Graceful Slim (Aciagrion gracile)

View the above photo record (by Walter Neser) in OdonataMAP here.

Find the Graceful Slim in the FBIS database (Freshwater Biodiversity Information System) here.

Family Coenagrionidae

Aciagrion gracileGRACEFUL SLIM

Identification

Small size

Length up to 39mm; Wingspan around 46mm.

Aciagrion gracile has a noticeably slender and elongate build.

Males have a bright green upper thorax with greenish-blue sides. The long, slender abdomen is black above and brownish below. The terminal segments are bright blue. Postocular spots are bright greenish-blue.

Most similar to Aciagrion dondoense. The two species are best told apart in the hand by the shape of the claspers.

Click here for more details on identification.

Aciagrion gracile – Immature Male
Near Tshipise, Limpopo
Photo by John Wilkinson

Habitat

This species inhabits thick bushy verges of shallow grassy pans and marshes. Found in hot, humid woodland and forest regions.

Behaviour

Aciagrion gracile is a crepuscular species, that is most active at dusk and is easily overlooked The males are most often found between thick bush and grasses at the edge of the wetland. The females are usually found among emergent grasses and reeds further out into the water.

Active from January to April (see Phenology below).

Status and Conservation

This species is uncommon and rather localised in South Africa. It has likely been under-recorded due to its secretive, crepuscular behaviour. In South Africa Aciagrion gracile is listed as Vulnerable in the IUCN Red List of Threatened Species. It is listed globally as of Least Concern as it has a wide distribution within the rest of Africa. The Graceful Slim is sensitive to habitat degradation and, for the most part, occurs only in undisturbed habitats.

Distribution

It is found from South Africa, up through east Africa to Uganda and Ethiopia. It also occurs in west Africa from Congo to Guinea.

Below is a map showing the distribution of records for Graceful Slim in South Africa. Taken from the OdonataMAP database as at February 2020.

The next map below is an imputed map, produced by an interpolation algorithm, which attempts to generate a full distribution map from the partial information in the map above. This map will be improved by the submission of records to the OdonataMAP section of the Virtual Museum.

Ultimately, we will produce a series of maps for all the odonata species in the region. The current algorithm is a new algorithm. The objective is mainly to produce “smoothed” maps that could go into a field guide for odonata. This basic version of the algorithm (as mapped above) does not make use of “explanatory variables” (e.g. altitude, terrain roughness, presence of freshwater — we will be producing maps that take these variables into account soon). Currently, it only makes use of the OdonataMAP records for the species being mapped, as well as all the other records of all other species. The basic maps are “optimistic” and will generally show ranges to be larger than what they probably are.

These maps use the data in the OdonataMAP section of the Virtual Museum, and also the database assembled by the previous JRS funded project, which was led by Professor Michael Samways and Dr KD Dijkstra.

Phenology

Dragonfly Atlas: Megan Loftie-Eaton, Ryan Tippett, Rene Navarro & Les Underhill
Dragonfly Atlas: Megan Loftie-Eaton, Ryan Tippett, Rene Navarro & Les Underhill
Megan Loftie-Eaton is our communications, social media and citizen science projects coordinator. Prior to her work for the BDI, she coordinated OdonataMAP, the Atlas of African Odonata. Ryan Tippett is an enthusiastic contributor to Citizen Science and has added many important and interesting records of fauna and flora. He has been a member of the VMU since 2014 and has currently submitted over 11000 records. He is also on the expert identification panel for the OdonataMAP project. Rene Navarro is the genius behind the Virtual Museum. Prof Les Underhill has been Director of the Animal Demography Unit (ADU) at the University of Cape Town since it started in 1991. Although citizen science in biology is Les’s passion, his academic background is in mathematical statistics.