Locally common dragonfly inhabiting fast flowing streams and rivers in submontane areas according to the de Fonseka (de Fonseka T., 2000) and hills and mountain regions as per bedjanic, M., et.al., 2007. However F.C. Fraser in 1933 noted that it is the commonest Gomphine in the island found in everywhere at all elevations (Fraser F.C. 1933). Probably what he meant is in suitable habitats as he elaborated further that it is a jungle insect usually found sunning itself on rocks in mid streams. With the recent distribution data of Brook Hooktail in the island M. Bedjanic concluded that P. henryi is not so common anymore, being known from around 70 localities concentrated in central and southwestern part of Sri Lanka (Bedjanic M., 2013) Above picture was taken at lowland rain forest stream of southwestern Sri Lanka (Indikada Mookalana – A heavily degraded secondary forest) with about 40m height above sea level (6°54.072'N, 80°09.724'E). Males Brook Hooktail can be easily distinguished from all others of the family by having long hook like down-curved anal appendages (insert). Female lack that expansion.
Fraser F.C. 1933 The Gomphines of Ceylon (Order Odnata), F.C. Fraser,
of Science (B) Vol. XVIII, Pt 1 Ceylon December
22, 1933 page 33
bedjanic, M., K. Conniff & G. |de Silva Wijeyeratne, 2007, Gehan's photo guide: Dragonflies of Sri Lanka. Jetwing Eco Holidays, Colombo 248p.
de Fonseka, T. (2000). The dragonflies of Sri Lanka. Wildlife Heritage Trust: Colombo. 304 p.
bedjanic, M. 2013 Paragomphus Campestris Spec.Nov., A New endemic dragonfly from Sri Lanka (Ansoptera:Gomphidae) Odonatologica 42(1): 45-53 March 1, 2013 (http://www.rufford.org/files/Odonatologica%2042(1)%2045-53%20March%201,%202013.pdf)