Invasive of the Pacifisc Northwest:

Bluegill, Lepomis macrochirus

Kaili Park

FISH 423: Olden

12/5/2014

Figure 1: Illustration of a . http://wdfw.wa.gov/fishing/washington/Species/1728/

Diagnostic information in shallow water 30-60 centimeters deep. This occurs in May – Classification June in their native range (Texas Parks and Wildlife). When adults spawn, : offspring hatch 2-3 days after Suborder: Percoidei fertilization and remain in the nest for up to 7 days (Neff & Cargnelli, 2004). Family: Centrachidae After being hatched in the littoral zone, the juvenile migrate to the : Lepomis limnetic zone of the pond or lake to feed, then return to the littoral zone in Species: Macrochirus (Rafinesque) the fall (Faber 1967, Werner 1967, Werner 1969). Common Name(s) Feeding habits Bream, Brim, , Copper Nose, Sunfish, Sunperch. Bluegill are trophic generalists and will eat pretty much anything that Basic identification key fits in to their mouths, from Bluegill are small, spiny, perch- zooplankton to small vertebr ates like fish that are native to freshwater (Ehlinger & Wilson 1988, Azuma bodies of the middle United States. 1992, Branstrator & Holl, 2000). They They belong to the category of have the ability to feed in all levels of along with sunfish and the water column. In the limnetic zone, smallmouth bass. They are they are known to feed on distinguishable from other species of microzooplankton such as copepod sunfish by the dark spot at the base of nauplii, rotivers, and cladocerans their dorsal fin. The dorsal fin can (Siefert 1972, Barkoh & Modde 1987, have 9 to 11 spines which are Bremigan & Stein 1994). connected to the rayed portion of the Reproductive strategies dorsal fin. The anal fin has 3 spines. Coloration is generally a dark oli ve green on top, a reddish -orange belly, and vertical bars on their sides. These colors can be more intense on breeding males (Texas Parks and Wildlife) . They average in size from 10 to 20 centimeters, but can grow up to 28 centimeters (Washington Department of Fish and Wildlife). Bluegill typically school in large groups in the shallows when the temperature is to their liking.

Life-history and basic ecology Figure 2: Bluegill spa wning bed. (Photo Life cycle from When water temperature reaches http://www.rattletrapramblings.com/2009/ 20 degrees Celcius, bluegill begin to 05/06/bluegill -beds-on-harris/) Bluegill have interesting The bluegill are generally a hardy reproductive habits. When conditions species, but prefer warmer waters of signal spawning, male and female fish 17 to 21 degrees Celsius (Michigan gather in a shallow part of the pond or Department of Natural Resources). lake. The male fish make nests in gravel substrate in grouped aggregates, In experimentation, it was found or spawning beds. If the substrate is that the chronic lethal maximum for mud, the nests can be dug through the bluegill was 21.5 degrees Celsius mud and down into the gravel. Females (Hickman & Dewey 1973). Critical then come in and deposit eggs, which thermal temperatures are dependent on the males then fertilize. This colonial what the fish are acclimatized to. In an nesting is an advantage for the experiment by Beitinger et al. (2000) it survival of the eggs. Male fish stay was found that fish acclimatized to 16 with the nest for 7-10 days, never degree Celsius water had a critical leaving, even to eat. The fish thermal temperature of 31.5 degrees aggressively keep predators such as Celsius, while those acclimated to 24 the banded mystery snail ( Viviparus degree celcius water had a critical georgianus) or the bullhead (Ictalurus thermal temperature of 37.5 degrees species) at bay (Gross & MacMillan Celsius. 1981). Nests are guarded after the eggs hatch and while the juveniles stay in the nest for as many as 7 days after hatching (Neff & Cargnelli 2004).

This mode of reproduction is not without its intricacies and variables. It is not unusual for neighboring male and female bluegill to predate on other eggs in the spawning bed, but overall the fish are safer as a group. Defense terretories overlap, and fish on the Figure 3: A school of bluegill near a perimeter of the bed keep nests in the rocky lake bottom (photo from middle safer (Gross & MacMillan 1981). Size of male fish affects h ow http://www.miseagrant.umich.edu/explore/ many times and how early in the native-and-invasive-species/species/fish - season the individual gets to spawn. species-in-michigan-and-the-great- Larger fish may nest multiple times in one breeding season, and they get an lakes/bluegill/) earlier start. Smaller males may nest only once and get a later start than Biotic associations (pathogens, larger males (Cargnelli & Neff 20 06). parasites, commensals)

Environmental optima and tolerances A variety of parasites are known to use bluegill as a host. These Bluegill prefer shallow water parasites include Dactylogyrus species and complex habitat with plenty of (gill flukes), Ergasilus caeruleus, cover, which can include weeds, logs, Protocephalus species (fish or drop-offs. Although the species tapeworms), Spinitectus species, and tends to prefer shallow water, they Leptorhynchoides species (Neff & may move to deeper water in the Cargnelli 2004). instance of high water temperature. Figure 4: Native and non-native distribution of bluegill in the United States lower 48. Native range is shown in orange, non-native range is shown in red. (Photo from http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=385http://nas.er.usgs.gov/queries/factsheet.aspx?Specie sID=385http://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=385

Parasites aren’t all that may live the disadvantage of slower growth as a within a bluegill’s body. Some result (Raikow 2004). research has been done on the stomach bacterial communities of invasive Current geographic distribution bluegill. Different bacterial communities are present in bluegill that feed on different parts of the native food web (Yonekura et al. 2007).This is a way that bacterial commensalism assists in the impact of invasive bluegill.

An environmental biotic interaction can occur where invasive bluegill and invasive zebra mussels (Dreissena polymorpha) share a water body. These two species compete for the same microzooplanktonic food, yet zebra mussels are much better at eating it all first. Bluegill, as a result, have Figure 5: Non-native distribution in Washington State. Colors indicate species emphasis for recreational fishing (Photo invasive bluegill is for young anglers from to practice fishing (Texas Parks and Wildlife). http://wdfw.wa.gov/fishing/washington/Sp ecies/1728/) Factors influencing establishment and spread.

Distribution in the PNW and the Bluegill are something of a United States. super-fish. The species are incredibly hardy and able to live in a wide variety Bluegill are native to the middle of climates and habitats. They exhibit and eastern regions of North America, a high fecundity, laying many eggs in but now are introduced throughout a nest. Many of these eggs survive to North America and to 20 other hatching because of the high parental countries worldwide (Welcomme care from male bluegill guardsmanship 1992). Originally, the species is native of the nest. These two traits together to well-known places including the make bluegill reproduction highly Great Lakes, and the Mississippi successful and their population fast - River. growing (Hashagen 1973, Barwick History of invasiveness 1984). When bluegill are newly introduced to an area, they do not need The bluegill spread throughout a very high propagule pressure to the United States as a sportfish and as establish and spread relatively quickly, a foragefish for largemouth bass. It as was seen in the study by Kawamura was spread to other countries such as et al. (2010). Once they are Japan intentionally. In 1960, fifteen introduced, they have a high bluegill were given to Japan as a gift morphological, physiological, and from the mayor of Chicago. In the behavioral adaptability to their new present day, all bluegill in Korea and environment (Gross & Charnov 1980, Japan have lineages that can be traced Ehlinger et al. 1997, Chi pps et al. back genetically to those same fifteen 2004). Sometimes, humans will fish (Kawamura et al. 2010). facilitate the establishment of bluegill by increasing genetic diversity as was Invasion process the case in . Th e bluegill here were too small according to local Pathways, vectors, and routes of anglers, which was probably due to a introduction. limited genetic background when The pathway through which introduced. Because of this, larger bluegill were introduced across the bluegill from Florida were imported to United States is through introduction help the population grow larger and for recreational fishing. The fish faster (Moyle 1976). aren’t a popular fish, there are Potential ecological and/or economic some niche enthusiasts however. The impacts fish were brought inin many places not only for fishing, but as a Bluegill have a big presence in for largemouth bass (Kawamura et al. any foodweb. The fish can eat a wide 2010). The species is targeted more variety of prey, pretty much anything than any other sunfish due to its vigor that can fit in its mouth. This creates when caught on a hook, as well as its significant interactions with any native easy catchability. Some sources make organisms on multiple trophic levels. the point that the main purpose of Even with reduced genetic variation in an introduced population, one little an impact, even if it is only seasonal group of fish can become a big with breeding season. persistent problem. A main way bluegill pose an environmental hazard Economical impacts from is that they out-compete other bluegill are not as pertinent as the organisms of the same trophic level f or ecological ones. Bluegill support the food. Combined with the high survival industry that is recreational fishing in and rapid expansion of bluegill, more than one way, so having them competition for resources can be around is more of an economical deadly for other aquatic populations benefit. against this contender (Yonekura et al. 2007). As time goes on, an individual bluegill’s impact on the environme nt increases as their need and ability to catch prey increases. Smaller fish tend to hide in cover, like aquatic plants. This gives them less access to the variety prey that their water body has to offer. As the bluegill grow, however, the situation shifts and they are able to venture into open -water. At this point in their life cycle they are able to access food resources previously unavailable, and therefore Figure 6: A small, juvenile bluegill have a greater presence and impact (photo from http://microfishing.com/about/) (Mittelbach 1981).

In California, bluegill are known to outcompete the native Sacramento perch spatially. The vivacious bluegill chase Sacramento perch out of optimal habitat, even spawning areas. Sacramento perch are consequently forced in to habitat where they are more vulnerable to predation (Moyle et al. 1974, M oyle 1976).

Also in California, bluegill are likely to blame for the decline of native California ranid frogs and California Tiger Salamander, as they compete for the same food resources (Hayes & Jennings 1986).

Bluegill dig many sizable nests during the breeding season. What implications this may have on native aquatic flora and other species using Figure 7: A large bluegill mount and the habitat is not fully understood. young angler (photo from Physical change of the substrate is still https://www.landbigfish.com/staterecords/ fishrecords.cfm?ID=14) Management strategies and control implications for fish recruitment methods across systems.

In the United States, there are Cargnelli, L.M., Neff, B.D. 2006. no real radical measures in place to Condition-dependent nesting in eradicate bluegill. In other countries, bluegill sunfish Lepomis such as Korea and Japan, the release of macrochirus. Journal of bluegill is strictly prohibi ted. There, Ecology. 75:627-633. bluegill are ranked as one of the most important invasive species. The se Chipps, S.R>, Dunbar, J.A., Wahl, countries are urgently trying to vilify D.H. 2004. Phenotypic variation the populations (Kawamura et al. and vulnerability to predation in 2006). juvenile bluegill sunfish (Lepomis macrochirus). Information on the management Oceologia. 138:32-38. and control of bluegill in the state of Washington and the entire United Ehlinger T.J., Wilson D.S. 1988. States of America is obscure. The fish Complex foraging polymorphism are quite loved by anglers an d not in bluegill sunfish. Proceedings much is being done to eradicate them of the National Academy of despite the significant damage already Sciences of the United States of done by the conspicuous little fish. America. 85: 1878-1882.

Lieterature cited Ehlinger, T.J., Gross, M.R., Phillip, D.P. 1997. Morphological and Azuma, M. 1992. Ecological release in growth rate differences between feeding behavior: the case of bluegill males of alternative in Japan. reproductive life histories. Hydrobiologia. 243:269-276. North American Journal of Fisheries Management. 17:533- Barkoh, A., Modde, T. 1987. Feeding 542. behavior of intensively cultured bluegill fry. Progressive Fish- Faber, D.J. 1967. Limnetic larval fish Culturist.49:204-207. in northern Wisconsin lakes. Journal of the Fisheries Barwick, D.H. 1984. Role of fish Research Board of Canada. distribution on estimates of 24:927-937. standing crop in a cooling reservoir. North American Gross, M.R., Charnov, E.L. 1980. Journal of Fisheries Alternative male life histories in Management. 4:308-313. bluegill sunfish. Proceedings of the National Academy of Branstrator, D.K., Holl, C.M. 2000. Sciences of the United States of Planktivory by bluegill America. 77:6937-6940. (Lepomis macrochirus) on Leptodora kindti in a small Gross, M.R., MacMillan A.M. 1981. North American lake. Predation and the evolution of Hydrobiologia. 437:101-106. colonial nesting in bluegill sunfish (Lepomis macrochirus). Bremigan, M.T., Stein, R.A. 1994. Behavioral Ecology and Gape-dependent larval foraging Sociobiology. 8(3):163-174. and zooplankton size: Hashagen, K.A. 1973. Population and Aquatic Sciences. 61:497- structure changes and yields of 504. during the initial eight years of impoundment of a Siefert, R.E. 1972. First food of the warmwater reservoir. California larval , white fish and game. 59:221-244. sucker, bluegill, emerald shiner, and rainbow smelt. Hayes, M.P., Jennings, M.R. 1986. Decline of ranid frog species in Transactions of the American Fisheries western North America: are society. 101:219-225. bullfrogs (Rana catesbeiana) responsible? Journal of Welcomme, R.L. 1992. A history of Herpetology. 20(4):490-509. international introductions of inland aquatic species. ICES Kawamura, K., Yonekura, R., Ozaki, Journal of Marine Science. Y., Katano, O., Taniguchi, Y., 194:3-14. Saitoh, K. 2010. The role of propagule pressure in the Werner R.G. 1967. Intralacrustine invasion success of bluegill movements of bluegill fry in sunfish, Lepomis macrochirus, Crane Lake, Indiana. in Japan. Molecular Transactions of the American ecology.19:5371-5388. Fisheries Society. 96:416-420.

Mittelbach, G.G. 1981. Foraging Werner, R.G. 1969. Ecology of efficiency and body size: a limnetic bluegill (Lepomis study of optimal diet and habitat macrochirus) fry in Crane Lake, use by bluegills. Ecology. Indiana. The American Midland 62(5):1370-1386. Naturalist Journal. 81:164-181.

Moyle, P.B., Matthews, S.B., Yonekura, R., Kawamura, K., Uchii, K. Bonderson, N. 1974. Feeding 2007. A peculiar relationship habits of the Sacramento perch, between genetic diversity and Archoplites interruptus. adaptability in invasive exotic Transactions of the American species: bluegill sunfish as a Fisheries Society. 103(2):399- model species. Ecological 402. Research. 22:911-919.

Neff, B.D., Cargnelli, L.M. 2004. Other key sources of information Relationships between condition Integrated Taxonomic Information factors, parasite load and System paternity in bluegill sunfish, Lepomis macrochirus. http://www.itis.gov/ Environmental Biology of Fishes. 71:297-304. Michigan Sea Grant

Raikow, D.F. 2004. Food web http://www.miseagrant.umich.edu/ interactions between larval bluegill (Lepomis macrochirus) Michigan Department of Natural and exotic zebra mussels Resources (Dreissena polymorpha). http://www.michigan.gov/ Canadian Journal of Fisheries Moyle, P.B. 1976. Inland fishes of California. Univeristy of California Press, Berkeley.

Nonindigenous Aquatic Species http://nas.er.usgs.gov/

Texas Parks & Wildlife http://tpwd.texas.gov/

Washington Department of Fish and Wildlife http://wdfw.wa.gov/

Expert contact information in PNW

Washington Department of Fish and Wildlife Fish Program

Phone: (360)902-2700

Email: [email protected]

Washington Department of Fish and Wildlife Aquatic Invasive Species

Phone: 1-(888) 9339-247

Current research and management efforts.

There is ongoing research taking place in Japan and Korea concerning the ecological effect of invasive bluegill. In the United States and Washington State, there seems to be less of a concern about the species harming the native environment.

There are no extensive, publicly involved management efforts being made currently.