Afronurus namnaoensis Braasch & Boonsoong, 2010

Boonsoong, Boonsatien & Braasch, Dietrich, 2013, Heptageniidae (Insecta, Ephemeroptera) of Thailand, ZooKeys 272, pp. 61-93 : 82-83

Afronurus namnaoensis Braasch & Boonsoong, 2010 Figs 3A4D8 C–D 9A

Afronurus namnaoensis Braasch & Boonsoong, 2010: 1-3, Figs 6-13. (orig.)

Larva.

Braasch and Boonsoong 2010: 1-3, Figs 6-13.

Adult.

Braasch and Boonsoong 2010: 2-3, M, Figs 1-4; F, fig. 5.

Eggs.

The egg chorion of Afronurus namnaoensis is decorated with granules and two kinds of KCTs: small KCTs concentrated at each pole and much larger oval KCTs located equatorially (Fig. 8C); micropyles have an ovoid to round sperm guide (Fig. 8D), visible in the equatorial area. The micropyle is interposed between adjacent equatorial KCTs.

Distribution.

Phromlaeng stream (Chaiyaphum province); Yakraue stream (Petchabun province); Nam Lang river, Pangmapa/Soppong (Mae Hong Son province); Chiang Mai province.

Diagnosis.

Male of Afronurus namnaoensis is separated from Vietnamese Afronurus cervina in lacking a median penial cone, by the less deeply notched lobal apex, and titillators curved laterally and in their more medial position. Vietnamese Afronurus dama presents a terminal apex of the penis slightly notched at the inner angles, whereas Afronurus namnaoensis is recognized by somewhat elevated corners on both sides of the apices. Larvae are recognizable by an unmarked forehead, pointed and weakly curved gill 1 and smoothly rounded triangular gill 5 with crosswise projection. Two Vietnamese species, Afronurus meo and Afronurus mnong (Nguyen & Bae, 2003) have gills lacking these projections (Figs 8-10, Figs 18-20, Nguyen and Bae 2003).

Habitat and biology.

Larvae of Afronurus namnaoensis (Fig. 9A) are probably the most abundant species on rocks and stones in Nam Lang River and elsewhere in current waters of northern and northeastern Thailand. These mayflies are an important food source for headwater stream fishes ( Cyclocheilichthys apogon , Devario regina , Opsarius pulchellus , and Rasbora rasbora ).

Remarks.

Braasch and Boonsoong (2010) described this species from Thailand based on nymphal and imaginal specimens, and deposited them in the ZMKU, Bangkok. The larvae of Afronurus namnaoensis are the most abundant species in current waters of Thai streams.