Glyptothorax vatandousti, Jouladeh-Roudbar & Ghanavi & Freyhof, 2023

Jouladeh-Roudbar, Arash, Ghanavi, Hamid Reza & Freyhof, Jörg, 2023, Glyptothorax vatandousti, a new species of torrent catfish from the upper Karkheh drainage in Iran (Teleostei: Sisoridae), Zootaxa 5315 (1), pp. 37-58 : 44-55

Glyptothorax vatandousti , new species

( Figs. 3–9 )

Holotype. BIAUBM 1-H, 1, 90 mm SL; Iran: Kermanshah prov., Kangavar stream at Kangavar Kohne , 34.34849, 47.98972.

Paratypes. AJRPC 10 , 3 , 83–91 mm SL; FSJF 4113, 4 , 74–89 mm SL; MNCN-ICTIO 296.950–296.953 4, 65 – 87 mmSL; MZLU L020 /000001-3, 3, 66 – 83 mm SL; same data as holotype .

Material used in molecular genetic analysis. AJRPC A100 , OQ883980 ; A102, OQ883981; same data as holotype .

Diagnosis. Glyptothorax vatandousti is distinguished from its congeners in the Persian Gulf basin by a deep and short caudal-peduncle (caudal peduncle depth 1.1–1.3 in length vs. 1.3–1.8 in G. silviae , G. alidaeii , G. galaxias , G. sardashtensis , 1.6–2.5 in G. armeniacus , G. cous , G. daemon , G. sardashtensis ; see Table 6 for details of all species, and G. steindachneri ), a wider thoracic adhesive apparatus (apparatus length 0.8–1.1 in width vs. 1.1–1.8 in G. silviae , G. alidaeii , G. galaxias , G. hosseinpanahii , G. sardashtensis , G. pallens ; see Table. 6 for details of these species), a roundish anterior end of medial pit (vs. pointed in G. pallens , G. shapuri , G. silviae , G. alidaeii , G. hosseinpanahii , G. galaxias ), and without or with one pale, triangle-shaped blotch in front of dorsal-fin origin (vs. prominent in G. silviae , G. alidaeii , G. galaxias , G. armeniacus , G. daemon , G. pallens , G. kurdistanicus and G. hosseinpanahii ).

Glyptothorax vatandousti is closely related to G. galaxias , a species that occurs in the Karkheh drainage; but both species have not yet been recorded together. The new species is distinguished from G. galaxias by having 5–8 serrae on inner margin of ossified pectoral fin-ray (vs. 11–14), deeper body (21–25 vs. 17–21% SL and caudal-peduncle (13–16 vs. 10–12% SL), wider thoracic adhesive apparatus (apparatus length 0.8–1.1 in width vs. 1.2–1.6), shape of caudal fin (shortest middle caudal-fin ray 62–80% of the longest ray of upper caudal-fin lobe vs. 41–60%), blunt head (vs. pointed), few or very short anteromedial striae on thoracic adhesive apparatus (vs. many and long).

From the additional species known from the Karkheh drainage, i.e. G. galaxias , G. alidaeii and G. cous , G. vatandousti is distinguished by the following combination of characters: from G. alidaeii by having 5–8 serrae on the inner margin of ossified pectoral fin-ray (vs. 11–12), shape of caudal fin (shortest middle caudal-fin ray is 62–80% of the longest ray of the upper caudal-fin lobe vs. 44–57%), deeper body (21–25 vs. 16–20% SL), shorter adipose-fin length (13–16 vs. 17–21% SL), wider thoracic adhesive apparatus (apparatus length 0.8–1.1 in width vs. 1.1–1.3), thoracic adhesive apparatus with few and short anteromedial striae (vs. many and long), head, back and flank with dark-brown blotches usually larger than eye diameter (vs. dark-brown blotches usually smaller than eye diameter), blunt and roundish head (vs. pointed), and rounded caudal-fin lobes (vs. pointed); from G. cous , by having the dorsal and lateral head and predorsal back having many ovoid or round warts (vs. with many large, elongated, bony tubercles), and few or very short anteromedial striae on thoracic adhesive apparatus (vs. many and long).

The new species is distinguished from G. kurdistanicus , a species found in the upper Tigris south to the Sirvan drainage, by having moderately elevated thoracic adhesive apparatus with few and short anteromedial striae (vs. elevated thoracic adhesive apparatus with many long striae), and a longer caudal-peduncle (16 – 20 vs. 13 – 16% SL); from G. pallens , another species found in the Sirvan drainage, by having 5–8 serrae on inner margin of ossified pectoral fin-ray (vs. 11–13), thoracic adhesive apparatus moderately elevated (vs. strongly elevated), longer inner (31–45 vs. 12–23% HL) and outer mandibular barbel (50–81 vs. 32–43% HL), wider thoracic adhesive apparatus (apparatus length 0.8–1.1 in width vs. 1.2–1.4), shape of caudal fin (shortest middle caudal-fin ray 62–80% of the longest ray of the upper caudal-fin lobe vs. 44–52%), rounded caudal fin lobes (vs. pointed), and flank with small and large, blackish or dark-brown blotches (vs. lacking black or brown spots or blotches); from G. sardashtensis found in the Lesser Zab drainage, by having 5–8 serrae on inner margin of ossified pectoral fin-ray (vs. 10–14), deeper body (21–25 vs. 17–19% SL), greater distance between pectoral and pelvic-fin origins (31–40 vs. 29–31% SL), deeper caudal peduncle (13–16 vs. 10–11% SL), shorter adipose-fin (13–16 vs. 17–25% SL), shorter pectoral fin (13–19 vs. 25–27% SL), shape of caudal fin (shortest middle caudal-fin ray is 62–80% of the longest ray of the upper caudal-fin lobe vs. 51–58), wider thoracic adhesive apparatus (apparatus length 0.8–1.1 in width vs. 1.1–1.3), caudal peduncle depth 1.1–1.3 in its length (vs. 1.3–1.8), flank with small and large, blackish or dark-brown blotches (vs. plain flank, without spots or blotches or with few, very small, dark-brown dots on head, dorsal-, and adipose-fin bases), without, or a pale, triangle-shaped blotch in front of dorsal-fin origin (vs. three yellowish blotches, arranged in crescent-shaped pattern), and pelvic-fin origin completely behind vertical of dorsal-fin origin (vs. below or slightly behind vertical of dorsal-fin origin).

Glyptothorax vatandousti is distinguished from G. silviae and G. shapuri by having 5–8 serrae on inner margin of ossified pectoral fin-ray (vs. 9–10 in G. shapuri , 8–11 in G. silviae ), shape of caudal fin (shortest middle caudal-fin ray 62–80% of longest ray of upper caudal-fin lobe vs. 43–49% in G. silviae , 49–46% in G. shapuri (data from Mousavi-Sabet et al. 2021)), deeper body (body depth 21–25% SL vs. 17–19 in G. silviae ), smaller eye (eye diameter 7 – 13% HL vs. 16–18 in G. shapuri (data from Mousavi-Sabet et al. 2021)), deeper caudal-peduncle (13–16 vs. 11–13% SL in G. silviae ), shorter adipose-fin length (13–16 vs. 60–20% SL in G. silviae ), flank with many black spots (vs. without spots in in G. shapuri ), with small and large, blackish or dark-brown blotches usually larger than eye (vs. many, irregular shaped and set blotches smaller than eye in G. shapuri ); from G. hosseinpanahii by having 5–8 serrae on inner margin of first pectoral fin-ray (vs. 9–10), deeper body (body depth 21–25 vs. 18–20% SL), shorter anal-fin base length (9–13 vs. 13–15% SL), shape of caudal fin (shortest middle caudal-fin ray is 62–80% of longest ray of the upper caudal-fin lobe vs. 46–51%), few or very short anteromedial striae on thoracic adhesive apparatus (vs. many and long), rounded caudal fin lobes (vs. pointed), and head, back and flank with dark-brown blotches larger than eye diameter (vs. irregular dark-brown spots or small blotches smaller than eye diameter); from G. armeniacus and G. daemon by having few, or very short anteromedial striae on thoracic adhesive apparatus (vs. many and long), and thoracic adhesive apparatus moderately elevated (vs. strongly elevated); and from G. steindachneri by having short adipose-fin, its length 0.5–0.7 times (vs. 1.5–3.0), larger than distance between base of last dorsal-fin ray and adipose fin origin, 5–8 serrae on inner margin of ossified pectoral fin-ray (vs. 13–17), medial pit of thoracic adhesive apparatus without striae (vs. with striae), and dorsal and lateral head and predorsal back with having many ovoid or round warts (vs. large, elongated, bony tubercles).

Description. Morphometric data in Table 3 . Head depressed; body stout and subcylindrical. Dorsal head profile straight, predorsal profile convex: Profile rising from tip of snout to dorsal-fin origin, then almost straight, sloping softly ventrally from origin of dorsal fin to end of the body. Ventral profile straight to end of caudal peduncle. Pelvic-fin origin clearly behind vertical of dorsal-fin origin. Caudal-peduncle depth 1.1–1.3 times in length. Anus and urogenital openings located at vertical through middle of adpressed pelvic fin. Skin on head, back and flank covered by small, roundish or ovoid warts. Warts smaller and denser set on gill cover. Lateral line complete and midlateral. Head broad, triangular when viewed laterally and spade shape when viewed from above. Snout blunt. Anterior nare round, posterior nare ovoid, both separated by base of nasal barbel. Eye and pupil ovoid, horizontal axis longest; located in dorsal half of head. Largest individual recorded 91 mm SL.

Barbels in four pairs. Maxillary barbel broad and thick, extending to, slightly in front of or beyond pectoral-fin base, velum at proximal part of barbel attached to head closer to posterior nare than to eye, many thick warts on outer base of velum, velum smooth. Nasal barbel broad, reaching beyond eye. Inner mandibular barbel extending to isthmus. Outer mandibular barbel reaching pectoral-fin origin or slightly beyond pectoral-fin base. Mouth inferior, a narrow premaxillary tooth band exposed when mouth is closed. Oral teeth small and villiform, in irregular rows on all tooth-bearing surfaces. Premaxillary teeth appearing in single broad semilunate band. Dentary teeth in a single crescentic band, consisting of two separate halves tightly bound at midline.

Thoracic adhesive apparatus with striae or narrow longitudinal pleats located in a rhombic field extending from isthmus to base of second branched pectoral-fin ray. Anteromedial striae few and short ( Figs. 6 and 8 ). Medial pit wide, without striae, its anterior end roundish. Anterolateral edges of thoracic adhesive apparatus almost straight or slightly concave. Length of thoracic adhesive apparatus 0.8–1.1 times its width. Dorsal fin with two visible unbranched rays and 5½ (n=15) branched rays. Anal fin with one unbranched and 5½ (2) or 6½ (13) branched fin rays. Pelvic fin with one unbranched and 5 (15) branched rays. Pectoral fin with one unbranched and 7 (1), 8 (13) or 9 (1) branched fin rays. Anterior margin of pectoral-fin smooth, posterior margin slightly concave, with 5–8 serrations. Caudal fin slighly forked with equal rounded lobes.

Coloration. In formalin-fixed individuals: dorsal and lateral surfaces of head and body pale-grey to greyish brown, fading to pale-grey or beige on ventral surfaces of head and anterior belly, and on pectoral and pelvic-fin bases. Belly without any pattern. Head, back and flank with a fine, pale-brown mottled pattern overlaid by small and large, blackish or dark-brown blotches. Latero-sensory pores same colour as surrounding tissue. Adipose fin with a pale-grey blotch behind origin and a pale-grey posterior margin. All other fins with a dark-grey or blackish base, followed by a pale-yellowish band, thereafter a dark-grey or brown band and a yellowish margin; appearing as dark-grey or blackish fins with a whitish or yellowish band and margin; yellowish margin in caudal fin often absent, or reduced to a large or small blotch on each lobe. Pattern in fins dissociated and lost in large individuals. Maxillary and nasal barbels grey or blackish dorsally, pale-grey ventrally and velum pale-grey or beige. Mandibular barbels beige or pale-grey.

Etymology. The species is named for Saber Vatandoust (Qaemshahr), for his contributions to the taxonomy of fishes in Iran. Saber Vatandoust was also the ichthyology professor of the first author, AJR, at the Azad Islamic University of Babol. A noun in genitive, indeclinable.

Distribution. Glyptothorax vatandousti is found in the lower reaches of the Kangavar stream, particularly at its confluence with the Gamasiab River. These rivers are parts of the Karkheh drainage, a major tributary of the Tigris. In addition to the Gamasiab drainge, we have recorded this species in two additional locations: the Aran stream and the Chardavol River (depicted as red dots in Fig. 1 ). These records are over 10 years old, and despite several attempts, we were unable to find the species at these places since.

Habitat. Unlike other Glyptothorax species from Western Asia, G. vatandousti was only found in shallow and slow-moving streams. Naturally, there has not been any study to decide if the ecology of G. vatandousti is different from other species of the genus. The Kangavar stream ( Fig. 11 ), where this species was found in abundance, has a relatively narrow width of around 1.5 meters, clear water with a rubble bed, and moderately fast current. The habitat of G. vatandousti is facing serious threats due to human activities. Water from the Kangavar and Gamasiab is used for irrigation in nearby agricultural farms, which can significantly alter the water flow and quality, leading to habitat degredation. In addition, the frequent passage of trucks and other vehicles near the Kangavar result in soil erosion and sedimentation, which can negatively impact the species’ survival and reproduction.

Figures

FIGURE 1. Records of Glyptothorax species in Iran

FIGURE 3. Glyptothorax vatandousti, BIAUBM 1-H, holotype, 90 mm SL; Kangavar stream.

FIGURE 4. Glyptothorax vatandousti paratypes; from top: AJRPC 10, 83 mm SL; FSJF 4113, 82 mm SL, AJRPC 10, 82 mm SL; Kangavar stream.

FIGURE 5. Glyptothorax vatandousti paratypes; from top: AJRPC 10, 83 mm SL; FSJF 4113, 82 mm SL, AJRPC 10, 82 mm SL; Kangavar stream.

FIGURE 6. Glyptothorax vatandousti paratypes; from top: AJRPC 10, 83 mm SL; FSJF 4113, 82 mm SL, AJRPC 10, 82 mm SL; Kangavar stream.

FIGURE 7. Glyptothorax vatandousti, paratypes, from top: AJRPC 10, 82 mm SL; FSJF 4113, 82 mm SL, AJRPC 10, 91 mm SL; Kangavar stream.

FIGURE 8. Glyptothorax vatandousti paratypes; from left: AJRPC 10, 82 mm SL; AJRPC 10, 91 mm SL, FSJF 4113, 82 mm SL; Kangavar stream.

FIGURE 9. Left: G. galaxias: ~ 110 mm SL; uncatalogued, Iran: Behesht abad River; right: G. vatandousti: MNCN, 91 mm SL, Kangavar stream.

FIGURE 11. Kangavar stream, type locality of Glyptothorax vatandousti.