Winter 2016 American Currents 26

CURRENT STATE OF THE INVASION: 50 YEARS OF THE BLACK ACARA IN FLORIDA

Ryan CrutchfieldFishMap.org

The Black Acara or Two-spotted Cichlid (Cichlasoma bi-maculatum) is one of the earliest and best established of the invasive freshwater species in south Florida. It currently is known to be established in 11 watersheds and is likely es-tablished in many more (Figure 1). The Black Acara is estab-lished in the Kissimmee (03090101), Western Okeechobee Inflow (03090103), Lake Okeechobee (03090201), Everglades (03090202), Big Cypress Swamp (03090204), Caloosahatchee (03090205), Manatee (03100202), Tampa Bay (03100206), and Crystal-Pithlachascotee (03100207) watersheds (USGS 2015). It has also been reported in the Charlotte Harbor watershed (03100103) and Myakka watershed (03100102) (Nunziata and Skidmore 2014). The second edition of the Peterson Guide to Freshwater Fishes states that the Black Acara is established in Florida south of Lake Okeechobee (Page and Burr 2011).

Native to South America, the history of the Black Acara in Florida begins when it was first reported in 1965 as be-ing established in Fort Lauderdale in Broward County (Ri-vas 1965), although it is thought that the populations started showing up in Miami in the late 1950s (Kahn 1980). It was identified at the time as Aequidens portalegrensis which is an obsolete name for Cichlasoma portalegrensis, known as the Port Acara, Porthole Cichlid, Port Cichlid, or Red Port Aca-ra. This species is also sometimes called the Black Acara and it is possible that the shared common name as well as simi-lar appearance was the reason behind this identification. Up until the 1950s the Black Acara were farmed in Florida for the aquarium trade because it was a popular fish, but when

Ryan Crutchfield is an angler, explorer, archaeologist, and soft-ware developer living in the Tampa Bay area. He graduated from Auburn University with a bachelor’s degree in anthro-pology and graduated from the University of Alabama with a master’s degree in archaeology. He is an avid species hunter and has caught 146 species of fishes to date with hook and line. He founded and developed FishMap.org in 2013 to help anglers, aquarium hobbyists, scientific researchers, and anyone with a passion for fishes to learn about the species near them and to visually explore their ranges. A Florida native, he has become recently interested in the many invasive fish species in the state and documenting and understanding their expansion.

Photos by the author.

Several Black Acara from Hillsborough County, Florida, showing the variation within the species.

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air cargo shipments made more colorful fishes readily avail-able, the dull Black Acara were abandoned by the farmers and released (Courtenay and Stauffer 1990; Helfman 2007). They were referred to in the aquarium trade as a very drab fish that is too common to stock (Kahn 1980). From these initial releases the fish has spread steadily through the state from Ft. Lauderdale and Miami into the Everglades and up through Lake Okeechobee and finally up along the western

coast of Florida as far north as Pasco County (FishMap.org 2015).

For current Black Acara collection records there are 183 records from FishNet 2 (FishNet 2, 2015), 317 records from the Nonindigenous Aquatic Species (NAS) database (USGS 2015), and 51 records from the Early Detections & Distribu-tion Mapping System (EDDMapS 2015). Many of these re-cords are shared between the agencies and the USGS NAS records are the most thorough and include data from both EDDMapS and FishNet 2. Using the USGS NAS collection data we can map the spread of the Black Acara from the 1960s to today (Figure 2).

The reasons for the success of the Black Acara’s spread through the state is its year-round breeding cycle and abil-ity to withstand low oxygen. (Lee et al. 1980). Additional reasons have been reported as high fecundity, parental care of young, a prolonged spawning season, and adaptabil-ity towards spawning sites (Courtenay et al. 1974). These traits have enabled the Black Acara to establish and main-tain high populations across the state. Additionally, they have been located in almost every type of habitat outside of deep water. They are found in canals, sloughs, ponds, riv-ers, mixed swamp forest, freshwater marsh, cypress forest, cypress prairie, herbaceous prairie, coastal marshes, and all wetlands (Ellis et al. 2006). However, the Black Acara is susceptible to cold weather as was seen in 2010 during cold weather in Everglades National Park when many dead Black Acara and other species were found. The water temperature fell below 6°C and the lethal temperature for Black Acara is

Figure 2. Black Acara locations to date.

Figure 1. Current reported watersheds with established popu-lations.

Winter 2016 American Currents 28

listed as 8.9°C (Hallac et al. 2010). Cold weather is likely the only thing that will stop the spread into the northern Florida counties.

Initially, due to the species rapid expansion, it was feared that the Black Acara would become the dominant species across the southern part of the state. Courtenay predicted that at the turn of the century that Black Acara and other cichlids would be the dominant freshwater fishes in Florida. He is quoted as saying, “You can’t get rid of them. They have spread too far.” (Kahn 1980). It was also predicted that every indication pointed to the Black Acara becoming the domi-nant freshwater fish in South Florida within a decade (Cour-tenay et al. 1974). However, more recent studies have actually found that the Black Acara has declined in some locations after an initial population explosion. In the Everglades, it was found that the Black Acara and Pike Killifish (Belonesox be-lizanus) both displayed patterns of rapid population growth followed by decline and a stable lower population (Trexler et al. 2000). They are certainly established and expanding, but they have not taken over the waterways as of yet.

My own experience with Florida’s Black Acaras comes mostly from Hillsborough County, although I have also captured some in the Big Cypress National Preserve. Many guides and species descriptions will say that Black Acara prefer ditches and other disturbed habitats but I have found them in almost every habitat in Hillsborough County in-cluding headwater streams, ditches, and lakes (Figures 3-4). I have always also found them heavily intermixed with native species, particularly Spotted Sunfish (Lepomis punctatus)

and Bluegill (Lepomis macrochirus). They prefer heavy veg-etation and can be found closer to the shore. Additionally, I have never found them to exist except in huge numbers. It is not hard to capture 25 or more within a short span of time.

My future endeavors are to explore the watersheds where the Black Acara has not been reported, but where it most likely exists. I will start with the watersheds to the east and south of Tampa and also examine the watersheds northwest of Lake Okeechobee. I will also try and see if I can find the northernmost range of the Black Acara. I hope to clarify the actual range and add data to the records. References

Courtenay, W.R., Jr., and J.R. Stauffer, Jr. 1990. The introduced fish problem and the aquarium fish industry. Journal of the World Aquaculture Society 21(3):145-159.Courtenay, W. R., Jr., H.F. Sahlman, W.W. Miley, II, and D.J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6(4):292-302.EDDMapS. 2015. Early Detection & Distribution Mapping System. The University of Georgia Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed September 25, 2015.Ellis, G., M. Zokan, J. Lorenz, and W.F. Loftus. 2006. Biscayne National Park freshwater fish inventory and monitoring Final Report. Report from Audubon of Florida to NPS Florida Caribbean Inventory & Monitoring Network, Miami, FL.FishMap.org. 2015. Black Acara Cichlasoma bimaculatum. Available online at http://fishmap.org/species/Black-Acara.html; last accessed September 25, 2015

Figure 3. Black Acara habitat: Sweetwater Creek, Hillsbor-ough County, Florida.

Figure 4. Black Acara habitat: retention pond, Hillsborough County, Florida.

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FishNet 2. 2015. FishNet 2 Portal. National Science Foundation – National Biological Information Infrastructure. Available online at http://www.fishnet2.net/; last accessed September 25, 2015.Hallac, D.J. Kline, J. Sadle, S. Bass, T. Ziegler, and S. Snow. 2010. Preliminary effects of the January 2010 cold weather on flora and fauna in Everglades National Park. Homestead: Biological Resources Branch, South Florida Natural Resources Center, Everglades and Dry Tortugas National Parks.Helfman, G.S. 2007. Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources. Washington: Island Press.Kahn, J. 1980. Professor Says Imported Fish Causing Threat. The Palm Beach Post 10 Nov. sec. C1.Lee, D.S., C.R. Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister, and J.R. Stauffer, Jr. 1980. Atlas of North American Freshwater Fishes. Publication #1980-12 of the

North Carolina Biological Survey, North Carolina State Museum of Natural History, Raleigh, North Carolina. Nunziata, C.A., and B.K. Skidmore. 2014. Florida Collecting Guide: A Guide to Collecting, Identification and Aquarium Maintenance of Florida’s Non-Game Fishes. 4th Edition. St. Petersburg: Michael F. Jacobs.Page, L.M., and B.M. Burr. 2011. Peterson field guide to freshwater fishes of North America north of Mexico. Boston: Houghton Mifflin Harcourt.Rivas, L.R. 1965. Florida fresh water fishes and conservation. Quarterly Journal of the Florida Academy of Science 28(3):255-258.Trexler, J. C., W.F. Loftus, F. Jordon, J. J. Lorenz, J.H. Chick, and R.M. Kobza. 2000. Empircial assessment of fish introductions in a subtropical wetland: an evaluation of contrasting views. Biological Invasions 2:265-277. USGS. 2015. Nonindigenous Aquatic Species Database, Gainesville, FL. http://nas.er.usgs.gov, Sept 21, 2015.

peaceful, very undemanding in terms of care, and should be a presence in the hobby for a long time to come. References

Boschung, H.T., Jr., and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington, D. C.Cashner, M.F., K.R. Piller, and H.L. Bart. 2011. Phylogentic relationships of the North American cyprinid subgenus Hydrophlox. Molecular Phylogenetics and Evolution 59: 725-735.Mayden, R.L. 1989. Phylogentic studies of North American minnows, with emphasis on the genus Cyprinella (Teleostei: Cypriniformes). Miscellaneous Publications of the Museum of Natural History, University of Kansas:1-189.Mayden, R.L., A. M. Simons, R.M. Wood, P.M. Harris, and B.R. Kuhajda. 2006. Molecular systematics and classification of North American notropin shiners and minnows

(Cypriniformes: Cyprinidae) p. 72-101. In Studies of North American Desert Fishes in Honor of E.P. (Phil) Pister Conservationist. M. De Lourdes Lozano-Vilano and A.J. Contreras-Balderas (editors). Direccion de Puclicaciones, Universidad Autonoma de Nuevo Leon, Monterrey, Mexico.Page, L.M., and B.M. Burr. 2011. Peterson field guide to freshwater fishes of North America north of Mexico. Boston: Houghton Mifflin Harcourt.Swift, C.C. 1970. A review of the eastern North American cyprinid fishes of the Notropis texanus species group (subgenus Alburnops), with a definition of the subgenus Hydrophlox, and materials for a revision of the subgenus Alburnops. Ph.D. dissertation, Florida State University.

Editor’s Note: Just before this issue went to the printer, Evan Poellinger (La Crescent, MN) found a mail order source for the species and locked them in at half price while making a large order with several NANFA members: Imperial Tropi-cals, http://www.imperialtropicals.com/MiscFish.html

ing in between these stripes fades from a light, golden color to a light blue over the posterior half of the body. Iridescent bright blue coloration is evident in the fins, particularly on the anal fin, and blue also noted at the base of the caudal.

Congratulations to Dr. Scanlan for successfully spawn-ing another fascinating native killie and in the process in-creasing our understanding of this highly localized species.References

Page, L.M., and B.M. Burr. 2011. Peterson field guide to freshwater fishes of North America north of Mexico. Boston: Houghton Mifflin Harcourt.

Rohde, F.C., R.G. Arndt, J.W. Foltz, and J.M. Quattro. 2009. Freshwater fishes of South Carolina. University of South Carolina Press, Columbia.Shute, J.R., P.W. Shute, and D.G. Lindquist. 1981. Fishes of the Waccamaw River drainage. Brimleyana No: 6:1-24.Stager, J.C., and L.B. Cahoon. 1987. The age and trophic history of Lake Waccamaw, North Carolina. The Journal of the Elisha Mitchell Scientific Society 103(1):1-13.Tracy, B.H., W.C. Starnes, F.C. Rohde, and R. Heise. 2013. North Carolina’s Imperiled Fish Fauna, Part XII. http://nc.fisheries.org/wp-content/uploads/2014/10/Fall2013Newsletter.

(Waccamaw Killifish, continued from page 22)

(Rainbow Shiner, continued from page 25)