Alainites gasithi Yanai & Gattolliat, 2022

Yanai, Zohar, Sroka, Pavel & Gattolliat, Jean-Luc, 2022, Two new species of Alainites (Ephemeroptera, Baetidae) from the Mediterranean biodiversity hotspot, ZooKeys 1118, pp. 73-95 : 73

Alainites gasithi Yanai & Gattolliat sp. nov.

Figs 4 , 5 , 6

Alainites species L55 in Samocha 1972

Material examined.

Holotype. Israel. 1 female nymph; Wadi Al-Qassab , Maymon Spring, 33°06.74'N, 35°39.62'E, 290 m a.s.l., 4.iv.2016, Z. Yanai leg., SMNH (385900) . Paratypes. Israel. 9 nymphs, same data as holotype. 5 nymphs SMNH (385901), 2 nymphs MZL (GBIFCH 00972062), 2 nymphs IECA • 10 nymphs, Maymon Spring , 33°06.74'N, 35°39.62'E, 290 m a.s.l., 22.vi.2014, Z. Yanai leg., 7 nymphs SMNH (385895), 3 nymphs MZL (GBIFCH 00971882) • 2 nymphs, same locality, 13.iv.2018, Z. Yanai leg., SMNH (385896) • 4 nymphs (1 on slide), same locality, 26.iii.2019, Z. Yanai leg., SMNH (385892, 385893, 385894) • 10 nymphs (2 on slides), Tina (Nutra) Stream, 33°04.70'N, 35°38.63'E, 72 m a.s.l., 15.vii.2014, Z. Yanai leg., SMNH (385902, 385903, 385904, 385905) • 5 nymphs, same locality, 6.xi.2015, Z. Yanai & S. Cohen leg., SMNH (385898, 385899) • 1 nymph, same locality, 16.v.2016, Z. Yanai & A. Charvet leg., SMNH (385897) • 1 nymph, same locality, 10.iii.2017, Z. Yanai & J.-L. Gattolliat leg., MZL (GBIFCH 00971972) • 4 nymphs (1 on slide), same locality, 27.iii.2019, Z. Yanai leg., SMNH (385906, 385907) • 7 nymphs (1 on slides), Gilbon Stream, old mill, 33°02.45'N, 35°38.40'E, 76 m a.s.l., 29.x.2015, Z. Yanai leg., SMNH (385889, 385890) • 4 nymphs, Divsha Stream, 33°05.41'N, 35°38.90'E, 150 m a.s.l., 6.xi.2015, Z. Yanai & S. Cohen leg., SMNH (385887, 385888) • 1 nymph, 'Ayit Waterfall, 32°57.28'N, 35°45.23'E, 470 m a.s.l., 4.iv.2016, Z. Yanai leg., SMNH (385891). Additional non-type material. Israel. 1 nymph, Jordan River , ' Ateret Fortress, 33°00.19'N, 35°37.72'E, 63 m a.s.l., 16.v.2016, Z. Yanai & A. Charvet leg., SMNH (385908) .

Differential diagnosis.

The species is distinct amongst other West Palaearctic Alainites species based on the combination of (1) six pairs of abdominal gills, (2) paraproct prolongation with spines only along the border, (3) serration between prostheca and mola, and (4) low number of dorsal setae on its fore-femora (10-20) and fore-tibiae (6-12).

Description of nymph.

Length. Female body 3.7-4.0 mm; cerci broken; median caudal filament 1.3-1.4 mm (ca. 2/3 of cerci); male body 3.7-3.9 mm; cerci broken; median caudal filament ca. 2/3 of cerci.

Colouration (Fig. 4 ). General colouration pale to medium brown. Head uniformly pale brown with vermiform marks faintly visible on vertex and frons. Turbinate eyes in male nymphs medium brown. Legs ecru, except a broad area on upper side of femora. Thorax medium brown without mark or pattern. Abdominal tergites medium brown without any pattern. Abdominal sternites pale to medium brown. Cerci ecru to pale brown without bands or pattern.

Head. Antennae (Fig. 5A ) close to each other, with a narrow interantennal carina; scape with few deep scale insertions and few setae. Dorsal surface of labrum (Fig. 5B ) with one central long seta, distolateral arc of three or four simple medium to long, stout setae, and scattered small fine setae; ventral surface with 5-10 submarginal small pointed setae; distal margin fringed with ca. 20 short, followed by seven or eight long, feathered setae. Right mandible (Fig. 5C ) smooth, not shagreened, with sparse fine setae; incisors composed of eight apically rounded, distinct denticles, outer- and innermost denticles smaller than others; prostheca reduced and bifid with numerous thin setae; outer half of margin between prostheca and mola serrated, tuft of setae absent; apex of mola with tuft of setae. Left mandible (Fig. 5D ) smooth, with sparse fine setae; incisors composed of seven apically rounded, distinct denticles, outer- and innermost denticles smallest; prostheca with medium denticles and comb-shaped structure; margin between prostheca and mola almost entirely serrated, without setae; apex of mola with tuft of setae. Hypopharynx (Fig. 5E ) trilobed, apically covered with thin setae; lingua with small central protuberance; superlingua slightly longer than lingua. Maxillae (Fig. 5F ) apex with three elongated and curved teeth and a tooth-like dentiseta; crown with two rows of setae, first row with small setae, second row with two long stout feathered dentisetae; palp two-segmented, reaching or slightly exceeding the apex of galealacinia, length of segment I subequal to segment II; segment II apically rounded, with few thin setae. Labium (Fig. 5G ) with glossae subequal to paraglossae; inner margins of glossae with 7-10 stout medium setae, apical margin with 7-11 long stout setae, ventral surface with few thin scattered setae; dorsal surface with row of ca. 7 medium setae; paraglossae of constant width, with three rows of 10-12 long, stout, simple setae apically; labial palp three-segmented; segment I nearly half the length of segments II and III combined; segment II with dorsal oblique row of four medium setae; segment III conical, asymmetrical.

Thorax. Forelegs (Fig. 6A ). Trochanter with four or five marginal short stout pointed setae. Femora dorsally with one row of 10-20 medium, stout setae; dorsoapical setal patch formed by two stout, medium setae; ventral margin with pointed short setae; lateral margin with sparse scale bases, mainly on apical half. Tibiae dorsally with ca. six (rarely up to 10-12) setae and single apical seta; ventral margin with small pointed scales and apical patch formed of four or five stout setae; tibiopatellar suture present; lateral margins with few scales and numerous scale bases. Tarsi bare dorsally; ventral margin with 10-15 small pointed setae; lateral margins with numerous scale bases. Tarsal claws (Fig. 6B ) hooked with one row of 7-13 (usually 10-11) medium teeth, apical setae absent. Mid and hindlegs similar to forelegs, except midtibiae (Fig. 6C ) usually with 9-11 pointed setae on the dorsal margin and hind tibiae usually with 5-7 such setae. Hindwing pads present.

Abdomen. Terga (Fig. 6D ) with numerous scale bases, smooth, not shagreened, distal margin of tergite IV with triangular spines, at least twice longer than wide. Sterna shagreened with scales and scale bases; posterior margin smooth without spination. Gills (Fig. 6E ) on segments II-VII, elliptic, symmetrical and serrated on margins of distal half; tracheation well visible and well divided; gill VII similar to gills II to VI. Paraproct (Fig. 6F ) with abundant scale bases, no setae; margin with six or seven triangular spines of varying size inner to prolongation and numerous medium spines outer to prolongation; prolongation margined with about 15 elongated medium spines, without spines on ventral surface; cercotractor with scale bases, margin with medium spines.

Imagos.

Unknown.

Etymology.

The name is a noun in apposition. The first author dedicates the species to his former mentor Prof. Avital Gasith (1943-). He is, in many aspects, the founder of freshwater ecology research in Israel. He trained the majority of the local active experts and contributed significantly to our understanding of freshwater systems and taxa, and to their conservation.

Distribution and ecology.

Typical habitats of A. gasithi sp. nov. include spring-fed brooks in the western slopes of the Golan Heights, with shallow running waters upon basalt bedding. Little is known about the seasonality of this species as it has been rarely collected. Mature nymphs were collected in the spring and early summer (late March to June). Interestingly, the examined specimens were collected mainly in 2014-2019, and despite continuing research and much effort in the same sites, the species was not collected in 2020-2021, an observation that may indicate inter-annual fluctuations in population sizes. However, the species is very rare even in positive sampling event, suggesting that further research is needed for estimation of meta-population structure and stability.

Figures

Figure 4. Alainites gasithi sp. nov., habitus: lateral view (top) and dorsal view (bottom).

Figure 5. Alainites gasithi sp. nov., nymph, characters of the head A antenna base B labrum (left side dorsal view, right side ventral view) C right mandible (ventral view) D left mandible (ventral view) E hypopharynx F maxilla G labium (left side dorsal view, right side ventral view). B-G presented to the same scale.

Figure 6. Alainites gasithi sp. nov., nymph, characters of the thorax and abdomen A foreleg B tarsal claw of foreleg C tibia of midleg D distal margin of tergum IV E gill IV F paraproct (with detail of prolongation).