“Northern sunfish”的意思、由来-开放百科全书

The northern sunfish (Lepomis peltastes) is a North American species of freshwater fish in the sunfish family (Centrarchidae) of order Perciformes. Lepomis peltastes was traditionally recognized as a subspecies of longear sunfish (Lepomis megalotis) but is often considered to be a separate species.^[1] However, this change remains controversial.^[2]

Identification

The northern sunfish (Lepomis peltastes) and the longear sunfish (Lepomis megalotis) contain very few physical variations. Both are generally small, vibrantly scaled fish with bright, elongated opercular flaps which give the fish an appearance of an ear. This "ear" is a key factor in differentiating the two fish. Lepomis peltastes opercular flaps tend to have an outline of white and red, while Lepomis megalotis outlines are strictly white. Although each species coloration is nearly identical, the patterns which form from these colors are not. The northern sunfish tends to have more of a lateral stripe and speckled turquoise pattern along its sides, while the longear sunfish tends to have spotting on its sides, still in turquoise. Each fish also has "war paint" all the way from the mouth to the edge of the gill flap in the same color as the speckles or spots. Both also contain olive sides and bright orange bellies. These few differences between Lepomis peltastes and Lepomis megalotis leave these fish incredibly hard to distinguish from one another.^[3] In all other aspects, these fish look near identical.

The northern sunfish is usually regarded as a subspecies of the longear sunfish due to little and/or improper justification as to why this fish should be elevated as a separate species.^[4] The assertion, brought about by Carl Leavitt Hubbs over three decades ago, has yet to be clarified with ichthyologists.

Habitat and Range

The northern sunfish inhabits the uppermost portions of the United States, such as the Saint Lawrence River and the Great Lakes Region, as well as the Hudson Bay, Mississippi River, and portions of Ontario. This fish is found in generally small, quiet, temperate streams or rivers with sandy banks or rocky bottoms. Northern sunfish prefer to be near vegetation where they can avoid strong currents.^[5]

Diet

Northern sunfish mostly dine on insects and other invertebrates found in or near the water.^[6] They have been known to prey on mites, microcrustaceans, fish eggs, mollusks, filamentous algae, and small fish. Lepomis peltastes is well known for feeding at the water's surface more frequently than other sunfish.

Conservation

Lepomis peltastes is listed as threatened (since 1979) by the state of Wisconsin. This is the only state with a formal recognition of this status condition.^[7] High water turbidity, agricultural runoff and pollution could be factors in this. Minnesota evaluated the fish's spotty distribution in their streams, and reported that Lepomis peltastes was dependent on incredibly specific water conditions.^[8] A push to list the species as special concern has risen from Minnesota's findings.

References

1. ^Bailey, R. M., W. C. Latta, and G. R. Smith. 2004. An atlas of Michigan fishes with keys and illustrations for their identification. University of Michigan Museum of Zoology, Miscellaneous Publications 192, Ann Arbor.
2. ^Hubbs, C. L., K. F. Lagler, and G. R. Smith. 2004. Fishes of the Great Lakes region, revised edition. University of Michigan Press, Ann Arbor.
3. ^Michigan - Dearborn, University Of. "Fish." Friends of the Rouge:. University of Michigan - Dearborn, Web. 04 Jan. 2015. Rouge Watershed - Northern Longear Sunfish.
4. ^Jennings, Martin. "Online Fishes of Wisconsin." Fishes of Wisconsin. Fishes of Wisconsin, June 2013. Web. 04 Jan. 2015. Fishes of Wisconsin - Longear Sunfish {{webarchive|url=https://web.archive.org/web/20150104095803/http://infotrek.er.usgs.gov/wdnr_fishes/account.jsp?species_param=1464 |date=2015-01-04 }}.
5. ^Torres, Armi G. "Lepomis Peltastes Summary Page." FishBase. Web. 04 Jan. 2015. Fishbase - Lepomis Peltastes.
6. ^Lyons, John. "Wisconsin Department of Natural Resources." Longear Sunfish (Lepomis Megalotis). DNR of Wisconsin, 07 Oct. 2014. Web. 04 Jan. 2015. Wisconsin DNR - Longear Sunfish.
7. ^"Critter Catalog." BioKIDS. Ed. William Fink, Allison Poor, and Mary Mullaney. University of Michigan, 2003. Web. 04 Jan. 2015. BioKIDS - Creek Perch.
8. ^Ceas, Patrick, and Jean Porterfield. "Minnesota State Wildlife Grants Program." Life Histories of the Northern Longear Sunfish (Lepomis Megalotis Peltastes) and Pugnose Shiner (Notropis Anogenus) in Minnesota, with Examinations of Other Rare Non-game Fishes (2012): 1+. Minnesota Department of Natural Resources. Minnesota State DNR, 2012. Web. 5 May 2015. <Minnesota State Wildlife Grants Program (Lepomis megalotis peltastes)>