The St. Croix snaketail dragonfly, or Ophiogomphus susbehcha has occurred twice in the St. Croix River of Minnesota and Wisconsin (USA), and once in the Chippewa River of Wisconsin. The Chippewa River is a tributary of the St. Croix River. However, more recent evidence implies O. susbehcha may also occur eastward, to Pennsylvania and Maryland. An examination of Ophiogomphus edmundo in Pennsylvania determined that it may actually be a previously unidentified subspecies or a sister species to O. susbehcha. After this determination, O. susbehcha was also discovered along the Potomac River near Frederick, Maryland. This species is rare; it most likely has fewer than ten occurrences worldwide and has a total global range of 250-20,000 square km. Ophiogomphus susbehcha is very rare wherever it is found, and has a spotty distribution pattern and discontinuous range. This is characteristic of sensitive species, which tend to be strongly affected by habitat fragmentation. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
Ophiogomphus susbehcha is most likely a large river obligate. Its habitat is a riparian area with high quality water and stable flow. Larvae burrow to the river or stream bottom in deep water of medium to large, fast-flowing, and clear streams and rivers. The bottom of these streams and rivers are composed of mixed gravel, sand, and rock. Adults forage in fields and possibly in trees. Ophiogomphus susbehcha prefers larger streams than other Snaketail species. It is characteristic of Ophiogomphus adults to patrol the rivers in which larvae inhabit. Adults also tend to forage in nearby wetlands, lowland forests, and mature upland forests that have a closed canopy with a low understory. They do not usually occur in cleared or cultivated regions.
All of the known Minnesota populations of O. susbehcha occur in riverine habitats in comparatively undisturbed forests. GIS analysis of O. susbehcha populations in Minnesota implies associations with forested river-bottom wetlands which are bordered by upland deciduous or mixed deciduous and coniferous forest. These have generally included Ulmus (elm), Fraxinus (ash), Populus (poplar), Betula (birch), and Pinus (pine) tree genera, with inclusions of mature Acer (maple) species and Tilia americana (basswood). The terrestrial vegetation is generally unfragmented with a large proportion of the land owned by the federal or state government. Human population density in these areas is low. In geological terms, the Minnesota habitat of O. susbehcha is characterized by sandstone, limestone, and shale deposits. The terrain is flat to moderately inclined. Common sites include glacial outwash plains. Soils are mainly alfisols with sand and sandy loam surfaces and sandy or gravelly subsurfaces. The area's hydrology includes the presence of many springs and streams with high water quality. The annual precipitation input during the growing season is 48-53 cm. Ophiogomphus susbehcha is apparently very sensitive to river pollution, siltation, and/or low dissolved oxygen levels. Therefore, it is generally found in the most pristine rivers and streams. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
Adult O. susbehcha is a large dragonfly with a cobra-shaped clubtail. It is approximately 5 cm in length, and has gray eyes which are widely separated. Its thorax is dark bluish-green with a single lateral black stripe. Ophiogomphus susbehcha has black legs as well as a black shoulder stripe. Its abdomen has yellow dorsal spots, which vary among segments. The yellow dorsal spots are pale and triangular in segments S2-S7, a brighter rectangle on segment S8, and a rounded spot on segment S9. Segment S10 is entirely yellow, which distinguishes this species from closely related species. Females have black postocular horns.
Larval O. susbehcha is slightly flattened dorsal-ventrally. Its abdomen is oval, cylindrical, and slightly pointed. It also has brownish-black spots. It lacks dorsal abdominal spines and has divergent wing cases. The male epiproct is longer than its cerci. Ophiogomphus susbehcha larva are larger than the majority of other Ophiogomphus species in Minnesota and Wisconsin. Also, O. susbehcha larva closely resemble Ophiogomphus howei, the Pygmy Snaketail, except that O. susbehcha larva are much larger.
Most members of Odonata have mouths which have been adapted for biting and a prehensile labium, which in family Gomphidae lacks a notch on the medium lobe. Members of Odonata have six legs, all of which are located near the head. The legs are rarely used for walking, but rather are used for perching and capturing prey. Members of Odonata have a long and slender body. They have two pairs of long wings, which are alike in size and venation. Each wing has a node or joint in the vein near the center of the front margin. They have small, hairlike antennae, and mouthparts which are designed specifically for chewing.
Larval members of suborder Anisoptera have no external gills. Instead, they have a rectal chamber which is used for gaseous exchange. They draw water into this chamber through the anus, then expel it. This is also a means of motility. This rectal respiratory chamber is unique to members of Anisoptera. ("Ophiogomphus susbehcha", 2013; Borror and White, 1970; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965; Sabet-Peyman, 2006; Wellhouse, 1926)
Members of Ophiogomphus usually have a 2-year life cycle. After hatching the larvae burrow into the river bottom, which is a sandy substrate. Larvae spend the winter in the river bottom and emerge as adults the following summer. Ophiogomphus larvae generally undergo 9 to 15 molts between instar stages. Ophiogomphus susbehcha larvae reach maturity between late May and late June. Once mature, they emerge from the water in mid-morning, and crawl away from the shoreline. They then undergo transformation, which lasts for several hours. They molt into winged adults while resting on rocks, vegetation, or on large tree trunks. The newly emerged adult, called a teneral, rests for an hour or two while its wings dries. After the adult flies away, it leaves its exuviae (or caste larval skin) behind. Their flight season extends into early August. Members of Ophiogomphus often undergo a winter diapause as the final instar larvae. This allows members of the same generation to respond synchronistically to rising temperatures in spring. (Gibbs, et al., 2004; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
Ophiogomphus males tend to patrol rivers. They will mate while perched along the shoreline on bushes and trees. Odonata dragonflies do not generally perform courtship behaviors. Intraspecific competition among males for the chance to mate is severe. Most dragonfly species are polygynandrous.
The mating procedure of members of Odonata is unique. Before mating, the male will bend the end of his abdomen forward. He will then transfer is sperm to a bladder-like organ in the second abdominal sternite. Using terminal claspers, he will grasp the female around the neck. The female will then bend her abdomen to the second sternate of the male. This is where the transfer of sperm takes place. (Lyons, 1999; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965; Sabet-Peyman, 2006)
Females will oviposit without the male, by randomly submerging their abdomens into the river. This disperses their eggs directly into the current. Ophiogomphus susbehcha becomes mature in late May to late June, at the time of emergence from the river bottom. Ophiogomphids are not territorial, but will patrol along streams and rivers when searching for a mate. ("Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965)
Females provide provisioning in the eggs, as well as lay the eggs in a suitable aquatic environment. Otherwise, they do not provide any parental care. ("Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
The lifespan of members of Ophiogomphus is usually two years. ("Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
Ophiogomphus susbehcha is a motile, predatory species. Adult members of Ophiogomphus are not territorial, and often perch in treetops in the evening and early morning. While resting, members of Anisoptera usually hold their wings outstretched.
Adult members of suborder Anisoptera have a regular route they patrol. They will fly up and down this area at regular intervals, looking for prey. Once prey is found they will deviate from their course. After the pursuit, they will return to their route. When a rival attempts to capture the same prey, members of Anisoptera will click their mandibles and rustle their wings while flying agilely. Members of family Gomphidae usually fly steadily, without hovering. (Borror and White, 1970; Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Ross, 1965)
Within a catchment, it is most probable that there are no barriers to movement for adult O. susbehcha among microhabitats. This also applies for larger areas with major obstructions to water flow.
Adults Odonates have been known to fly over great distances. The average distance estimated for a flight between reproductive and foraging sites is less than 200 m, but can sometimes be greater than 1 km. Distance traveled is usually greatest for river-breeding Odonates. A population may be defined by the river drainage basin in which it lives. Although adult members of Ophiogomphus forage for food in wooded areas, they usually remain within 30 meters of the river or stream from which they emerged. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
Most members of Odonata have large heads, with compound eyes composed of almost 28,000 ommatidia (individual units). Their eyes are large in proportion to the rest of their bodies and cover most of the head. Most of their brain (greater than 80%) is devoted to analyzing visual signals. Most members of Odonata have very small antennae. They are very efficient hunters. Tactile connections are used during mating, as males grasp the females by the head with their terminal appendages. (Sabet-Peyman, 2006)
Ophiogomphus susbehcha is an insectivore, as an adult and a larva. Larval members of Ophiogomphus tend to eat other insect larvae, including midge and mayfly nymphs. As adults, they forage for other flying insects that are their size or smaller. They usually hunt away from the edge of the water, in adjacent forested areas. They may fly to the top of the canopy to search for food. (Dunkle, 2013; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013)
Members of Odonata are preyed upon by birds, lizards, frogs, spiders, fish, water bugs, and other large dragonflies. However, they have very well developed visual responses and agile flight capabilities, which enables them to avoid predators. Larvae also have coloration that acts as camouflage in their aquatic environment. (Sabet-Peyman, 2006)
Ophiogomphus susbehcha is a predator to many other insects, and is prey to a large host of other organisms. This makes this dragonfly species an intrinsic part of its ecosystem. Ophiogomphus susbehcha has been observed in the largest numbers along medium-sized, clear, clean rivers that have a fast current and pools and riffles. In these areas overall habitat diversity, and thus biological diversity, is high. This implies that O. susbehcha interacts with many other species.
The spread of the invasive Dreissena polymorpha (Zebra Mussels) in the Lake Superior basin may have a negative impact on O. susbehcha. ("Resource Brief: Dragonflies & Damselflies", 2009; "Ophiogomphus susbehcha/St. Croix Snaketail", 2013; Sabet-Peyman, 2006)
Odonates serve humans by functioning as bioindicators of ecosystem well-being. They can be used to assess ecosystem health and diversity. Many research projects regarding odonates have been carried out. They also serve to keep the mosquito and other flying insects population regulated. (Lyons, 1999; Schultz, 2009; Wellhouse, 1926)
There are no known adverse effects of O. susbehcha on humans.
Ophiogomphus susbehcha is listed on the IUCN Red List with a status of "least concern" and a stable population trend. It was not found at all on the US Federal Endangered Species List, nor on CITES. NatureServe lists O. susbehcha as G2-imperiled because of its rarity and susceptibility to water quality degradation. This species is endangered according to the Wisconsin Department of Natural Resources and is also listed by them as a Federal Species of Concern. The Minnesota Department of Natural Resources lists O. susbehcha as "Special Concern," for the state of Minnesota, with no federal status. ("CITES", 2013; "Endangered Species Program", 2013; "IUCN Red List of Threatened Species Version 2012.2", 2012)
Ann Horner (author), Minnesota State University, Mankato, Robert Sorensen (editor), Minnesota State University, Mankato, Angela Miner (editor), Animal Diversity Web Staff.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
mainly lives in water that is not salty.
having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.
a distribution that more or less circles the Arctic, so occurring in both the Nearctic and Palearctic biogeographic regions.
Found in northern North America and northern Europe or Asia.
An animal that eats mainly insects or spiders.
fertilization takes place within the female's body
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
uses sight to communicate
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2012. "IUCN Red List of Threatened Species Version 2012.2" (On-line). Accessed March 27, 2013 at http://www.iucnredlist.org.
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Minnesota Department of Natural Resources. 2013. "Ophiogomphus susbehcha/St. Croix Snaketail" (On-line). Minnesota DNR. Accessed March 25, 2013 at http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=IIODO12180.
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2013. "Saint Croix Snaketail (Ophiogomphus susbehcha)" (On-line). Wisconsin DNR. Accessed March 26, 2013 at http://dnr.wi.gov/topic/endangeredresources/animals.asp?mode=detail&speccode=iiodo12180.
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Dunkle, . 2013. "Ophiogomphus susbehcha" (On-line). NatureServe. Accessed March 25, 2013 at http://www.natureserve.org/explorer/servlet/NatureServe?sourceTemplate=tabular_report.wmt&loadTemplate=species_RptComprehensive.wmt&selectedReport=RptComprehensive.wmt&summaryView=tabular_report.wmt&elKey=108266&paging=home&save=true&startIndex=1&nextStartIndex=1&reset=false&offPageSelectedElKey=108266&offPageSelectedElType=species&offPageYesNo=true&post_processes=&radiobutton=radiobutton&selectedIndexes=108266.
Gibbs, E., B. Bradeen, D. Boland. 2004. Spatial and Temporal Segregation Among Six Species of Coexisting Ophiogomphus (Odonata: Gomphidae) in the Aroostook River, Maine. Northeastern Naturalist, 11: 295-312.
Lyons, R. 1999. "Damsels and Dragons - the Insect Order Odonata" (On-line). Accessed March 27, 2013 at http://casswww.ucsd.edu/archive/personal/ron/CVNC/odonata/ips_odonata.html.
Ross, H. 1965. A Textbook of Entomology 3rd edition. New York, USA: John Wiley & Sons, Inc..
Sabet-Peyman, J. 2006. "Introduction to the Odonata" (On-line). UCMP Berkely. Accessed March 27, 2013 at http://www.ucmp.berkeley.edu/arthropoda/uniramia/odonatoida.html.
Schultz, T. 2009. Diversity and Habitats of a Prairie Assemblage of Odonata at Lostwood National Wildlife Refuge, North Dakota. Journal of the Kansas Entomological Society, 82: 91-102.
Wellhouse, W. 1926. How Insects Live. New York, USA: The Macmillan Company.