Glyptothorax silviae Coad, 1981

Freyhof, Jörg, Kaya, Cüneyt, Abdullah, Younis Sabir & Geiger, Matthias F., 2021, The Glyptothorax catfishes of the Euphrates and Tigris with the description of a new species (Teleostei: Sisoridae), Zootaxa 4969 (3), pp. 453-491 : 477-479

Glyptothorax silviae Coad, 1981

( Fig. 25–27 )

Glyptothorax silviae Coad, 1981:291

Material examined. CMNFI 1979-0390A, 67.6 mm SL, holotype; CMNFI 1979-0390B, 2, paratypes, 44–51 mm SL; Iran: Khuzestan prov.: stream 3 km south of Bagh`e Malek, a tributary to Rud-e Zard or Ab-e Ala, Jarrahi River drainage , 31.483 49.908 (photographs only) .— FSJF 2214, 1, 57 mm SL; Iran: Sangan at Sangan, 31.2587 51.2858 .— FSJF 3243, 24, 31–48 mm SL; Iran: Beshar at Doruhan , 30.8521 51.3420 .

Material used in molecular genetic analysis. FSJF-DNA 2006; Iran: Beshar at Doruhan , 30.8521 51.3420 (GenBank accession numbers: MW770718, MW770731 ). —FSJF-DNA 2611; Iran: Behesht Abad River north of Ardal , 75 km south-west of Shahr-e-kord, 32.0343 50.6327 (GenBank accession number: MW770721 ) .

Diagnosis. Glyptothorax silviae is distinguished from its congeners in the Euphrates and Tigris drainages by lacking tubercles and warts on the dorsal and lateral head, back and flank (vs. with tubercles and/or warts in all other species). It is further distinguished from G. armeniacus , G. cous , and G. kurdistanicus by having very few and short or no anteromedial striae (vs. present and well developed in G. armeniacus and G. cous ), an elevated thoracic adhesive apparatus, longer than wide (vs. not elevated, as wide as long in G. cous , usually wider than long in G. kurdistanicus ), extending from the isthmus to the base of 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 ). See below for characters to distinguish G. silviae from other Glyptothorax in the Middle East.

Other characters useful for identification are: adipose-fin short, its length 0.9–1.1 times of the distance between the base of last dorsal-fin ray and the adipose-fin origin; head blunt, spade-shaped, short, 20–25% SL; medial pit without striae; flank without or with few back blotches or black spots. Size up to 135 mm SL.

Distribution. Coad (2014) suggests that G. silviae is endemic to Iran, where it is found in the Karkheh and Karun Rivers in the Tigris drainage as well as in the coastal rivers of the Gulf south to the Mond and Shur Rivers ( Jouladeh-Roudbar et al. 2020).

Remarks. Jouladeh-Roudbar et al. (2020) show an individual identified as G. silviae from the Sirvan drainage ( Fig. 27 ) but this individual was caught in the Karun (Arash Jouladeh-Roudbar, pers. comm. 2020). Another individual from the Sirvan identified by Jouladeh-Roudbar et al. (2020) as G. kurdistanicus looks similar to G. silviae and the Glyptothorax of this area needs to be re-studied. Our sequenced materials identified here as G. silviae consist of juveniles only and their identification remains to be confirmed. We cannot fully exclude that additional species might be present in the area. Therefore, the diagnostic character states used in this study are taken from Coad (2014) and checked in the additional material that we examined.

Figures

FIGURE 25. Glyptothorax silviae, from top: CMNFI 1979-0390A, 67.6 mm SL, holotype; CMNFI 1979-0390B, 51 mm SL, 44 mm SL, paratypes; Iran: stream 3 km south of Bagh`e Malek.

FIGURE 26. Glyptothorax silviae, from left: CMNFI 1979-0390A, 67.6 mm SL, holotype; CMNFI 1979-0390B, 51 mm SL, 44 mm SL, paratypes; Iran: stream 3 km south of Bagh`e Malek.

FIGURE 27. Glyptothorax silviae, not preserved, about 110 mm SL; Iran: Maroun River drainage. Photo: Arash Jouladeh- Roudbar.