Ephoron ookaewae Techakijvej & Sareein & Hwang & Bae & Phalaraksh 2021, sp. nov.
Creators: name: Techakijvej, Chotiwut
name: Sareein, Nattawut
name: Hwang, Jeong Mi
name: Bae, Yeon Jae
name: Phalaraksh, Chitchol
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Polymitarcyidae
Ephoron
Ephoron ookaewae

description: Ephoron ookaewae Techakijvej & Phalaraksh, sp. nov.
(Figs. 1–4)
Diagnosis. Ephoron ookaewae sp. nov. can be distinguished from the other species of the genus by the following characters, in the larvae: 5–7 spike-like tubercles on dorsal side of mandibular tusk, mandibular tusk not curved inwards as much as in other species, mandible with small triangular shaped spine between outer and inner incisors, head with three to four-pointed median frontal process. In the adult: male and female forewing with 4 intercalaries between CuA and CuP, male hindwings with MA forked near middle of wing. And in the eggs: acorn shaped with concave indentation at posterior area, chorion sculptured in hexagonal netted pattern, convex area inside each cell.
Material. Holotype (Freshwater Biomonitor Research Laboratory: FBRL, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand) male imago (in alcohol) from Thailand: Nakonsawan Province, Ping River (Fig. 1a), 59 m a.s.l., 15°45’10.6”N 100°05’10.1”E, 4.iii.2018, hand net, C. Techakijvej col. Paratypes (FBRL): 1 male mature larva (same data as holotype) and 10 male imagos, and 10 female subimagos with eggs, from Nakonsawan Province, Ping River, 59 m a.s.l., 15°43’43.4”N 100°07’00.6”E, 6.xi.2019, light trap (Fig. 5a–b), C. Techakijvej col. Additional material, 1 mature larva and eggs for SEM, 2 larvae and 4 adults (2 males and 2 females) for DNA extraction (same data as adult paratypes).
Description. Male imago. (Figs. 1a–d) Length (mm) (n=10): body (excluding caudal filament and cerci) 10.4– 11.1; forewings 7.4–8.7; hindwings 4.1–4.4; caudal filament 0.4–0.6; cerci 21.4–24.4. Head. Head as wide as pronotum, whitish to very pale yellowish, antennae whitish (Fig. 1a). Ecdysal line outlined with black, from margin of lateral ocelli to mid-line. Thorax. Pronotum whitish with brown pattern (Fig. 1a), meso- and metanotum, pale yellowish. Legs (Fig. 1d). Forelegs (5.92 mm), forefemur with dark brown line on dorsal and ventral surfaces, foretibiae with brown line along its length, length ratio of forefemur to foretibiae = 1: 2.9, length ratio of five foretarsal segments = 0.2: 2.2: 1.4: 1.3: 1, tarsi with whitish forked claws. Mid- and hindlegs reduced, whitish. Mid-leg (1.78 mm), length ratio of midfemur and midtibia = 1: 0.8, length ratio of three midtarsal segments = 1: 0.9: 1. Hindleg (2.36 mm), length ratio of hindfemur to hindtibia = 1: 0.7, length ratio of three hindtarsal segments = 1: 0.7: 0.8. Wings (Fig. 1b), forewing hyaline, numerous cross-veins. Main vein of costal margin brownish, particularly near the wing base. Membrane on costal area especially pterostigma whitish, AA to wing base whitish and posterior margin pale whitish, fork of MA distal to fork of RS, 4 intercalaries between CuA and CuP. Hindwing hyaline, costal projection well developed, 1 intercalary between RA and RS, MA forked near middle of hindwing, 1 intercalary between CuA and CuP. Abdomen. Abdominal terga whitish, with dark brownish markings becoming darker and wider posteriorly, separated laterally and meeting at the posterior end. Genitalia: forceps 4-segmented, penes whitish (width: 1.23-1.25 mm), penis lobes straight and diverging laterally, apex of each lobe hooked (Fig. 1c). Cerci well-developed, caudal filament reduced.
Female sub-imago. Length (mm) (n=10): body (excluding caudal filament and cerci) 13.7–13.8; forewings 10.9–11.4; hindwings, 4.5–4.9; caudal filament, 5.7–6.1; cerci, 7.7–8.5. Head. Markings and color similar to male. Thorax. Color and pattern same as male. All legs reduced (Fig. 1e). Foreleg (2.53 mm), forefemora with dark brown line on dorsal and ventral surfaces, foretibia dark brown, length ratio of forefemur to foretibia = 1: 1.1, foretarsus whitish, length ratio of five foretarsal segments = 1: 1.6: 1.4: 0.9: 1.2. Mid- and hindlegs whitish. Midleg (2.41 mm), length ratio of midfemur and midtibia = 1: 1.3, length ratio of three midtarsal segments = 1: 0.6: 0.7. Hindleg (3.20 mm), length ratio of three hindtarsal segments = 1: 1.2: 1. Forewing whitish hyaline, numerous cross veins. Main vein of costal margin brownish especially near the wing base. Membrane of wing in costal area especially pterostigma whitish. Four intercalaries between CuA and CuP. Hindwing, costal projection well developed, no intercalary vein between RA and RS. Abdomen. Abdominal terga whitish, with dark brownish markings, becoming darker and wider at posterior end. Caudal filament and cerci developed, with setae.
Mature larvae (Fig. 2–3). Length (mm) (n=2): body (excluding mandibular tusks, caudal filament and cerci) 10.0–10.3; mandibular tusks 0.95–0.98; caudal filament 3.9–4.0; cerci 6.7–6.7. Head. Head as wide as pronotum, whitish. Ecdysal line outlined as in male imago. Head with a three to four-pointed median frontal process (Fig. 2c). Mandibular tusks shorter than maximal width of pronotum, straight with apex curved upwards, in lateral view (Fig. 2b). Tusks with 5–7 tubercles, tubercles smaller at base, with dense group of short setae on upper surface near bases of tusk (Fig. 2c) and long setae on lateral surface. Right mandible (Fig. 3a) with small triangular shaped spine between outer and inner incisors (Fig. 3b). Maxillary and labial palp, two segmented. Thorax. Pronotum whitish, brown pattern as in male imago. Meso and metanotum pale yellowish, wing pad dark brown (Fig. 2a). Forelegs stout and fossorial with rows of long setae. Inner side of forefemur has a U-shaped row of setae. Foretibiae flattened, with two rows of ventral tubercles along margins. Middle legs small. Abdomen. Same color and pattern as male. Gills whitish, gills present on abdominal segments 1–7, black dot on gills base, gill 1 single, gills 2–7 forked and each lamella with fringed lateral margin (Fig. 2d). Caudal filament and cerci with setae.
Egg. (Figs. 4a–e) Length (µm) (n=10) cap width 230–266, width 161–209. Eggs acorn shaped (Figs. 4a–b) with a concave indentation at anterior area (Figs. 4 b-c). Eggs with one polar cap (multi-unit cap; Gaino & Flannagan 1995), length ratio of polar cap to egg length = 0.39: 1. Micropyles are located around the base of the polar cap (Fig. 4e). Chorion sculptured in hexagonal netted pattern, convex area inside each cell, about 12 µm in diameter (Fig. 4d). Eggs form two elongate oval pale-yellowish eggs masses. Length of eggs masses are 5.46–5.53 mm (n=10).
Etymology. The species name ookaewae is dedicated to Assoc. Prof. Dr. Ookaew Prakobvitayakit (Chiang Mai University). Dr. Prakobvitayakit are well-known researcher on the aquatic ecology of Thailand, over 40 years, until retirement. The gender is female.
DNA barcoding. Sequences of Ephoron ookaewae sp. nov. were deposited in a GenBank database (MW168821).
Habitat and ecology. Ephoron ookaewae sp. nov. larvae were found in U-shaped burrows in hard clay (Fig. 5c–d) in moderately deep water (30–50 cm) and moderate flow (0.3–0.4 m /sec) of a large river. Some physicochemical variables of water at the moment of collection: temperature 31°C, pH 8.56, Conductivity 265 µS/cm, dissolved oxygen 9.2 mg /L and turbidity 11 NTU. Adult swarm densities increase between 7:00 p.m. and 8:00 p.m. (GMT +7 hrs). Emergence of male imagos occurred about one hour after sunset and female subimagos emerged about 15–20 minutes after males.
description: Published as part of Techakijvej, Chotiwut, Sareein, Nattawut, Hwang, Jeong Mi, Bae, Yeon Jae & Phalaraksh, Chitchol, 2021, A new species of Ephoron Williamson, 1802 (Ephemeroptera: Polymitarcyidae) from Thailand, pp. 392-402 in Zootaxa 4985 (3) on pages 394-398, DOI: 10.11646/zootaxa.4985.3.6, http://zenodo.org/record/4956267