Megabranchiella Phlai-ngam & Tungpairojwong, 2022
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publication ID |
https://dx.doi.org/10.3897/zookeys.1125.90802 |
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publication LSID |
lsid:zoobank.org:pub:F4ACDB4D-5BC1-415C-B098-5D494A15263A |
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persistent identifier |
https://treatment.plazi.org/id/A9F66B30-FEDB-46FA-B8E7-D6A338E10D63 |
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taxon LSID |
lsid:zoobank.org:act:A9F66B30-FEDB-46FA-B8E7-D6A338E10D63 |
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treatment provided by |
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scientific name |
Megabranchiella Phlai-ngam & Tungpairojwong |
| status |
gen. nov. |
Genus Megabranchiella Phlai-ngam & Tungpairojwong gen. nov.
Type species.
Megabranchiella scutulata sp. nov., by present designation.
Included species.
Megabranchiella longusa sp. nov.
Megabranchiella scutulata sp. nov.
Diagnosis.
Larva (Figs 1 View Figure 1 - 3 View Figure 3 ). Larval body ventrally flattened (Fig. 4 View Figure 4 ). Margins of head capsule relatively densely covered with fine, long setae. Antenna without process on scape, margins of scape and pedicel densely covered with long, fine, simple setae; flagellum short, covered with scattered long, fine, simple setae. Mouthparts relatively compact. Labrum (Fig. 5A View Figure 5 ) broadly rounded, dorsally with one central seta and a row of setae reduced in number. Mandibles with smooth margin between mola and prostheca, without setae, right and left prostheca comb-shaped. Maxilla (Fig. 5H View Figure 5 ) with 2-segmented palp, with a small tip at apex. Labium compact (Fig. 5K View Figure 5 ), glossa and paraglossa covered with stout setae, labial palp 3-segmented, terminal segment rounded. Thorax broad; forewing pad broad, large, divergent; hindwing pad highly reduced. Femur with a regular row of long, stout, setae on dorsal margin, surface covered with scattered tiny spine-like setae anteromedially, ventral femoral patch present. Tibia with long feathered setae on dorsal margin, covered with scattered fine setae and short, pectinate setae. Tarsus without preapical setae, tarsal claw with one row of denticles. Abdominal tergites covered with scattered long, fine setae; posterior margin smooth. Abdominal gills segment I (Fig. 6D View Figure 6 ) ventrally oriented, enlarge covering abdominal sternites II to V; gill margin smooth without setae. Abdominal gills segment II-VII dorsolaterally oriented, gill margins with densely covered with long fine setae. Gonostily under larval cuticule Acentrella -type (Fig. 6E View Figure 6 ). Paraproct surface with notched scales and long setae; distal margin smooth without prolongation. Caudal filaments with swimming setae; median filament reduced to shorter than 0.4 × of cerci length.
Winged stage.
Unknown.
Etymology.
Megabranchiella is a combination of Mega - in reference to the enlarged, - branchio - in reference to gills and - iella in reference to the genera Liebebiella and Acentrella which are most certainly the closely related genera. The " Megabranchiella " refers to the remarkable enlarged abdominal gill segment I of baetid mayfly. The gender is feminine.
Description.
Larva (Figs 1 View Figure 1 - 3 View Figure 3 ). Body Relatively short and ventrally flattened (Fig. 4 View Figure 4 ), covered with scattered long, fine setae; head and thorax in lateral view rounded.
Head. Antenna. ca. 2 × as long as head length; scape, pedicel and flagellum without process, without scale bases and spines, covered with scattered long, fine setae; flagellum covered with scattered long, fine setae in each segment.
Labrum (Fig. 5A View Figure 5 ). Broadly rounded; wider than long; dorsal surface with one central seta and a row of setae reduced in number, long scattered simple setae along dorsal margin, scattered simple, hairlike setae; distal margin with anteromedian notch shallow, disterolateral margin with long feathered setae; distomedial margin with a row of small, short, feathered setae.
Right mandible (Fig. 5B-D View Figure 5 ). Canine with almost completely fused outer and inner incisors, incisors well developed, apically rounded; prostheca robust, apically with small denticles and comb-shaped structure; edge between mola and prostheca smooth, without setae; molar area with numerous small, apically rounded teeth; apex of mola with tuft of spines like setae.
Left mandible (Fig. 5E-G View Figure 5 ). Canine with almost completely fused outer and inner incisors, well developed incisors, apically rounded; prostheca robust, apically with small denticles; margin between mola and prostheca smooth, without setae; molar area with numerous small, round teeth, apex of mola with tuft of thin setae.
Maxilla (Fig. 5H View Figure 5 ). Short and compact; galea-lacinia (Fig. 5I View Figure 5 ) with long, robust, simple setae under crown. Inner dorsal row of setae with three denti-setae, distal denti-seta tooth-like, middle denti-seta slender, bifid and pectinate (Fig. 5J View Figure 5 ), proximal denti-seta slender, pectinate; innermost denticles with a row of robust, simple setae; medially with one seta and four short to long, simple setae. Short, stocky, 2-segmented maxillary palp, with scattered small setae; distal segment with distinct, small tip.
Labium (Fig. 5K View Figure 5 ). Short and compact; glossa basally broad, narrower toward apex, slightly shorter than paraglossa; paraglossa sub-rectangular, broader than glossa, apically curved inward, apical margin with three rows of medium stout setae; labial palp 3-segmented, segment II with small distolateral expansion, segment III rounded, ventral surface covered with scattered setae.
Hypopharynx (Fig. 5M View Figure 5 ). Lingua subequal to superlingua, apically rounded, with apical tuft of fine, long, simple setae; superlingua with distal margin slightly incurved, margin covered with fine simple setae.
Thorax. Forewing pads. Highly developed related to body size; clearly divergent.
Hindwing pads. Highly reduced.
Forelegs (Figs 7A View Figure 7 , 12A View Figure 12 ). Dorsal margin of femur with a row of long, simple setae; short, stout, lanceolate, laterally pectinate setae and scattered fine hair-like setae along dorsal and ventral margins; femora patch present; dorsal surface with scattered tiny spine-like setae anteromedially; scattered long translucent scales present; dorsal margin of tibia with a row of long, simple setae; several broad, lanceolate, laterally pectinate setae and scattered hair-like setae along dorsal and ventral margins, patella-tibial suture present; tarsus dorsally with a row of spine-like simple setae, ventral margin bare or with a row of spine-like simple setae, surface covered with scattered fine hair-like setae; tarsal claw with one row of denticles increasing in length toward apex, subapical setae absent. Midlegs and hindlegs. As forelegs.
Abdomen (Fig. 6B View Figure 6 ). Tergites. Posterior margin smooth, posterior marginal spines reduced to absent, tergal surface with scattered stout, fine, hair-like setae and scattered long translucent scales distally. Gonosyli under larval cuticule Acentrella -type (Fig. 6E View Figure 6 ).
Gills. Seven pairs of gills present on abdominal tergites I-VII; gills I enlarged to covered abdominal sternites II-V, oriented ventrally (Fig. 6D View Figure 6 ), gill margin smooth, without fine hair-like setae; gills II-VII slightly oval, oriented dorsolaterally, gills margin smooth with scattered, long, fine hair-like setae.
Paraproct (Fig. 7E View Figure 7 ). Margin smooth without marginal spines and without prolongation at posterior margin.
Caudal filaments. Inner margin of cerci with very thin, long setae; median filament reduced shorter than 0.4 × of cerci length, lateral margins with very thin, long setae.
Winged stage.
Unknown.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.