Squalius semae, a new species of chub from the Euphrates River, Eastern Anatolia (Teleostei: Cyprinidae)
Davut Tura
Maurice Kottelat
Esra Bayçelebi
Zoology in the Middle East
2017
63
1
33
42
Davut Tura & Maurice Kottelat & Esra Bayçelebi, 2017
Davut Tura & Maurice Kottelat & Esra Bayçelebi
2017
[185,356,1449,1472]
Actinopterygii
Cyprinidae
Squalius
Animalia
Cypriniformes
2
35
Chordata
species
semae
sp. nov.
Holotype. FFR 724, 197mm SL; Turkey: ErzurumProv.: Serçeme Stream(tributary of Karasu Stream) ( 39°56.85’N 40°48.24’E); D. Turan, E. Bayçelebi& C. Kaya, 26.v.2013. – Paratypes. FFR 725, 26, 133– 228 mmSL; same data as holotype. – FFR 669, 9, 121– 174 mmSL; Turkey: Erzurum: Sırlı Stream(tributary of Karasu Stream) ( 40°13.06’N 41°06.03’E); D. Turan& R. Buyurucu, 23.iv.2005. – FFR 593, 52, 50–161 mmSL; Turkey: Erzurum: Toprakkale Stream(tributary of Karasu Stream), ( 40°14.51’N 40°59.67’E); D. Turan& R. Buyurucu, 15.viii.2009. – FFR 700, 8, 91–200 mmSL; Turkey: MuşProv.: Karasu Stream(a tributary of Murat River) ( 38°38.94’N 41°46.98’E); D. Turan, E. Bayçelebi& C. Kaya, 22.ix.2013. – FFR 703, 4, 86–123 mmSL; Turkey: MuşProv.: Murat River( 38°51.97’N 41°00.00’E); D. Turan, E. Bayçelebi& C. Kaya, 22.ix.2013. – FFR 710, 5, 86–123 mmSL; Turkey: AğrıProv. Doğubeyazıt Dist.: Murat River( 39°36.81’N 43°30.98’E); D. Turan, E. Bayçelebi& C. Kaya, 16.vii.2012. – FFR 722, 13, 64–123 mmSL; Turkey: MuşProv.: Mercimekkale Stream(tributary of Murat River) ( 38°04.07’N 41°31.73’E); D. Turan, E. Bayçelebi& C. Kaya, 22.ix.2013. – FFR 727, 2, 165– 190 mmSL; Turkey: TunceliProv.: Pülümür Stream( 39°08.39’N 39°38.31’E); C. Kaya& M. Kocabaş, 27.x.2013. – CMK 26645, 4, 174– 195 mmSL; Turkey: ErzurumProv.: Serçeme Stream(tributary of Karasu Stream) ( 39°56.85’N 40°48.24’E); D. Turan, E. Bayçelebi& C. Kaya, 26.v.2013. Allfrom the Euphrates Riverdrainage.
Diagnosis. Squalius semae sp. n.is distinguished from all other species of Squaliusin eastern Anatoliaby the combination of the following characters: mouth slightly subterminal to terminal, with a marked chin in males, slightly marked in females; the upper lip thick, slightly projecting beyond lower lip, its anterior width approximately 1.7–2.0 times its width at the corner of the mouth; scale pockets somewhat narrow, with dense dark brown pigments, and almost covered by the posterior margin of preceding scales; a band of densely-set dark brown or blackish pigments along the posterior margin of each flank scale; head length 26.0–32.2% SL, approximately 1.1–1.3 times body depth; anal, pelvic and pectoral fins with numerous black pigments on rays; dorsal fin with numerous black pigments on rays and membranes; dorsal-fin origin behind pelvic-fin base; posteriormost point of anal fin at tip of 3th or 4th branched ray; caudal fin slightly forked, lobes slightly rounded; and 41–46 total lateral line scales. Comparison with closely related species. Squalius semaeis distinguished from S. berakby having numerous black pigments on anal-fin rays in life ([ Figure 3A], vs. Table 2. Frequency distribution of meristic features of three species of Squaliusfrom Euphrates River drainages. Total lateral line scales N 39 40 41 42 43 44 45 46 mean S. semae 30 - - 2 2 10 13 1 1 43.4 S. seyhanensis 16 - - - 1 - 7 5 3 44.5 S. berak 16 - - 4 5 7 - - - 42.1 Transv. line scales Above lateral line Below lateral line N 6 7 8 9 mean 3 4 5 mean S. semae 30 - 5 25 - 7.8 6 24 - 3.8 S. seyhanensis 16 - - 14 2 8.1 3 13 - 3.8 S. berak 16 - - 16 - 8.0 11 5 - 3.3 Branched anal-fin rays Branched dorsal-fin rays N 7½ 8½ 9½ mean 7½ 8½ 9½ mean S. semae 30 1 28 9 8.0 1 29 - 8.0 S. seyhanensis 16 1 15 - 7.9 1 15 - 7.9 S. berak 16 5 11 - 8.1 2 14 - 7.7 pigments on rays orange in live specimens, greyish when preserved [ Figure 3B]); by the absence of a dark stripe on the upper part of the flank, from the head to the end of the caudal peduncle (vs. presence of a faint dark stripe); by having thicker rays in all fins (thick and fleshy, vs. slender and not fleshy) and the tip of the snout rounded (vs. slightly pointed). It also differs from S. berakin the pigmentation pattern on the scales. In S. semae,there is a band of densely-set dark brown or blackish pigments along the posterior margin of each flank scale, resulting in a contrasted reticulate pattern ( Figure 2a). In S. berakthere are a few grey pigments along the posterior margin of each scale (Figure 2b). Squalius semae sp. n.is distinguished from S. seyhanensisby having black pigments on anal-fin rays in life ([ Figure 3A] vs. pigments orange in life, greyish when preserved [ Figure 3B]). Squalius semae sp.n.is further distinguished from S. seyhanensisby the width of the gape of the mouth smaller than its length (vs. width greater than its length). Besides, the two species differ in the pigmentation pattern on the scales. In S. semae sp.n., the scale pockets are somewhat narrow, with faintly dense dark brown or blackish pigments, and almost covered by the posterior margin of preceding scales ( Figure 2a). In S. seyhanensis, the scale pockets are broad, exposed and densely covered by melanophores forming a black crescent-shaped mark, and approximately one third of the pigments on scale pockets are covered by the posterior margin of preceding scales ( Figure 2c). Squalius semae sp.n.has a narrower band of densely-set pigments along the posterior margin of each scale than observed in S. seyhanensis . Kaya, Turan, and Ünlü (2016)identified the Squaliuspopulations of Batmanand Silvan streams (Tigris River drainage) as Squaliussp. Squalius semae sp. n.is distinguished from Squaliussp. by having numerous black pigments on anal and pelvic-fin rays in life (vs. anal and pelvic-fin rays with orange pigments). Further the two species differ in the pigmentation pattern of the scales. In S. semae sp. n., the scale pockets are somewhat narrow and almost covered by the posterior margin of preceding scales, and there is a band of densely-set dark brown or blackish pigments along the posterior margin of each scale, resulting in a contrasted reticulate pattern. In Squaliussp., the scale pockets are somewhat large and not covered by the posterior margin of preceding scales, and there are a few melanophores along the posterior margin of the scales. Figure 2. Pigments on flank scales: (a) Squalius semae sp. n., FFR 669, 174 mm SL; (b) S. berak, FFR 775, 164 mm SL; (c) S. seyhanensis, FFR 729, 228 mm SL. Figure 3. Pigments on rays and membranes of anal-fin of Squaliusspecies from Euphrates River: A: S. semae sp. n., FFR 725, 187 mm SL; B: S. berak, FFR 775, 164 mm SL; C: S. seyhanensis, FFR 729, 228 mm SL. Squalius semae sp. n.is distinguished from S. adanaensisby having numerous black pigments on anal and pelvic-fin rays (vs. anal and pelvic fins without black or orange pigments) and thicker and fleshy fin rays (vs. slender and not fleshy). Further the two species differ in the pigmentation pattern of the scales and the shape of flank scales. In S. semae sp. n., there is a band of densely-set dark brown or blackish pigments along the posterior margin of each scale, resulting in a contrasted reticulate pattern; flank scales have a smooth posterior margin. In S. adanaensis, there are no or only few melanophores along the posterior margin of the scales; most flank scales have a somewhat undulating posterior margin. The two species are also distinguished by the shape of the mouth. In S. semae sp. n., the width of the gape of the mouth is slightly smaller than its length, the corner of the mouth is in front of a vertical through the anterior margin of the eye, and the upper lip is thick (the width of the upper lip at the tip of the snout is 1.7–2.0 times its width at the corner of the mouth). In S. adanaensis, the length of the mouth gape is approximately equal to its width, the corner of the mouth is about below the anterior margin of the eye, and the upper lip is thin (the width of the upper lip at the tip of the snout is 1.3–1.5 times its width at the corner of the mouth). Squalius semae sp. n.is distinguished from S. turcicusby the presence of black pigments on anal-fin rays (vs. absence) and the shape of the body in specimens larger than about 160 mmSL (dorsal profile of body convex and ventral profile approximately as convex as dorsal profile, vs. dorsal profile of body straight and ventral profile convex). The two species further differ by the pigmentation pattern of the scales. In S. semae sp. n., there is a band of densely-set dark brown or blackish pigments along the posterior margin of each flank scale, resulting in a contrasted reticulate pattern ( Figure 2a; vs. a few light brown pigments) and the caudal fin has a greyish margin (vs. with black margin). Squalius semae sp. n.further differs from S. turcicusby having a round- ed snout (vs. pointed), a less rounded outer margin of the anal fin (slightly convex, vs. convex), a distinct chin in males (vs. indistinct), the dorsal fin with slightly convex outer margin (vs. straight or slightly convex), and thicker fin rays (thick or fleshy, vs. thin). Figure 4. Distribution of the species of Squaliusin Anatolia: S. adanaensis(), S. anatolicus (), S. aristotelis(), S. berak(), S. cappadocicus(), S. carinus(), S. cephaloides(), S. cii( n), S. fellowesii(), S. kosswigi(), S. kottelati(), S. lepidus(▲), S. orientalis(), S. pursakensis(), S. recurvirostris(), S. semae sp. n.( ©), S. seyhanensis(), S. turcicus(*) and Squaliussp. ( ¢). Squalius semae sp. n.is distinguished from S. orientalisby the presence of black pigments on anal- and pelvic-fin rays (vs. anal and pelvic-fin rays with orange pigments). Squalius semae sp. n.has a band of densely-set dark brown or blackish pigments along the posterior margin of each flank scale, resulting in a contrasted reticulate pattern ( Figure 2a; vs. few melanophores). It further differs from S. orientalisin having fewer branched anal-fin rays (7½ or 8½, mean 7.9, vs. 8½ or 9½, mean 8.8), a somewhat longer and more slender head (head length 26.0–32.2% SL, mean 27.7, vs. 23.9– 27.7, mean 25.6; head depth at nape 58-65% HL, mean 61.3, vs. 63–72, mean 68.1), and by having a very faintly distinct vertical black bar behind the opercle (vs. conspicuous), and denser melanophores along the free margin of each flank scale. Figure 5. Scatterplot of the scores of the first two principal components (PC I against PC II) on 28 morphometric characters for 63 specimens of three species of Squalius: S. berak(Ǫ), S. semae sp. n.(∆) and S. seyhanensis(+). Squalius semae sp. n.is distinguished from S. kottelatiand S. lepidus(of the lepidus-group) by the lower jaw not projecting (vs. projecting), by having fewer branched anal-fin rays (7½ or 8½, mean 7.9, vs. 8–10½, mean 9.4), and a blunt (vs. pointed) head in males. Further, it has fewer lateral line scales than S. lepidus(total 41–46, vs. 48–49). Squalius semae sp. n.is further distinguished from S. kottelatiby the absence of a broad dark stripe on the upper part of the flank from the head to the end of the caudal peduncle (vs. presence). The three species of the S. cephalusgroup present in the Euphrates River drainage ( S. seyhanensis, S. semae sp. n.and S. berak) were compared using principal component analysis (PCA). The PCA was performed on 28 morphometric characters. The PCA shows that the new species almost separated from S. seyhanensisand S. berakas well as from each other ( Figure 5). The most important loadings on PC II are for the body depth, distance between pelvic-fin origin and anal fin origin, the height of the dorsal and anal fins, the length of the upper caudal lobe, the length and width of the snout, and the head width.
Description.Body shape as in Figure 1a–b; morphometric and meristic data are given in Tables 1–2. Body moderately deep, slightly compressed laterally. Dorsal profile of body convex, ventral profile approximately equal to dorsal profile. Head long (length 26.0–32.2% SL), approximately 1.1–1.3 times body depth, its dorsal profile slightly convex above eye and convex on snout. Mouth slightly subterminal to terminal, its corner not reaching vertical through anterior margin of eye. Length of mouth gape approximately slightly greater than its width. Upper lip thick, anterior width approximately 1.7–2.0 times width at corner of mouth. Snout with rounded tip. Dorsal fin with 4 simple and 7½ (1) or 8½* (29) branched rays, its height approximately equal to pectoral-fin length, outer margin slightly convex. Pectoral fin short, its length 16.4–20.0% SL, outer margin rounded, with 15–17 branched rays. Pelvic fin rounded, with 1 simple and 8 branched rays. Anal fin with 3 simple and 7½ (1), 8½* (28) or 9½ (9) branched rays, fleshy, outer margin convex posteriorly. Caudal fin slightly forked, lobes slightly rounded. Total number of lateral line scales 41 (2), 42 (2), 43 (10), 44* (13), 45 (1) or 46 (1); 7* (5) or 8 (25) scale rows between lateral line and dorsal-fin origin; 3 (6) or 4* (24) scale rows between lateral line and anal-fin origin. Gill rakers 3 + 8–9 = 11–12 on outer side of first gill arch. Pharyngeal teeth 5.2–2.5, distinctly hooked, serrated. Sexual dimorphism.There are small tubercles on the head in the males, which are absent in the females. Colouration.In life, general body colour silvery, pelvic, anal and pectoral fins yellowish, and dorsal and caudal fins light greyish. Numerous black pigments on anal, pelvic and pectoral fin rays. Dorsal fin with numerous black pigments on rays and membranes. A faint narrow black bar behind opercle. Formalin-fixed adults and juveniles dark brown on back and upper part of flank, yellowish on belly. Faint black bar behind opercle. Dorsal and caudal fins dark grey; pectoral, pelvic and anal fins light greyish. Scale pockets with dense dark brown or blackish pigments, and almost covered by posterior margin of preceding scales. A band of densely-set dark brown or blackish pigments along posterior margin of each flank scale, resulting in a contrasted reticulate pattern ( Figure 2a). Anal, pelvic and pectoral fins with black pigments on rays ( Figure 3A). Dorsal fin with numerous black pigments on rays and membranes.
Etymology.The species is named for Sema Turan, the beloved wife of the first author. Distribution and Notes on Biology. Squalius semae sp. n.is presently known from Sırlı, Toprakkale and Serçeme streams (tributaries of Karasu Stream), Pülümür Stream and Murat River (northeastern drainage of Euphrates) ( Figure 4). It inhabits cool, swift flowing water, with a cobble and pebble bottom. Salmo euphrataeus, Oxynoemacheilussp., Alburnoides velioglui, Alburnus mossulensisand Capoeta umblawere collected with S. semae sp. n.The maximum size observed in the field was about 600 mmSL.
1611943263
FFR
Turkey
39.9475
Karasu Stream
11
40.804
Serceme Stream
2
35
FFR 724, 197
1
Erzurum
holotype
1611943259
2013-05-26
FFR
D. Turan & E. Baycelebi & Kaya
Turkey
40.217667
Karasu Stream
11
41.1005
Sirli Stream
2
35
FFR 725, 26, FFR 669, 9
1
Erzurum
paratype
1611943250
2005-04-23
FFR
D. Turan & R. Buyurucu
Turkey
40.241833
Karasu Stream
11
40.9945
Toprakkale Stream
2
35
FFR 593, 52
1
Erzurum
paratype
1611943254
2009-08-15
FFR
D. Turan & R. Buyurucu
Turkey
38.649
Murat River
11
41.783
Karasu Stream
2
35
FFR 700, 8
1
Mus
paratype
1611943268
2013-09-22
FFR
D. Turan & E. Baycelebi & Kaya
Turkey
3
36
38.866165
Murat River
11
41.0
2
35
FFR 703, 4
1
Mus
paratype
1611943257
2013-09-22
FFR
D. Turan & E. Baycelebi & Kaya
Turkey
39.6135
Murat River
11
43.516335
Agri Prov. Dogubeyazit Dist.
3
36
FFR 710, 5
1
Agri
paratype
1611943258
2012-07-16
FFR
D. Turan & E. Baycelebi & Kaya
Turkey
38.067833
Murat River
11
41.52883
Mercimekkale Stream
3
36
FFR 722, 13
1
Mus
paratype
1611943269
2013-09-22
FFR
D. Turan & E. Baycelebi & Kaya
Turkey
39.13983
Pulumur Stream
11
39.6385
3
36
FFR 727, 2
1
Tunceli
paratype
1611943267
2013-10-27
CMK
C. Kaya & M. Kocabas
Turkey
39.9475
Karasu Stream
11
40.804
Serceme Stream
3
36
CMK 26645, 4
1
Erzurum
paratype
1611943261
2013-05-26
D. Turan & E. Baycelebi & Kaya
Turkey
Euphrates River
All
3
36
1
Erzurum
paratype