Northern Billabongfly (Austroagrion exclamationis)

The Northern Billabongfly (Austroagrion exclamationis) is a damselfly species of the family Coenagrionidae, which contains 30 species in Australia.

The identification key to the family Coenagrionidae consists of 54 couplets, 16 of which are pertinent to Austroagrion exclamationis. Click on the numbers on the right to display the corresponding couplets. Or click on the ALLin1 button to see all the relevant couplets together in a single, scrollable window.

#	Family	Species	Couplet No.
	Coenagrionidae	Northern Billabongfly (Austroagrion exclamationis)	Coenagrionidae: Key couplet 1 of 54 ○ Damselflies without this combination of characters b ↑ Coenagrionidae: Key couplet 14 of 54 ● Anal vein leaving wing margin nearer to or beyond level of Ac ● Basal segment of hindwing anal vein, if present, not more than half length of Ac b ↑ Coenagrionidae: Key couplet 35 of 54 ○ Damselflies with dark brown or black markings on pale background (reddish, yellow, green, blue, pale brown), or substantially dark, the dark areas in either case often with metallic sheen b ↑ Coenagrionidae: Key couplet 37 of 54 ● Pterostigma of forewing similar in size to that of hindwing ● Female lacking ventral spine on abdominal segment 8 b ↑ Coenagrionidae: Key couplet 38 of 54 ● Pterostigma markedly longer than wide b ↑ Coenagrionidae: Key couplet 40 of 54 ○ No such markings on thorax or abdomen b ↑ Coenagrionidae: Key couplet 41 of 54 ○ Synthorax blue and black b ↑ Coenagrionidae: Key couplet 42 of 54 ○ Antealar sinus black b ↑ Coenagrionidae: Key couplet 44 of 54 ○ Abdominal segment 4 and 5 more than half black above ⇒ genus: Austroagrion b ↑ Coenagrionidae: Key couplet 45 of 54 ● Abdominal segment 7 black ● Segment 8 blue, usually with small to large distal, mid-dorsal black mark ● Segment 9 blue with generally large, distal, mid-dorsal black mark b ↑ Coenagrionidae: Key couplet 46 of 54 ● Superior and inferior anal appendages almost equal in length ⇒ species: Northern Billabongfly (Austroagrion exclamationis) a ↑ Coenagrionidae: Key couplet 48 of 54 ● Posterior lobe of pronotum without forwardly directed, finger-like process on each side b ↑ Coenagrionidae: Key couplet 50 of 54 ○ Upper surface of abdominal segment 1 brown to black, with or without orange-brown dorsal and lateral marks ● Anal vein leaving wing margin at Ac b ↑ Coenagrionidae: Key couplet 51 of 54 ○ Synthoracic terga partially dark brown to black ○ Abdominal tergum 1 with triangular to parallel-sided dark brown to black dorsal mark lacking pale mid-dorsal line ⇒ genus: Austroagrion b ↑ Coenagrionidae: Key couplet 52 of 54 ● Central part of posterior lobe of pronotum rounded triangular b ↑ Coenagrionidae: Key couplet 53 of 54 ● Central part of posterior lobe of pronotum with acutely V-shaped ridge on upper surface ⇒ species: Northern Billabongfly (Austroagrion exclamationis) a ↑
1			Coenagrionidae: Key couplet 1 of 54 ● Arculus in hindwing situated beyond distal antenodal crossvein by at least the length of subcostal part of antenodal ○ Very small damselflies, hindwing shorter than 14 mm ⇒ genus: Agriocnemis a ↑ b ↓ ○ Damselflies without this combination of characters
2			Coenagrionidae: Key couplet 14 of 54 ● Anal vein leaving wing margin well basal to the level of Ac in both wings, so there is a basal segment of anal vein about the same length as Ac a ↑ b ↓ ● Anal vein leaving wing margin nearer to or beyond level of Ac ● Basal segment of hindwing anal vein, if present, not more than half length of Ac
3			Coenagrionidae: Key couplet 35 of 54 ○ Orange-red to yellowish green damselflies without dark thoracic markings a ↑ b ↓ ○ Damselflies with dark brown or black markings on pale background (reddish, yellow, green, blue, pale brown), or substantially dark, the dark areas in either case often with metallic sheen
4			Coenagrionidae: Key couplet 37 of 54 ● Pterostigma of forewing markedly larger than that of hindwing ● Female with ventral spine on apex of abdominal segment 8 ⇒ species: Blue Slim (Aciagrion fragile) a ↑ b ↓ ● Pterostigma of forewing similar in size to that of hindwing ● Female lacking ventral spine on abdominal segment 8
5			Coenagrionidae: Key couplet 38 of 54 ● Pterostigma very small, almost as long as wide ⇒ species: Blue-Banded Longtail (Archibasis mimetes) a ↑ b ↓ ● Pterostigma markedly longer than wide
6		Male only	Coenagrionidae: Key couplet 40 of 54 ○ Extensive dull orange to red markings on head, thorax and anterior abdomen ⇒ species: Red & Blue Damsel (Xanthagrion erythroneurum) a ↑ b ↓ ○ No such markings on thorax or abdomen
7		Male only	Coenagrionidae: Key couplet 41 of 54 ○ Synthorax with extensive brown or yellow areas, sometimes pruinescent ⇒ genus: Pseudagrion a ↑ b ↓ ○ Synthorax blue and black
8		Male only	Coenagrionidae: Key couplet 42 of 54 ● Antealar sinus partially to substantially blue a ↑ b ↓ ○ Antealar sinus black
9		Male only	Coenagrionidae: Key couplet 44 of 54 ○ Abdominal segment 4 and 5 more than half blue above ⇒ species: Swamp Bluet (Coenagrion lyelli) (part) a ↑ b ↓ ○ Abdominal segment 4 and 5 more than half black above ⇒ genus: Austroagrion
10		Male only	Coenagrionidae: Key couplet 45 of 54 ● Abdominal segment 8 entirely blue ● Posterior part of segment 7 usually blue ● Segment 9 blue, occasionally with small, distal mid-dorsal black mark ⇒ species: South-Western Billabongfly (Austroagrion cyane) a ↑ b ↓ ● Abdominal segment 7 black ● Segment 8 blue, usually with small to large distal, mid-dorsal black mark ● Segment 9 blue with generally large, distal, mid-dorsal black mark
11		Male only	Coenagrionidae: Key couplet 46 of 54 ● Superior and inferior anal appendages almost equal in length ⇒ species: Northern Billabongfly (Austroagrion exclamationis) a ↑ b ↓ ● Superior appendages much longer than inferiors
12		Female only	Coenagrionidae: Key couplet 48 of 54 ● Posterior lobe of pronotum with forwardly directed, finger-like process on each side a ↑ b ↓ ● Posterior lobe of pronotum without forwardly directed, finger-like process on each side
13		Female only	Coenagrionidae: Key couplet 50 of 54 ○ Posterior half of upper surface of abdominal tergum 1, excluding membrane, blue ● Anal vein leaving wing margin basal to Ac, forming short stalk ⇒ species: Swamp Bluet (Coenagrion lyelli) (part) a ↑ b ↓ ○ Upper surface of abdominal segment 1 brown to black, with or without orange-brown dorsal and lateral marks ● Anal vein leaving wing margin at Ac
14		Female only	Coenagrionidae: Key couplet 51 of 54 ○ Synthoracic terga, between wing bases, pale orange ○ Abdominal tergum 1 with triangular bronze dorsal mark partly divided by anterior, orange mid-dorsal line ⇒ species: Red & Blue Damsel (Xanthagrion erythroneurum) a ↑ b ↓ ○ Synthoracic terga partially dark brown to black ○ Abdominal tergum 1 with triangular to parallel-sided dark brown to black dorsal mark lacking pale mid-dorsal line ⇒ genus: Austroagrion
15		Female only	Coenagrionidae: Key couplet 52 of 54 ● Central part of posterior lobe of pronotum elongate, broadened at tip ⇒ species: Pilbara Billabongfly (Austroagrion pindrina) a ↑ b ↓ ● Central part of posterior lobe of pronotum rounded triangular
16		Female only	Coenagrionidae: Key couplet 53 of 54 ● Central part of posterior lobe of pronotum with acutely V-shaped ridge on upper surface ⇒ species: Northern Billabongfly (Austroagrion exclamationis) a ↑ b ↓ ● Central part of posterior lobe of pronotum with slightly raised margin and rounded apex