Published records of Schindleria in the Red Sea: star = S. qizma n. sp., in Thuwal; filled circle = S. elongata, S. nigropunctata (Fricke & Abu El-Regal, 2017a, b), S. praematura (Abu El-Regal and Kon, 2019), and S. edentata (Ahnelt et al., 2022), all in Hurghada; black square = Schindleria sp. (Al-Solami and Abu El-Regal, 2020) and S. parva (Abu El-Regal et al., 2021), both in Jeddah; empty circle = Schindleria sp., in Thuwal (Robitzch et al., 2021). The map is from https://www.landkartenindex.de/kostenlos/cliparts/cliparts_gruppe_1/saudiarabien.gif.

Holotype of Schindleria qizma (NMW 99999), female, 10.6 mm SL; Thuwal, Saudi Arabia. Same specimen shown in reflected (white) and transmitted light (dark). Arrows indicate position of swim bladder. Scale bar = 1 mm.

Paratype of Schindleria qizma (NMW 100000), female, 10.7 mm SL; Thuwal, Saudi Arabia. A head in lateral view. B head in dorsal view. Scale bar = 0.5 mm.

Head of Schindleria qizma, paratype (NMW 100000), 10.7 mm SL, lateral view. Note toothless jaws. DEN = dentary; MX = maxilla; PMX = premaxilla. Scale bar = 0.1 mm.

Comparison of caudal-fin skeleton in Schindleria. A Schindleria qizma (NMW 100000), paratype, 10.7 mm SL, preserved in ethanol, not stained: urostyle straight and ending inside hypural plate. B Schindleria sp. (uncatalogued), 16.9 mm SL, preserved in ethanol, stained with cephalopod ink. C Schindleria sp. (CAS 38797), 17.7 mm SL, cleared (muscles were digested) and stained with Alcian blue; procurrent rays not shown. B, C flexed urostyle, hook-like tip fused to hypural plate. HPU = haemal spines of preural vertebrae; hy = hypural plate; NPU = neural spines of preural vertebrae; pu2 and pu3 = second and third preural vertebra; ur = urostyle; 1–6 = procurrent rays, last ray elongated. Scale bar = 0.5 mm.

Caudal-fin skeleton in Schindleria qizma; A holotype (NMW 99999), 10.6 mm SL; B paratype (NMW 100001), ~10.9 mm SL; C paratype (NMW 100000), 10.7 mm SL. hy = hypural plate; ur = urostyle, straight and inserted into hypural plate. Each arrow indicates a procurrent ray; asterisk = no procurrent ray developed. Scale = 0.5 mm.

Comparison of urogenital region in Schindleria females. A Schindleria qizma (NMW 99999), holotype, 10.7 mm SL; asterisks indicate paired bilobed projections on left and right side of urogenital opening; arrow indicates urogenital opening covered by mucus. B Schindleria qizma, (NMW 100000), paratype, 10.7 mm SL. C Schindleria praematura (NMW 86241), 18.5 mm SL; urogenital papilla with two short, hornlike projections. A1 = first anal-fin ray; UG = urogenital papilla; a = anterior; v = ventral. Scale = 0.5 mm.