Baetis samochai Koch, 1981

Yanai, Zohar, Gattolliat, Jean-Luc & Dorchin, Netta, 2018, Taxonomy of Baetis Leach in Israel (Ephemeroptera, Baetidae), ZooKeys 794, pp. 45-84 : 45

Baetis samochai Koch, 1981 Figures 4F, 16, 17

" Baetis L34": Samocha 1972: 6, pl XX, figs 1-8.

Baetis samochai : Koch 1981: 121-128, figs 1-14; Koch 1988: 94; Tanatmış 1999; Kazancı 2001; Salur et al. 2016: 74; Bojková et al. 2018: 95.

Notes.

As the original description ( Koch 1981) was superficial, lacked important diagnostic characters, and some of the drawings were of poor quality, we provide a more detailed description below.

Differential diagnosis.

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.

Description.

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 4F; Koch 1981: fig. 12).

Head. Dorsal surface of labrum (Figure 16B; fig. 5 in Koch 1981) with scattered fine setae and seta bases, one median pair of long setae and distolateral arc of setae composed of 7-8 long, simple, stout setae; lateral margin with 4-6 small, fine setae; ventral surface with 4-5 small, stout setae laterodistally; distal margin with row of ca. 30 fine, long, feathered setae. Right and left mandibles with two sets of denticles relatively deeply cleft (Figure 16C, E; Koch 1981: figs 6, 7), outer denticle very broad, constituting most of outer set. Maxilla (Figure 16F; Koch 1981: fig. 10) with four broad teeth; lacinia with two rows of setae, one row with abundant small setae ending with stouter and longer setae, second row with two serrated, stout dentisetae; base of lacinia with row of five stout setae; one seta perpendicular to lacinia margin; palpus 2-segmented, segment II longer than segment I, exceeding galea-lacinia in length; segment II with thin setae and apical nipple, apical scale absent. Labium (Figure 16G): palpus 3-segmented; segment II with slightly developed distolateral protuberance; segment III symmetrical, rounded.

Thorax. Legs (Figure 17A; Koch 1981: fig. 11): Dorsal margin of femora with many scattered short, stout setae.

Abdomen. Distal margin of terga with slender triangular spines, more than twice longer than broad (Figure 17C; space between spines wider than originally illustrated by Koch 1981: fig. 10). Gills elongate with developed tracheation (Figure 17D, E; Koch 1981: fig. 14); gill IV twice as long as following tergum. Paraproct (Figure 17F) with abundant seta bases, few hair-like setae and rarely pointed submarginal spatulas; margin with 16-19 long, triangular spines; postero-lateral extension with fewer seta bases, margin with 15-20 triangular spines almost as long as those of paraproct.

Affinities.

As discussed by Koch (1981), this species belongs to the Baetis vernus species group sensu Müller-Liebenau (1969), although the median caudal filament is clearly shorter than the cerci. This species corresponds to the undescribed " Baetis L34" sensu Samocha (1972: 46, pl XX).

Distribution and ecology.

Baetis samochai is known from Israel, Lebanon, Syria ( Koch 1981, 1988), Turkey ( Tanatmış 1999; Kazancı 2001; Salur et al. 2016), and Iran ( Bojková et al. 2018). In Israel it was recorded by Samocha (1972) exclusively from the northern Golan Heights, but we found numerous populations throughout the Golan Heights, Hula Valley, and the Upper Jordan River and its tributaries. This species may have been overlooked by Samocha or has become more abundant since his study. Unlike most Baetis species, B. samochai was reported from lotic as well as lentic habitats, with abundant aquatic vegetation ( Koch 1981). Indeed, we found this species in Israel in diverse ecological niches, including ponds, marshes and streams with moderate or rapid currents (Figure 2A, B, D, E). It is most typically found in calm microhabitats with abundant vegetation along waterbody margins. Mature nymphs were found mostly in spring ( March–May), whereas adults were found in winter ( November–December), suggesting that the species has at least two generations per year.

Material examined.

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.