Glyptothorax steindachneri ( Pietschmann, 1913 )

Glyptothorax steindachneri ( Pietschmann, 1913) View in CoL

( Fig. 28–30 View FIGURE 28 View FIGURE 29 View FIGURE 30 )

Glyptosternum s teindachneri Pietschmann, 1913:93 View in CoL

Material examined. BMNH 1968.12.13.465-70, 3, 64–67 mm SL; 1968.12.13.471, 3, 60–97 mm SL; Syria: Euphrates at Al Mayadine, 35.029 40.452 (photographs only).— SMF 23678 About SMF , 1 About SMF , 77 mm SL; Syria: Nahr Al-Khabur about 16 km southeast of al-Hasaka, 36.43 40.87.— SMF 28644 About SMF , 3 About SMF , 112–130 mm SL; Syria: Euphrates at Der ez Zor, 35.52 39.91.— SMF 28694 About SMF , 4 About SMF , 146–156 mm SL; Syria: Euphrates at Raqqa, 35.93 38.99.— ZMH 4431 , 3 , 107–138 mm SL; Turkey: Euphrates at Kemalye, 39.2625 38.5019.

Material used in molecular genetic analysis. None.

Diagnosis. Glyptothorax steindachneri is distinguished from its congeners in the Euphrates and Tigris drainages by having a very long adipose-fin, its length is 1.5–3.0 times (vs. 0.6–1.2 in other species) larger than the distance between the base of last dorsal-fin ray and the adipose-fin origin; the medial pit of the thoracic adhesive apparatus with striae (vs. without striae), and there are 13–17 serrae on the inner margin of the ossified pectoral fin-ray (vs. 7–14).

Glyptothorax steindachneri is further distinguished from G. armeniacus , G. cous , G. kurdistanicus , and G. silviae by the caudal-peduncle depth 1.8–2.5 times in its length (vs. 1.1–1.6 in G. kurdistanicus ), having many large, elongated, bony and striated tubercles on the dorsal and lateral head and predorsal back (vs. absent in G. armeniacus , G. kurdistanicus , and G. silviae ), a slightly elevated thoracic adhesive apparatus (strongly elevated in G. armeniacus and G. silviae ), 1.1 – 1.5 times longer than wide (vs. 0.8 – 1.1 in G. cous , 0.7 – 0.9 in G. kurdistanicus ), extending from the isthmus to the base of the last pectoral-fin ray or to the posterior limit of the pectoral-fin base (vs. to base of first or third branched pectoral-fin ray in G. kurdistanicus ). The thoracic adhesive apparatus is well delineated at its posterior margin (poorly delineated in G. cous ), completely situated on the horse-shoe shaped swelling (vs. extending beyond the swelling, usually onto the pectoral-fin base in G. cous ), the head is pointed and short, 21–23% SL (vs. blunt and spade-shaped, 24–28% SL in G. armeniacus , 28–30% in G. cous , 27–30 in G. kurdistanicus ), and there are no or few small black spots on the flank (vs. many large blotches and/or spots in G. cous ). Size up to 190 mm SL.

Distribution. Glyptothorax steindachneri seems to be widespread in the Euphrates and Tigris. It is recorded from the Tigris at Mossul, the Euphrates in Syria, the Nahr Al-Khabur, a tributary of the Euphrates in Syria, and the Lesser Zab River in Iraq.

Remarks. The description by Pietschmann (1913) is informative and gives some very useful characters. But no figures are provided and the syntypes are missing in NMW, where hundreds of jars with Pietschmann’s fish collection are still await sorting. Anja Palandacic (pers. comm., 2020) looked through the jars at our request but did not find the types of G. steindachneri . There is one jar (NMW) with three Glyptothorax specimens collected by Pietschmann at an unknown date (NMW 94378). They are labelled as coming from “ Armenia ” without any further information. These three specimens measure 122, 141 and 219 mm in total length (89, 115, 185 mm SL) and are identified as G. cous . They do not agree with the character states given by Pietschmann (1913) for G. steindachneri . Pietschmann described G. steindachneri based on two syntypes of 150 and 189 mm total length and it is very evident that NMW 94378 does not correspond to the types of G. steindachneri . At Pietschmann’s times, Armenia was much larger than today and covered considerable parts of the upper Euphrates and Tigris drainage and we have no doubt that NMW 94378 was collected from that region. These fish make clear that Pietschmann did collect other Glyptothorax in the Euphrates and has compared different species that he had in hand when describing G. steindachneri . Coad (1981) shortly mentioned that G. steindachneri “may be a synonym of G. cous ”. Indeed, we identify BMNH 1968 12.13.470-471, identified by Coad (1981) as G. cous , as G. steindachneri . But ZMH 4431 identified as G. armeniacus by Coad (1981) are also identified as G. steindachneri by us. Glyptothorax steindachneri is continuously listed for the fauna of Iraq (for example Coad 2010) but no positive record of G. steindachneri was published and we are the first to clarify its identity.

Indeed, G. steindachneri seems to be widespread in the Euphrates and Tigris drainage and we expect it to occur in all the countries in the catchment region. It might be continuously misidentified as G. cous , which is usually misidentified as G. kurdistanicus .

The most important characters given by Pietschmann (1913) are: “Die Oberseite des Kopfes ist mit zahlreichen, länglichen, unregelmässigen Hautwarzen versehen, die Fettflosse sehr langgestreckt, ihre Basislänge grösser als die Entfernung ihres Ursprunges vom Ende der Dorsalbasis. Die Pektorale besitzt einen sehr starken, breiten, an seinem hinteren Rande mit ungefähr 17 bis 18 Dornen versehenen Stachel.“ [The upper side of the head has numerous, longish, irregular skin warts, the adipose fin is much elongated, its base being longer than the distance from its origin to the end of the dorsal-fin base. The pectoral fin possesses a strong, broad spine supplied with about 17–18 thorns on its posterior margin.]

Catfish identified here as G. steindachneri have striated, elongated tubercles on the head, which might be called skin-warts ( Fig. 29 View FIGURE 29 ) and this character state is only shared with G. cous . Only in G. steindachneri , the adipose fin base is much longer than the distance between the adipose-fin origin and the end of the dorsal-fin base (adipose-fin length 1.5–3.0 times larger than the distance between base of last dorsal-fin ray and adipose-fin origin in G. steindachneri vs. 0.6–1.2 in all other species, 0.6–1.2 in G. cous ). In addition, G. steindachneri has more serrae on the pectoral spine than all other Glyptothorax examined for this study (13–17 vs. 7–14 in other species). Therefore, we are very confident that our materials are correctly identified as G. steindachneri despite the absence of types or figures in the original description.

The tubercles on the head are absent or very shallow and without surface structure in the three individuals of G. steindachneri from Turkey (ZMH 4431). As discussed under G. cous above, we expect that this skin ornamentation has been scraped-off by careless handling of these fishes.