Ephemera pictipennis
General appearance
Body size large up to 25mm long (excluding antennae & cerci)
Body cylinderical & elongated (abdominal segments VII-IX greatly extended), cream yellow to yellowish brown body with purpish feathery gills
Head
* Frontal process concave anteriorly to bifurcate & its length longer than width
* Mandibular tusks curved laterally-dorsally without denticle - right tusk reduced to 3/5 of
left tusk length
Details for mouthparts
illustrated in the following pictures
Thorax
Legs fossorial for digging burrow
Details for legs
illustrated in the following pictures
Abdomen
Abdomen yellow with dark purple markings on terga (shown in late stage)
7 pairs of abdominal gills arising dorsally: gill I bi-lamellae simple & slender, gills II-VII bi-lamellae feathery
Cerci length about half of body length, fringed with dense hairy setae
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Legs |
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Its mouthparts of labrum, mandibles, maxillae and labium are illustrated as follow (hypopharynx is excluded).
Labrum |
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Maxillae |
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Mandibles |
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Labium |
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Distribution:
In Hong Kong, specimens are recorded from Lam Tsuen River, Ma Po Mei (nr. Lam Kam Road), Chung Lung, Tai Po Kau Forest Stream and Kap Lung.
Reference:
Dudgeon, D. (1996) The life history, secondary production and microdistribution of Ephemera spp. (Ephemeroptera: Ephemeridae) in a tropical forest stream. Archiv für Hydrobiologie 135: 473-483.
Remarks:
This species is univoltine in Hong Kong streams. Adult emergence is highly synchronized during the middle ten days of April (Dudgeon, 1996).