herein, the Blackbanded Sunfish
state status in Maryland was elevated from Threatened to Endangered.
The status of this species in nearby states, such as Delaware and Virginia
indicate that it may be regionally imperiled. Along with our management
effort in Maryland, we also plan to communicate our results to the natural
resource management agencies in adjacent jurisdictions in hopes of initiating
a region-wide collaboration for the conservation of this species and the
unique coastal plain habitats it represents.
We thank Paul Kazyak for his work on earlier surveys and for providing the impetus
for rare species surveys in Maryland. We also thank Rebecca Chalmers, Rachel
Gauza, Joseph Smith, and Gerald Mack for their hard work in field sampling for this
study. We also thank Rick Schaefer, Brett Coakley, Kenneth Booth, and Jerry Stivers
for providing the most recent record of Blackbanded Sunfish in Maryland. We are
also grateful to Ron Klauda, Dan Boward, Jim McCann, Scott Smith, and Jonathan
McKnight for their guidance, advice, and assistance. This study was funded in part
by State Wildlife Grant funds provided to the state wildlife agencies by US Congress,
and administered through the Maryland Department of Natural Resources’ Natural
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