Research Article |
Corresponding author: Zohar Yanai ( yanaizohar@gmail.com ) Academic editor: Ben Price
© 2018 Zohar Yanai, Jean-Luc Gattolliat, Netta Dorchin.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Yanai Z, Gattolliat J-L, Dorchin N (2018) Taxonomy of Baetis Leach in Israel (Ephemeroptera, Baetidae). ZooKeys 794: 45-84. https://doi.org/10.3897/zookeys.794.28214
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The taxonomy and systematics of the genus Baetis Leach (Ephemeroptera: Baetidae) in Israel is clarified for the first time as part of an ongoing comprehensive survey of the Israeli mayfly fauna. Six clearly defined species are currently recognized in Israel, four of which are described here as new to science. The validity of all species is supported by a molecular analysis of the mitochondrial COI gene. A key for the identification of the Israeli species based on the nymphal stage is provided, as well as data on their distribution patterns and ecology. The local fauna represents four Palearctic species groups, three of which reach their limit of distribution range in Israel. Baetis species typically inhabit lotic, pristine habitats in northern Israel, with few exceptions for some species that can be found in the Dead Sea area or in ephemeral ponds.
Aquatic insects, Baetis , Israel, mayflies, Palestinian Authority
Baetis Leach, 1815 is one of the richest mayfly genera with approximately 160 species worldwide (
Some Baetis species are widely distributed whereas others are confined to very limited areas. All feed mainly on detritus and periphyton (
The knowledge about mayflies from the Levant varies with country. The Lebanese and Syrian faunas are relatively well known, mostly thanks to studies by Dia, Thomas and Koch (e.g.,
The Israeli mayfly fauna currently numbers 17 species in seven families (Baetidae, Caenidae, Ephemerellidae, Heptageniidae, Leptophlebiidae, Oligoneuriidae and Prosopistomatidae). Except for Baetidae, the fauna is considered to be well-known, and only limited new discoveries are expected.
The Baetidae, by far the richest and most common family in Israel, remain poorly studied.
In the present paper, we provide the first comprehensive taxonomic treatment of the genus Baetis in Israel, based on integrative study of nymphal morphology and molecular analysis. We include a key to nymphs of all species and a description of four new species. The present study contributes to a better understanding of the Israeli mayfly fauna and may promote the development of local biological indices for water quality.
Collecting was done in over 400 sites around Israel and the Palestinian Authority (Figure
Typical Baetis habitats in Israel and the Palestinian Authority: A Senir Stream, a main source of the Jordan River B Hula nature reserve, a marshland habitat C Keziv Stream, a pristine stream in a forested area in the Upper Galilee D Ateret Fortress, a site in the Upper Jordan River system E Maymon Spring, a small spring-fed brook in the Upper Jordan River system, the Golan Heights F Zippori Stream, a lowland stream in the Lower Galilee G Perat Stream (Wadi Qelt) in the eastern Judean Mountains H Arugot Stream, a desert stream in the arid water system of the Dead Sea.
For the phylogenetic reconstruction we used freshly collected nymphs from populations throughout the distribution range of each species in Israel. DNA was extracted using the DNAeasy blood and tissue kit and BioSprint 96 extraction robot (Qiagen Inc., Hilden, Germany), implementing the non-destructive protocol outlined by
Molecular reconstruction was conducted on 48 newly obtained sequences, as well as three B. monnerati specimens from Jordan (
In the present study, two described and four new species of Baetis were found in Israel, all are well supported by the molecular phylogenetic analysis of mitochondrial COI sequences (Figure
A Maximum Likelihood phylogenetic reconstruction based on sequences of the mitochondrial COI gene obtained from Israeli and related species. The validity of six Israeli species is confirmed and strongly supported. Gray shaded clades represent cryptic species that are morphologically indistinguishable from the species described here. Bootstrap values above 70% are indicated next to the nodes.
Intraspecific (bold) and interspecific genetic distances among sequences of the mitochondrial COI gene of the six Israeli Baetis species (mean, minimum–maximum).
B. samochai | B. pacis | B. noa | B. monnerati | B. aureus | B. golanensis | |
B. samochai | 0.5% | |||||
0.0%–0.7% | ||||||
B. pacis | 26.5% | 0.3% | ||||
26.1%–27.1% | 0.0%–0.7% | |||||
B. noa | 18.7% | 22.0% | 2.3% | |||
17.7%–19.4% | 21.3%–22.3% | 0.0%–3.5% | ||||
B. monnerati | 13.5% | 18.6% | 20.6% | 0.7% | ||
11.9%–15.3% | 17.7%–19.6% | 18.6%–21.3% | 0.0%–2.1% | |||
B. aureus | 12.4% | 23.0% | 18.6% | 13.9% | 0.0% | |
12.0%–12.8% | 22.2%–23.1% | 18.6%–18.6% | 13.6%–14.5% | 0.0%–0.0% | ||
B. golanensis | 13.5% | 27.0% | 15.5% | 15.0% | 14.3% | 0.0% |
13.5%–13.5% | 27.0%–27.1% | 15.2%–16.0% | 14.3%–15.2% | 14.3%–14.3% | 0.0%–0.0% |
The main diagnostic morphological characteristics of the genus pertain to nymphs and include the cylindrical body, two pairs of wing pads, absence of setae between prostheca and mola of both mandibles, simple stout prostheca on both mandibles, presence of femoral villopore, robust tarsal claws with a single row of denticles, gills consisting of a single lamella on abdominal segments I–VII, unmodified paraproct and three caudal filaments (
Baetis aureus is unique within its potential species groups in having a relatively short median caudal filament (half-length of cerci) and scale bases on the surface of the abdominal terga only slightly wider than seta bases. In Israel it is distinguishable by the long gills, elongate body, and wide, triangular spines along the distal margin of terga.
Length (mature nymphs). Female (n = 17): 4.2–4.5 mm (summer generation) to 5.3–7.2 mm (winter generation); cerci 2.6–5.4 mm; median caudal filament 1.7–2.7 mm. Male (n = 8): 4.5–4.7 mm (summer) to 6.0–7.1 mm (winter); cerci 2.9–4.1 mm; median caudal filament 1.6–2.6 mm.
Colouration. General colour light brown to yellow (Figure
Head. No carina between antennae; pedicel almost bare (Figure
Thorax. Forelegs (Figure
Abdomen. Terga shagreened with few thin setae, seta bases and very small scale bases (only slightly wider than seta bases); distal margin of all terga with row of triangular spines as broad as long (spines longer and more pointed on terga VII to IX), with spaces between them no broader than spine length (Figure
Baetis aureus exhibits the main characters of the B. vernus and B. buceratus species groups sensu
In the B. vernus species group, seven species were reported from the West Palearctic region, and differ from B. aureus as follows: Baetis vernus Curtis, 1834 has a mola with two small auxiliary spines at the outer side of the subtriangular process (figure 91 in
Baetis aureus differs from all other known species of the B. buceratus species group (see
Aureus (Latin for golden) refers to the general colour of the nymph body.
This species is common in the northern regions of Israel: Lower and Upper Galilee, Hula Valley and Golan Heights, and rare in the Yarqon stream. It is found in habitats of running, pristine water, particularly in small creeks but also in larger streams such as the Keziv and Zippori (Figure
Holotype. ISRAEL: 1 Nymph, Gamla Stream (Peham Springs), 32.9672°N, 35.8201°E, ca 690 m a.s.l., 04.iv.2016, Z. Yanai, SMNHTAU291999. Paratypes. ISRAEL: 88N, Barqan Stream, 25.v.2011, Y. Hershkovitz; 1N, Gilbon Stream (upstream Devora Waterfall), 09.iv.2014, Z. Yanai; 1N, Yarqon Stream (national park), 10.iv.2014, Z. Yanai; 4N (1N on slide), Ammud Stream (Yaqim Spring), 20.v.2014, Z. Yanai; 1N, Fit Spring, 10.vi.2014, Z. Yanai; 9N (2N on slides), Gaaton Junction, 17.vi.2014, Z. Yanai & D. Mayer; 3N, Zippori Stream (Ras Ali), 02.iii.2015, Z. Yanai; 1N, Gilbon Stream (upstream Devora Waterfall), 29.x.2015, Z. Yanai & Y. Brenner; 107N (1N on slide), Keziv Stream (Hardalit Spring), 07.xi.2015, Z. Yanai & S. Cohen; 17N, Keziv Stream (Tamir Spring), 07.xi.2015, Z. Yanai & S. Cohen; 1N, Zippori Stream (Zippori Springs), 07.xi.2015, Z. Yanai & S. Cohen; 40N, Zippori Stream (Ras Ali), 07.xi.2015, Z. Yanai & S. Cohen; 19N, Gamla Stream (Peham Springs), 04.iv.2016, Z. Yanai; 154N (1N on slide), Zippori Stream (Zippori Springs), 19.iv.2016, Z. Yanai; 24N (1N on slide), Rosh Pinna Stream (Rosh Pinna), 15.x.2016, Z. Yanai; 6N, Yarqon Stream, 14.v.2017, Y. Hershkovitz. Other material. ISRAEL: 4N, Zippori Stream (Yivqa Spring), 21.ii.2014, Z. Yanai; 5N (1N on slide), Keziv Stream (Hardalit Spring), 17.vi.2014, Z. Yanai & D. Mayer; 4N, Ammud Stream (Poem Spring), 18.v.2015, Y. Hershkovitz & T. Eshcoly.
Baetis
A12:
Baetis
lutheri
:
Among the species with well-developed median caudal filaments in the B. lutheri species group, B. golanensis is the only one with a combination of the following characters: right mandibular incisors of similar size, irregular blunt quadrangular spines on the distal margin of terga, and non-sclerotized protuberances next to the coxae. This is the only species in Israel with a developed median caudal filament that also has ventral protuberances near coxa bases and subapical setae on the claws.
Length (mature nymphs). Female (n = 11): 5.1–6.3 mm; cerci 2.2–2.9 mm; median caudal filament 1.4–2.4 mm. Male (n = 9): 4.6–6.1 mm; cerci 2.2–3.0 mm; median caudal filament 1.7–2.4 mm.
Colouration. General colour brown (Figure
Head. No carina between antennae; antennae with few fine setae, pedicel without distal lobe (Figure
Thorax. Forelegs (Figure
Abdomen. Terga shagreened, with few thin setae and many seta bases, without scales or scale bases; distal margin of all terga with irregular row of blunt, quadrangular spines, with occasional fine seta (Figure
The new species clearly belongs to the Baetis lutheri species group sensu
Baetis lutheri Müller-Liebenau, 1967 appears to be the closest species to B. golanensis, based on its morphology, yet differs from it by the incisors of the right mandible, which is variable in size, the arrangement and shape of the setae along the dorsal margin of femur, and the more regular, blunt teeth along the distal margin of the terga (
Baetis lutheri has a wide distribution in the West Palearctic (
The species name reflects its presently known distribution range, the Golan Heights.
Baetis golanensis is a rare species in Israel. It was reported by Samocha (as “Baetis A12”) from springs and streams in the western Golan and a few localities along the upper Jordan River. This restricted distribution is confirmed in the present study. Two distinct habitats are typical for B. golanensis in Israel: streams with large water discharge and rapid currents (upper Jordan River; Figure
Holotype. ISRAEL: 1N, Divsha Spring, 33.0901°N, 35.6483°E, ca. 150 m a.s.l., 11.v.2016, Z. Yanai & N. Dorchin, SMNHTAU292000. Paratypes. ISRAEL: 14N (3N on slides), Divsha Spring, 10.vi.2014, Z. Yanai; 77N, Divsha Spring, 06.xi.2015, Z. Yanai & S. Cohen; 74N, Divsha Spring, 11.v.2016, Z. Yanai & N. Dorchin; 19N, Divsha Spring, 17.v.2016, Z. Yanai; 3N, Divsha Spring, 02.x.2016, Z. Yanai & N. Truskanov; 16N (1N on slide), Tina Spring, 10.iii.2017, Z. Yanai & J.-L. Gattolliat; 4N, Divsha Spring, 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 44N, Yehudiyya Stream, 11.iii.2017, Z. Yanai & J.-L. Gattolliat. Other material. ISRAEL: 1N, Maymon Spring, 22.vi.2014, Z. Yanai; 6N (1N on slide), Gilbon Stream (downstream Gilbon Spring), 15.vii.2014, Z. Yanai; 4N, Divsha Spring, 11.v.2015, Y. Hershkovitz & T. Eshcoly; 1N, Orevim Stream, 11.v.2015, Y. Hershkovitz; 14N, Samakh Stream, 13.v.2015, Y. Hershkovitz & T. Eshcoly; 11N, Jordan River (Ateret Fortress), 29.x.2015, Z. Yanai & Y. Brenner; 7N, Senir Stream (Bet Hillel), 05.xi.2015, Z. Yanai & S. Cohen; 16N, Tina Spring, 06.xi.2015, Z. Yanai & S. Cohen; 2N, Gilbon Stream (upstream Devora Waterfall), 11.v.2016, Z. Yanai & N. Dorchin; 2N, Tina Spring, 16.v.2016, Z. Yanai & A. Charvet; 162N, Jordan River (Ateret Fortress), 16.v.2016, Z. Yanai & A. Charvet; 1N, Senir Stream (Beth Hillel), 17.v.2016, Z. Yanai & A. Charvet; 3N, Jordan River (Neot Mordekhay), 01.vi.2016, Y. Hershkovitz; 8N (2N on slides), Jordan River (Ateret Fortress), 16.x.2016, Z. Yanai.
Baetis
monnerati
Gattolliat & Sartori in
This species (Figures
Baetis monnerati belongs to the B. buceratus species group sensu
Baetis monnerati is the most abundant and widespread Baetis species in the Israeli fauna. It is common in the Golan Heights, Hula Valley, Upper and Lower Galilee, Jordan Valley, eastern Judean Mountains, and the Dead Sea area. Outside of Israel it is found in Jordan (
Holotype. JORDAN: 1N, Wadi Weida’a, 15.xii.2010, C. Monnerat. Other material. ISRAEL: 3N, Fit Spring, 31.v.2014, Z. Yanai; 4N, Zippori Stream (Ras Ali), 02.iii.2015, Z. Yanai; 9N, Qazabiyye Springs, 11.v.2015, Y. Hershkovitz & T. Eshcoly; 86N, Meron Stream (Meron Spring), 12.v.2015, Y. Hershkovitz & T. Eshcoly; 125N, Iyyon Stream (Qiryat Shemona), 12.v.2015, Y. Hershkovitz & T. Eshcoly; 70N, Samakh Stream, 13.v.2015, Y. Hershkovitz & T. Eshcoly; 25N, Jordan River (Ateret Fortress), 29.x.2015, Z. Yanai & Y. Brenner; 97N, Senir Stream (Bet Hillel), 05.xi.2015, Z. Yanai & S. Cohen; 20N (2N on slides), Zippori Stream (Zippori Springs), 07.xi.2015, Z. Yanai & S. Cohen; 19N, Keziv Stream (Hardalit Spring), 07.xi.2015, Z. Yanai & S. Cohen; 4N, Yehudiyya Stream, 27.iii.2016, Y. Hershkovitz; 11N, Iyyon Stream (Qiryat Shemona), 05.iv.2016, Z. Yanai; 66N, Iyyon Stream (nature reserve), 05.iv.2016, Z. Yanai; 340N (1N on slide), Arugot Stream, 09.v.2016, Z. Yanai; 31N, Enan Stream, 17.xi.2016, Z. Yanai & L. Goren; 160N (1N on slide), Dawid Stream, 07.iii.2017, Z. Yanai & J.-L. Gattolliat; 210N, Arugot Stream, 07.iii.2017, Z. Yanai & J.-L. Gattolliat; 100N, Senir Stream (Bet Hillel), 09.iii.2017, Z. Yanai & J.-L. Gattolliat; 130N, Senir Stream (nature reserve), 09.iii.2017, Z. Yanai & J.-L. Gattolliat; 20N, Iyyon Stream (nature reserve), 05.iv.2016, Z. Yanai & J.-L. Gattolliat; 8N, Tina Spring, 10.iii.2017, Z. Yanai & J.-L. Gattolliat; 23N, Hula (nature reserve), 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 250N, Jordan River (Ateret Fortress), 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 34N, Jordan River (Ariq Bridge), 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 38N, Yehudiyya Stream, 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 80N, Daliyyot Stream, 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 4N, Rekhesh Stream (Rekhesh Spring), 04.v.2017, E. Elron. PALESTINIAN AUTHORITY: 23N (1N on slide), Perat Stream (nature reserve), 14.vi.2014, Z. Yanai; 1N (on slide), Perat Stream (nature reserve), 20.vi.2015, Z. Yanai; 9N, Perat Stream (nature reserve), 24.i.2017, Z. Yanai & K. Tamar; 120N, Perat Stream (nature reserve), 08.iii.2017, Z. Yanai & J.-L. Gattolliat; 8N, Pezael Springs, 08.iii.2017, Z. Yanai & J.-L. Gattolliat.
“Baetis L53”:
Baetis noa is distinguishable from all known species of Rhodobaetis by the following combination of characters: seven setae on labrum, three rows of setae on paraglossae, triangular spines along tergal margins (tergum III and onward), spines on gill margins, ca. 15 triangular teeth along paraproct margin, and 6–8 triangular spines of similar size along cercotractor margin. This is the only representative of Rhodobaetis in Israel, and therefore the only one to exhibit the group characteristics, namely body covered by spatulated scales (particularly along the distal margin of the abdominal terga) and stout spines along the gill margins.
Length (mature nymphs). Female (n = 24): 4.8–8.1 mm; cerci 1.9–3.0 mm; median caudal filament 1.3–2.3 mm. Male (n = 12): 4.4–6.0 mm; cerci 2.0–2.3 mm; median caudal filament 1.3–1.7 mm.
Colouration. General colour brown (Figure
Head. No carina between antennae; pedicel with elongate spatulated scales apically (Figure
Thorax. Forelegs (Figure
Abdomen. Terga densely covered with numerous spatulated scales, scale bases and few thin hair-like setae; distal margin of all terga with numerous spatulas, terga I to IV without spines, terga V and VI with few broad, blunt triangular spines (Figure
Baetis noa belongs to the subgenus Rhodobaetis Jacob, 2003 (Baetis rhodani species group sensu
The Central European species B. rhodani rhodani (Pictet, 1843) (B. rhodanis.s.) differs from B. noa by having long setae on the dorsal margin of femora and not many tergal scales (
Baetis noa matches the characters of the undescribed “Baetis L53” as outlined in
The name is a noun in apposition. The species is dedicated to Noa Truskanov, the partner, source of inspiration, and closest friend of the senior author.
This species is known from the tributaries of the Jordan River and from brooks and springs in the Golan Heights, where it inhabits streams of diverse sizes and current velocities (Figs
Holotype. ISRAEL: 1N, Senir Stream (nature reserve), 33.2331°N, 35.6223°E, ca 130 m a.s.l., 09.iii.2017, Z. Yanai & J.-L. Gattolliat, SMNHTAU292002. Paratypes. ISRAEL: 2N, Senir Stream (Bet Hillel), 09.vi.2014, Z. Yanai; 3N (1N on slide), Senir Stream (nature reserve), 15.vii.2014, Z. Yanai; 3N, Dan Stream (Dafna), 29.vii.2015, Z. Yanai; 7N, Dan Stream (Tel Dan), 05.xi.2015, Z. Yanai & S. Cohen; 2N (on slides), Senir Stream (nature reserve), 05.xi.2015, Z. Yanai & S. Cohen; 6N, Dan Stream (Tel Dan), 31.v.2016, Y. Hershkovitz; 68N, Dan Stream (Dan), 31.v.2016, Y. Hershkovitz; 24N (1N on slide), Senir Stream (nature reserve), 09.iii.2017, Z. Yanai & J.-L. Gattolliat; 80N, Dan Stream (Tel Dan), 10.iii.2017, Z. Yanai & J.-L. Gattolliat; 2N, Dan Stream (Dan), 07.v.2017, Z. Yanai; 13N, Yehudiyya Stream, 12.iv.2018, Z. Yanai; 36N, Dan Stream (Dafna), 13.iv.2018, Z. Yanai. Other material. ISRAEL: 8N (1N on slide), Hermon Stream (Panyas Springs), 19.ii.2014, Z. Yanai; 16N (1N on slide), Maymon Spring, 22.vi.2014, Z. Yanai; 18N, Senir Stream (nature reserve), 15.vii.2014, Z. Yanai; 3N, Senir Stream (Bet Hillel), 05.xi.2015, Z. Yanai & S. Cohen; 54N, Maymon Spring, 04.iv.2016, Z. Yanai; 10N, Dan Stream (Dafna), 31.v.2016, Y. Hershkovitz.
“Baetis L12”:
“Baetis sp.”:
Within the Baetis lutheri species group, B. pacis is distinguishable by the following combination of characters: greatly reduced median caudal filament, non-sclerotized protuberances next to coxae, and body not covered with spatulae. In Israel it is easily recognized by its very short median caudal filament.
Length (mature nymphs). Female (n = 13): 5.0–7.6 mm; cerci 2.7–4.5 mm; median caudal filament minute (< 0.2 mm). Male (n = 10): 4.0–6.0 mm; cerci 2.2–4.1 mm; median caudal filament minute (< 0.2 mm). Usually, specimens from the Perat Stream population are smaller than those in northern Israel.
Colouration. General colour brown (Figure
Head. No carina between antennae; pedicel almost bare, without distal lobe (Figure
Thorax. Forelegs (Figure
Abdomen. Terga shagreened with few thin setae and many seta bases, without scales; distal margin with row of blunt quadrangular spines (Figure
The species belongs to the Baetis lutheri species group sensu
Baetis lutheri differs from B. pacis by having longer setae on the dorsal margin of femora, densely shagreened terga surface and less reduced median caudal filament (
This species corresponds to the undescribed “Baetis L12” of
This species occurs in Israel, the Palestinian Authority, and apparently also in Jordan. Its name reflects our yearning for regional peace.
Baetis pacis is distributed mainly in the tributaries of the Jordan River (i.e., Senir, Dan and Iyyon; Figure
Holotype: ISRAEL: 1N, Senir Stream (nature reserve), 33.2331°N, 35.6223°E, ca 130 m a.s.l., 09.iii.2017, Z. Yanai & J.-L. Gattolliat. SMNHTAU292001.–Paratypes. ISRAEL: 80N (1N on slide), Senir Stream (nature reserve), 09.iii.2017, Z. Yanai & J.-L. Gattolliat; 6N, Iyyon Stream (nature reserve), 05.iv.2016, Z. Yanai; 30N (1N on slide), Senir Stream (nature reserve), 17.v.2016, Z. Yanai & A. Charvet; 13N (1N on slide), Dan Stream (Dan), 31.v.2016, Y. Hershkovitz; 2N, Dan Stream (Dafna), 31.v.2016, Y. Hershkovitz; 16N, Senir Stream (Bet Hillel), 09.iii.2017, Z. Yanai & J.-L. Gattolliat; 1N, Dan Stream (Tel Dan), 10.iii.2017, Z. Yanai & J.-L. Gattolliat. Other material. ISRAEL: 1N, Divsha Spring, 06.xi.2015, Z. Yanai & S. Cohen; 1N, Divsha Spring, 11.v.2016, Z. Yanai & N. Dorchin; 1N, Iyyon Stream (nature reserve), 01.vi.2016, Y. Hershkovitz; 1N, Divsha Spring, 02.x.2016, Z. Yanai & J.-L. Gattolliat. –PALESTINIAN AUTHORITY: 1N, Perat Stream (nature reserve), 20.vi.2015, Z. Yanai; 37N, Perat Stream (nature reserve), 11.xi.2015, Z. Yanai & S. Cohen; 22N, Perat Stream (nature reserve), 23.v.2016, Z. Yanai & L. Friedman; 6N (2N on slides), Perat Stream (nature reserve), 24.i.2017, Z. Yanai & K. Tamar; 2N, Perat Stream (nature reserve), 30.i.2017, Z. Yanai & N. Truskanov; 12N, Perat Stream (nature reserve), 08.iii.2017, Z. Yanai & J.-L. Gattolliat.
“Baetis L34”:
Baetis
samochai
:
As the original description (
Baetis samochai is well distinguishable by the following combination of characters: canines of both mandibles with a very broad outer tooth; maxillary palp longer than galea-lacinia; dorsal margin of femora with abundant small, strong setae; elongate body; long gills (about twice the length of following abdominal segment); distal margin of terga with needle-like spines; abdominal colouration yellowish brown with whitish, central longitudinal stripe.
Length (of full-grown specimens). Female (n = 22): 6.0–8.2 mm; cerci 4.0–6.5 mm; median caudal filament 2.6–3.7 mm. Male (n = 14): 5.6–7.5 mm; cerci 3.1–6.1 mm; median caudal filament 2.2–3.2 mm.
Colouration. General colour yellowish brown with longitudinal stripe on entire body (Figure
Head. Dorsal surface of labrum (Figure
Thorax. Legs (Figure
Abdomen. Distal margin of terga with slender triangular spines, more than twice longer than broad (Figure
As discussed by
Baetis samochai is known from Israel, Lebanon, Syria (
ISRAEL: 6N, Senir Stream (nature reserve), 11.iii.2015, Z. Yanai; 2N, Daliyyot Stream, 26.iii.2014, Z. Yanai; 1N, Hermon Stream (Panyas Springs), 09.vi.2014, Z. Yanai; 1N, Jordan River (haPeqaq Bridge), 10.vi.2014, Z. Yanai; 6N, Keziv Stream (Hardalit Spring), 17.vi.2014, Z. Yanai; 1N (on slide), Senir Stream (nature reserve), 15.vii.2014, Z. Yanai; 5N, Hula (nature reserve), 01.xii.2014, Z. Yanai; 11N, Jordan River (haHamisha Bridge), 08.xii.2014, Z. Yanai; 3N, Enan Stream, 29.iv.2015, L. Goren; 3N (1N on slide), Hula (nature reserve), 29.iv.2015, L. Goren; 1N, Rezaniyya Winter Pool, 29.iv.2015, L. Goren; 1N, Qazabiyye Springs, 29.iv.2015, L. Goren; 3N, haKefar Spring, 11.viii.2015, E. Elron; 87N (2N on slides), Gamla Stream (Peham Springs), 28.iii.2016, Y. Hershkovitz; 6N (1N on slide), Gamla Stream (Peham Springs), 04.iv.2016, Z. Yanai; 21N (1N on slide), Ayit Stream (Ayit Waterfall), 04.iv.2016, Z. Yanai; 1N, El-Mahfi Winter Pool, 20.iv.2016, L. Goren; 6N, Qazabiyye Springs, 20.iv.2016, L. Goren; 3N, Dan Stream (Dan), 20.iv.2016, L. Goren; 1N, Divsha Spring, 11.v.2016, Z. Yanai & N. Dorchin; 6N (1N on slide), Jordan River (Ateret Fortress), 16.v.2016, Z. Yanai & A. Charvet; 2N, Jordan River (Neot Mordekhay), 01.vi.2016, Y. Hershkovitz; 6N, Hula (nature reserve), 16.xi.2016, Z. Yanai & L. Goren; 14N, Enan Stream, 17.xi.2016, Z. Yanai & L. Goren; 61N, Senir Stream (nature reserve), 09.iii.2017, Z. Yanai & J.-L. Gattolliat; 7N, Jordan River (Ariq Bridge), 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 1N, Yehudiyya Stream, 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 1N, Ayit Stream (Ayit Waterfall), 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 190N, Hula (nature reserve), 11.iii.2017, Z. Yanai & J.-L. Gattolliat; 41N, Hula (nature reserve), 08.v.2017, L. Goren; 2N, Yehudiyya Stream, 12.iv.2018, Z. Yanai; 1N, El-Muayer Winter Pool, 25.iv.2018, E. Elron; 2N, Parag Winter Pool, 25.iv.2018, E. Elron.
1 | Gills with single lamella, claw with single row of teeth, hind wing pads present, carina between eyes absent, setae between mola and prostheca absent in both mandibles, simple prostheca in both mandibles, paraproct without expansion | Baetis sensu stricto, 2 |
– | At least one of the characters different than above | other Baetidae |
2 | Median caudal filament reduced to 10 segments at most (Figure |
Baetis pacis sp. n. |
– | Median caudal filament at least 1/2 length of cerci | 3 |
3 | Gill margins with short spines (Figure |
Baetis noa sp. n. |
– | Gill margins without spines (e.g., Figure |
4 |
4 | Gills elongate (almost two terga long). Body elongate and tubular. Terga generally yellow | 5 |
– | Gills oval (slightly longer than consecutive tergum). Body somewhat compressed dorso-ventrally. Terga generally brown or with conspicuous brown spots | 6 |
5 | Triangular spines on distal margin of terga as long as broad (Figure |
Baetis aureus sp. n. |
– | Triangular spines on distal margin of terga twice as long as broad (Figure |
Baetis samochai |
6 | Spines along distal margin of terga regular, triangular (Figure |
Baetis monnerati |
– | Spines along distal margin of terga irregular, blunt, quadrangular (Figure |
Baetis golanensis sp. n. |
The present work is the first thorough taxonomic study on Israeli mayflies to have been conducted for more than two decades, and increases the Israeli mayfly fauna by 35%. The six Baetis species occurring in Israel represent four species groups sensu
Our study was based exclusively on recent collections (2014–2018) by us or by colleagues. Comparison of these newly collected specimens to old material collected by Samocha (early 1970s) and Ortal (1980s–1990s) was impossible due to its poor condition. The collecting details mentioned by
The highest diversity of Baetis species in Israel, as well as for Israeli mayflies in general, is found in the northern stream system (Figure
Except for the fairly abundant B. monnerati, most of the Israeli Baetis species face threats that result from the frail status of their habitats. Severe water shortage in recent years affects mainly the northern water courses of Israel, and loss of aquatic habitats due to development or pollution is evident throughout the country. Sensitive Baetis populations are likely to degrade accordingly, a trend that has probably already began. Isolated populations of B. pacis (Perat Stream) and B. aureus (Yarqon Stream) are probably relicts of a continuous distribution pattern in the past, rendering these populations and their habitats of high conservation value.
We thank Eldad Elron, Tuvia Eshcoly, Liron Goren, and Yaron Hershkovitz who contributed material from their collections. Shai Cohen assisted in the field survey. Marion Podolak, Christophe Praz, and Sereina Rutschmann assisted in various aspects of the phylogenetic analysis; Sereina Rutschmann also kindly provided unpublished reference sequences for the analysis. Michel Sartori contributed to various aspects of the study. Material was collected for this study under collecting permits number 40223, 40720, 41168, 41547, and 41897 by the Israel Nature and Parks authority. The study was supported by the Israel Taxonomy Initiative (ITI).
Baetis collecting sites with coordinates and altitudes.
Collecting details and GenBank accession numbers for the specimens used in the molecular analysis. Codes correspond to those in Figure 3.