Cordulegastridae

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Cordulegastridae
Anotogaster sieboldii
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Odonata
Infraorder: Anisoptera
Family: Cordulegastridae
Genera[1]

The Cordulegastridae are a family of Odonata (dragonflies) from the suborder Anisoptera. They are commonly known as spiketails.[2] Some vernacular names for the species of this family are biddie and flying adder.[3] They have large, brown or black bodies with yellow markings, and narrow unpatterned wings. Their bright eyes touch at a single point, and they can be found along small, clear, woodland streams, flying slowly 30 to 70 cm above the water. When disturbed, however, they can fly very rapidly. They usually hunt high in forest vegetation, and prefer to capture prey resting on leaves or branches (known as gleaning).[4]

Taxonomy[edit]

Within the family Cordulegastridae there are 51 species amongst three different genera. These genera include Anotogaster, Cordulegaster, and Neallogaster, which have 15, 30, and 6 species respectively [5]

The name Cordulegastridae comes from the Greek kordylinus, 'club-shaped' and gaster, belly. The common name spiketails refers to the females' prominent ovipositors.[2]

Description[edit]

Dragonflies within this family are typically large, between 2.5 to 3 inches long. They are characteristically black in color and have blue-green eyes. On their large black bodies they have paired yellow spots along the length of their abdomen. Females and males are generally similar but two key differences are the color of the forehead and the terminal segment of their abdomen. Males have yellow foreheads and slightly clubbed abdomen whereas females have brown foreheads and an ovipositor extending from the end of the abdomen.[6]

Natural history[edit]

Life cycle and behavior[edit]

A typical lifespan of Cordulegastridae dragonflies is 3–5 years.[7] Adults are usually active and flying between spring and early summer with a peak in June.[8]

The Cordulegastridae usually lay their eggs in the sand in shallow water, the female hovering just above the water with her body in a vertical position, and making repeated dips into the water with her abdomen.[9] The females trap air bubbles with hairs along their bodies to allow them to reach the bottom of the water and deposit eggs into the substrate.[10] Males are remarkably territorial and their territorial behavior varies based on the oviposition of the females.[8]

Cordulegastridae nymph buried in substrate

Cordulegastridae nymphs will almost entirely conceal themselves in sand or silt, exposing only their eyes to see, antennae for sensing prey, and the tip of their abdomen to breathe dissolved oxygen.[11] Nymphs will consume any prey they can capture, going as far as eating smaller larvae of the same species.[12] This family captures their prey by extending their labium, categorizing them as ambush predators.[7]

Habitat[edit]

Since nymphs are aquatic and adults are terrestrial, their habitats are quite different. The preferred habitat of Cordulegastridae nymphs are small lotic or flowing streams with clean sand and silt substrates.[10][7] Adults on the other hand fly above clear streams and small rivers in the woods, with females only entering the water to lay their eggs.[6]

Distribution[edit]

Map showing the frequency of reported Cordulegastridae dragonfly sightings around the globe.

Their distribution includes North America, South America, Europe, Asia and Africa.[13] All eight species in North America belong to the genus Cordulegaster.[3]

Conservation[edit]

The endangered Cordulegaster helladica endemic to Greece

Although the conservation status of many if not most species of this family is unknown, there are multiple species that are of concern. From the Conservation Status Assessment of Odonata for the Northeastern United States, Cordulegaster erronea and Cordulegaster bilineata were identified as highly vulnerable, and Cordulegaster obliqua was identified as moderately vulnerable.[14] There are five species of concern according to the International Union for Conservation of Nature and Natural Resources (IUCN), Cordulegaster bidentata, Cordulegaster heros, Cordulegaster trinacriae, Cordulegaster helladica and Cordulegaster sarracenia. C. bidentata, C. trinacriae and C. heros are identified as Near Threatened and found in Europe. Most threatened however are C. helladica and C. sarracenia which are Endangered on the IUCN Red List due to significant habitat loss.[15][failed verification]

References[edit]

  1. ^ Martin Schorr; Martin Lindeboom; Dennis Paulson. "World Odonata List". University of Puget Sound. Retrieved 11 August 2010.
  2. ^ a b Berger, Cynthia (2004). Dragonflies: Wild Guide. Stackpole Books. ISBN 0-8117-2971-0.
  3. ^ a b Tim Manolis; Timothy D. Manolis (April 2003), Dragonflies and Damselflies of California (California Natural History Guides (Paperback)) (in German), University of California Press, p. 40, ISBN 0-520-23567-3
  4. ^ Munroe, Kevin (2012). "Spiketail family – Cordulegastridae" (PDF). Dragonflies of North Virginia. Retrieved 22 August 2017.
  5. ^ "Families & Genera of Odonata | University of Puget Sound". www.pugetsound.edu. Retrieved 2023-11-13.
  6. ^ a b "WOS: Cordulegaster maculata". wiatri.net. Retrieved 2023-11-13.
  7. ^ a b c Thorp, James H.; Covich, Alan P. (2001). Ecology and classification of North American freshwater invertebrates (2nd ed.). San Diego: Academic Press. ISBN 978-0-12-690647-9.
  8. ^ a b Joachim Poethke, Hans; Kaiser, Heinrich (1987-01-01). "The territoriality threshold: a model for mutual avoidance in dragonfly mating systems". Behavioral Ecology and Sociobiology. 20 (1): 11–19. doi:10.1007/BF00292162. ISSN 1432-0762. S2CID 22679802.
  9. ^ Donald Joyce Borror; Dwight Moore DeLong (1971). An introduction to the study of insects. New York, Holt, Rinehart and Winston. ISBN 978-0-03-082861-4.
  10. ^ a b Cummins, R. W.; Merritt, K. W. (1966). An Introduction to the Aquatic Insects of North America. Dubuque, IA: Kendall/Hunt Publishing. ISBN 0-8403-7588-3.
  11. ^ Tennessen, Kenneth (2019), Tennessen, Kenneth J. (ed.), "Cordulegastridae", Dragonfly Nymphs of North America: An Identification Guide, Cham: Springer International Publishing, pp. 307–328, doi:10.1007/978-3-319-97776-8_9, ISBN 978-3-319-97776-8, S2CID 239137100
  12. ^ Burcher, Chris L.; Smock, Leonard A. (July 2002). "Habitat Distribution, Dietary Composition and Life History Characteristics of Odonate Nymphs in a Blackwater Coastal Plain Stream". The American Midland Naturalist. 148 (1): 75–89. doi:10.1674/0003-0031(2002)148[0075:HDDCAL]2.0.CO;2. ISSN 0003-0031. S2CID 86275679.
  13. ^ "Cordulegastridae". www.gbif.org. Retrieved 2023-11-13.
  14. ^ "Conservation Assessment of Odonata (Dragonflies and Damselflies) in the Northeastern Region - NY Natural Heritage Program". www.nynhp.org. Retrieved 2023-11-13.
  15. ^ "IUCN Red List of Threatened Species". November 13, 2023. Retrieved November 13, 2023.