Serratella elissa, Jacobus, Luke M. & Zhou, - F., 2009

Jacobus, Luke M. & Zhou, - F., 2009, Two new species of Asian Serratella Edmunds (Ephemeroptera: Ephemerellidae), Zootaxa 2268, pp. 52-58 : 55-58

Serratella elissa , new species

( Figs. 4–6)

Type material. HOLOTYPE: Iran, Guilan River at Lanak Waterfall, 37º00’N, 49º52’E, no collection date, larva [ PERC]. PARATYPES: same data, four larvae [ PERC]. Iran, Havigh River, 20 km south of Astara, 30- IV-1973, SF&KD Kimball, seven larvae [ USNM].

Larva (preserved in ethanol). Length: body 6.5–7.3 mm; antennae 1.4–1.7 mm; caudal filaments 3.7–4.0 mm. Body color yellow to light brown, sometimes with dark brown shading. Head: Color light brown with variable, dark brown maculae. Antennal scape and pedicel brown; flagellar segments light brown, darker distally, with whorl of fine, hairlike setae distally on each segment; hairlike setae one-half length of respective segment. Vertex rough. One to two pairs of spiculate, suboccipital bumps present. Clypeus with short setae. Labrum with irregular, transverse row of long, fine setae. Mandible not extending beyong margin of head capsule, with few fine, sublateral setae. Maxilla ( Fig. 4) with few subdistal setae, three fimbriate medial setae, and palp with three segments. Labium with palp segment 3 length about one-half that of segment 2. Thorax: Nota without prominent protuberances and with few fine setae, sometimes with brown maculation; pronotum with no anterolateral projections. Coxae and trochanters dark brown. Femora with subproximal and subdistal dark brown bands; forefemur with broad subdistal band of few long, sharp setae; mid- and hindfemora each with scattered hairlike setae and with sparse row of few, spatulate setae recumbent on posterior margin. Tibiae dark brown basally, grading to pale distally and with scattered hairlike setae. Tarsi brown with dark brown basal band and with scattered hairlike setae. Claws ( Fig. 5) with seven to nine denticles and with subdistal setae; denticles nearly subequal in size; subdistal setae sometimes difficult to discern. Abdomen: Terga without paired, submedian spines; paired tufts of fewer than four spatulate setae present on at least some posterior margins. Terga 6, 7, 9, and 10 usually dark brown to black. Dorsal lamellae of gills falcate, with brown trilobed pattern; ventral lamella of gill 6 deeply cleft; gill 7 inserted near posterolateral corner. Sterna with dark brown to black sublateral maculation; sterna 9 and 10 dark brown to black. Caudal filaments uniformly yellow to light brown, few basal segments dark brown; segments with distal whorls of stout setae and fine setae, sometimes with few long, hairlike setae laterally.

Subimagoes and Adults. Unknown.

Egg. Unknown.

Addition to data matrix. elissa ?? 1 0 0 0 0 0 0 0 0 0 0 - 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0???????

Larval Variability. Body color of the new species varies from nearly uniform yellow with few or no markings to brown with distinct dark and pale markings. The caudal filaments are variable with respect to the presence or absence of lateral hairlike setae. Larvae tend to differ in body shape, depending on the instar examined; earlier instars tend to be more compact and dorsoventrally flattened than later instars.

Diagnosis. Serratella elissa is distinguished from other Hyrtanellini by the combination of having at least some abdominal terga with distinctive paired tufts of spatulate setae on the posterior margins ( Fig. 6), gills 3 that are not operculate and claws with denticles nearly subequal in size ( Fig. 5). This new species is somewhat similar in general appearance to Quatica euphratica (Kazanci) and Serratella karia (Kazanci) , from Turkey. These species are distinguished easily from S. elissa by the dorsal armature of thorax and abdomen ( Kazanci, 1990). Serratella elissa also resembles species of the Teloganpsis mesoleuca (Brauer) species group, which includes also T. bauernfeindi (Thomas, Marie & Dia) , T. maculocaudata (Ikonomov) and T. subsolana (Allen) ( Jacobus & McCafferty, 2008; Jacobus, 2009; Ubero-Pascal & Sartori, 2009). Serratella elissa is distinguishable from these by its abdominal armature and lack of elongate apical denticles on the tarsal claws. Serratella elissa superficially resembles Ephemerella mucronata (Bengtsson) , of the tribe Ephemerellini, but S. elissa is distinguishable by its having deeply cleft ventral lamellae of gills 6, a character shared by all Hyrtanellini ( Jacobus & McCafferty, 2008).

Couplet 20 of the recent key to ephemerellid larvae ( Jacobus & McCafferty, 2008: 247) should be modified so that S. elissa will pass through and not be misidentified as Torleya major (Klapálek) . Part 20 should include the following: and gills 3 semi-operculate. Part 20’ should include the following: and gills 3 not semi-operculate.

Etymology. The specific epithet is a noun in apposition, referring to one of three fictitious stepsisters in Edmund Spenser’s The Faerie Queene.