A new species of Schindleria (Teleostei: Gobiiformes: Gobiidae) from the Red Sea (Saudi Arabia) with a specialized caudal-fin complex

Species of the gobiid genus Schindleria are among the smallest and fastest reproducing vertebrates of the oceans. We describe a new species, Schindleria qizma, from the Red Sea, Saudi Arabia. It is an extreme example of progenesis, within the already paedomorphic genus, with morphological traits clearly differentiating it from its congeners. Schindleria qizma has a unique, unflexed notochord with a straight urostyle of which the tip is inserted into the hypural cartilage, rather than the typical flexed notochord with an upturned urostyle of the other species of Schindleria. Schindleria qizma belongs to the short dorsal-fin type of Schindleria. It is further characterized by an elongated but relatively deep body; a short dorsal fin originating just slightly anterior to the anal fin (predorsal-fin length 59.4% of SL vs. preanal-fin length 60.2% of SL); a head continuously increasing in depth posteriorly with a straight dorsal profile; a short snout (18.6% of head length); large eyes (34.4% of head length); a short pectoral-radial plate (6.3% of SL); 13 dorsal-fin rays; 11 anal-fin rays; 0–2 procurrent rays (where the last procurrent ray is short, if present); an anal fin with the first anal-fin ray situated opposite the second dorsal-fin ray; toothless oral jaws; females with few (10–11, total) but very large (4.6% of SL) eggs and with a conspicuous urogenital papilla characterized by a wide urogenital opening flanked by two long, bilobed projections; a dorsally pigmented swim-bladder; blackish, iridescent eyes, capped by a silvery layer with irregular rows of black dots or blotches; and no additional external pigmentation on its body, at least in preserved specimens.