Sunday, 15 June 2014

An eventful day at Tay Thien - Ophiogomphus sinicus

June 15 I went to Tay Thien again. It was partially cloudy and I was not too happy with that, but it was warmer than yesterday and there eventually were good spells of sun. I ran into several cool species. The first I want to share is another Onychogomphid. Last year, when we were discussing the possibility of several Lamelligomphus species in Vietnam, Sebastien showed a photo of a Gomphid with huge pincers as appendages. Clearly it was not Lamelligomphus, but we did not know what the alternative was. I decided today to first look at the stream where he had seen it. I did not see a lot going up the stream, but on the way back all of a sudden I saw it, sitting on a stone in midstream. I was able to first take some pictures and then to catch it for in hand shots. The stream where I caught it is a low elevation, really bordering the plains, and runs through a relatively open area, although the hills are covered in degraded forest. But later in the day, when I walked the path to the nunnery at Tay Thien (a different stream) I saw two more right next to the nunnery, so in the middle of the forest on the stream at 350m altitude.
Anyway, it is Ophiogomphus sinicus. A rather weird Ophiogomphus at that. It was first included in Onychogomphus as Onychogomphus sinicus, but after studies were done on the larval stages, it was transferred. Well, I guess there are good reasons to do so, but it sure as hell does not look like regular Ophiogomphus species. It is known from a large part of Southern China, although locations are scarce, for instance Guangdong and Guangxi. Not too surprising it occurs in Northern Vietnam.

Ophiogomphus sinicus, male, perched on rock in stream
In hand, the same male

Face of O. sinicus. There is not much difference with Lamelligomphus, really

Appendages in dorsal view
And in ventral view. Note the dorsal tooth at 1/3rd of superior and inferior appendages
And to be complete, ventral view

The shape of the anterior and posterior hamuli

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