Journal of Threatened Taxa | www.threatenedtaxa.org | 26 December 2018 | 10(15): 13029–13031

Ischnura fountaineae (Insecta: Odonata: Zygoptera) in Oman, eastern Arabia

Elaine Mary Cowan ¹ & Peter John Cowan ²

¹ School of Education, University of Aberdeen, AB24 3FX, Scotland, UK

²Department of Biological Sciences and Chemistry, University of Nizwa, Birkat Al Mawz, Sultanate of Oman

¹ e.m.cowan@abdn.ac.uk, ² desertmammal@yahoo.com (corresponding author)

doi: https://doi.org/10.11609/jott.4664.10.15.13029-13031 | ZooBank: urn:lsid:zoobank.org:pub:FA557694-487F-4769-98FB-E491175A0D2E

Editor: K.A. Subramanian, Zoological Survey of India, Chennai, India. Date of publication: 26 December 2018 (online & print)

Manuscript details: Ms # 4664 | Received 20 September 2018 | Final received 30 October 2018 | Finally accepted 23 November 2018

Citation: Cowan, E.M. & P.J. Cowan (2018). Ischnura fountaineae (Insecta: Odonata: Zygoptera) in Oman, eastern Arabia. Journal of Threatened Taxa 10(15): 13029–13031; https://doi.org/10.11609/jott.4664.10.15.13029-13031

Copyright: © Cowan & Cowan 2018. Creative Commons Attribution 4.0 International License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

Funding: None.

Competing interests: The authors declare no competing interests.

Acknowledgements: We thank the moderator of the All Odonata website gallery. David Chelmick gave us the URL for the Fons Peels dragonfly website.

We considered Ischnura fountaineae Morton, 1905 to occur, in Oman, only in the western Hajar mountains of northern Oman (fairly close to the United Arab Emirates) based on records in the Mahadah area by the late Bob Reimer (Cowan & Cowan 2017; Reimer et al. 2009). We had not knowingly recorded the species at that time, however, the author Elaine M. Cowan (EMC) remembered that she had photographed a very blue eyed individual with pale blue thorax, without a hint of green, at ‘Hoota’ Wadi (Arabic: valley) pool (Cowan & Cowan 2013, 2015). This pool (23.071⁰N & 57.368⁰E, elevation 680m) is near the Al Hoota cave tourist complex in the southern foothills of the Jebel Akhdar range (the central and highest part of the Hajar mountains). In February 2018, EMC submitted the photograph (Image 1) to the expert-moderated All Odonata website gallery (www.allodonata.com) for an ID opinion. The moderator replied that it was indeed I. fountaineae and the photo is on display there as such.

Confident identification of Ischnura fountaineae from photographs had seemed a challenge. Grunwell (2010) felt the best distinguishing feature for males from a male I. evansi (the commonest Ischnura in Oman, Cowan & Cowan 2017) was the downwards sloping to the front of the lower edge of the black on the upperside of segment 2 of the abdomen. Dijkstra & Lewington (2006) considered the diagnostic field characters of mature male I. fountaineae to be the sky blue ground colour of the thorax and abdomen base, without a hint of green, and their shining black markings. The postocular spots are small. In the hand, males are reliably identified by the anal appendages (Dijkstra & Lewington 2006; contra Reimer et al. 2009). The best gallery of online photos of I. fountaineae is perhaps that on the Fons Peels website (www.dragonflypix.com). Immature males do not have any trace of green but are whitish with black markings (Galliani et al. 2017). Reimer et al. (2009) stated that I. evansi and I. fountaineae can be most easily distinguished in the field by the colouration of the thorax and first few segments of the abdomen and the antehumeral stripes on the thorax. In I. evansi the colour is greenish-blue and there are always clearly visible stripes of the same colour on the shoulders. Ischnura fountaineae is sky-blue without a hint of green, the same colour as the blue that occurs on the eighth abdominal segment (i.e., the ‘tail-light’). The antehumeral stripe may be missing, interrupted or very narrow. Our understanding of the diagnostic field characters (i.e., visible on a digital photograph) is that male I. fountaineae have a pale blue thorax, the same colour as the tail-light, and blue eyes (the anterior of the eyes can sometimes appear greenish). The positive identification of females may be difficult under field conditions (Dijkstra & Lewington 2006).

Boudot et al. (2015) presented a map of the world distribution of I. fountaineae. According to them, the species occurs across northern Africa from eastern Morocco to Egypt, east to Kazakhstan and westernmost China. They show a southern outlier, in eastern Saudi Arabia, Qatar, United Arab Emirates and northern Oman south to about 22.5⁰N. Reimer et al. (2009) presented the occurrence of I. fountaineae in the United Arab Emirates, the Mahadah area of the western Hajar, Oman and interestingly mentioned that photographs by Gary Feulner of Ischnura males and females along irrigation channels among cultivation on the Saiq plateau at c. 2000m elevation in the Jebel Akhdar range of Oman appeared to show I. fountaineae. The species has not been reported by other observers in Oman (Cowan & Cowan 2017, 2018; Lambret et al. 2017).

Reviewing our archive of photographs from Oman, we now have eight records of I. fountaineae at Hoota Wadi pool. These are: 11 September 2013, 11, 19 January, 19 August, 9, 16 September 2015 and 19 (Image 1), 25 January 2016. We also have three records from Wadi Qtm (23.072⁰N & 57.627⁰E, 1,970m), which is on the Saiq plateau of Jebel Akhdar and has an irrigation channel (falaj) and pools. These three records are: 11 April (Image 2), 25 August (Images 3, 4) 2014 and 18 April 2016. The records of 11 April 2014 and 18 April 2016, at Wadi Qtm, were erroneously reported as I. evansi in Cowan & Cowan (2017). The apparent status of I. fountaineae in Oman should be “uncommon Western Hajar and Jebel Akhdar regions” (see Cowan & Cowan 2017 for further information about these regions and sites).

Ischnura evansi (Image 5) which is clearly differentiated by green eyes and greenish thorax was photographed at the Hoota Wadi pool on most visits there (including the 8 dates when I. fountaineae was recorded). Ischnura senegalensis is found elsewhere in Oman but is mainly coastal. Ischnura senegalensis has a deep black ‘saddle’ on S2 of the abdomen separating two patches of surrounding colour (Image 6).

References

Boudot, J-P., E. Riservato & S. Hardersen (2015). Ischnura fountaineae Morton, 1905, pp. 127–128. In: Boudot, J-P. & V.J. Kalkman (eds.). Atlas of the European Dragonflies and Damselflies. Netherlands: KNNV Publishing, 381pp.

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